Persistent pain and its predictors after starting anti-tumour necrosis factor therapy in psoriatic arthritis: what is the role of inflammation control?

OBJECTIVE

While considerable focus has been placed on pain due to inflammation in psoriatic arthritis (PsA), less is reported on pain despite inflammation control. Here, we aimed to investigate the occurrence/predictors of persistent pain, including non-inflammatory components, after starting anti-tumour necrosis factor (anti-TNF) therapy.

METHOD

Bionaïve PsA patients starting a first anti-TNF therapy 2004-2010 were identified (South Swedish Arthritis Treatment Group register; N = 351). Outcomes included unacceptable pain [visual analogue scale (VAS) pain > 40 mm], and unacceptable pain despite inflammation control (refractory pain; VAS pain > 40 mm + C-reactive protein < 10 mg/L + ≤ 1 swollen joint of 28), assessed at 0, 3, 6, and 12 months. Baseline predictors were estimated by logistic regression.

RESULTS

Upon starting anti-TNF therapy, 85% of patients reported unacceptable pain, falling to 43% at 3 months and then remaining stable. After 12 months, refractory pain constituted 63% of all unacceptable pain. Higher baseline VAS pain/global, worse physical function and lower health-related quality-of-life were associated with a higher risk of unacceptable/refractory pain at 12 months. More swollen joints and higher evaluator's global assessment were associated with a lower risk of 12-month refractory pain.

CONCLUSIONS

A substantial proportion of PsA patients reported unacceptable pain throughout the first anti-TNF treatment year. At 12 months, refractory pain constituted about two-thirds of this remaining pain load. More objective signs of inflammation at anti-TNF initiation were associated with less future refractory pain. This highlights insufficient effect of biologics in patients with inflammation-independent pain, warranting alternative treatments.

OP0302 IS INCREASED RISK OF UROLITHIASIS IN AXIAL SPONDYLOARTHRITIS DRIVEN BY GUT INFLAMMATION? RESULTS FROM THE SPARTAKUS COHORT

Background

A nationwide, Swedish study found a doubled urolithiasis risk in ankylosing spondylitis (AS) compared to population controls.[1] Inflammatory bowel disease (IBD) is a known risk factor for urolithiasis, e.g. via enteric hyperoxaluria causing calcium oxalate stones.[2] With microscopic gut inflammation in around 50% of axial spondyloarthritis (axSpA) patients,[3] and overt IBD in 5-10%, gut inflammation may also drive the increased urolithiasis risk in axSpA.

Objectives

To study whether axSpA patients with a history of urolithiasis have an increased prevalence of comorbid IBD or display elevated biomarkers of gut inflammation/pathology.

Methods

AxSpA patients in the population-based SPARTAKUS cohort study in southern Sweden (non-radiographic axSpA [nr-axSpA] n=86, ASAS criteria; AS n=168, modified New York criteria) self-reported their history of prior urolithiasis (no/yes). Faecal (F) calprotectin and ASCA (anti-Saccharomyces cerevisiae antibodies) in serum were measured by commercially available ELISAs (Calpro AS; ORGENTEC Diagnostika). For a subgroup of patients (n=164), presence of gut dysbiosis was also assessed by the GA-Map Dysbiosis Test (Genetic Analysis). Demographics, disease/treatment characteristics, comorbid IBD and the gastrointestinal biomarkers (F-calprotectin/ASCA/dysbiosis) were compared between patients with versus without prior urolithiasis. Finally, the same biomarkers were also compared between patients with versus without urolithiasis history, after exclusion of subjects with known IBD.

Results

Urolithiasis history was reported by 13% (n=33) of the axSpA patients, and comorbid IBD was significantly more common in this group (27% versus 6.8%, p<0.001; Table 1). F-calprotectin levels were also significantly higher among patients with prior urolithiasis, as was presence of gut dysbiosis (Table 1). ASCA seropositivity did not differ between the groups. Moreover, prior urolithiasis was associated with longer disease duration and AS-phenotype. After exclusion of cases with comorbid IBD, urolithiasis history was reported by 10% (24 of 230 patients). F-calprotectin elevation ≥100 mg/kg remained significantly associated with urolithiasis history also in this population, while only being numerically increased when assessed as a continuous variable (p=0.053; Figure 1). Gut dysbiosis also remained associated with prior urolithiasis in the non-IBD population (56% [9 of 16 patients with prior urolithiasis] versus 30% [40 of 132 patients without], p=0.037), whereas ASCA status did not differ between the groups (data not shown).

Table 1.Urolithiasis historyNo, n=221Yes, n=33Male sex115 (52%)23 (70%)Age, years50 (13)59 (12)*Disease duration, years25 (14)31 (14)*AS (versus nr-axSpA)141 (64%)27 (82%)*Inflammatory bowel disease15 (6.8%)9 (27%)*ASAS 3-month NSAID score31 (40)37 (48)Ongoing bDMARD therapy87 (39%)16 (49%)bDMARD therapy ever113 (51%)20 (61%)ASDAS-CRP1.8 (1.0)1.9 (0.8)BASFI2.0 (2.1)2.7 (2.6)BASMI2.9 (1.5)4.3 (2.1)*F-Calprotectin, mg/kg*# Mean (SD)58 (97)115 (176) Median (IQR)29 (49)39 (152)F-Calprotectin ≥100 mg/kg28 (14%)10 (32%)*ASCA IgA ≥10 U/ml12 (5.7%)4 (13%)ASCA IgG ≥10 U/ml45 (21%)10 (33%)Gut dysbiosis†45 (32%)17 (71%)*

Mean (SD) or n (%) if not otherwise stated. † GA-Map Dysbiosis Test, dysbiosis index ≥3. * p<0.05 by Chi2-test or Student t-test, as appropriate. # Log10-transformed values compared. Missing ≤13%, except for gut dysbiosis available in 140/24 patients without/with urolithiasis history.

Conclusion

The current results lend support to the hypothesis that the increased urolithiasis risk in axSpA may be driven by gut inflammation/pathology. Prospective studies are, however, needed to assess the causality.

References

[1]Jakobsen AK, et al. PLoS One. 2014;9:e113602.

[2]Corica D, et al. J Crohns Colitis. 2016;10:226-35.

[3]Van Praet L, et al. Ann Rheum Dis. 2013;72:414-7.

Disclosure of Interests

Johan K Wallman Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer, Elisabeth Mogard Consultant of: Novartis, Jonas Sagard: None declared, Lars Erik Kristensen Speakers bureau: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen Pharmaceuticals, Merck Sharp & Dohme, Novartis, Pfizer, UCB Pharma, Consultant of: AbbVie, Amgen, Bristol-Myers Squibb, Celgene, Eli Lilly, Janssen Pharmaceuticals, Merck Sharp & Dohme, Novartis, Pfizer, UCB Pharma, Elisabet Lindqvist: None declared, Tor Olofsson Consultant of: Eli Lilly, Merck Sharp & Dohme

AB0662 Elevated fecal calprotectin in early systemic sclerosis

Background

Gastrointestinal (GI) morbidity is prevalent in systemic sclerosis (SSc), causing a reduction in quality of life and increased mortality, but has been difficult to assess objectively [1]. Elevated levels of fecal calprotectin (F-cal), a biomarker of GI inflammation, has previously been observed in patients with SSc [2]. F-cal has not been explored in early SSc and its diagnostic potential in the classification of SSc has not been studied.

Objectives

Our objectives were; 1) study F-cal levels in early SSc; 2) investigate the discriminatory power of F-cal; 3) explore F-cal in relation to GI features of SSc.

Methods

Consecutive referred patients with suspected new-onset SSc without concurrent non-SSc GI disease were invited to this study. Patients were classified as SSc if meeting ACR-EULAR criteria, or SSc mimickers if they did not. GI symptoms and use of NSAID or PPI was noted. F-cal was measured and levels >50ug/g were classified as elevated. F-cal was also measured in age- and sex matched controls without rheumatological disease.

Results

Of 137 patients, 92 were classified as SSc and 45 as SSc mimickers. Elevated F-cal was significantly more common in SSc patients compared to the control group (38% vs 7.3%; p < 0.001) but not compared to the SSc mimicker patients (38% vs 31%; p = 0.427). The median F-cal level was higher in SSc patients compared to controls (35 µg/g vs ≤30 µg/g; p ≤ 0.001) but not compared to the SSc mimicker patients (35 µg/g vs ≤30 µg/g; p = 0.248). Elevated F-cal was not associated with any GI symptoms. Elevated F-cal was more common in patients who used PPI (OR 7.14; 95% CI 2.56-29.93; p < 0.001).

Conclusion

In this study, we demonstrate that elevated levels of F-cal are prevalent already in the early stages of SSc. These results are in line with previous data suggesting that GI involvement may be present in early SSc.

Table 1.

Frequency of GI features and association to F-cal elevation (n = 92)

GI features (n, %)Normal F-cal, n = 57Elevated F-cal, n = 35Odds Ratio (95% CI)Dysphagia19 (35%)12 (34%)0.99 (0.41-2.41)Reflux symptoms33 (59%)23 (68%)1.46 (0.60-3.56)Fecal incontinence9 (16%)3 (8.6%)0.50 (0.08-2.22)Patient-reported involuntary weightloss11 (20%)8 (23%)1.21 (0.43-3.39)Dilated esophagus on HRCT8 (16%)8 (28%)1.95 (0.64-5.94)NSAID use12 (21%)6 (17%)0.78 (0.26-2.30)PPI use23 (40%)29 (83%)7.14 (2.56-19.93)Figure 1.

F-cal measurements by group. Median value represented by horizontal bar.

References

[1]Frantz C et al. Impaired quality of life in systemic sclerosis and patient perception of the disease: A large international survey. Semin Arthritis Rheum 2016;46:115-23.

[2]Marie I et al. Fecal calprotectin in systemic sclerosis and review of the literature. Autoimmun Rev 2015;14:547-54.

Acknowledgements

This study was funded by the Anna-Greta Crafoord Foundation, the Swedish Rheumatism Association, Stiftelsen Ulla och Roland Gustafssons Donationsfond.

Disclosure of Interests

Viggo Hamberg: None declared, Johan K Wallman Consultant of: Consultant of AbbVie, Amgen, Celgene, Eli Lilly, Novartis., Grant/research support from: Research support from AbbVie, Amgen, Eli Lilly, Novartis, Pfizer., Elisabeth Mogard Consultant of: Consultant of Novartis, Elisabet Lindqvist: None declared, Tor Olofsson Consultant of: has performed consulting tasks for Merck Sharp & Dohme and for Eli Lilly, Kristofer Andréasson: None declared

POS0547 THE ADVANTAGE OF TIGHT CONTROL AND TREAT TO TARGET IN NEW-ONSET RA PATIENTS IN DAILY RHEUMATOLOGY PRACTICE: RESULTS FROM A CONTEMPORARY UNIVERSITY CLINIC INCEPTION COHORT

Background

Since 2018, all patients with new-onset rheumatoid arthritis (RA) at the Department of Rheumatology, Skane University Hospital, Lund, Sweden, are offered to participate in a ”tight control” and ”treat to target” (TC+T2T) follow-up strategy. This strategy includes regular follow-up visits to a rheumatologist (at diagnosis and 3, 6, 12, 18, 24 months) plus physical/telephone consultations with a rheumatology nurse between physician visits, both with disease activity assessments and, if needed, adjustment/intensification of anti-rheumatic treatment aiming for remission.

Objectives

To explore the possible advantages of integrating this TC+T2T strategy over routine care, aiming more systematically for remission (DAS28<2,6 or CDAI≤2,8), in clinical practice of new-onset RA.

Methods

Patients followed by the TC+T2T strategy were compared to new-onset RA patients followed according to routine care at the same department and during the same period. Data on disease and treatment characteristics, as well as outcome measures during follow-up were retrieved from the Swedish Rheumatology Quality register (SRQ). In total, 156 patients with at least 3 months follow-up between 2018 and 2021 were included; 95 followed according to the TC+T2T strategy and 61 according to routine care. Percentage females/mean age at onset/mean symptom duration at diagnosis were 79%/57 years/4 months (TC+T2T) and 62%/62 years/7 months (routine care). The change in DAS28 and CDAI from baseline to 12 months follow-up were compared between the two strategies by linear regression analyses, adjusted for sex, age, symptom duration, and DAS28 or CDAI, respectively, at baseline. In addition, changes in patient-reported outcomes (fatigue, pain and HAQ) are calculated.

Results

Disease and treatment characteristics at inclusion (diagnosis) are summarized in the Table 1.

Table 1.TC+T2T group (n=95)Controls (n=61)Swollen 28 joint count,6,6 (4)5,1 (5)Tender 28 join count8,2 (5)6,2 (6)ESR48,1 (29)37,7 (25)CRP21,3 (29)16,9 (23)DAS285,5 (1)4,6 (1)CDAI24,5 (11)18,3 (11)HAQ1,01 (0,6)0,98 (0,7)Fatigue (VAS)50,1 (29)46,6 (30)Pain (VAS)57,9 (24)47,3(30)ACPA positive (%)77%53%Radiographic changes in hands or feet at inclusion (%)12%18%Smoker (%)16%7%Methotrexate started at inclusion (%)78%85 %Prednisolone started at inclusion (%)100%97%

Mean and standard deviation (SD) if not otherwise stated.

The TC+T2T strategy resulted in greater improvements in DAS28 and CDAI scores from inclusion to 12 months follow up (p=0,025 and p=0,026; respectively; Figure 1). Beyond improvements in DAS28 and CDAI, a significant decrease in patient-reported outcomes (fatigue and pain) during 12 months from diagnosis was observed (Figure 1).

Conclusion

Compared to routine rheumatology practice, the implementation of a ”tight control” and ”treat to target” strategy resulted in a greater improvement in disease activity and an early and sustained improvement in patient-reported outcomes. Our results suggest that this type of strategy should be integrated into daily clinical practice of new-onset RA.

Disclosure of Interests

Jon Thorkell Einarsson: None declared, Katarina Friberger Pajalic: None declared, Caroline Bengtsson: None declared, Elisabeth Mogard: None declared, Elisabet Lindqvist: None declared, Carmen Roseman: None declared, Olafur Palsson: None declared, Johan K Wallman Consultant of: Consultant of AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: Research support from AbbVie, Amgen, Eli Lilly, Novartis, Pfizer.

Tor Olofsson Consultant of: consultant of MSD, Meliha C Kapetanovic Consultant of: Abbvie, Pfizer, GSK, Grant/research support from: unrestricted grants from Pfizer and Roche.

POS0983 LIFESTYLE IN AXIAL SPONDYLOARTHRITIS - COMPARISONS BETWEEN PATIENTS AND CONTROLS, AXIAL SPONDYLOARTHRITIS SUBTYPES, MALE AND FEMALE PATIENTS, AND ITS ASSOCIATION WITH DISEASE AND HEALTH OUTCOMES. RESULTS FROM THE SPARTAKUS COHORT

Background

Healthy lifestyle behaviours are associated with better health outcomes and quality of life in the general population (1, 2). In patients with axial spondyloarthritis (axSpA), however, little is known regarding multiple lifestyle behaviours and their associations with disease and health outcomes.

Objectives

To study lifestyle behaviours in patients with axSpA in relation to healthy controls, between axSpA subtypes and male and female patients, respectively, and to assess how the presence of two or more unhealthy lifestyle factors associate with disease and health outcomes.

Methods

We performed a cross-sectional study of 250 well-characterized axSpA patients (167 with radiographic axSpA [r-axSpA; ASAS and/or modified New York criteria], 83 with non-radiographic axSpA [nr-axSpA; ASAS criteria]) and 48 controls (frequency-matched to the patients for age and sex), participating in the population-based SPARTAKUS study in southern Sweden. Self-reported data on smoking, alcohol use, physical activity, dietary habits, and objectively measured body mass index (BMI), respectively, for all subjects was categorized as fulfilling national recommendations or not (healthy/unhealthy), and summarized in an index (0-5, indicating the number of unhealthy lifestyle factors). The index was also dichotomized into 0-1 vs. 2-5 unhealthy lifestyle factors. Comparisons between patients and controls, axSpA subtypes (r-axSpA vs. nr-axSpA), and between male and female patients were performed by Student’s t-test/Chi-square test, as appropriate. Linear regression analyses were used to explore associations between having ≥2 unhealthy lifestyle factors (yes/no) and disease and health outcomes.

Results

Characteristics and lifestyle factors for axSpA patients and controls are presented in the Table 1. Reporting ≥2 unhealthy lifestyle factors was more common in axSpA patients than controls (35% vs. 19%, p=0.029), while no difference was found between the axSpA subtypes (Figure 1 a and b). Male patients more often reported several unhealthy lifestyle factors than female patients (Figure 1 c), with more frequent unhealthy alcohol use (19% vs. 9%, p=0.023) and overweight/obesity; BMI ≥25 (63% vs. 50%, p=0.043), while smoking, physical activity, and dietary habits were similar. In addition, older patients displayed more unhealthy lifestyle factors (Figure 1 d). Having ≥2 unhealthy lifestyle factors was associated with worse disease activity (ASDAS-CRP) (β-est [95% CI]) (0.34 [0.11: 0.58]), physical function (BASFI) (0.73 [0.18; 1.28]), pain (1.03 [0.39; 1.67]), fatigue (0.95 [0.24; 1.66]), and quality of life (EQ-5D) (-0.09 [-0.15; -0.02]) in axSpA patients, adjusted for age, sex, and axSpA subtype (all p≤0.010)

Table 1.

Characteristics and lifestyle factors

r-axSpA/nr-axSpA combined n = 250Controls n =48Female sex116 (46%)24 (48%)Age, years51 (13)51 (14)Symptom duration, years7.7 (7.6)N/AASDAS-CRP1.8 (0.9)N/ABASFI2.0 (2.2)N/ABASMI3.0 (1.6)N/ANRS patients’ global health3.1 (2.5)1.1 (1.1)*NRS pain3.1 (2.5)1.5 (1.6)*NRS fatigue3.5 (2.8)2.2 (2.0)*EQ-5D utility0.72 (0.24)0.90 (0.12)*Ongoing csDMARD54 (22%)N/AOngoing bDMARD103 (41%)N/AOngoing glucocorticoids18 (7%)N/ASmoking, not fulfil rec.31 (12%)2 (4%)Alcohol, not fulfil rec.35 (14%)5 (10%)Physical activity, not fulfil rec.72 (29%)8 (17%)Dietary habits, not fulfil rec.35 (14%)5 (10%)BMI, not fulfil rec.142 (57%)15 (31%)*

Mean (SD) or n (%). * p<0.05 by Chi2-test or Student t-test, as appropriate. Missing data: ≤ 2%.

Conclusion

Unhealthy lifestyle behaviours were more common in axSpA patients than controls, and in male axSpA patients compared to females. Having two or more unhealthy lifestyle factors was associated with worse disease activity, physical function, pain, fatigue, and quality of life in the axSpA patients.

References

[1]Aleksandrova K, et al. BMC Medicine. 2014;12:168

[2]Lacombe J, et al. BMC Public Health. 2019;19:900

Disclosure of Interests

Elisabeth Mogard Consultant of: Novartis, Tor Olofsson Consultant of: Eli Lilly, Merck Sharp & Dohme, Ann Bremander: None declared, Jonas Sagard: None declared, Johan K Wallman Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer, Elisabet Lindqvist: None declared

POS0073 COMPARISON OF TIME FROM METHOTREXATE INITIATION TO START OF A b/tsDMARD IN PSORIATIC ARTHRITIS VERSUS RHEUMATOID ARTHRITIS. A NATIONWIDE REGISTER-BASED STUDY

Background

In Sweden, methotrexate (MTX) is recommended as first-line DMARD for both psoriatic arthritis (PsA) and rheumatoid arthritis (RA). Whereas in RA the use of MTX monotherapy is supported by efficacy data from randomized trials, in PsA no clear efficacy has been demonstrated in placebo-controlled trials. Therefore, the use of MTX in PsA is mostly based on clinical experience and results from studies not primarily designed to evaluate MTX efficacy.

Objectives

To compare time from MTX initiation until start of a biological or targeted synthetic DMARD (b/tsDMARD), as marker of insufficient MTX response, in previously DMARD-naïve, incident cases with PsA and matched, corresponding, reference subjects with RA.

Methods

Patients with PsA, having collected a prescription of MTX as their first ever DMARD any time between 2011 through 2018, and with a first ever PsA diagnosis in the Swedish National Patient Register within two years prior to this date, were included. Each individual was required to have a visit in rheumatology, but no visit in dermatology, within 6 weeks prior to MTX initiation, to ensure that PsA rather than psoriasis was the main reason for MTX treatment. For each individual with PsA, a corresponding individual with incident RA was identified, matched on sex, age, and year of MTX initiation. Only PsA cases with an identified RA comparator were included. All individuals with a diagnosis indicating axial spondyloarthritis prior to MTX start were excluded. The data were enriched through linkage to other national registers.

Follow-up was defined as the time from MTX initiation until start of any b/tsDMARD. Censoring was performed at the first of death, migration or 31 Dec 2020. Time until start of a b/tsDMARD was compared for PsA and RA through crude survival curves and conditional Cox-regression, crude and adjusted for comorbidity, level of education and patient global health.

Results

3098 patients with PsA, and their individually matched RA comparators were included. At initiation of MTX, PsA cases had a mean 28-joint disease activity score (DAS28) of 4.0 and RA-controls of 4.6, while patient-reported global health was 51 (of 100) for both groups and number of swollen joints (28-joint count) 4.0 for PsA and 6.8 for RA, Table 1. The comorbidity burden was similar at baseline.

Table 1.

Characteristics of PsA cases and matched RA controls at start of MTX.

Psoriatic arthritis N=3098Rheumatoid arthritis N=3098Age, mean (sd)55 (14)55 (14)Sex, male49%49%Length of education, yrs <1020%24% 10-1251%49% >1228%26%Diabetes1, 27.4%6.7%Myocardial infarction11.3%1.8%Malignancy14.7%5.0%Congestive heart disease10.2%0.2%Chronic lung disease11.6%2.2%Use of anti-depressive drugs1, 315.4%11.4%DAS28-CRP, mean (sd)44.0 (1.1)4.6 (1.2)Patient global, mean (sd) 451 (23)51 (23)CRP, median (IQR) 47 (14)10 (21)Tender joint count (28), mean (sd) 45.2 (4.9)7.0 (5.7)Swollen joint count (28), mean (sd) 44.0 (4.1)6.8 (5.2)

1) Diagnosis within 5 years. 2) Also identified by collecting ≥1 prescription of anti-diabetics in 1 year. 3) Identified by collecting ≥1 prescription within 1 year before methotrexate start. 4) Data on disease activity variables available for 28-36% of PsA and 56-62% of RA.

During a mean follow-up of 4.5 and 4.4 years, 34% and 33% of PsA and RA patients, respectively, started a b/tsDMARD, of whom 63% and 84% had also used ≥1 non-MTX conventional synthetic DMARD before the b/tsDMARD initiation. The crude survival curves for time from MTX initiation until start of a b/tsDMARD were identical for PsA and RA, Figure 1A. The adjusted HR for starting a b/tsDMARD in PsA compared with RA was 0.99 (95% CI 0.90-1.09). No calendar time trends were observed (Figure 1B and C).

Conclusion

In this study, the risk of escalating treatment from MTX, by adding or switching to a b/tsDMARD, was identical in PsA cases and matched RA controls. This supports a good response to MTX in PsA, similar to that in RA. Due to the matching, neither the results from the PsA nor the RA populations may be fully generalizable.

Disclosure of Interests

Ulf Lindström: None declared, Daniela Di Giuseppe: None declared, Sofia Exarchou Consultant of: AbbVie, Amgen, Janssen, Novartis, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer, Gerd-Marie Alenius: None declared, Tor Olofsson Consultant of: Merck Sharp & Dohme, Eva Klingberg: None declared, Lennart T.H. Jacobsson Speakers bureau: Janssen, Eli Lilly, Novartis, Consultant of: Janssen, Eli Lilly, Novartis, Johan Askling Grant/research support from: Abbvie, Astra-Zeneca, BMS, Eli Lilly, MSD, Pfizer, Roche, Samsung Bioepis, Sanofi, and UCB., Johan K Wallman Consultant of: AbbVie, Amgen, Celgene, Eli Lilly, Novartis, Grant/research support from: AbbVie, Amgen, Eli Lilly, Novartis, Pfizer

OP0249 CHARACTERISTICS ASSOCIATED WITH POOR COVID-19 OUTCOMES IN PEOPLE WITH PSORIASIS AND SPONDYLOARTHRITIS: DATA FROM THE COVID-19 PsoProtect AND GLOBAL RHEUMATOLOGY ALLIANCE PHYSICIAN-REPORTED REGISTRIES

Background

Some factors associated with severe COVID-19 outcomes have been identified in patients with psoriasis (PsO) and inflammatory/autoimmune rheumatic diseases, namely older age, male sex, comorbidity burden, higher disease activity, and certain medications such as rituximab. However, information about specificities of patients with PsO, psoriatic arthritis (PsA) and axial spondyloarthritis (axSpA), including disease modifying anti-rheumatic drugs (DMARDs) specifically licensed for these conditions, such as IL-17 inhibitors (IL-17i), IL-23/IL-12 + 23 inhibitors (IL-23/IL-12 + 23i), and apremilast, is lacking.

Objectives

To determine characteristics associated with severe COVID-19 outcomes in people with PsO, PsA and axSpA.

Methods

This study was a pooled analysis of data from two physician-reported registries: the Psoriasis Patient Registry for Outcomes, Therapy and Epidemiology of COVID-19 Infection (PsoProtect), comprising patients with PsO/PsA, and the COVID-19 Global Rheumatology Alliance (GRA) registry, comprising patients with PsA/axSpA. Data from the beginning of the pandemic up to 25 October, 2021 were included. An ordinal severity outcome was defined as: 1) not hospitalised, 2) hospitalised without death, and 3) death. A multivariable ordinal logistic regression model was constructed to assess the relationship between COVID-19 severity and demographic characteristics (age, sex, time period of infection), comorbidities (hypertension, other cardiovascular disease [CVD], chronic obstructive lung disease [COPD], asthma, other chronic lung disease, chronic kidney disease, cancer, smoking, obesity, diabetes mellitus [DM]), rheumatic/skin disease (PsO, PsA, axSpA), physician-reported disease activity, and medication exposure (methotrexate, leflunomide, sulfasalazine, TNFi, IL17i, IL-23/IL-12 + 23i, Janus kinase inhibitors (JAKi), apremilast, glucocorticoids [GC] and NSAIDs). Age-adjustment was performed employing four-knot restricted cubic splines. Country-adjustment was performed using random effects.

Results

A total of 5008 individuals with PsO (n=921), PsA (n=2263) and axSpA (n=1824) were included. Mean age was 50 years (SD 13.5) and 51.8% were male. Hospitalisation (without death) was observed in 14.6% of cases and 1.8% died. In the multivariable model, the following variables were associated with severe COVID-19 outcomes: older age (Figure 1), male sex (OR 1.53, 95%CI 1.29-1.82), CVD (hypertension alone: 1.26, 1.02-1.56; other CVD alone: 1.89, 1.22-2.94; vs no hypertension and no other CVD), COPD or asthma (1.75, 1.32-2.32), other lung disease (2.56, 1.66-3.97), chronic kidney disease (2.32, 1.50-3.59), obesity and DM (obesity alone: 1.36, 1.07-1.71; DM alone: 1.85, 1.39-2.47; obesity and DM: 1.89, 1.34-2.67; vs no obesity and no DM), higher disease activity and GC intake (remission/low disease activity and GC intake: 1.96, 1.36-2.82; moderate/severe disease activity and no GC intake: 1.35, 1.05-1.72; moderate/severe disease activity and GC intake 2.30, 1.41-3.74; vs remission/low disease activity and no GC intake). Conversely, the following variables were associated with less severe COVID-19 outcomes: time period after 15 June 2020 (16 June 2020-31 December 2020: 0.42, 0.34-0.51; 1 January 2021 onwards: 0.52, 0.41-0.67; vs time period until 15 June 2020), a diagnosis of PsO (without arthritis) (0.49, 0.37-0.65; vs PsA), and exposure to TNFi (0.58, 0.45-0.75; vs no DMARDs), IL17i (0.63, 0.45-0.88; vs no DMARDs), IL-23/IL-12 + 23i (0.68, 0.46-0.997; vs no DMARDs) and NSAIDs (0.77, 0.60-0.98; vs no NSAIDs).

Conclusion

More severe COVID-19 outcomes in PsO, PsA and axSpA are largely driven by demographic factors (age, sex), comorbidities, and active disease. None of the DMARDs typically used in PsO, PsA and axSpA, were associated with severe COVID-19 outcomes, including IL-17i, IL-23/IL-12 + 23i, JAKi and apremilast.

Acknowledgements

We thank all the contributors to the COVID-19 PsoProtect, GRA and EULAR Registries.

Disclosure of Interests

None declared

POS0237 GUT DYSBIOSIS LINKED TO WORSE DISEASE STATUS IN AXIAL SPONDYLOARTHRITIS

Background:

Based on clinical and genetic associations, axial spondyloarthritis (axSpA) and inflammatory bowel disease (IBD) are suspected to have a linked pathogenesis. Gut dysbiosis, intrinsic to IBD, has also been observed in axSpA. It is, however, not established to what degree gut dysbiosis is associated with axSpA disease severity.

Objectives:

To compare presence and degree of gut dysbiosis between axSpA patients and controls, and to explore whether gut dysbiosis is associated with axSpA disease activity, function and pain.

Methods:

The GA-map Dysbiosis Test (Genetic Analysis, Oslo, Norway) was used to identify and grade gut dysbiosis based on faecal samples from 44 non-radiographic axSpA (nr-axSpA; ASAS criteria) and 88 ankylosing spondylitis (AS; modified New York criteria) patients without IBD, consecutively enrolled in a population-based cohort study, and from 46 controls without rheumatic disease or IBD (frequency-matched to the patients for age/sex). The GA-map Dysbiosis Test is a validated method grading microbiota aberration on a 1-5 scale (Dysbiosis Index, DI), where ≥3 denotes dysbiosis. Analysis of covariance (ANCOVA) was used to compare DI between axSpA patients (nr-axSpA and AS combined) and controls, adjusted for age, sex, body mass index (BMI) and smoking. Within the axSpA group, disease activity (ASDAS-CRP; BASDAI), function (BASFI) and pain (VAS pain) were compared between patients with various DI levels by One-way analysis of variance (ANOVA) or Kruskal-Wallis test, as appropriate. Finally, axSpA patients were subdivided by presence of dysbiosis (DI ≥3 vs. <3) followed by comparison of ASDAS-CRP, BASDAI, BASFI, VAS pain and Evaluator´s global assessment of disease activity (EvalGlobal; 0-4: remission-maximal) by ANCOVA. Analyses were conducted unadjusted and adjusted for age, sex, BMI, smoking, axSpA subtype, gut inflammation (faecal calprotectin ≥50 mg/kg), irritable bowel syndrome symptoms (ROME III criteria), ASAS 3-month NSAID score and cs/bDMARD treatment.

Results:

Characteristics of the patients/controls are shown in the Table 1. Gut dysbiosis (DI≥3) was observed in 33% of axSpA patients and 17% of controls. DI was significantly higher among the patients (β-estimate [bootstrapped 95%CI] for the between-group difference: 0.34 [0.04-0.65]; p=0.027). In the axSpA group, higher DI was associated with worse scores in all assessed outcomes (Figure 1, panel A). Moreover, presence of dysbiosis (DI≥3) was associated with worse ASDAS-CRP, BASDAI, BASFI, VAS pain and EvalGlobal (Figure 1, panel B; EvalGlobal not shown in the Figure: unadjusted β [bootstrapped 95%CI]: 0.32 [0.09-0.55], adjusted: 0.28 [0.03-0.52] for patients with DI ≥3 vs. <3), with between-group differences remaining significant after adjustment, except for ASDAS-CRP (p=0.079) and VAS pain (p=0.064).

Table 1.All patients n=132Nr-axSpAn=44ASn=88Controlsn=46Male sex, n (%)72 (55)17 (39)55 (63)23 (50)Age, y53 (13)48 (12)55 (13)51 (14)Symptom duration, y26 (14)21 (11)28 (14)Body mass index, kg/m227 (4.3)27 (4.2)27 (4.3)25 (3.3)Smoking ever, n (%)43 (33)9 (20)34 (39)13 (28)CRP, mg/L3.7 (5.3)2.3 (2.4)4.3 (6.1)F-Calprotectin ≥50 mg/kg, n (%)46 (35)12 (27)34 (39)Evaluator´s global, 0-4, median (IQR)1 (0-1)1 (0-1)1 (0-1)ASDAS-CRP1.8 (0.9)1.9 (0.9)1.8 (0.9)BASDAI3.1 (2.2)3.3 (1.9)3.0 (2.4)BASFI2.0 (2.1)2.0 (1.7)2.1 (2.2)VAS pain, cm3.3 (2.5)3.4 (2.2)3.2 (2.7)IBS symptoms, n (%)43 (33)15 (34)28 (32)ASAS 3-month NSAID score37 (44)36 (44)37 (44)Ongoing csDMARD, n (%)24 (18)9 (20)15 (17)Ongoing bDMARD, n (%)56 (42)19 (43)37 (42)

Mean (SD) unless otherwise specified. y, years; IBS, irritable bowel syndrome

Conclusion:

Gut dysbiosis, present to a higher degree in axSpA patients than controls, is associated with worse axSpA disease activity and function. These associations appear independent of gut inflammation and both NSAID and immunomodulatory treatment. This provides further evidence for an important link between disturbances in gastrointestinal homeostasis and axSpA manifestations, and implies that gut dysbiosis may be a novel biomarker for severe disease.

Disclosure of Interests:

Jonas Sagard: None declared, Tor Olofsson Consultant of: Eli Lilly, Merck Sharp & Dohme, Elisabeth Mogard: None declared, Jan Marsal Consultant of: AbbVie, Bristol-Myers Squibb, EuroDiagnostica, Ferring, Hospira, Janssen-Cilag, Merck, Sharp & Dohme (MSD), Otsuka, Pfizer, Sandoz, Takeda, Tillotts, UCB Pharma, Grant/research support from: AbbVie, Ferring, and Pfizer, Kristofer Andréasson: None declared, Mats Geijer Speakers bureau: UCB Pharma, AbbVie, Novartis, Pfizer, Lars Erik Kristensen Speakers bureau: Pfizer, AbbVie, Amgen, UCB, Celegene, BMS, MSD, Novartis, Eli Lilly, Janssen pharmaceuticals, Consultant of: Pfizer, AbbVie, Amgen, UCB, Celegene, BMS, MSD, Novartis, Eli Lilly, Janssen pharmaceuticals, Elisabet Lindqvist: None declared, Johan K Wallman Consultant of: Celgene, Eli Lilly, Novartis

OP0014 COMPARISON OF ANTERIOR UVEITIS OCCURRENCE DURING TREATMENT WITH SECUKINUMAB, ADALIMUMAB, INFLIXIMAB AND ETANERCEPT IN SPONDYLOARTHRITIS

Background:

Randomized controlled trials indicate that compared to tumor necrosis factor inhibitors (TNFi), secukinumab (SEC) has similar efficacy regarding axial inflammation in spondyloarthritis (SpA), better efficacy regarding cutaneous psoriasis, but is inferior in inflammatory bowel disease (IBD). However, the efficacy of SEC compared to TNFi in anterior uveitis (AU) has not been extensively studied.

Objectives:

To compare the occurrence of AU in patients with SpA treated with SEC, adalimumab (ADA), infliximab (IFX) or etanercept (ETN), in clinical practice.

Methods:

Patients with ankylosing spondylitis or undifferentiated SpA starting either SEC, ADA, IFX or ETN, in 2015 through 2017, were identified in the Swedish Rheumatology Quality register, and were linked to the national patient register for identification of AU. AU-flares were defined as the number of visits with an AU diagnosis, separated by a ≥60 days penalty interval, within ophthalmology outpatient care, during the respective bDMARD treatment.

Follow-up started at the bDMARD initiation, and ended at the first of Dec 31st2017, death, emigration or discontinuation date of the bDMARD.

To assess and accommodate treatment channeling, crude incidence rates for AU-flares were determined (A) for all bDMARD treatment starts, (B) excluding patients with an AU diagnosis during the year prior to the bDMARD start, and (C) in addition, excluding all first line bDMARD treatment starts.

Hazard ratios (HR) for time until a first on-treatment AU diagnosis were estimated using Cox regression (ADA=reference), adjusted for sex, age, and any history of AU, and estimating robust confidence intervals to account for the individuals contributing multiple lines of treatment.

Results:

In total, 2,684 patients (52% women) contributed 3,255 treatment initiations. SEC was less frequently used as first line bDMARD and there was channeling of patients with previous AU, towards treatment with ADA, and away from ETN (Table 1). Further, AU occurred almost exclusively in patients with a pre-treatment history of AU (data not shown).

Table 1.AnalysisTreat-ment starts, NPrevious AU1Age at treat-ment start, mean (sd)N Previous bDMARD, medianHR (95% CI) for first AU-diagnosisAU flares, NFollow-up2, yearsA. All treatment starts, N=3255SEC33321%48 (13)22.0 (1.2-3.3)52241ADA87234%44 (12)1Ref175973IFX71421%43 (14)00.9 (0.6-1.4)68677ETN133617%44 (14)00.9 (0.7-1.3)1021290B. Excluding patients with prior AU within 1 year before treatment start, N=2907SEC30413%47 (13)23.1 (1.4-7.3)10212ADA71119%44 (13)1Ref18792IFX63311%43 (14)01.0 (0.4-2.3)8599ETN125912%44 (14)01.8 (1.0-3.4)431204C. Excluding patients with prior AU within 1 year before treatment start and first line bDMARD, N=1288SEC28414%48 (13)22.5 (1.0-6.2)10198ADA37418%45 (13)1Ref11384IFX18512%45 (14)21.3 (0.4-4.0)4166ETN44517%47 (14)11.9 (0.9-4.0)23439

1) Anterior uveitis between 2001 and treatment start; 2) Total follow-up time for analyses of incidence rate.

The incidence rates of AU-flares were higher for SEC and ETN compared to ADA and IFX, in the analyses (B, C) accommodating for channeling, figure 1.

Compared to ADA, the adjusted HRs of a first on-treatment AU-diagnosis were also higher for SEC and ETA, Table 1.

Conclusion:

In clinical practice, SEC and ETN are associated with a higher incidence of AU than ADA and INF, suggesting a poorer protective effect of SEC and ETN against AU. These preliminary results should be interpreted in light of pronounced treatment channeling, which was only partly accommodated for.

Disclosure of Interests:

Ulf Lindström: None declared, Karin Bengtsson: None declared, Tor Olofsson: None declared, Daniela Di Giuseppe: None declared, Bente Glintborg Grant/research support from: Grants from Pfizer, Biogen and Abbvie, Helena Forsblad-d’Elia Grant/research support from: Unrestricted grant from Novartis., Consultant of: Advisory Board Fees from Sandoz, Novartis, and Abbvie, Lennart T.H. Jacobsson Consultant of: AbbVie, Eli Lilly, Janssen, Novartis and Pfizer, Johan Askling Grant/research support from: JA acts or has acted as PI for agreements between Karolinska Institutet and the following entities, mainly in the context of the ARTIS national safety monitoring programme of immunomodulators in rheumatology: Abbvie, BMS, Eli Lilly, Merck, MSD, Pfizer, Roche, Samsung Bioepis, Sanofi, and UCB Pharma

Consultation prevalence among children, adolescents and young adults with pain conditions: A description of age- and gender differences

BACKGROUND

Pain is a common complaint presented in healthcare, but most epidemiological pain research has focused either on single pain conditions or on the adult population. The aim of this study was to investigate the 2017 consultation prevalence of a wide range of pain conditions in the general population of young people.

METHODS

We used the Skåne Healthcare Register, covering prospectively collected data on all healthcare delivered (primary and secondary care) to the population in the region of Skåne, southern Sweden (population 2017 n = 1,344,689). For individuals aged 1-24 in 2017 (n = 373,178), we calculated the consultation prevalence, stratified by sex and age, and the standardised morbidity ratio (SMR) to assess overall healthcare consultation.

RESULTS

A total of 58,981 (15.8%) individuals consulted at least once for any of the predefined pain conditions. Of these, 13.5% (n = 7,996) consulted four or more times for pain. Abdominal pain, joint pain/myalgia, headache and back/neck pain were the most common complaints. Overall, females had higher consultation prevalence than males: 17.6% versus 14.1% (p < .0001). SMR was 1.82 (95% CI = 1.74-1.87) for females with pain and 1.51 (95% CI = 1.42-1.56) for males with pain. Consultation prevalence increased with age, but this pattern varied between sex and pain condition.

CONCLUSIONS

Among individuals under the age of 25, a significant proportion consult for pain already in early ages, and they also have high healthcare consultation rates for conditions other than pain. The even higher consultation rates among young females need additional attention, both in the clinic and in research.

SIGNIFICANCE

We present comprehensive 1-year healthcare consultation prevalence data covering all levels of care. A significant proportion of children, adolescents and young adults consult for different pain conditions at multiple occasions warranting greater clinical awareness.

Predictors of work disability after start of anti-TNF therapy in a national cohort of Swedish patients with rheumatoid arthritis: does early anti-TNF therapy bring patients back to work?

OBJECTIVES

To examine predictors of work ability gain and loss after anti-tumour necrosis factor (TNF) start, respectively, in working-age patients with rheumatoid arthritis (RA) with a special focus on disease duration.

METHODS

Patients with RA, aged 19-62 years, starting their first TNF inhibitor 2006-2009 with full work ability (0 sick leave/disability pension days during 3 months before bio-start; n=1048) or no work ability (90 days; n=753) were identified in the Swedish biologics register (Anti-Rheumatic Treatment In Sweden, ARTIS) and sick leave/disability pension days retrieved from the Social Insurance Agency. Outcome was defined as work ability gain ≥50% for patients without work ability at bio-start and work ability loss ≥50% for patients with full work ability, and survival analyses conducted. Baseline predictors including disease duration, age, sex, education level, employment, Health Assessment Questionnaire, Disease Activity Score 28 and relevant comorbidities were estimated using Cox regression.

RESULTS

During 3 years after anti-TNF start, the probability of regaining work ability for totally work-disabled patients was 35% for those with disease duration <5 years and 14% for disease duration ≥5 years (adjusted HR 2.1 (95% CI 1.4 to 3.2)). For patients with full work ability at bio-start, disease duration did not predict work ability loss. Baseline disability pension was also a strong predictor of work ability gain after treatment start.

CONCLUSIONS

A substantial proportion of work-disabled patients with RA who start anti-TNF therapy regain work ability. Those initiating treatment within 5 years of symptom onset have a more than doubled 3-year probability of regaining work ability compared with later treatment starts. This effect seems largely due to the impact of disease duration on disability pension status.

PROX1 is a predictor of survival for gliomas WHO grade II

Background:

The clinical course of World Health Organisation grade II gliomas remains variable and their time point of transformation into a more malignant phenotype is unpredictable. Identification of biological markers that can predict prognosis in individual patients is of great clinical value. PROX1 is a transcription factor that has a critical role in the development of various organs. PROX1 has been ascribed both oncogenic and tumour suppressive functions in human cancers. We have recently shown that PROX1 may act as a diagnostic marker for high-grade gliomas. The aim of this study was to address the prognostic value of PROX1 in grade II gliomas.

Methods:

A total of 116 samples were evaluated for the presence of PROX1 protein. The number of immunopositive cells was used as a variable in survival analysis, together with established prognostic factors for this patient group.

Results:

Higher PROX1 protein was associated with poor outcome. In the multivariate analysis, PROX1 was identified as an independent factor for survival (P=0.024), together with the presence of mutated isocitrate dehydrogenase 1 R132H protein, and with combined losses of chromosomal arms 1p/19q in oligodendrocytic tumours.

Conclusion:

PROX1 is a novel predictor of survival for grade II gliomas.

Wilms' tumor gene 1 protein represses the expression of the tumor suppressor interferon regulatory factor 8 in human hematopoietic progenitors and in leukemic cells

Wilms' tumor gene 1 (WT1) is a transcription factor involved in developmental processes. In adult hematopoiesis, only a small portion of early progenitor cells express WT1, whereas most leukemias show persistently high levels, suggesting an oncogenic role. We have previously characterized oncogenic BCR/ABL1 tyrosine kinase signaling pathways for increased WT1 expression. In this study, we show that overexpression of BCR/ABL1 in CD34+ progenitor cells leads to reduced expression of interferon regulatory factor 8 (IRF8), in addition to increased WT1 expression. Interestingly, IRF8 is known as a tumor suppressor in some leukemias and we investigated whether WT1 might repress IRF8 expression. When analyzed in four leukemia mRNA expression data sets, WT1 and IRF8 were anticorrelated. Upon overexpression in CD34+ progenitors, as well as in U937 cells, WT1 strongly downregulated IRF8 expression. All four major WT1 splice variants induced repression, but not the zinc-finger-deleted WT1 mutant, indicating dependence on DNA binding. A reporter construct with the IRF8 promoter was repressed by WT1, dependent on a putative WT1-response element. Binding of WT1 to the IRF8 promoter was demonstrated by chromatin immunoprecipitation. Our results identify IRF8 as a direct target gene for WT1 and provide a possible mechanism for oncogenic effects of WT1 in leukemia.

Deregulation of the Wilms' tumour gene 1 protein (WT1) by BCR/ABL1 mediates resistance to imatinib in human leukaemia cells

The Wilms' tumour gene 1 (WT1) protein is highly expressed in most leukaemias. Co-expression of WT1 and the fusion protein AML1-ETO in mice rapidly induces acute myeloid leukaemia (AML). Mechanisms behind expression of WT1, as well as consequences thereof, are still unclear. Here, we report that the fusion protein BCR/ABL1 increases expression of WT1 mRNA and protein via the phosphatidylinositol-3 kinase (PI3K)-Akt pathway. Inhibition of BCR/ABL1 or PI3K activity strongly suppressed transcription from WT1 promoter/enhancer reporters. Forced expression of BCR/ABL1 in normal human progenitor CD34+ cells increased WT1 mRNA and protein, further supporting the notion of BCR/ABL1-driven expression of WT1 in human haematopoietic cells. Forced expression of WT1 in K562 cells provided protection against cytotoxic effects of the ABL1 tyrosine kinase inhibitor imatinib, as judged by effects on viability measured by trypan blue exclusion, metabolic activity, annexin V and DAPI (4', 6-diamidino-2-phenylindole) staining. None of the isoforms provided any detectable protection against apoptosis induced by arsenic trioxide and only very weak protection against etoposide, indicating that WT1 interferes with specific apoptotic signalling pathways. Our data demonstrate that WT1 expression is induced by oncogenic signalling from BCR/ABL1 and that WT1 contributes to resistance against apoptosis induced by imatinib.

Microarray-based classification of a consecutive series of 121 childhood acute leukemias: prediction of leukemic and genetic subtype as well as of minimal residual disease status

Gene expression analyses were performed on 121 consecutive childhood leukemias (87 B-lineage acute lymphoblastic leukemias (ALLs), 11 T-cell ALLs and 23 acute myeloid leukemias (AMLs)), investigated during an 8-year period at a single center. The supervised learning algorithm k-nearest neighbor was utilized to build gene expression predictors that could classify the ALLs/AMLs according to clinically important subtypes with high accuracy. Validation experiments in an independent data set verified the high prediction accuracies of our classifiers. B-lineage ALLs with uncharacteristic cytogenetic aberrations or with a normal karyotype displayed heterogeneous gene expression profiles, resulting in low prediction accuracies. Minimal residual disease status (MRD) in T-cell ALLs with a high (>0.1%) MRD at day 29 could be classified with 100% accuracy already at the time of diagnosis. In pediatric leukemias with uncharacteristic cytogenetic aberrations or with a normal karyotype, unsupervised analysis identified two novel subgroups: one consisting mainly of cases remaining in complete remission (CR) and one containing a few patients in CR and all but one of the patients who relapsed. This study of a consecutive series of childhood leukemias confirms and extends further previous reports demonstrating that global gene expression profiling provides a valuable tool for genetic and clinical classification of childhood leukemias.

A novel and cytogenetically cryptic t(7;21)(p22;q22) in acute myeloid leukemia results in fusion of RUNX1 with the ubiquitin-specific protease gene USP42

Although many of the chromosomal abnormalities in hematologic malignancies are identifiable cytogenetically, some are only detectable using molecular methods. We describe a novel cryptic t(7;21)(p22;q22) in acute myeloid leukemia (AML). FISH, 3'RACE, and RT-PCR revealed a fusion involving RUNX1 and the ubiquitin-specific protease (USP) gene USP42. The genomic breakpoint was in intron 7 of RUNX1 and intron 1 of USP42. The reciprocal chimera was not detected - neither on the transcriptional nor on the genomic level - and FISH showed that the 5' part of USP42 was deleted. USP42 maps to a 7p22 region characterized by segmental duplications. Notably, 17 kb duplicons are present 1 Mb proximal to USP42 and 3 Mb proximal to RUNX1; these may be important in the genesis of t(7;21). This is the second cryptic RUNX1 translocation in hematologic malignancies and the first in AML. The USPs have not previously been reported to be rearranged in leukemias. The cellular context in which USP42 is active is unknown, but we here show that it is expressed in normal bone marrow, in primary AMLs, and in cancer cell lines. Its involvement in the t(7;21) suggests that deregulation of ubiquitin-associated pathways may be pathogenetically important in AML.

Autologous del(20q)-positive erythroid progenitor cells, re-emerging after DLI treatment of an MDS patient relapsing after allo-SCT, can provide a normal peripheral red blood cell count

A 54-year-old RhD-negative male with del(20q)-positive myelodysplastic syndrome was transplanted with bone marrow from an HLA-identical RhD-positive sibling donor. Cytogenetic relapse was detected 21 months after stem cell transplantation (SCT), with reappearance of the original del(20q)-positive clone and reversion to recipient RhD-negative blood group. The patient received sequential donor lymphocyte infusions (DLIs), resulting in mild graft-versus-host disease and pure red cell aplasia. At 2 years post DLI, the patient remains in a stable condition, despite a dominance of recipient-derived erythro- and granulopoiesis originating in del(20q)-carrying progenitor cells. We conclude that reappearance of autologous erythropoiesis, upon relapse after allogeneic SCT, may be predictive of erythropenia after DLI and that re-emerging autologous del(20q)-positive erythropoiesis post DLI can provide a normal peripheral red blood cell count. Furthermore, in patients relapsing after blood-group-mismatched transplantation, a possible reversion to recipient blood group should be considered prior to blood transfusion or DLI.

Establishment and phenotypic characterization of human U937 cells with inducible P210 BCR/ABL expression reveals upregulation of CEACAM1 (CD66a)

Chronic myeloid leukemia (CML) is characterized by the expression of the P210 BCR/ABL fusion protein. The molecular mechanisms behind this oncogene-mediated hematological disease are, however, not fully understood. Here, we describe the establishment and phenotypic characterization of U937 cells in which P210 BCR/ABL can be conditionally expressed using tetracycline. The induction of BCR/ABL in the obtained clones resulted in a rapid phosphorylation of the STAT1, STAT3 and STAT5 molecules, consistent with the findings in other model systems. Phenotypic characterization of the clones revealed that BCR/ABL induces a slight decrease in the proliferation and viability, without a marked effect on cell cycle distribution, the rate of apoptosis or on cellular differentiation, as judged by several cell surface markers and capacity to reduce nitro blue tetrazolium. Interestingly, BCR/ABL was found to upregulate the expression of carcinoembryonic-related antigen (CEA)CAM1 (CD66a), which is a plasma membrane-linked glycoprotein belonging to the CEAs and involved in signal transduction and cellular adhesion. The expression of CEACAM1 was reversible upon imatinib treatment in BCR/ABL-expressing U937 cells as well as in BCR/ABL-positive K562 cells. The established cell lines may prove useful in further modeling and dissection of BCR/ABL-induced leukemogenesis.

The Yersinia HPI is present in Serratia liquefaciens isolated from meat

AIMS

The aim of the study was to screen the Enterobacteriaceae flora of meat for the presence of bacteria harbouring the Yersinia high-pathogenicity island (HPI).

METHODS AND RESULTS

Bacteria from 29 meat and 29 liver samples were isolated on violet-red bile glucose agar. A total of 197 isolates were screened for the presence of the irp2 gene, encoded within the HPI, by PCR. One isolate that was positive for irp2 gene was also positive for the fyuA, irp1, ybtP/ybtQ, ybtX/ybtS and int/asn tRNA genes by PCR. The presence of fyuA, irp1 and irp2 genes was confirmed by Southern hybridization.

CONCLUSIONS

The isolate was identified as Serratia liquefaciens by sequencing of the 16S rRNA gene and by ribotyping.

SIGNIFICANCE AND IMPACT OF THE STUDY

This is the first report of a Serratia harbouring the Yersinia HPI. Serratia is a frequently occurring Enterobacteriaceae genus in chill-stored meat.

Acute myeloid leukemia with inv(16)(p13q22): involvement of cervical lymph nodes and tonsils is common and may be a negative prognostic sign

Acute myeloid leukemia (AML) with inv(16)(p13q22) or the variant t(16;16)(p13;q22), is strongly associated with the FAB subtype M4Eo. A high incidence of CNS involvement was reported in the 1980s, but otherwise little is known about the pattern of extamedullary leukemia (EML) manifestations in this AML type. We have compiled clinical and cytogenetic data on 27 consecutive AML cases with inv(16)/t(16;16) from southern Sweden. In general, these AMLs displayed the clinical features that have previously been described as characteristic for this disease entity: low median age, hyperleukocytosis, M4Eo morphology, and a favorable prognosis. However, CNS leukemia was only seen in relapse in one patient diagnosed in 1980, whereas the most common EML manifestation in our series was lymphadenopathy (5/27, 19%), most often cervical with or without gross tonsillar enlargement. A review of previously published, clinically informative cases corroborates that lymphadenopathy, with preference for the cervical region, is the most common EML at diagnosis in inv(16)-positive AML (58/175, 33%). CNS leukemia, on the other hand, has been reported in only 17% of the cases, mostly in the relapse setting, with a diminishing frequency over time, possibly due to protective effects of high-dose cytarabine. Other reported EML sites include the scalp, ovaries, and the intestine. Cervicotonsillar EML was in our series associated with a shorter duration of first remission, (P < 0.05), and may hence prove to be an important clinical parameter when deciding treatment strategies in AML with inv(16)/t(16;16).

Fusion of the BCR and the fibroblast growth factor receptor-1 (FGFR1) genes as a result of t(8;22)(p11;q11) in a myeloproliferative disorder: the first fusion gene involving BCR but not ABL

Constitutive activation of tyrosine kinases as a consequence of chromosomal translocations, forming fusion genes, plays an important role in the development of hematologic malignancies, in particular, myeloproliferative syndromes (MPSs). In this respect, the t(9;22)(q34;q11) that results in the BCR/ABL fusion gene in chronic myeloid leukemia is one of the best-studied examples. The fibroblast growth factor receptor 1 (FGFR1) gene at 8p11 encodes a transmembrane receptor tyrosine kinase and is similarly activated by chromosomal translocations, in which three alternative genes-ZNF198 at 13q12, CEP110 at 9q34, and FOP at 6q27-become fused to the tyrosine kinase domain of FGFR1. These 8p11-translocations are associated with characteristic morphologic and clinical features, referred to as "8p11 MPS." In this study, we report the isolation and characterization of a novel fusion gene in a hematologic malignancy with a t(8;22)(p11;q11) and features suggestive of 8p11 MPS. We show that the breakpoints in the t(8;22) occur within introns 4 and 8 of the BCR and FGFR1 genes, respectively. On the mRNA level, the t(8;22) results in the fusion of BCR exons 1-4 in-frame with the tyrosine kinase domain of FGFR1 as well as in the expression of a reciprocal FGFR1/BCR chimeric transcript. By analogy with data obtained from previously characterized fusion genes involving FGFR1 and BCR/ABL, it is likely that the oligomerization domain contributed by BCR is critical and that its dimerizing properties lead to aberrant FGFR1 signaling and neoplastic transformation.

Minimum entropy deconvolution of pulse-echo signals acquired from attenuative layered media

In this article deconvolution of ultrasonic pulse-echo data acquired from attenuative layered media is considered. The problem is divided in two subproblems: treating the sparse reflection sequence caused by the layered structure of the media and treating the frequency-dependent attenuation. The first subproblem is solved by means of joint maximum a posteriori estimation of the assumed zero mean, white, nonstationary reflection sequence and its corresponding sequence of unknown standard deviations. This approach leads to an algorithm that seeks minimum entropy solutions for the reflection sequence and therefore the algorithm serves as a novel link between the classical Wiener filter and methods for sparse or minimum entropy deconvolution. The second subproblem is solved by introducing a new signal processing-oriented, linear discrete-time model for frequency-dependent attenuation in isotropic and homogeneous media. The deconvolution algorithm is tested using simulated data and its performance for real normal incidence pulse-echo data from a composite material is also demonstrated. The results show that the algorithm, in combination with the attenuation model, yields estimates that reveal the internal structure of the composite and, thus, simplify the interpretation of the ultrasonic data.

Isodicentric 7p, idic(7)(q11.2), in acute myeloid leukemia associated with older age and favorable response to induction chemotherapy: a new clinical entity?

Three adult de novo acute myeloid leukemias (AML M1, M2, and M4) with an isochromosome 7p are presented. No additional abnormalities were detected by G-band and multicolor, using combined binary ratio labeling, fluorescence in situ hybridization (FISH) analyses, indicating that the i(7p) was the sole, i.e., the primary, chromosomal aberration. Although the patients were elderly--68, 72, and 78 years old--they all responded very well to chemotherapy, achieving complete remission lasting more than a year. Further FISH analyses, using painting, centromeric, as well as 7q11.2-specific YAC probes, revealed that the i(7p) contained two centromeres and that the breakpoints were located in 7q11.2. Thus, the abnormality should formally be designated idic(7)(q11.2). The detailed mapping disclosed a breakpoint heterogeneity, with the breaks in 7q11.2 varying among the cases, being at least 1,310 kb apart. Furthermore, the breakpoints also differed within one of the cases, being located on both the proximal and the distal side of the most centromeric probe used. Based on our three patients, as well as on a previously reported 82-year-old patient with AML M2 and idic(7)(q11) as the only chromosomal change, we suggest that this abnormality, as the sole anomaly, is associated with AML in elderly patients who display a good response to induction chemotherapy and, hence, have a favorable prognosis. Furthermore, the heterogeneous breakpoints in 7q11.2 suggest that the important functional outcome of the idic(7)(q11.2) is the genomic imbalance incurred, i.e., gain of 7p and loss of 7q material, rather than a rearrangement of a specific gene.

Carbohydrate groups of alpha1-microglobulin are important for secretion and tissue localization but not for immunological properties

The role of the carbohydrates for the structure and functions of the plasma and tissue protein alpha1-microglobulin (alpha1m) was investigated by deletion of the sites for N-glycosylation by site-directed mutagenesis (N17,96-->Q). The mutated cDNA was expressed in a baculovirus-insect cell system resulting in a nonglycosylated protein. The biochemical properties of N17,96Q-alpha1m were compared to nonmutated alpha1m, which carries two short non-sialylated N-linked oligosaccharides when expressed in the same system. Both proteins carried a yellow-brown chromophore and were heterogeneous in charge. Circular dichroism spectra and antibody binding indicated a similar overall structure. However, the secretion of N17,96Q-alpha1m was significantly reduced and approximately 75% of the protein were found accumulated intracellularly. The in vitro immunological effects of recombinant nonmutated alpha1m and N17,96Q-alpha1m were compared to the effects of alpha1m isolated from plasma, which is sialylated and carries an additional O-linked oligosaccharide. All three alpha1m variants bound to human peripheral lymphocytes and mouse T cell hybridomas to the same extent. They also inhibited the antigen-stimulated proliferation of peripheral lymphocytes and antigen-stimulated interleukin 2-secretion of T cell hybridomas in a similar manner. After injection of rats intravenously, the blood clearance of recombinant nonmutated and N17,96Q-alpha1m was faster than that of plasma alpha1m. Nonmutated alpha1m was located primarily to the liver, most likely via binding to asialoglycoprotein receptors, and N17,96Q-alpha1m was located mainly to the kidneys. It is concluded that the carbohydrates of alpha1m are important for the secretion and the in vivo turnover of the protein, but not for the structure or immunological properties.

Maximum a posteriori deconvolution of ultrasonic signals using multiple transducers

A new method for deconvolution of ultrasonic pulse-echo measurements employing multiple-transducer setup is proposed in the paper. An optimal way of estimating the material reflection sequence for a linear signal generation model using maximum a posteriori estimation is proposed. The method combines the measurements from a number of transducers covering different frequency bands yielding an optimal estimate of the reflection sequence. The main idea of this approach is to complement the information unavailable from one transducer in some frequency bands with the information from the other transducers. The method is based on the assumption that the measurements are performed using transducers with identical apertures and apodization, which are located exactly at the same position relative to the test object during the measurement. An error analysis presented in the paper proves that when the above assumptions are fulfilled, the proposed method, by utilizing more data for estimation, consistently yields more accurate reflection sequence estimates than the classical Wiener filter. Experimental evidence is presented using both simulated and real ultrasonic data as a verification of the correctness of the multiple-transducer model and the estimation scheme. An illustration of the advantages of the method is also given using real ultrasonic data.

Granulocyte interactions with GM-CSF and G-CSF secretion by endothelial cells and monocytes

We have, in previous studies, characterized the cytokine and cellular regulation of GM-CSF and G-CSF production by monocytes and endothelial cells. In this study, we investigated the regulatory role of granulocytes. The addition of granulocytes to endotoxin-stimulated monocytes dose-dependently decreased both GM-CSF and G-CSF concentrations, presumably by absorbing the cytokines. A similar dose-dependent decrease in GM-CSF concentration was found when granulocytes were added to IL-1-stimulated endothelial cells. In contrast, G-CSF secretion by endothelial cells responded to granulocytes in a biphasic fashion. At low granulocyte concentrations, endothelial cells responded with an increased G-CSF secretion, but at high concentrations of granulocytes G-CSF secretion was down modulated. Our results suggest that there exist two loops between granulocytes and endothelial cells for regulating G-CSF activity. Granulocytes can stimulate G-CSF secretion by activated endothelial cells but can also decrease the biological activity by absorbing the cytokine. These mechanisms might be involved in the regulation of the local and systemic levels of granulocytes.

Maximum a posteriori deconvolution of sparse ultrasonic signals using genetic optimization

Deconvolution of sparse spike sequences has received much attention in the field of seismic exploration. In certain situations in ultrasonic non-destructive testing (NDT) of materials, similar conditions as those found in seismic exploration occur. One example is the problem of detecting disbonds in layered aluminum structures. The reflection sequence convolved with the impulse response of the transducer results in masking closely spaced reflections. Deconvolution of these signals may reveal the reflection sequence and thus make the interpretation easier. In this paper we use the Bernoulli-Gaussian (BG) distribution for modeling the signal generation. This relatively simple model allows maximum a posteriori (MAP) estimation of the reflection sequence. A derivation of the MAP criterion is given for clarity. We propose a genetic algorithm for optimizing the MAP criterion. The genetic algorithm approach is motivated by the fact that the criterion is non-convex, implying that the criterion may have more than one local minimum point. The probability of obtaining the global optimal solution is increased by using the proposed genetic algorithm. One of the key features in genetic algorithms, the so-called cross-over operator, has been modified and adapted to the structure of the BG deconvolution problem to improve the efficiency of the search. The algorithm is tested on simulated data using the probability of detection (PD) and probability of false alarm (PFA) as evaluation criteria. The algorithm is also tested on real ultrasonic data from a layered aluminum structure. The results show considerable improvements in the possibility of interpreting the signals.

Linear reduction of clonal cells in stem cell enriched grafts in transplanted multiple myeloma

In 30 patients with multiple myeloma who were scheduled for peripheral blood stem-cell transplantation, a quantitative analysis of the stem cells following enrichment by anti-CD34 was carried out. To detect the cells of the specific myeloma clone, polymerase chain reaction (PCR) was performed using unique allele-specific oligo primers for the immunoglobulin heavy chain rearrangement. The clonogenic cells before and after stem-cell enrichment, were quantified by a limiting dilution assay and a highly sensitive semi-nested PCR combined with a real-time quantitative PCR. In order to accomplish a statistically adequate end-point analysis, a large number of PCR analyses (40 per sample) were performed. By this technique the lowest detection limit observed was one myeloma cell per 106 cells. Myeloma cells were detected in 29/30 samples from the CD34-enriched fraction. The CD34 selection procedure resulted in a median 28-fold enrichment of CD34+ haemopoietic precursor cells. The stem-cell selection reduced the median concentration of clonal cells per million total cells by half, with a highly significant linear relationship between the number of myeloma cells before and after stem cell enrichment. The median depletion of clonal cells by the overall procedure was 2.15 log units, corresponding to a reduction of the total quantity of clonal cells reinfused into the patients by at least 99.3%. We conclude that CD34+ cell enrichment led to a reliable tumour cell depletion of the order of 2 log, which may not be sufficient since the total number of tumour cells in the leukapheresis product was 7.2 log (median).

T lymphocytes downregulate granulocyte-macrophage colony-stimulating factor secretion from stimulated monocytes by increasing the secretion of monocyte-derived interleukin-10

In previous studies we characterized the cytokine regulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) secretion by endothelial cells and monocytes and found differences in secretion pattern within and between these cell systems. In this study, the regulatory effect of T lymphocytes on CSF secretion was examined. T lymphocytes had no effect on CSF secretion by endothelial cells. In contrast, the addition of T lymphocytes significantly and dose dependently downregulated GM-CSF, but not G-CSF, secretion by monocytes. In one of our previous studies it was shown that interleukin-4 (IL-4) and interleukin-10 (IL-10) were the most potent inhibitory cytokines of CSF secretion by monocytes. Both these cytokines are produced by T lymphocytes. However, the downregulating effect on monocyte GM-CSF secretion was not due to increased secretion of T-lymphocyte-derived IL-4 or IL-10. Instead, the presence of T lymphocytes increased the secretion of monocyte-derived IL-10. It was shown earlier than IL-10 regulates CSF secretion by monocytes in an autocrine manner. Our data indicate that T lymphocytes might interfere with this autocrine regulation and thereby influence monocyte function in immune response and cell proliferation.

A secreted proform of neutrophil proteinase 3 regulates the proliferation of granulopoietic progenitor cells

Myeloid leukemia cells, the human promyelocytic cell line HL-60, and a subpopulation of normal marrow cells produce a leukemia-associated inhibitor (LAI) that reversibly downmodulates DNA synthesis of normal granulopoietic progenitor cells colony-forming unit granulocyte-macrophage (CFU-GM). We isolated an active 125-kD component of LAI from HL-60 conditioned medium (CM), subjected it to cyanogen bromide cleavage and show by amino acid sequencing of the resulting peptides that it consists of a complex of the serine proteinase inhibitor alpha1-antitrypsin and a 31-kD fragment that retained the S-phase inhibitory activity, but resisted sequencing. This finding suggested that the 31-kD fragment originated from one of the neutrophil serine proteases (ie, elastase, proteinase 3, or cathepsin G) produced by normal promyelocytes, as well as HL-60 cells, for storage in primary granules and partly secreted during synthesis as enzymatically inactive proforms. Immunoblot analysis showed that the 125-kD complex contained proteinase 3 (PR3), and immunoprecipitation of PR3 from HL-60 CM abrogated the S-phase inhibitory activity, whereas immunoprecipitation of cathepsin G or elastase did not. Immunoprecipitation of PR3 from CM of a subpopulation of normal marrow cells also abrogated the S-phase inhibitory effect. Furthermore, CM from rat RBL and murine 32D cell lines transfected with human PR3 both reduced the fraction of CFU-GM in S-phase with 30% to 80% at 1 to 35 ng/mL PR3, whereas CM of the same cells transfected with cathepsin G or elastase did not. Also, an enzymatically silent mutant of PR3 exerted full activity, showing that the S-phase modulatory effect is not dependent on proteolytic activity. Amino acid sequencing of biosynthetically radiolabeled PR3 showed that PR3 from transfected cells is secreted after synthesis as proforms retaining amino terminal propeptides. In contrast, mature PR3 extracted from mature neutrophils has only minor activity. The inhibitory effect of secreted PR3 is reversible and abrogated by granulocyte (G)- or granulocyte-macrophage colony-stimulating factor (GM-CSF). Experiments with highly purified CD34(+) bone marrow cells suggested that PR3 acts directly on the granulopoietic progenitor cells. These observations suggest a role for PR3 in regulation of granulopoiesis, and possibly in suppression of normal granulopoiesis in leukemia.

Clinical utility of immunoglobulin heavy chain gene rearrangement identification for tumour cell detection in multiple myeloma

In an attempt to define the clinical utility of immunoglobulin heavy chain (IgH) gene rearrangement identification for tumour cell detection in multiple myeloma, we investigated 36 consecutive newly diagnosed patients intended for high-dose chemotherapy in a study protocol. After identification of the IgH rearrangement, an allele specific oligonucleotide (ASO) was constructed and used in a semiquantative PCR for minimal residual disease (MRD) evaluation. The myeloma-specific IgH gene rearrangement could be identified and an ASO primer constructed in 24 (67%) of the patients. All of these patients underwent transplantation; 22 were autologous, of whom three had PCR-negative stem cell harvests, and two were allogeneic. 10 patients achieved a clinical complete response (CR) and five were PCR negative in sequential bone marrow analyses. In patients not achieving CR, PCR negativity was occasionally found, but in general the PCR results reflected the clinical status of the patients. No consistent relationship between the bone marrow MRD status and the clinical course was found, and early relapses occurred also in PCR-negative patients.

Receptor for alpha1-microglobulin on T lymphocytes: inhibition of antigen-induced interleukin-2 production

The human plasma protein alpha1-microglobulin (alpha1m) was found to inhibit the antigen-induced interleukin-2 (IL-2) production of two different mouse T-helper cell hybridomas. Alpha1m isolated from human plasma and recombinant alpha1m isolated from baculovirus-infected insect cell cultures had similar inhibitory effects. Flow cytometric analysis showed a binding of plasma and recombinant alpha1m to the T-cell hybridomas as well as to a human T-cell line. Radiolabelled plasma and recombinant alpha1m bound to the T-cell hybridomas in a saturable manner and the binding could be eliminated by trypsination of the cells. The affinity constants for the cell binding were calculated to be 0.4-1 x 10(5) M(-1) using Scatchard plotting, and the number of binding sites per cell was estimated to be 5 x 10(5)-1 x 10(6). The cell-surface proteins of one of the T-cell hybridomas were radiolabelled, the cells lysed and alpha1m-binding proteins isolated by affinity chromatography. SDS-PAGE and autoradiography analysis of the eluate revealed major bands with Mr-values around 70, 35 and 15 kDa. The results thus suggest that alpha1m binds to a specific receptor on T cells and that the binding leads to inhibition of antigen-stimulated IL-2 production by T-helper cells.

IL-10 as an autocrine regulator of CSF secretion by monocytes: disparate effects on GM-CSF and G-CSF secretion

In previous studies of endogenous granulocyte-macrophage colony-stimulating factor (GM-CSF) and granulocyte colony-stimulating factor (G-CSF) production, we found several differences in the secretion pattern within and between different cell systems; for example, CSF secretion by endothelial cells is not affected by any major downregulatory factors, whereas monocyte CSF secretion is modulated by several mechanisms. In this study, we characterized the factors that inhibit CSF secretion by monocytes. Three cytokines have inhibitory effects: interleukin (IL)-4, IL-10, and IL-13. Among these, IL-4 and IL-10 have higher potency than IL-13. IL-4 and IL-13 affect GM-CSF and G-CSF secretion to the same extent. In contrast, exogenously added IL-10 has a stronger inhibitory effect on GM-CSF secretion than on G-CSF secretion. We also found that monocytes produce IL-10 with an autocrine downregulatory effect, and that this autocrine IL-10 reaches concentrations at which in most cases only GM-CSF (not G-CSF) secretion is significantly affected. We postulate that the disparate effect of IL-10 on monocyte secretion of the two CSFs reflects their physiological functions, with GM-CSF being mainly a proinflammatory cytokine working in the local compartment and G-CSF functioning mainly as a cell recruiting factor.

Bernard-Soulier syndrome Karlstad: Trp 498-->Stop mutation resulting in a truncated glycoprotein Ib alpha that contains part of the transmembranous domain

In Bernard-Soulier syndrome, a hereditary bleeding disorder, the platelets are deficient in the glycoprotein (GP) Ib-IX-V complex, a major receptor for the von Willebrand factor. The components of the complex are encoded by separate genes. Patients with this syndrome have a variable expression level of the receptor protein on platelets depending on the specific genetic abnormality. We describe a patient with life-long bleeding symptoms, who is homozygous for a unique stop mutation. Trp 498-->Stop in the GPIb alpha gene, resulting in a truncated GPIb alpha polypeptide chain. In contrast to previously reported truncated forms of GPIb alpha, this form contains a portion of the transmembranous domain as well as the juxtamembranous cysteines engaged in a disulphide bond with GPIb beta. Flow cytometry with GPIb alpha antibodies demonstrated the presence of GPIb on the patient's platelets, although in reduced amounts compared to normal controls. GPIX was similarly detectable. Immunoblotting demonstrated that the patient synthesized a truncated GPIb alpha of the expected size of 130 K, which was, however, sensitive to proteolysis. These studies show that GPIb alpha lacking the intracytoplasmic tail can be expressed at the platelet surface provided elements of the transmembranous domain are present.

Altered expression of the retinoblastoma tumor-suppressor gene in leukemic cell lines inhibits induction of differentiation but not G1-accumulation

The retinoblastoma tumor-suppressor gene, RB, has been implicated in tumor suppression, in regulation of the cell cycle, and in mediating cell differentiation. RB is necessary for hematopoiesis in mice, and aberrant RB-expression is associated with the progress and prognosis of leukemia. We have used antisense oligonucleotides, established clones stably expressing an antisense RB construct, and also established clones over expressing the retinoblastoma protein (pRb) to study the role of RB expression in monocytic differentiation induced by all-trans retinoic acid (ATRA) or 1-alpha-25-dihyroxycholecalciferol (Vit D3) in the monoblastic cell line U-937 and erythroid differentiation induced by transforming growth factor beta1 (TGFbeta1) and hemin in the erythroleukemic cell line K562. A reduction in pRb production in antisense RB-transfected U-937 clones was shown. Antisense oligonucleotides as well as expression of the antisense RB construct suppressed differentiation responses to ATRA or Vit D3, as judged by the capability to reduce nitro blue tetrazolium, by the appearance of monocyte-related cell surface antigens and by morphologic criteria. K562 cells showed decreased differentiation response to TGFbeta1, but not to hemin, when incubated with antisense oligonucleotides. U-937 antisense RB-transfected cells were also suppressed in their ability to upregulate levels of hypophosphorylated pRb when induced to differentiate. Although U-937 cells incubated with antisense oligonucleotides and clones expressing the antisense RB construct were hampered in their ability to differentiate on incubation with ATRA or Vit D3, the induced G0/G1-accumulation was similar to differentiating control cells treated with ATRA or Vit D3. Intriguingly, U-937 clones overexpressing RB were also inhibited in their differentiation response to ATRA or Vit D3 but not inhibited in their ability to respond with G0/G1 accumulation when induced with these substances. The results indicate that pRb plays a role in induced differentiation of U-937 cells as well as K562 cells involving mechanisms that, at least partially, are distinct from those inducing G1 accumulation.

Clonal CD5-positive B lymphocytes in myelodysplastic syndrome with systemic vasculitis and trisomy 8

Bone marrow and peripheral blood from a myelodysplastic syndrome (MDS) patient with trisomy 8 and associated systemic vasculitis was investigated for clonal lymphoid lineage involvement using simultaneous metaphase and interphase fluorescence in situ hybridization (FISH) and immunocytochemistry with antibodies against CD13 (granulocytic), glycophorin A (GPA, erythroid), and the lymphocytic antigens CD3. CD5, CD20, and CD22. Trisomy 8 was detected in 55% of CD13+, 40% of GPA+, 6% of CD5+, and 5% of CD20/22+, but not in CD3+ cells. In a complementary experiment using interphase FISH on bone marrow cells sorted by flow cytometry, 13% of CD5/CD19 double-positive cells (76% purity) were found to be trisomic. The results indicate the existence of a small CD5-positive B-lymphoid clone as part of the MDS process in this patient. Since CD5/19-positive cells have been proposed to be autoantibody producing, this finding might be a clue to the pathogenesis underlying the propensity for MDS patients to develop immune-mediated complications.

Effects of immunosuppressive drugs and antibiotics on GM-CSF and G-CSF secretion in vitro by monocytes, T lymphocytes and endothelial cells

We studied the effects of eight antibiotics, cyclosporin and corticosteroids on the in vitro secretion of GM-CSF and G-CSF by monocytes. T lymphocytes and endothelial cells. The aim was to evaluate a possible mechanism for these drugs in the delay of haemopoietic recovery after high-dose chemotherapy or bone marrow transplantation. Corticosteroids were prominent inhibitors of GM-CSF secretion by monocytes and T lymphocytes, but not by endothelial cells. In contrast, G-CSF secretion by monocytes was unchanged whereas that of endothelial cells was enhanced in the presence of corticosteroids. Cyclosporin efficiently down-regulated GM-CSF secretion by T lymphocytes and had also a minor effect on CSF secretion by endothelial cells, whereas monocyte secretion was unaffected. Stimulated T lymphocytes derived from patients under treatment with cyclosporin had impaired capacity to secrete GM-CSF compared to controls. Among the antibiotics, cephalosporins inhibited GM-CSF secretion by T lymphocytes, and GM- and G-CSF secretion by endothelial cells. Ciprofloxacin and sulphmethoxazole had minor effects on GM-CSF secretion by T lymphocytes and endothelial cells. No antibiotic significantly influenced GM-CSF secretion by monocytes.

Cytokine regulation of GM-CSF and G-CSF secretion by human umbilical cord vein endothelial cells (HUVEC)

The cytokine regulation of granulocyte-macrophage colony-stimulating factor (GM-CSF) and G-CSF secretion by human umbilical cord vein endothelial cells (HUVEC) using quantitative immunoassays was studied. Unstimulated HUVEC produced no CSF. Interleukin 1 (IL-1), TNF and lipopolysaccharides (LPS) had stimulatory effects, with IL-1 being the most potent. GM-CSF and G-CSF secretion followed the same pattern, except that more GM-CSF was secreted. Exposure to stimuli for 30 min induced secretion, and detectable amounts in supernatants were found after 4 h incubation. CSF secretion was strictly regulated by the presence of a stimulus in a concentration dependent manner, and there were no signs of any endogenous downregulatory mechanism. No other cytokine tested had any stimulatory effect of its own. However, addition of IL-3 to stimulated HUVEC enhanced both GM-CSF and G-CSF secretion in a dose-dependent manner. In addition, TNF, and to a lesser degree LPS, enhanced IL-1-induced secretion. The only cytokine with a prominent downregulatory effect was IFN-gamma. IL-4 and IL-10, which downregulate CSF secretion by monocytes, had only minor effects.

Expression of the p53 tumor suppressor gene induces differentiation and promotes induction of differentiation by 1,25-dihydroxycholecalciferol in leukemic U-937 cells

Leukemic U-937 cells, which lack normal p53, were stably transfected with a temperature-sensitive mutant of p53 to investigate the consequences for growth and differentiation. On induction of wild-type p53 activity at the permissive temperature, some of these cells underwent maturation as judged by the capacity for oxidative burst and the appearance of monocyte related cell surface molecules. Moreover, wild-type p53-expressing cells were more sensitive than p53-negative control cells to induction of differentiation by 1,25-dihydroxycholecalciferol; a twofold to fourfold increase of the fraction of cells showing signs of terminal maturation was observed when wild-type p53-expressing cells were incubated with 1,25-dihydroxycholecalciferol at concentrations that only slightly affected control cells. Whereas wild-type p53 activity per se induced maturation of certain cells, other underwent cell death judging from the reduced capability to exclude trypan blue and the appearance of fragmented DNA in flow cytometric analysis. The p53-induced cell death could be inhibited by incubation with 1,25-dihydroxy-cholecalciferol, but not all-trans retinoic acid. Thus, 1,25-dihydroxycholecalciferol, seemed to increase the survival of wild-type p53-expressing cells and to cooperate with wild-type p53 to induce differentiation. The data imply that p53-mediated maturation in U-937 cells depends on optimal regulation of signals for differentiation, survival and proliferation, and suggest a role for p53 in the differentiation induction of leukemic cells.

Aggressive course of primary plasma cell leukemia with unusual morphological and cytogenetic features

A case of aggressive plasma cell leukemia with unusual morphological and cytogenetic features is reported. A 65-year-old man was admitted to hospital due to anemia, thrombocytopenia, and renal insufficiency. Bone marrow examination and peripheral blood smear revealed a large number of pleomorphic cells with convoluted and multilobulated nuclei. Immunohistochemistry of the bone marrow biopsy was negative for anti-keratin antibodies CAM.5.2 and AE1/AE3, but positive for EMA. The immunophenotypic features of these cells were suggestive of plasma cell origin with positivity for CD38, CD56, CD9, and CD44 and a weak positivity for CD71 and CD45 (40% of the cells), while all other markers of hematopoietic origin were negative. Furthermore, a serum protein electrophoresis showed a monoclonal component type IgG-kappa of 70 g/l. The cytogenetic analysis demonstrated a hypotetraploid clone with multiple numerical and structural abnormalities. Although some of the aberrations found are associated with plasma cell malignancies--e.g., structural rearrangement of chromosome 1, del(6q), and monosomy 13--the karyotypic complexity in the present case is unusual. The course of the disease was very aggressive, and the patient died 3 days after admission.

Specific binding and uptake of extracellular nicotinamide in human leukemic K-562 cells

Extracellular nicotinamide is well recognized as the primary precursor to the cellular synthesis of NAD. NAD is a pivotal molecule in regulating the energy and redox potentials of cells via synthesis of ATP and NAD(P)/NAD(P)H ratios. NAD turnover in cells is very rapid due to NAD catabolism via ADP-ribosylation reactions. These facts suggest that the cellular uptake and transport of nicotinamide may not be a passive process but a highly regulated cellular event. We have utilized radiometric procedures to characterize the uptake of [14C]nicotinamide in human leukemic K-562 cells. At physiologically relevant doses of nicotinamide (< 100 microM), the uptake was saturable with a Km of 2.3 +/- 1.0 microM and a Vmax of about 1.5 +/- 0.5 pmol/10(6) cells/min. Kinetic studies revealed that nicotinamide was first taken up intracellularly and then immediately converted to NAD and 1-methyl nicotinamide. All of the nicotinamide taken up into the cell was bound tightly to plasma membranes (25,000 g pellet) with Kd values between 3.2 and 12.7 microM and a Bmax of 1.56 pmol/10(6) cells. The specificity of nicotinamide binding was demonstrated by competitive inhibition experiments using NAD analogs, nicotinamide derivatives, and agonists or antagonists of plasma membrane receptors. We conclude that there is specific binding of nicotinamide, followed by intracellular uptake and immediate synthesis to NAD.