Venous thromboembolism risk is lower in patients with atopic dermatitis than other immune-mediated inflammatory diseases: A retrospective, observational, comparative cohort study using US claims data

BACKGROUND

Certain immune-mediated inflammatory diseases (IMIDs) may increase patients' risk for venous thromboembolisms (VTEs), yet how atopic dermatitis (AD) influences VTE risk remains unclear.

OBJECTIVE

Describe VTE incidence in patients with AD compared with other IMIDs and unaffected, AD-matched controls.

METHODS

This retrospective, observational, comparative cohort study used Optum Clinformatics United States claims data (2010-2019) of adults with AD, rheumatoid arthritis (RA), Crohn's disease (CD), ulcerative colitis (UC), psoriasis (PsO), psoriatic arthritis (PsA), or ankylosing spondylitis (AS). Unaffected control patients were matched 1:1 with patients with AD.

RESULTS

Of 2,061,222 patients with IMIDs, 1,098,633 had AD. Patients with AD had a higher VTE incidence (95% CI) than did unaffected, AD-matched controls (0.73 [0.72-0.74] versus 0.59 [0.58-0.60] cases/100 person-years). When controlling for baseline VTE risk factors, however, AD was not associated with increased VTE risk (HR 0.96 [0.90-1.02]). VTE risk was lower in patients with AD versus RA, UC, CD, AS, or PsA; VTE risk was similar to patients with PsO.

LIMITATIONS

Disease activity and severity were not accounted for.

CONCLUSION

AD did not increase VTE risk when accounting for underlying risk factors. AD was associated with lower VTE risk compared with several rheumatologic and gastrointestinal IMIDs.

A time-course prediction model of global COVID-19 mortality

Introduction

The COVID-19 pandemic has caused over 6 million deaths worldwide and is a significant cause of mortality. Mortality dynamics vary significantly by country due to pathogen, host, social and environmental factors, in addition to vaccination and treatments. However, there is limited data on the relative contribution of different explanatory variables, which may explain changes in mortality over time. We, therefore, created a predictive model using orthogonal machine learning techniques to attempt to quantify the contribution of static and dynamic variables over time.

Methods

A model was created using Partial Least Squares Regression trained on data from 2020 to rank order the significance and effect size of static variables on mortality per country. This model enables the prediction of mortality levels for countries based on demographics alone. Partial Least Squares Regression was then used to quantify how dynamic variables, including weather and non-pharmaceutical interventions, contributed to the overall mortality in 2020. Finally, mortality levels for the first 60 days of 2021 were predicted using rolling-window Elastic Net regression.

Results

This model allowed prediction of deaths per day and quantification of the degree of influence of included variables, accounting for timing of occurrence or implementation. We found that the most parsimonious model could be reduced to six variables; three policy-related variables - COVID-19 testing policy, canceled public events policy, workplace closing policy; in addition to three environmental variables - maximum temperature per day, minimum temperature per day, and the dewpoint temperature per day.

Conclusion

Country and population-level static and dynamic variables can be used to predict COVID-19 mortality, providing an example of how broad temporal data can inform a preparation and mitigation strategy for both COVID-19 and future pandemics and assist decision-makers by identifying population-level contributors, including interventions, that have the greatest influence in mitigating mortality, and optimizing the health and safety of populations.

Prevalence and burden of atopic dermatitis involving the head, neck, face, and hand: A cross sectional study from the TARGET-DERM AD cohort

BACKGROUND

Atopic dermatitis (AD) is severely burdensome, and there has been poor characterization of any differences in impact based on the area affected.

OBJECTIVE

To estimate the prevalence and HRQoL impact of head/face/neck/hand (HFNH) involvement among patients with moderate-to-severe atopic dermatitis.

METHODS

All TARGET-DERM AD registry patients with moderate/severe Investigator Global Assessment (vIGA-AD) were assessed using the Patient Oriented SCORing Atopic Dermatitis, Patient Oriented Eczema Measure (POEM) and the (Children's) Dermatology Life Quality Index ((C)DLQI).

RESULTS

541 participants met the criteria (75.0% adults) and 84% (N = 453) reported HFNH involvement. HFNH and non-HFNH involved participants had similar characteristics; 55.2% female and 46.9% White. Compared to the non-HFNH involved, the involved had severe vIGA-AD (28.5% vs 16.3%, P = .02) and higher median body surface area affected (15% vs 10%, P ≤ .01) and were twice as likely to have higher (C)DLQI and POEM scores.

LIMITATIONS

This was an analysis of real-world and patient reported outcome data.

CONCLUSION

Real-world HFNH involved AD patients were associated with significantly worse quality of life, POEM/(C)DLQI, and more severe disease. Detailed assessments of specific areas affected by AD are needed to personalize treatment.

Do Atopic Dermatitis Patient-Reported Outcomes Correlate With Validated Investigator Global Assessment? Insights From TARGET-AD Registry

BACKGROUND

Research examining associations between the clinician-reported validated Investigator Global Assessment for AD (vIGA-AD) and patient-reported disease burden is sparse. This study aims to evaluate the relationship between vIGA-AD with patient-reported disease severity and quality of life (QoL).

METHODS

A cross-sectional analysis was conducted using a September 2021 data cut from the TARGET-DERM AD study, a real-world, longitudinal cohort of children, adolescents, and adults with AD enrolled at 44 academic and community dermatology and allergy sites in the US. Clinical AD severity was measured using vIGA-AD while disease severity and QoL were assessed by the Patient Oriented Eczema Measure (POEM) and (Children’s) Dermatology Life Quality Index (C/DLQI), respectively. Patient characteristics, clinical- and patient reported-outcomes were assessed by stratified POEM and C/DLQI categories using descriptive statistics. Associations with vIGA-AD were evaluated using unadjusted and adjusted ordinal logistic regression and linear regression models.

RESULTS

The analysis cohort (n=1,888) primarily consisted of adults (57%), females (56%), and patients with private insurance (63%). Unadjusted analyses suggest that clinical AD severity was associated with age, with more adolescents and adults having moderate/severe vIGA-AD than pediatric patients. Clinical AD severity was also associated with disease severity, with greater POEM scores observed at greater vIGA-AD severity levels (r = 0.496 and 0.45 for adults and pediatrics, respectively). Clinical AD severity and QoL were positively correlated, with greater CDLQI/DLQI scores at greater vIGA-AD severity levels (r = 0.458 and 0.334 for DLQI and CDLQI, respectively). After adjusting for demographics and other risk factors, vIGA-AD continued to show significant associations with POEM and DLQI/CDLQI. Compared to patients with clear/almost clear disease, adults and pediatrics with moderate-to-severe AD were 8.19 and 5.78 times as likely to be in a more severe POEM category, respectively. Similarly, compared to patients with clear/almost clear disease, adults and pediatrics with moderate/severe AD were 6.69 and 3.74 times as likely to be in a more severe DLQI/CDLQI category. Adjusted linear regression analyses of DLQI in adults showed significant differences by vIGA-AD level, with mild AD and moderate/severe AD associated with a 2.26-point and 5.42-point greater DLQI relative to clear/almost clear AD.

CONCLUSIONS

In this real-world study of patients with AD, greater clinician-reported disease severity is positively correlated with higher patient-reported disease severity and lower QoL. J Drugs Dermatol. 2023;22(4): doi:10.36849/JDD.7473 Access Supplementary Material here Citation: Guttman-Yassky E, Bar J, Rothenberg Lausell C, et al. Do atopic dermatitis patient-reported outcomes correlate with validated investigator global assessment? Insights from TARGET-AD registry. J Drugs Dermatol. 2023;22(4):344-355. doi:10.36849/JDD.7473.

317 Comparative risk of venous thromboembolism (VTE) among patients with atopic dermatitis (AD) or other immune-mediated diseases: a cohort study using United States claims data

Patients with rheumatoid arthritis (RA) or inflammatory bowel disease (IBD) are at increased risk for thrombotic events, but less is known about the underlying risk of VTE with immune-mediated skin conditions. The objective of our study was to describe the incidence of VTE among patients diagnosed with AD and compare VTE incidence among patients with other immune-mediated inflammatory diseases, as well as among individuals without such conditions. This retrospective, observational, comparative cohort study used a large national administrative claims database Optum® (Clinformatics® Data Mart). Adults (aged ≥18 years) diagnosed with AD, RA, IBD (Crohn’s disease [CD] or ulcerative colitis [UC]) or other immune-mediated diseases during 2010–2019 were included. Disease cohorts were not mutually exclusive. A non-diseased control population with no such diagnoses was matched 1 : 1 to patients in the AD cohort by age, sex and calendar time of cohort entry. All patients had to have at least 12 months of enrolment (baseline) before a confirmed diagnosis (or matched cohort entry date for controls) and at least 1 day of follow-up data following diagnosis. All patients received normal clinical care and were followed until the earliest VTE event, end of health plan enrolment, death or end of data availability (30 June 2021). The primary outcome was the incidence of VTE (deep vein thrombosis [DVT] or pulmonary embolism [PE]) defined as an inpatient hospitalization with a VTE diagnosis and length of stay ≥1 day or an outpatient VTE diagnosis followed by initiation of an anticoagulant within 7 days. Incidence per 100 person-years (PY) and 95% CI were calculated. Crude and adjusted hazard ratios (HRs) were determined using Cox proportional hazards regression models and adjusted for demographic and comorbid disease factors. The secondary outcome was the incidence of VTE limited to inpatient events. A total of 1,098,633 adults with AD were included in the analysis; the mean (SD) age was 54.1 (18.5) years, 65.3% were female and 1.1% had a history of VTE. A total of 15,456 VTE events (primary outcome) were reported among patients with AD during 2,113,668.9 PY for a crude incidence (95%CI) of 0.73 (0.72, 0.74) cases/100 PY. The incidence of VTE was 1.33 (1.30, 1.36) cases/100 PY among patients with RA or IBD (n = 578,021) and 0.59 (0.58, 0.60) cases/100 PY among AD-matched controls. The adjusted risk for VTE was higher among patients with RA or IBD compared with patients with AD with an adjusted HR (95% CI) of 1.46 (1.43, 1.49). Patients with AD had a slightly higher risk for VTE compared with AD-matched controls with an adjusted HR of 1.09 (1.06, 1.12). Similar results were observed when DVT and PE were assessed separately. Patients with CD or UC had the highest risk for VTE relative to patients with AD with an adjusted HR of 1.61 (1.54, 1.69) and 1.57 (1.5, 1.63), respectively. Patients with RA also had a higher risk for VTE relative to patients with AD with an adjusted HR of 1.42 (1.38–1.46). Similar results were also observed when the assessment of the incidence and risk of VTE was limited to inpatient events. Patients with RA or IBD had a higher risk of VTE compared with patients with AD. The risk of VTE was slightly higher among patients with AD compared with AD-matched controls. Because VTE risk is increased in RA and IBD during periods of active disease, observed rates may depend on the proportion of patients with uncontrolled disease. Characterization of baseline VTE risk among patients with AD may better inform treatment benefit–risk assessments and shared decision-making.

Predictors of Treatment Change Among Patients with Rheumatoid Arthritis Treated with TNF Inhibitors as First-Line Biologic Agent in the USA: A Cohort Study from Longitudinal Electronic Health Records

BACKGROUND

Previous observational studies utilizing administrative claims data have largely been unable to consider clinical factors that may be related to patterns of drug use among patients with rheumatoid arthritis (RA).

OBJECTIVE

To understand predictors of treatment changes following initiation of a tumor necrosis factor inhibitor (TNFi) using nation-wide electronic health record (EHR) data in the USA.

METHODS

The Optum Immunology Condition EHR data (01/01/2011-09/30/2019) was used to identify a population of adult patients with RA initiating a TNFi as the first line biologic disease-modifying anti-rheumatic drug (DMARD). The primary outcome was any treatment change during the 1-year post-index period defined as cycling to a different TNFi or switching to non-TNFi biologic or targeted synthetic DMARDs. Secondary outcomes were the individual components of TNFi cycling and switching, examined separately. To identify predictors of DMARD treatment changes, we used a least absolute shrinkage and selection operator (LASSO) regression model. Model c-statistics and odds ratios (ORs, 95% confidence intervals (CIs)) of predictors were reported.

RESULTS

We identified 24,871 patients with RA who initiated a TNFi. The mean age was 55.5 (± 13.7) years and 77.2% were female. Among the TNFi initiators, 22.2% experienced TNFi cycling or switching during the 1-year follow-up time. Predictors that are associated with higher likelihood of TNFi cycling or switching included female gender (OR: 1.26, 95% CI: 1.16-1.36) and glucocorticoid use (OR: 1.30, 95% CI: 1.21-1.40). In contrast, inflammatory bowel disease (OR: 0.62, 95% CI: 0.48-0.78), psoriasis (OR: 0.82, 95% CI: 0.70-0.95), recent use of methotrexate (OR: 0.89, 95% CI: 0.81-0.97), and vitamin D intake (OR: 0.92, 95% CI: 0.85-0.99) were negatively associated with TNFi cycling or switch.

CONCLUSIONS

Gender, glucocorticoid use, inflammatory bowel disease, psoriasis, and vitamin D intake were identified as significant predictors of TNFi cycling or switching for TNFi initiators in the RA population. Predicting treatment change remains challenging even with large detailed EHR data. This study aimed to identify key determinants of treatment changes among patients with rheumatoid arthritis (RA) initiating a tumor necrosis factor inhibitor (TNFi) as their first-line biologic disease-modifying antirheumatic drug (DMARD) in routine care settings using a US nation-wide longitudinal electronic health record (EHR). Among 24,871 patients with RA who initiated a TNFi, 22.2% experienced TNFi cycling or switching during the 1-year follow-up time. Female patients and those who used glucocorticoids were more likely to experience TNFi cycling or switching, whereas inflammatory bowel disease, psoriasis, recent methotrexate use, and vitamin D intake were negatively associated with the outcome. However, predicting treatment change remains challenging even with larger detailed EHR data potentially due to unmeasured factors such as prescriber's preference or patient's belief in the medication.

POS1207 REAL WORLD POPULATION-BASED ASSESSMENT OF COVID-19 OUTCOMES AMONG RHEUMATOID ARTHRITIS PATIENTS USING BIOLOGIC OR SYNTHETIC DMARDs

Background:

While some risk factors for severe COVID have been identified for patients with rheumatic diseases,1 few studies have investigated whether outcomes differ based on the type of rheumatoid arthritis (RA) treatment. Most existing reports have been limited to individual centers or voluntary reporting registries.2,3

Objectives:

To compare the occurrence of hospitalizations following COVID-19 diagnosis among patients with RA treated with various classes of DMARDs.

Methods:

A cohort of patients with confirmed COVID-19 (ICD10 diagnosis code or positive PCR or antigen test result) were identified within a large US electronic health record (EHR) dataset (Optum, Inc.) during the time period Feb 1, 2020 through Oct 14, 2020. From these, we identified RA patients (ICD10 RA diagnosis code) with treatment (most recent of JAK inhibitor [JAKi], biologic [bDMARD] or conventional synthetic [csDMARD] only) within the 12 months prior to COVID-19 diagnosis (i.e., index). The primary outcome was any hospitalization on or within 30 days after COVID-19 diagnosis. Multivariable logistic regression models compared users of JAKi’s to non-TNFi bDMARDs and csDMARDs (separately), as well as users of TNFi’s to non-TNFi bDMARDS and csDMARDs (separately), and were adjusted for age, gender, index month and baseline corticosteroid use. Sensitivity analyses included restriction of prevalent treatment use to within 180 days prior to COVID-19 diagnosis and restriction of csDMARDs to a group without hydroxychloroquine or chloroquine.

Results:

The study included 910 RA patients on DMARD treatment who were diagnosed with COVID-19 (mean age ± SD: 61±15, 80% female, 62% white. Of those, 26% (n=240) were hospitalized on or within 30 days after COVID-19 diagnosis. The proportion of patients hospitalized was highest in non-TNFi bDMARD users (37/87; 43%), followed by csDMARDs users (161/581; 28%) and lowest in JAKi (13/68; 19%) and TNFi users (29/174; 17%). In multivariable-adjusted models, no differences in risk of hospitalization were found comparing JAKi users to csDMARD users (aOR=0.71; 95% CI 0.37-1.36) or TNFi users to csDMARD users (aOR=0.67; 95%CI 0.43-1.06). Compared to non-TNFi bDMARD users, JAKi use and TNFi use was associated with reduced risk of hospitalization (JAKi aOR=0.32; 95%CI 0.14-0.71; TNFi aOR=0.34; 95%CI 0.18-0.62). Age and corticosteroid use were positively associated with 30-day hospitalization in all models. Results of sensitivity analyses were consistent with the main findings.

Conclusion:

In this study, roughly a quarter of RA patients with recent DMARD treatment were hospitalized within 30 days after COVID diagnosis. Patients treated with JAKi and TNFi therapies experienced the lowest risk of hospitalization, with risk of hospitalization significantly lower than non-TNFi bDMARDs. However, recent therapy recorded in the EHR may not reflect exposure at time of COVID-19 diagnosis and small sample size per treatment may limit interpretation.

References:

[1]Hyrich KL, Machado PM. Nat Rev Rheumatol 2020;1-2. doi:10.1038/s41584-020-00562-2

[2]Gianfrancesco MA, et al. Lancet Rheumatol 2020;2(5):e250-e253. doi:10.1016/S2665-9913(20)30095-3

[3]Veenstra J, et al. J Am Acad Dermatol 2020;83(6):1696-1703.

Acknowledgements:

Jonathan Johnson of Optum, Inc. provided dataset guidance and conducted data analyses. AbbVie funded this study, contributed to its design, participated in data collection, analysis, and interpretation of the data, and in the writing, review, and approval of the abstract. No honoraria or payments were made for authorship.

Disclosure of Interests:

Lani Wegrzyn Shareholder of: AbbVie, Employee of: AbbVie, Kevin Winthrop Consultant of: Pfizer, AbbVie, UCB, Eli Lilly & Company, Galapagos, GSK, Roche, Gilead, BMS, Regeneron, Sanofi, AstraZeneca, Novartis, Grant/research support from: BMS, Pfizer, Seoyoung Kim Grant/research support from: institutional research grants from Pfizer, AbbVie, Roche, BMS for unrelated studies, Yizhou Ye Shareholder of: AbbVie, Employee of: AbbVie, Carrie Huisingh Shareholder of: AbbVie, Employee of: AbbVie, Whitney Krueger Shareholder of: AbbVie, Employee of: AbbVie, anna maniccia Shareholder of: AbbVie, Employee of: AbbVie, Ryan Kilpatrick Shareholder of: AbbVie, Employee of: AbbVie.

POS1163 CHARACTERISTICS AND OUTCOMES IN A REAL-WORLD COHORT OF RHEUMATOID ARTHRITIS PATIENTS WITH COVID-19

Background:

While some risk factors for severe COVID-19 outcomes have been identified for the general population and patients with rheumatic diseases (1-3), what drives these outcomes in specific rheumatic disease remains unclear. In addition, these findings need to be assessed across various observational data sources to ensure external validity.

Objectives:

To describe the demographics, comorbidities, and severe COVID-19 outcomes among rheumatoid arthritis (RA) patients infected with SARS-CoV-2 in the United States.

Methods:

A large nationwide electronic health record database (Optum, Inc.) in the United States, with data range between February 1, 2020 and September 17, 2020, was used to describe the demographics, comorbidities, and severe COVID-19 outcomes of RA patients with confirmed COVID-19 diagnosis (diagnosis for COVID-19 or positive PCR or antigen test). Patients with a single diagnosis of RA (ICD-10 code) before the diagnosis of COVID-19 were included. Patients missing age or sex, under 18 years of age on COVID-19 diagnosis date, or having less than 15 months of activity prior to COVID-19 diagnosis in the data source were excluded. We described demographics, comorbidities, and severe COVID-19 outcomes, including death, hospitalization, ICU admission, and acute respiratory insufficiency (ARI) identified between 14 days prior to and 30 days after COVID-19 diagnosis. Mean and standard deviation (SD) was reported for continuous variables. For categorical variables, count (N) and proportion was reported.

Results:

We identified 2,948 patients diagnosed with RA and infected with SARS-CoV-2 (mean age± SD: 62 years ± 16, 77% female, 68% white). Of all identified patients, 38% were current or former smokers. For the 2,614 patients with BMI recorded, 78% were overweight or obese (mean BMI±SD: 31.2±8.3). The mean Charlson comorbidity index (CCI) was 3.6 (SD 3.2), with 87% of the study cohort having one or more comorbid condition, including hypertension (55%), type 2 diabetes (26%), COPD (20%), moderate to severe asthma (17%), coronary artery disease (17%), chronic kidney disease (13%), and heart failure (13%). Severe COVID-19 outcomes occurred in 618 (21%) patients. Among all RA patients with COVID-19, 137 patients (4.6%) experienced ARI, 484 patients (16.4%) were hospitalized (including 174 (5.9%) admitted to the ICU), and 155 patients (5.3%) died.

Conclusion:

Underlying medical conditions that are known or possible risk factors of severe illness from SARS-CoV-2 infection in the general population are common in this RA cohort from a large national EHR database. However, whether patients with RA are more vulnerable to severe COVID-19 outcome than the general population requires adjustment by age and other important confounders.

References:

[1]Gianfrancesco M, Hyrich KL, Al-Adely S, Carmona L, Danila MI, Gossec L, et al. Characteristics associated with hospitalisation for COVID-19 in people with rheumatic disease: data from the COVID-19 Global Rheumatology Alliance physician-reported registry. Ann Rheum Dis. 2020;79(7):859-66.

[2]Williamson EJ, Walker AJ, Bhaskaran K, Bacon S, Bates C, Morton CE, et al. Factors associated with COVID-19-related death using OpenSAFELY. Nature. 2020;584(7821):430-6.

[3]Gold JAW, Wong KK, Szablewski CM, Patel PR, Rossow J, da Silva J, et al. Characteristics and Clinical Outcomes of Adult Patients Hospitalized with COVID-19 - Georgia, March 2020. MMWR Morb Mortal Wkly Rep. 2020;69(18):545-50.

Disclosure of Interests:

Yizhou Ye Shareholder of: AbbVie Inc. and Pfizer Inc., Employee of: AbbVie Inc., Xiaomeng Yue Employee of: AbbVie Inc., Whitney Krueger Shareholder of: AbbVie Inc., Employee of: AbbVie Inc., Lani Wegrzyn Shareholder of: AbbVie Inc., Employee of: AbbVie Inc.

Randomized trial of high-dose chemotherapy with autologous haematopoietic stem cell support vs. standard-dose chemotherapy in breast cancer patients with 10 or more positive lymph nodes: Overall survival after 6 years of follow up

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Background: Investigation of high dose chemotherapy (HD-CT) supported by autologous hematopoietic stem cell transplantation compared with standard dose chemotherapy (SD-CT) as adjuvant treatment in patients with primary breast cancer and 10 or more axillary lymph nodes. Methods: Between November 1993 and September 2000 307 patients were randomized to receive the following cycles of Epirubicin (90 mg/m2), Cyclophosphamide (600 mg/m2) intervenously (every 21 days) either HD-CT of Cyclophosphamide (1500 mg/m2), Thiotepa (150 mg/m2) and Mitoxantrone (10 mg/m2) intervenously for 4 consecutive days followed by stem cell transplantation or standard dose chemotherapy SDCT in 3 cycles of Cyclophosphamide (500 mg/m2), Methotrexate (40 mg/m2) and Fluoruracil (600 mg/m2) intervenously on days 1 and 8 every 28 days. The primary end points were event-free survival and overall survival. Results: After a median follow-up of 6.1 years 166 events with respect to event-free survival (SD-CT: 91, HD-CT: 75) and 123 with respect to overall survival (SD-CT: 66 and HD-CT: 57) have been observed. The hazard ratio of HD-CT versus SD-CT is estimated as 0,80, p = 0,15. The hazard ratio for overall survival for high dose chemotherapy versus standard dose chemotherapy is estimated as 0,84, p = 0,33. Analysing the effect of treatment on event-free survival premenopausal patients, patients with tumor grade III and ER-positive patients had a better outcome with HD-CT with an interactive effect of 2.5 and 1.4. The significance was only shown in grade III patients in favour of HD-CT, (p = 0,049). The interactive effect of HD-CT with prognostic factors did not reach significance for overall survival. Conclusion: Even with a follow-up of 6.1 years there was only a trend in favour of high dose chemotherapy with respect to overall survival but without a statistical significance. A proper meta-analysis needs to be undertaken for an evaluation of subgroups of patients which might benefit from this treatment approach.

No significant financial relationships to disclose.

RNA trafficking in oligodendrocytes

A2RE and hnRNP A2 have been identified as important cis/trans determinants for MBP RNA trafficking in oligodendrocytes. Since A2RE-like sequences are found in several different transported RNAs, and since hnRNP A2 is expressed in most cell types, this may represent a general RNA trafficking pathway shared by a variety of different RNAs in different cell types. In oligodendrocytes, A2RE/hnRNP A2 determinants are involved in at least four steps in the RNA trafficking pathway: (1) export from the nucleus to the cytoplasm, (2) granule assembly in the perikaryon, (3) transport along microtubules in the processes, and (4) translation activation in the myelin compartment. The components of the cellular machinery mediating each of these steps are known. How A2RE/hnRNP A2 determinants interact with these components to mediate RNA trafficking is being investigated by a combination of: biochemistry to analyze molecular interactions in vitro, imaging to visualize molecular interactions in living cells, and computational modeling to simulate molecular interactions in the Virtual Cell.

RNA trafficking signals in human immunodeficiency virus type 1

Intracellular trafficking of retroviral RNAs is a potential mechanism to target viral gene expression to specific regions of infected cells. Here we show that the human immunodeficiency virus type 1 (HIV-1) genome contains two sequences similar to the hnRNP A2 response element (A2RE), a cis-acting RNA trafficking sequence that binds to the trans-acting trafficking factor, hnRNP A2, and mediates a specific RNA trafficking pathway characterized extensively in oligodendrocytes. The two HIV-1 sequences, designated A2RE-1, within the major homology region of the gag gene, and A2RE-2, in a region of overlap between the vpr and tat genes, both bind to hnRNP A2 in vitro and are necessary and sufficient for RNA transport in oligodendrocytes in vivo. A single base change (A8G) in either sequence reduces hnRNP A2 binding and, in the case of A2RE-2, inhibits RNA transport. A2RE-mediated RNA transport is microtubule and hnRNP A2 dependent. Differentially labelled gag and vpr RNAs, containing A2RE-1 and A2RE-2, respectively, coassemble into the same RNA trafficking granules and are cotransported to the periphery of the cell. tat RNA, although it contains A2RE-2, is not transported as efficiently as vpr RNA. An A2RE/hnRNP A2-mediated trafficking pathway for HIV RNA is proposed, and the role of RNA trafficking in targeting HIV gene expression is discussed.

Extracorporeal plateletpheresis induces the interaction of activated platelets with white blood cells

BACKGROUND AND OBJECTIVES

In this study we investigated whether platelet activation during apheresis results in the binding of platelets to white blood cells.

MATERIAL AND METHODS

Analysis of platelet-leukocyte interaction was performed using multiparameter, three-color flow cytometry.

RESULTS

Over the duration of the procedure, there was an increase in the surface expression of CD62p (P-selectin) and CD63 (p<0.05), and also in the binding of platelets to monocytes (p<0.05), neutrophilic granulocytes (p<0.05) and to CD3+ cells (initially to a low degree; p<0.05). Platelet binding to CD19+ cells did not change significantly.

CONCLUSION

This study demonstrates that platelets become activated during apheresis and that following this process, interaction with monocytes and neutrophilic granulocytes occurs.

Semi-automated flow cytometric analysis of CD34-expressing hematopoietic cells in peripheral blood progenitor cell apheresis products

BACKGROUND

The measurement of CD34+ cells is the most important step in the quality control of peripheral blood progenitor cell apheresis products. For this purpose, flow cytometry is applied. Recently, a new test kit has been introduced for the enumeration of CD34-expressing cells, in combination with software support for semi-automation of data acquisition and analysis.

STUDY DESIGN AND METHODS

This study evaluated the ProCOUNT kit. Ninety samples obtained from peripheral blood progenitor cell apheresis products from 39 patients with hemato-oncologic diseases were analyzed. For data acquisition and analysis, ProCOUNT software was used. Data comparison was performed with parallel measurements according to the International Society for Hematotherapy and Graft Engineering (ISHAGE) guidelines and the German reference protocol for analysis of CD34-expressing cells.

RESULTS

Correlation of the German and ISHAGE techniques was excellent (r2 = 0.99). The initial correlation coefficient of ProCOUNT analysis with the German protocol was r2 = 0.89. In 21 (23.3%) of 90 ProCOUNT analyses, a warning message was encountered from the ProCOUNT software. Following manual reevaluation of these data with CellQUEST software, a correlation of r2 = 0.96 with the German protocol and r2 = 0.97 with the ISHAGE analyses was obtained. ANOVA testing revealed significant differences between ProCOUNT and ISHAGE techniques (p<0.05) and between ProCOUNT and the German protocol (p<0.05). No statistically significant difference between ISHAGE and German protocol was observed (p = 0.19).

CONCLUSION

The ProCOUNT kit and software for semi-automated data acquisition and analysis represents a further step toward standardization of CD34 cell quantitation in peripheral blood progenitor cell apheresis products. However, the occurrence of software warnings is high, and analysis or data reevaluation by experienced staff is still mandatory. Therefore, currently there is no definite advantage of the kit and software over the existing guidelines for CD34+ analysis in peripheral blood progenitor cell grafts.

Expression of the adhesion molecules CD49d and CD49e on G-CSF-mobilized CD34+ cells of patients with solid tumors or non-Hodgkin's and Hodgkin's lymphoma and of healthy donors is inversely correlated with the amount of mobilized CD34+ cells

The yield of CD34+ PBPC and colony-forming units-granulocyte-macrophage (CFU-GM) in leukapheresis products and the expression of the adhesion molecules CD11a, CD31, CD49d, CD49e, CD54, CD58, CD62L, c-kit (CD117), Thy-1 (CD90), CD33, CD38, and HLA-DR on CD34+ PBPC were analyzed in patients with cancer of the testis (n = 10), breast cancer (n = 10), Hodgkin's disease (n = 20), high-grade (n = 20) and low-grade (n = 20) non-Hodgkin's lymphoma, and healthy donors (n = 20) undergoing G-CSF (filgrastim)-stimulated PBPC mobilization. For each disease entity, G-CSF was administered in two different doses, 10 microg G-CSF/kg body weight (BW)/day s.c. vs. 24 microg G-CSF/kg BW s.c./day in steady-state condition. Data were compared for each dose group separately. Patients with cancer of the testis and breast cancer mobilized significantly more CD34+ cells than patients with high-grade and low-grade non-Hodgkin's lymphoma and Hodgkin's disease (p<0.05). Correspondingly, expression of CD49d on CD34+ PBPC was significantly lower in the same patients with cancer of the testis compared with high-grade and low-grade non-Hodgkin's lymphoma and Hodgkins' disease and in patients with breast cancer compared with high-grade and low-grade non-Hodgkin's lymphoma, Hodgkins's disease, and healthy donors. Similar results were obtained for CD49e. These data suggest that the expression of the adhesion molecules CD49d and CD49e on G-CSF-mobilized CD34+ cells of patients with solid tumors, non-Hodgkin's lymphoma, Hodgkin's disease, and healthy donors is inversely correlated with the amount of mobilized CD34+ cells.

Localized hypothermia: impact on oxygenation, microregional perfusion, metabolic and bioenergetic status of subcutaneous rat tumours

The effect of localized hypothermia on microcirculatory and metabolic parameters in s.c. DS sarcomas on the hind foot dorsum of Sprague-Dawley rats was investigated. Tumours were cooled by superfusion of the tumour surface with cooled saline solution to 25 degrees C or 15 degrees C. Control tumours remained at 35 degrees C. These temperatures were maintained for 30 min. In tumour oxygenation measurements, hypothermia at 25 degrees C and 15 degrees C caused progressive decreases in the size of the fraction of pO2 measurements between 0 and 2.5 mmHg together with a reduction in pO2 variability. No significant changes in median or mean pO2 or in the fraction of pO2 measurements between 0 and 5 mmHg, and 0 and 10 mmHg were observed. Using laser Doppler flowmetry, red blood cell flux was found to decrease significantly upon 25 degrees C or 15 degrees C hypothermia treatment to 67% and 37% of starting values respectively, whereas no significant changes were seen in control tumours over the whole observation period. Viscosity was measured in blood and plasma samples over a range of temperatures and was found to increase with decreasing temperature. Assessment of tumour glucose levels showed an increased concentration of glucose following 15 degrees C hypothermia, an observation consistent with a 'slowing down' of glycolysis. No changes in lactate or adenylate phosphate levels were observed. As a way of improving tumour oxygenation, localized hypothermia may therefore be a useful means of radiosensitization.

Plexiform neurofibroma of the head and neck

Ten patients with plexiform neurofibroma of the head and neck were observed at M.D. Anderson Hospital between 1956 and 1978. The clinical presentation and the long-term follow-up of the most interesting cases are presented. This is a chronic disease that causes cosmetic and functional deformity because of the size or the position of the tumor, or both. No patient exhibited malignant transformation. Because all of the disease cannot be removed, the surgical procedures should not be radical but should be designed to relieve symptoms or improve cosmesis.

Nuclear magnetic resonance and infrared spectra of delta-24- and C-24 saturated steroids

The infrared (IR) and nuclear magnetic resonance (NMR) spectra of eight Delta(24)-steroids and nine C-24 saturated steroids were examined. NMR spectra allow unambiguous assignment of the biologically important Delta(24)-bond; introduction of a Delta(24)-bond causes the appearance of peaks at Delta 1.60 and 1.68 associated with the C-26, C-27 isopropylidene methyls, while C-24 saturated steroids of the cholestane series possess peaks at Delta 0.82 and 0.91 associated with the C-26, C-27 gem-dimethyls. IR spectra show a good correlation between the introduction of a Delta(24)-bond and a marked decrease in intensity of a band at 1365 cm(-1). NMR and IR spectra also allow an inference about the presence and location of nuclear double bonds in Ring B of cholesterol precursors.