Association between grip strength and electrical properties measured by bioimpedance spectroscopy in women with dementia aged 77 to 97 years living in group homes

Electrical properties estimated from the electrical resistance of the human body can serve as indicators of muscle tissue status and the risk of developing sarcopenia; however, to date, at least to the best of our knowledge, no studies have performed such an assessment in older individuals with advanced dementia. The present study examined the associations between grip strength, body composition and electrical properties using bioimpedance spectroscopy (BIS) in women aged 77-97 years residing in dementia group homes. A total of 33 participants were enrolled with an average age of 88.1±5.2 years; 57.6% of the participants had moderate or severe dementia. The resistance values of the participants were measured in the whole body, upper limbs and lower limbs using BIS, and their body composition, muscle mass index and electrical properties were estimated as indicators of muscle quality. In addition, grip strength was measured and the participants were classified into three groups (high, low and non-measurable) according to their cognitive function. The effect size (partial eta-squared and Cohen's d) was also evaluated. The Shapiro-Wilk test was used to assess the distribution of each variable; variables with non-normal distributions were analyzed following log transformation. Continuous variables were analyzed using a one-way analysis of variance and the Tukey-Kramer post hoc test was used. The post hoc sample size (statistical power: 1-β) analysis revealed a power of ~80% (i.e., 76.1-88.7%), considering the minimum power for sufficient participants. No differences were found in body composition or muscle mass index among the three grip strength groups. As regards the upper limbs, the electrical properties of the characteristic frequencies were significant (P=0.006; effect size, large), and the membrane capacitance (P=0.005; effect size, large) was significantly higher in the high-dose group than in the other groups. A significant association was detected among grip strength, upper limb characteristic frequency and membrane capacitance. Hence, electrical properties may be an indicator of muscle quality in older women identified as needing care for dementia.

AB0270 EFFECT OF METHOTREXATE USE ON JOINT AND LUNG DISEASE OUTCOMES IN PATIENTS HAVING RHEUMATOID ARTHRITIS WITH INTERSTITIAL LUNG DISEASE

Background

Interstitial lung disease (ILD) is a frequent complication of rheumatoid arthritis (RA). Although methotrexate (MTX) is an anchor drug for RA management, its use may worsen lung disease severity in patients with RA related ILD (RA-ILD). The safety and efficacy of MTX use in RA-ILD treatment have not been elucidated.

Objectives

We aimed to clarify the clinical characteristics of patients with RA-ILD and the effect of MTX use on joint and lung disease outcomes.

Methods

In this retrospective study, we included patients with RA-ILD who visited our department from 2011 to 2019 and underwent chest computed tomography (CT). RA was diagnosed using the 1987 ACR criteria or the 2010 ACR/EULAR classification criteria. During the abovementioned period, we defined the baseline as the time of the first chest CT scan; moreover, the final observation was defined as the time of the final chest CT scan in patients who underwent CT more than once, or as the final visit in those without a second chest CT scan. We excluded patients whose RA-ILD status could not be fully evaluated using chest CT scans due to other causes, including respiratory infections. Severe infections were defined as infectious events requiring hospitalization.

To identify the clinical characteristics of patients with RA-ILD, we compared the features of RA with versus without ILD at baseline. To clarify the effect of MTX use on RA-ILD outcomes, we compared the outcomes of patients with RA-ILD with versus without MTX use. Furthermore, we investigated factors associated with RA disease activity or ILD deterioration using multivariate analyses.

Results

In this study, we included 452 patients (mean age, 60.2 years; females, 78.5%; mean observational period, 77.5 months), 325 (71.9%) of whom underwent chest CT more than two times.

Patients with ILD (ILD; n=90, 19.9%) were older and had a higher RF positivity rate than those without ILD. Moreover, patients with ILD were treated with lower MTX use (20.2% vs. 52.9%, p<0.001; 1.46 vs. 3.53 mg/week, p<0.001) and TNF inhibitors exposure (21.1% vs. 13.1%, p<0.044) than those without ILD, albeit with similar uses of prednisolone and other bDMARDs, including tocilizumab and abatacept. DAS28-CRP was higher in patients with than in those without ILD at baseline (4.60 vs. 3.42, p=0.063) and at the final observation (2.42 vs. 2.09, p=0.025). Linear regression analysis showed that baseline age and ILD were significantly associated with DAS28-CRP at the final observation (β=0.206 and 0.173, respectively). Kaplan Meier analysis revealed that patients with ILD experienced severe infections and respiratory infections more frequently than those without ILD (log-rank test, p<0.001 and p<0.001).

Seventeen patients (20.2%) with ILD were treated with MTX. At baseline, these patients had similar ages and RF/ACPA positivity rates, as well as prednisolone and tDMARDs exposures, with higher bDMARD exposure (41.2 vs. 13.4%, p=0.016) compared to that in ILD patients without MTX use. DAS28-CRP was comparable in patients with and without MTX use at baseline, but was lower at the final observation in MTX-treated patients with ILD (1.41 vs. 2.73, p<0.001). Kaplan Meier analyses revealed no differences in the frequencies of severe infections, respiratory infections, or ILD deterioration between patients with and without MTX use. Cox regression analysis demonstrated that the risk factors for ILD deterioration included baseline age (hazard ratio [HR] 1.088; 95% confidence interval [CI] 1.037-1.147), but not MTX use (HR 1.666; 95% CI 0.472-5.876).

Conclusion

RA-ILD were treated with lower MTX use, which resulted in higher RA disease activity. In contrast, patients with RA-ILD treated with MTX had lower RA disease activity without ILD deterioration. As RA-ILD is undertreated, appropriate MTX use may be required for effective RA-ILD treatment

References

[1]Arthritis Rheumatol 2021;73:1108-23.

Disclosure of Interests

None declared

POS1339 FACTORS RELATED TO SERUM IgG4 ELEVATION AND DEVELOPMENT OF IgG4-RELATED DISEASE: DATA FROM RESIDENT EXAMINATION

Background

Elevated serum IgG4 levels are one of the characteristic findings in immunoglobulin G4 (IgG4)-related disease (IgG4-RD). Serum IgG4 levels have an impact to a certain extent on the diagnosis of IgG4-RD although there are some issues in their sensitivity and specificity. In the reports from Japan, China, USA, and Europe, elevated serum IgG4 levels were reported to be observed in 83-97% of patients with IgG4-RD [1-5]. In the past investigations of hospital patients, some studies reported that 10-15% of hospital patients with elevated serum IgG4 levels had IgG4-RD [6,7]. However, in general adults with no symptom, investigations of prevalence of elevated serum IgG4 levels and/or IgG4-RD have rarely been conducted.

Objectives

This study aimed to investigate the frequency of serum IgG4 elevation in the general Japanese population and its associated factors using data from resident examinations.

Methods

We measured the serum IgG4 levels in 1,204 residents who underwent a general medical examination in Ishikawa prefecture, Japan. Logistic regression analysis was used to search for factors related to elevated serum IgG4 levels. Secondary examinations were conducted for participants in whom elevation was identified.

Results

The mean serum IgG4 level was 44 mg/dL, and elevated serum IgG4 levels were observed in 42 patients (3.5%). Univariate logistic regression analyses showed that male sex, older age, lower estimated glomerular filtration rates based on cystatin C (eGFR-CysC), serum high-density lipoprotein cholesterol levels, and higher hemoglobin A1c (HbA1c) levels were associated with elevated serum IgG4 levels. Subgroup analyses in men showed that older age, lower eGFR-CysC levels, and higher serum HbA1c levels were associated with elevated serum IgG4 levels. In contrast, the analyses in women found no significant factors. One of the 10 residents who underwent secondary examinations was diagnosed with possible IgG4-related retroperitoneal fibrosis.

Conclusion

In the general population, elevated serum IgG4 levels are more common in elderly men, which is similar to the epidemiological features of IgG4-RD.

References

[1]Inoue D, et al. IgG4-related disease: dataset of 235 consecutive patients. Medicine (Baltimore). 2015;94(15):e680.

[2]Yamada K, et al. New clues to the nature of immunoglobulin G4-related disease: a retrospective Japanese multicenter study of baseline clinical features of 334 cases. Arthritis Res Ther. 2017;19(1):262

[3]Culver EL, et al. Elevated serum IgG4 levels in diagnosis, treatment response, organ involvement, and relapse in a prospective IgG4-related disease UK cohort. Am J Gastroenterol 2016;111:733–43.

[4]Lin W, et al. Clinical characteristics of immunoglobulin G4-related disease: a prospective study of 118 Chinese patients. Rheumatology (Oxford). 2015;54(11):1982–90.

[5]Carruthers MN, et al. The diagnostic utility of serum IgG4 concentrations in IgG4-related disease. Ann Rheum Dis 2015;74:14-18.

[6]James Yun, et al. Poor positive predictive value of serum immunoglobulin G4 concentrations in the diagnosis of immunoglobulin G4-related sclerosing disease. Asia Pac Allergy. 2014 Jul;4(3):172-176.

[7]Taiwo N Ngwa, et al. Sreum immunoglobulin G4 ｌevel is a poor predictor of immunoglobulin G4–related disease. Pancreas. 2014 Jul;43(5):704-7.

Disclosure of Interests

None declared

POS0615 CLINICAL DEMOGRAPHICS AND FACTORS AFFECTING DRYNESS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Background

Sjogren’s syndrome (SS) is known to coexist with rheumatoid arthritis (RA). However, the prevalence of RA with SS varies widely, from 2.4% to 30%, and some patients with RA without SS also show dryness. The prevalence and clinical demographics of dryness in patients with RA are not well recognized.

Objectives

The aim of this study was to clarify the prevalence, clinical demographics, and related factors of dryness in patients with RA who have not been diagnosed with (SS).

Methods

We enrolled 166 patients with RA (129 females, 37 males; mean age 65.8±14.3 years; disease duration 14.1±10.9 years; DAS28-CRP 2.30±0.92) who were not diagnosed with SS. We analyzed CRP, the estimated glomerular filtration rate (eGFR), RF, anti-CCP antibody, antinuclear antibody, anti-SS-A antibody (SSA), and disease activity score (DAS) 28-CRP, and identified treatments for RA. We used each question item of the EULAR SS Patient Reported Index (ESSPRI) to clarify dryness, somatic and mental fatigue, and pain. History of smoking, comorbidities, such as interstitial pneumonia, fibromyalgia, and psychiatric disorders, and narcotic and/or psychotropic medication use were determined from the medical records. We defined patients with dryness as greater than or equal to one point, and those with severe dryness as greater than or equal to five points, of the visual analog scale (VAS).

Results

Dryness was observed in 93/166 (56.0%) patients and severe dryness was identified in 57/166 (34.4%) patients, and SSA was positive in 23/139 patients(13.9%). We divided our patients into dryness and non-dryness groups and compared their clinical demographics. The dryness group was relatively younger (64.0±14.5 vs. 68.1±13.8 years, p=0.052), had a female predominance (89.2% vs. 63.0%, p<0.001), had severe fatigue (4.06±2.59 vs 2.60±2.78, p<0.001), and had severe pain (3.52±2.41 vs. 2.73±2.32, p=0.020). However, the prevalence of SSA did not significantly differ in this cohort, compared with the non-dryness group (19.3% vs. 11.8%, p=0.248). Next, we analyzed the clinical characteristics of the patients with severe dryness. The severe dryness group was younger (61.9±15.5 vs. 67.9±13.2 years, p=0.022), had higher eGFR (76.1±15.5 vs. 68.9±22.7, p=0.020), had more severe fatigue (4.89±2.42 vs. 2.85±2.63), p<0.001), and had more severe pain (4.16±2.51 vs. 2.65±2.18, p<0.001), compared with non-severe dryness group. The prevalence of SSA was also significantly higher in the severe dryness group (91.2% vs. 70.6%, p=0.002). We then performed a multifactorial analysis using logistic regression analysis with a stepwise method. Female sex (OR 3.739, 1.247-11.207) and VAS of fatigue (OR 1.269, 1.054-1.526) were found to independently relate to dryness.

Conclusion

More than half of the patients with RA had dryness, although only 13.9% of patients were SSA positive. Dryness was related to female predominance and fatigue. Simon et al. reported that SS was found in 2.42% of patients with RA (1). On the other hand, Harrold et al. reported that SS was found in 30% of patients with RA, and the prevalence of SS increased with duration of RA (2). Our data indicate that patients with fatigue, regardless of pain, tend to have dryness, which may be a key factor in diagnosing SS in patients with RA.

References

[1]Simon TA, Kawabata H, Ray N, et.al. Prevalence of Co-existing Autoimmune Disease in Rheumatoid Arthritis: A Cross-Sectional Study. Adv Ther. 2017 Nov;34(11):2481-2490.

[2]Harrold LR, Shan Y, Rebello S, et al. Prevalence of Sjögren’s syndrome associated with rheumatoid arthritis in the USA: an observational study from the Corrona registry. Clin Rheumatol. 2020 Jun;39(6):1899-1905.

Disclosure of Interests

None declared

POS0675 IMPACT OF PAST USE OF DISEASE MODIFYING ANTI-RHEUMATIC DRUGS ON JAK INHIBITOR TREATMENT FOR RHEUMATOID ARTHRITIS - DATA FROM THE FUKUI ISHIKAWA TOYAMA DATABASE OF RHEUMATOID ARTHRITIS

Background

Currently, five types of Janus kinase inhibitors (JAKis) are used for rheumatoid arthritis (RA) treatment. The number of cases in which multiple JAKis have been prescribed is increasing. However, the real-world efficacy and safety of JAKis and related factors require further evaluation.

Objectives

The primary objective of this study was to elucidate the impact of past use of disease-modifying anti-rheumatic drugs on RA treatment using JAKis. The secondary objective was to investigate the safety profiles of these agents in a real-world setting.

Methods

Of the 303 JAKi-treated patients in the Fukui Ishikawa Toyama Database of RA included in this study, 30 had switched from one JAKi to another (JJ group), 214 switched from a biologic agent to a JAKi (BJ group), and 47 were naïve to either biologics or JAKis (NJ group). We compared baseline factors, treatment response, and JAKi continuation rates among the three groups. Factors related to JAKi discontinuation were assessed using Cox regression analysis. Furthermore, we investigated adverse events and reported them using exposure-adjusted incidence rates (EAIR; incidence rates per 100 patient-years).

Results

Data from the 303 cases were analyzed (mean age = 63.6 years; female, 82%; mean RA duration, 176 months). Of the 303 patients, 118, 106, 50, and 29 were treated with tofacitinib, baricitinib, peficitinib, and upadacitinib, respectively, on initial observation. Rate of concomitant use with methotrexate and prednisolone was 52% and 49%, respectively.

Regarding efficacy, no significant differences were observed among the three groups in terms of treatment response and JAKi continuation rates, except for the 6-month treatment response between the JJ and NJ groups. Cox regression analysis of the 303 cases revealed that only past use of JAKis during the disease history was significantly associated with JAKi discontinuation. The Kaplan–Meier method showed that patients who previously used JAKis had significantly shorter median JAKi treatment duration than those without such a history (20.9 vs. 54.7 months; p = 0.012). Treatment response was significantly poor in patients who had previously used JAKis, especially 6 months after treatment initiation.

In terms of safety, the total exposure period for the 303 cases was 495 person-years, and the total number of adverse events was 161 (EAIR, 32.5). There were 12 cases (EAIR, 2.5) of serious infections, 23 cases (EAIR, 5.1) of herpes zoster, 7 cases (EAIR, 1.4) of malignant tumors, and 4 cases (EAIR, 0.8) of MACE. Adverse events led to JAKi discontinuation in 34 patients (EAIR, 6.9); the main causes of adverse events leading to treatment discontinuation were infectious diseases in 10 cases (EAIR, 2) and neoplasms in 4 cases (EAIR, 0.8). Within 1 year of initiating JAKi therapy, 21 patients discontinued treatment owing to adverse events, which accounted for 27% of the reasons for treatment discontinuation.

We also investigated cases of JAKi dose reduction, observed in 42 of the 303 cases. Among them, 10 patients required a re-increase in the JAKi dose, and 13 patients (56.5%) were able to maintain the reduced dose for more than 1 year. The remaining 19 patients were excluded from the analysis because the treatment duration at the lower dose had not exceeded 1 year at the time of data extraction. No difference in disease activity at the time of dose reduction was observed between those who maintained the new dose and those who did not (mean DAS28-CRP: 1.48 ± 0.26 vs. 1.89 ± 0.62).

Conclusion

Past use of JAKis may contribute to decreased response and continuation rates for JAKi treatment. In this study, conducted in Japan, development of herpes zoster was found to the most frequent adverse event among the priority survey items.

Acknowledgements

I have no acknowledgements to declare.

Disclosure of Interests

None declared

POS1349 IMMUNOGLOBULIN G4-RELATED KIDNEY DISEASE’S PREDISPOSITION TO CHRONIC RENAL DYSFUNCTION, COMPLICATIONS OF MALIGNANCY, AND MORTALITY: A LONG-TERM NATIONWIDE MULTICENTER STUDY IN JAPAN

Background

In immunoglobulin G4-related kidney disease (IgG4-RKD), persistent renal insufficiency may be observed despite the good initial response to glucocorticoids[1, 2]. However, its long-term prognosis in relation to renal function as well as malignancy and mortality has not been well clarified.

Objectives

To clarify the long-term renal prognosis, complications of malignancy, mortality, and factors related to those outcomes in IgG4-RKD.

Methods

We retrospectively reviewed the medical records of patients with IgG4-RKD diagnosed by the expert members of the IgG4-RKD working group in the Japanese Society of Nephrology. We investigated clinical, radiological, and histopathological features at baseline and course of renal function, complications of malignancy, and mortality during the long-term observation periods (median 71 months) in 75 patients. Using collected data, we calculated the crude incidence rates (IR) of chronic kidney disease (CKD) status, malignancy, and death. Cox regression analyses were performed to assess CKD-related factors. Additionally, we calculated the standardized incidence ratio (SIR) of malignancy and standardized mortality ratio (SMR) using national Japan statistics.

Results

Fifty-nine patients were male, and 16 were female (median age 70 years). At diagnosis, their median eGFR was 45.1 mL/min/1.73m2 (interquartile range [IQR] 28.6-69.9). Seventy-two patients (96%) were treated with prednisolone at a median initial dose of 30 (IQR 30-39) mg/day, leading to a reasonable initial improvement of renal function. The IR of CKD was 30.2/100 person-years, and 66.7% (50/75) of the patients showed CKD at the last visit. Age- and sex-adjusted Cox regression analyses indicated that lower eGFR (per 10 mL/min/1.73m2, hazard ratio [HR] 0.70, 95% confidence interval [CI] 0.61-0.80), pre-existing hypertension (HR 2.39, 95% CI 1.32-4.34), and wider areas with inflammation (>50% vs. <10%, HR 2.55, 95% CI 1.07-6.08) or fibrosis (>50% vs. <5%, HR 2.84, 95% CI 1.18-6.85) in the biopsied renal specimens at treatment initiation had a significant impact on the time to CKD. Eight patients (10.7%) died during follow-up due to malignancy, severe infection, cerebral hemorrhage, or myocardial infarction. The crude mortality rate was 1.76/100 person-years, and a SMR calculated according to national Japan statistics was 0.97 (95% CI 0.42-1.90). On the other hand, 15 patients were diagnosed as having malignancies during follow-up. The IR of malignancy was 3.71/100 person-years, and the SIR of malignancy was 1.80 (95% CI 1.03-2.93).

Conclusion

This study suggests that pre-treated renal insufficiency and extensive renal inflammatory and fibrotic lesions are related to CKD under glucocorticoid therapy in IgG4-RKD. Similarly with the whole IgG4-related disease, IgG4-RKD may have an increased incidence of malignancy but a mortality rate equivalent to the age- and sex-matched Japanese population.

References

[1]Saeki T et al. The clinical course of patients with IgG4-related kidney disease. Kidney Int. 2013 Oct;84(4):826-33.

[2]Mizushima I et al. Factors related to renal cortical atrophy development after glucocorticoid therapy in IgG4-related kidney disease: a retrospective multicenter study. Arthritis Res Ther. 2016 Nov 25;18(1):273.

Disclosure of Interests

None declared

POS0247 GLUCOCORTICOID TAPERING STRATEGY FOR ANCA-ASSOCIATED VASCULITIS: ADDRESSING THE GAP BETWEEN RECOMMENDATIONS AND REAL-WORLD PRACTICE

Background

Antineutrophil cytoplasmic antibody -associated vasculitis (AAV) is usually treated with combination of high-dose glucocorticoid (GC) and immunosuppressive agents, followed by tapering GC dose. Although the European League Against Rheumatism (EULAR) has specific recommendations for tapering the GC dose, clinicians often taper it slower than recommended due to concerns of potential disease relapse. However, such slower taper may prolong GC exposure for the patients, increasing the risk of adverse events, particularly infection.

Objectives

The aims of our study were (1) to clarify GC dose tapering in the treatment of AAV in a real-world setting, in contrast to the EULAR recommendation of 2015 and (2) to compare the incidence of AAV relapse and severe infection between patients underdoing EULAR-recommended tapering and those undergoing slower tapering than the recommendation.

Methods

In this multicenter (25 sites in Japan), observational, retrospective study of AAV, 541 patients who had initial or severe relapse were enrolled between January 2017 and June 2020. Of these, 349 patients with microscopic polyangiitis (MPA) or granulomatosis with polyangiitis (GPA) who entered in GC tapering phase after successful induction treatment were included. These patients were then grouped on the pace of GC tapering, defined as the GC dose at 12 weeks after treatment initiation: (1) EULAR group: 7.5-10 mg/day of GC, according to the EULAR recommendation of 2015, and (2) SLOWER group: >10 mg/day of GC. Their baseline characteristics and clinical outcomes were compared. Primary outcome was defined as relapse-free days from treatment initiation, whereas secondary outcome included the incidence of infectious events requiring hospitalization within 48 weeks from treatment initiation. Multivariable analysis was performed to assess the relationship between tapering pace and clinical outcomes.

Results

There were 44 patients (12.6%) in the EULAR group and 290 (83.2%) in the SLOWER group. Regarding baseline characteristics, compared with the EULAR group, the SLOWER group had significantly higher serum C-reactive protein level (EULAR, 5.89 ± 6.89 mg/dL vs SLOWER, 7.56 ± 6.01 mg/dL; p = 0.03), as well as a trend toward higher Birmingham Vasculitis Activity Score (version 3) (EULAR, 11.80 ± 7.01 SLOWER, 13.93 ± 7.06; p = 0.08) We did not observe any significant differences in the frequency of relapses between the two groups (EULAR, 8/44, 18.2% vs SLOWER, 55/290, 19.0%; p = 0.63). Multivariable Cox proportional hazard analysis revealed no relationship GC dose at 12 weeks from treatment initiation and incidence of relapse. However, upon logistic regression analysis, the SLOWER group was found to have significant higher risk of a severe infectious event within 48 weeks from treatment initiation (p = 0.046; hazard ratio, 1.27; 95% confidence interval, 1.004 – 1.601).

Conclusion

Our finding indicates that clinicians tended to taper GC slower for patients with higher disease activity. However, slower GC taper was not found to reduce the frequency of relapse. In addition, slower GC taper was found to increase the risk of a severe infection. Hence, clinicians should pay attention not only relapsing but also late GC taper resulting in the risk of serious infection, especially in patients with higher disease activity of AAV.

References

[1]Eur J Clin Invest 2015;45 (3): 346–368.

[2]Rheumatology (Oxford). 2021 Dec 24;61(1):205-212.

[3]Arthritis Res Ther. 2021 Mar 20;23(1):90.

[4]Scand J Rheumatol. 2022 Jan 20;1-13.

[5]J Rheumatol. 2018 Apr;45(4):521-528.

[6]Rheumatol Adv Pract. 2021 Mar 9;5(3):rkab018.

[7]Ann Rheum Dis. 2016 Sep;75(9):1583-94.

Figure 1.

Acknowledgements

We would like to thank Editage (www.editage.com) for English language editing.

Disclosure of Interests

None declared

AB0760 HIGH SERUM IGA LEVELS HAVE LIMITED CLINICAL SIGNIFICANCE IN PATIENTS WITH IGG4-RELATED DISEASE DIAGNOSED BY EXPERTS

Background:

While the diagnostic and classification criteria for IgG4-related disease (IgG4-RD) have been recently developed [1-3], it is known that, without appropriate exclusions, some non-IgG4-RDs may meet these criteria. In particular, hyper IL-6 syndromes, including Castleman disease, can be misdiagnosed as IgG4-RD. Some clinical findings, including elevated serum levels of C-reactive protein (CRP) or IgA, have been suggested to be useful for differentiating hyper IL-6 syndromes from IgG4-RD [4]. However, since few clinical studies have focused on IgG4-RD with high serum IgA levels, its clinical significance has not been well known.

Objectives:

This study aimed to clarify the clinical significance of high serum IgA levels in patients with IgG4-RD.

Methods:

We retrospectively investigated the clinical features of 170 patients with IgG4-RD on the basis of the presence or absence of elevated serum IgA levels (>410 mg/dL) at the time of diagnosis. The diagnosis of IgG4-RD was made by experts on the basis of the fulfillment of the comprehensive diagnostic criteria and/or each organ-specific diagnostic criteria.

Results:

Elevated serum IgA levels were observed in 18 patients (10.6%). In the patients with elevated serum IgA levels, serum CRP levels were higher (1.14 ± 1.18 vs. 0.31 ± 0.63 mg/dL, p=0.003) and the prevalence of relapse during the clinical course was lower (5.6% vs. 27.6%, p=0.046) than in those without elevated serum IgA levels. However, there were no significant differences in the other clinical features including the number of involved organs (2.4 ± 1.3 vs. 2.8 ± 1.6, p=0.443) and inclusion scores of the ACR/EULAR classification criteria (32 ± 14 vs. 36 ± 17, p=0.374). To evaluate the influence of serum IgA elevation on relapse, we performed Cox regression analysis, which showed that the elevated serum IgA levels had no significant association with lower incidence of relapse but a tendency of it (hazard ratio 0.997, 95% confidence interval 0.994-1.000, p=0.055) during the clinical course. In addition, a prompt improvement in the IgG4-RD responder index [5] during the clinical course was seen in the patients with serum IgA elevation, suggesting a similar good response to glucocorticoids as in those without it.

Conclusion:

The findings of the present study suggest that IgG4-RD patients with high serum IgA levels can be diagnosed and treated in the same way as those without it, although they may be characterized by mild serum CRP elevation.

References:

[1]Wallace ZS et al. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease. Ann Rheum Dis. 2020;79:77-87.

[2]Umehara H et al. The 2020 Revised Comprehensive Diagnostic (RCD) Criteria for IgG4-RD. Mod Rheumatol. 2020 Dec 4:1-14. doi: 10.1080/14397595.2020.1859710. Online ahead of print.

[3]Umehara H et al. Current approach to the diagnosis of IgG4-related disease - Combination of comprehensive diagnostic and organ - specific criteria. Mod Rheumatol. 2017;27:381-91.

[4]Sato Y et al. Systemic IgG4-related lymphadenopathy: A clinical and pathologic comparison to multicentric Castleman’s disease. Mod Pathol.2009;22:589-99.

[5]Carruthers MN et al. Development of an IgG4-RD Responder Index. Int J Rheumatol. 2012;2012:259408.

Disclosure of Interests:

None declared

POS1348 MORTALITY AND ITS RELATED FACTORS IN PATIENTS WITH IGG4-RELATED DISEASE: A JAPANESE SINGLE-CENTER STUDY

Background:

In recent years, IgG4-related disease (IgG4-RD) has become a widely recognized disorder. However, mortality and its related factors in this disease are not well known.

Objectives:

This study aimed to clarify mortality and its related factors in patients with IgG4-RD.

Methods:

We retrospectively reviewed the medical records of patients with IgG4-RD diagnosed by experts based on fulfillment of the Japanese comprehensive diagnostic criteria and/or the 2019 ACR/EULAR classification criteria for IgG4-RD at a single center in Japan. Using the collected data, we calculated the crude mortality rate and the standardized mortality ratio (SMR) using national Japan mortality statistics and investigated the cause of death. We performed Cox regression analyses to assess mortality-related factors.

Results:

A total of 179 patients with IgG4-RD were included: 124 were male (69.3%); the median age was 68 years (interquartile range [IQR] 60-75 years); and the median follow-up from diagnosis was 47 months (IQR 17-84). Ten patients (5.6%) in our cohort died during the follow-up period. Five died of malignancy, one of respiratory failure, two of infectious pneumonia, one of sudden cardiac event, and one of suspected aortic aneurysmal rupture. The crude mortality rate was 11.1 per 1,000 person-years. According to national Japan mortality statistics, 11.6 age- and sex-matched deaths were expected to occur within the follow-up period, resulting in a SMR of 0.86 (95% confidence interval [CI] 0.41-1.59). Univariate Cox regression analyses indicated that the number of affected organs at diagnosis (hazard ratio [HR] 1.45, 95% CI 1.02-2.05), serum creatinine levels at diagnosis (HR 1.82, 95% CI 1.06-3.12), and the presence of malignancy during the clinical course (HR 3.93, 95% CI 1.10-14.02) had a significant impact on the time to death, whereas the other factors including age at diagnosis and serum C-reactive protein and IgG4 levels at diagnosis did not.

Conclusion:

Our findings suggest that the mortality rate of patients with IgG4-RD does not significantly differ from that of the Japanese general population. Multi-organ involvement and renal dysfunction at diagnosis as well as malignancy during the clinical course may be associated with higher mortality. An appropriate clinical evaluation for the early detection of these risk factors is required at first diagnosis and during long-term follow-up.

Disclosure of Interests:

None declared

POS0527 ACUTE KIDNEY INJURY (AKI) IN PATIENTS WITH RHEUMATOID ARTHRITIS (RA)

Background:

Methotrexate has been an anchor drug for patients with rheumatoid arthritis (RA). However, it is strictly prohibited to prescribe MTX to patients with severely decreased renal function because it can induce a fatal adverse event such as pancytopenia in these patients. On the other hand, since the average age of RA patients is gradually increasing, and many of them already have mildly to moderately impaired renal function, their renal function can easily decrease to below the critical level of the estimated glomerular filtration rate. Therefore, new development of acute kidney injury (AKI) during MTX administration might induce a fatal adverse event, making the identification of patients susceptible to AKI very important.

Objectives:

To clarify the frequency of AKI and the factors involved in it in RA patients.

Methods:

Two hundred and fifty-two RA patients (211 females, 41 males, mean age 62.3 ± 12.5 years, disease duration 11.0 ± 9.5 years) diagnosed more than 3 years earlier and followed for more than 5 years, and also, others diagnosed ≥3 years earlier but followed for ≤5 years were enrolled. We measured BUN, Cr, RF and aCCP in patient serum, urinary proteins, urinary blood, and urinary casts and evaluated CDAI, SDAI, disease activity score (DAS) 28-CRP and DAS28-ESR. Steinbrocker functional classification and radiological grading were evaluated. History of diabetes mellitus, hypertension and hyperlipidemia was determined from the medical records. Medications for RA, including non-steroid anti-inflammatory drugs (NSAIDs), prednisolone, csDMARD (MTX, Tacrolimus, etc.), bDMARDs and tsDMARDs were evaluated. Estimated glomerular filtration rate (eGFR) was calculated by the new Japanese coefficient-modified Modification of Diet in Renal disease (MDRD) study equation. The criteria of AKI were that serum Cr increased by 0.3 mg /dl or increased by 1.5-fold between consecutive visits according to the KIDIGO criteria 1) and the report of Leither et al2).

Results:

Twenty (7.9%) patients developed AKI, 22 times. The causes of AKI were 10 infections, 6 dehydrations, 2 enteritis, 1 urticaria, 2 hypercalcemia due to VitD administration, and 1 ureteral stone. We divided our patients into group A (with AKI) and group B (without AKI). Group A was older (69.9±10.1 vs 61.7±12.6 years), had greater physician VAS (29.5±27.7 vs 15.7±18.3 mm), higher serum creatinine (0.79±0.19 vs 0.60±0.16 mg/dl), higher BUN (18.4±5.7 vs 15.1±4.4 mg/dl), lower eGFR(65.5±23.3 vs 86.4±22.4 ml/min), more frequent prednisolone administration (75.0% vs 41.9%), more frequent hyperlipidemia (50.0% vs 19.2%) and more frequent hypertension (60.0% vs 30.6%) than Group B by univariate analysis significantly (p<0.01). We then performed multifactorial analysis using logistic regression analysis. Greater physician VAS (OR 1.02, 1.00-1.04), lower eGFR (OR 1.04, 1.01-1.08) and prednisolone administration (OR 3.29, 1.02-10.63) were found as independent relevant factors for group A.

Conclusion:

Our study indicated that AKI developed in RA patients and suggested that renal function decline and prednisolone administration may be implicated. RA patients with impaired renal function and prednisolone administration need to be treated with special attention to the onset of AKI.

References:

[1]Kidney Disease: Improving Global Outcomes (KDIGO) Practice Guideline for Acute Kidney Injury. Kidney Int Suppl 2: 1-138, 2012

[2]Leither MD, Murphy DP, Bicknese L et al. The impact of outpatient acute kidney injury on mortality and chronic kidney disease: a retrospective cohort study. Nephrol Dial Transplant. 34:493-501, 2019

Disclosure of Interests:

None declared

FRI0503 VALIDATION OF THE 2019 ACR/EULAR CLASSIFICATION CRITERIA FOR IGG4-RELATED DISEASE IN A JAPANESE KIDNEY DISEASE COHORT: A MULTI-CENTER RETROSPECTIVE STUDY BY THE IGG4-RELATED KIDNEY DISEASE (IGG4-RKD) WORKING GROUP OF THE JAPANESE SOCIETY OF NEPHROLOGY

Background:

The 2019 ACR/EULAR classification criteria for IgG4-RD have recently been published1). In the criteria, patients with an inclusion criteria score of >20 without exclusion criteria are classified as having IgG4-RD.

Objectives:

To validate the 2019 ACR/EULAR classification criteria for IgG4-RD in a Japanese kidney disease cohort.

Methods:

The study involved Japanese patients diagnosed as having kidney disease between April 2012 and May 2019, for whom sufficient clinical information and data on serum IgG4 values and/or immunohistological staining for IgG4 in renal biopsy samples were known. These patients were classified as having IgG4-RKD or non-IgG4-RKD (mimickers) based on the 2019 ACR/EULAR classification criteria for IgG4-RD, and the results were evaluated by expert opinion.

Results:

Among 105 included patients, the expert panel diagnosed 55 as having true IgG4-RKD and 50 as mimickers. The final diagnoses among the mimickers were vasculitis (n=11), idiopathic tubulointerstitial nephritis (TIN) (n=5), drug-induced TIN (n=5), Sjögren’s syndrome (n=4) and others. Among the 55 true IgG4-RKD patients, 4 had exclusion criteria, and 50 of the remaining 51 had an inclusion criteria score of ≥20 points (sensitivity 90.9%). On the other hand, 49 of the 50 mimickers were classified as having non-IgG4-RKD (specificity 98.0%) (Table 1).

Table 1.

General characteristics and prevalence of individual items of true IgG4-RKD and non-IgG4-RKD (mimicker)

IgG4-RKD(true IgG4-RKD)(n=55)Non-IgG4-RKD(mimicker)(n=50)PAge at diagnosis,mean ±SD (years)69.9 ± 9.456.7 ± 17.4<0.001Male (%)76.4440.001Elevated serum IgG454/55 (98.2%)18/50 (36.0%)<0.001Serum IgG4 (mg/dl), mean±SD1028 ± 796226 ± 261<0.001Dense IgG4+Plasma cells (>10/hpf) in the kidney biopsy48/51 (94.1%)13/40 (32.5%)<0.001Storiform fibrosis in the kidney biopsy28/51 (54.9%)3/50 (6%)<0.001Hypocomplementemia39/55 (70.1%)7/42 (16.7%)<0.001Renal pelvis thickening/soft tissue5/55 (9%)1/50 (2%)0.20Bilateral renal cortex low-density areas29/55 (52.7%)7/50 (14.0%)<0.001Exclusion criteria present4/55 (7.3%)22/50 (44%)<0.001Total inclusion criteria points >20 without exclusion criteria50/55 (90.9%)1/50 (2%)<0.001

Conclusion:

The 2019 ACR/EULAR classification criteria for IgG4-RD showed good agreement with expert classification in this Japanese kidney disease cohort.

References:

[1] Wallace ZS, et al. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease. Ann Rheum Dis. 79:77-87, 2020

Disclosure of Interests:

None declared

FRI0188 THE CLINICOPATHOLOGICAL SIGNIFICANCE OF MODIFIED NATIONAL INSTITUTES OF HEALTH ACTIVITY AND CHRONICITY SCORING SYSTEM IN LUPUS NEPHRITIS; A MULTICENTER RETROSPECTIVE STUDY

Background:

The revised International Society of Nephrology/Renal Pathology Society (ISN/RPS) Classification of lupus nephritis (LN) 2018 defined a modified National Institutes of Health activity and chronicity scoring system for all LN classes [1]. As this was not arrived at by an evidence-based approach, its clinicopathological significance including prognostic value should be validated [1]. Furthermore, though the activity index included wire-loop lesion and hyaline deposits (WL), we previously demonstrated that WL was associated with serological immune abnormality, but not renal prognosis [2].

Objectives:

We conducted this study to clarify the relationships of modified activity score (AS) and chronicity score (CS) to clinical parameters at the time of renal biopsy and renal and life prognoses, and also to investigate the impact of AS without WL.

Methods:

We enrolled 138 Japanese LN patients subjected to renal biopsy in 11 hospitals from 2000 to 2019. We measured clinical findings at the time of renal biopsy, and determined the presence of comorbidities. We also measured serum creatinine and estimated glomerular filtration rate (eGFR) at the last patient visit, and recorded medications prescribed for LN. Renal biopsy findings were classified by the modified ISN/RPS classification 2018 including AS and CS for all LN classes. On stepwise multivariate analysis, we applied the variables with significant differences in univariate comparisons. The primary endpoint was chronic kidney disease (CKD; eGFR <60 ml/min/1.73m2) and/or death.

Results:

Of 138 patients (116 females; median 39 years old), class I, II, III, IV, and V included 2 (1.4%), 13 (9.4%), 43 (31.2%), 69 (50.0%), and 11 (8.0%), respectively. Median AS, AS without WL (AS-WL), and CS were 4, 3, and 2, respectively. AS ≥5 group (61 patients, 44.2%) had higher proteinuria, hematuria and serum anti-ds DNA antibodies levels and lower serum total protein (TP) and C3 levels than AS <5 group. CS ≥3 group (58 patients, 42%) had higher age, proteinuria, serum C3 levels, and frequency of hypertension (HT) and lower eGFR and serum anti-ds DNA antibodies and IgG levels than CS<3 group. Multiple regression analysis revealed significant associations between AS and hematuria, TP and C3 (β=0.312, -0.281, -0.213;p<0.001, 0.001, 0.009), and between CS and age (β=0.300;p=0.010). Next, patients who achieved the primary endpoint had higher age, frequencies of HT and hyperlipidemia and lower eGFR, serum TP and IgG levels than patients who did not. Observation period (median 36 vs 47 months,p=0.696) and medications for LN did not differ between these groups. Cox regression analysis revealed significant associations of prognosis with eGFR and TP clinically (β=0.955, 3.349;p=0.025, 0.008), and with CS pathologically (β=1.231,p=0.028). Neither AS nor AS-WL was included in the prognostic factors. Kaplan-Meier method with log-rank tests showed a significant difference in cumulative rate of CKD and/or death between CS ≥3 and CS <3 groups (p=0.049).

Conclusion:

AS and CS were related to different clinical parameters at the time of renal biopsy. CS was associated with renal and life prognoses, while neither AS nor AS-WL was. These results revealed that these scores have different clinicopathological significance in LN.

References:

[1]Bajema IM, et al. Kidney Int. 2018;93:789-96.

[2]Zoshima T, et al. Lupus 2019, accepted.

Disclosure of Interests:

None declared

FRI0166 HIGH FREQUENCY OF KIDNEY STONES AND/OR NEPHROCALCINOSIS IN PRIMARY SJOGREN’S SYNDROME MIGHT ACCELERATE CHRONIC RENAL DYSFUNCTION DUE TO TUBULOINTERSTITIAL DISEASE

Background:

The renal involvement of primary Sjögren’s syndrome (pSS) is characterized by distal renal tubular acidosis (RTA), tubulointerstitial nephritis (TIN), and/or glomerulonephritis [1,2]. Kidney stones and nephrocalcinosis are presumably caused by subclinical distal tubular acidosis, but its clinical significance has not been clarified.

Objectives:

This study aimed to clarify the frequency and clinical features of patients with pSS with kidney stones and/or nephrocalcinosis.

Methods:

We examined 59 patients with anti SS-A/Ro positive pSS who underwent abdominal computed tomography and/or ultrasound between 1998 and 2019 at Kanazawa University Hospital. We identified 2 groups of patients with primary Sjögren’s syndrome: 1) patients with kidney stones and/or nephrocalcinosis (group A: n=19) and 2) those without kidney stones and/or nephrocalcinosis (group B: n=40), and retrospectively analyzed their clinical features.

Results:

Kidney stones and/or nephrocalcinosis were confirmed in 19 of 59 (32%) patients with pSS. The patients comprised 4 males and 55 females with an average age of 60 years (range, 30 to 83 years) and mean observation period of 96 months (range 1 to 336 months). Estimated glomerular filtration rate (eGFR) at the time of diagnostic imaging (group A vs group B: 71.5 ml/min/1.73 m2vs 82.8 ml/min/1.73 m2; p=0.37) and eGFR at last follow up (group A vs group B: 59.3 ml/min/1.73 m2vs 74.7 ml/min/1.73 m2;p=0.03) of group A were lower than those of group B and urinary β2-microgloblin (group A vs group B: 7222 μg/mL vs 437 μg/mL; p=0.01) and urinary N-acetyl-β-D-glucosaminidase (group A vs group B: 5.8 U/L vs 3.9 U/L; p=0.22) of group A were higher than those of group B, while serum electrolytes (sodium, potassium, chloride, calcium, phosphorus), fractional excretion of calcium (group A vs group B: 1.2% vs1.5%; p=0.916), ESSDAI (group A vs group B: 7.6 vs 4.3; p=0.069), and eGFR decrease rate were not significantly different.

Conclusion:

32% patients with anti SS-A/Ro positive pSS had kidney stones and/or nephrocalcinosis in our cohort and their presence might accelerate chronic renal dysfunction due to tubulointerstitial disease (subclinical RTA or TIN).

References:

[1]Jain A et al. Renal involvement in primary Sjogren’s syndrome: a prospective cohort study. Rheumatol Int 2018; 38: 2251-62.

[2]Jasiek M et al. A multicentre study of 95 biopsy-proven cases of renal disease in primary Sjögren’s syndrome. Rheumatology 2017; 56: 362-70.

Acknowledgments:

We thank Mr. John Gelblum for critical reading of the manuscript.

Disclosure of Interests:

None declared

SAT0532 POSITIVE DISEASE-SPECIFIC AUTOANTIBODIES LOWER DIAGNOSTIC SENSITIVITY BUT HAVE LITTLE CLINICAL SIGNIFICANCE IN DIAGNOSING IgG4-RELATED DISEASE USING THE 2019 ACR/EULAR CLASSIFICATION CRITERIA IN DAILY CLINICAL PRACTICE

Background:

Recently, the 2019 ACR/EULAR classification criteria for IgG4-related disease (IgG4-RD) were published mainly to identify more homogeneous subjects for inclusion in clinical trials and observational studies [1]. However, although their high specificity is presumed to be useful to differentiate IgG4-RD from various mimickers, their value in daily clinical practice needs to be evaluated.

Objectives:

This study aimed to clarify the usefulness of the 2019 ACR/EULAR classification criteria for IgG4-RD and characteristics of false-negative patients in daily clinical practice.

Methods:

We retrospectively reviewed the medical records of 162 patients with IgG4-RD and 130 consecutive non-IgG4-RD patients (mimickers) diagnosed by experts whose serum IgG4 levels were measured at a single center in Japan. Using the collected data, we calculated sensitivity, specificity, and fulfillment rates for the entry criteria, exclusion criteria, and threshold of inclusion criteria points. In addition, to clarify the characteristics of false-negative cases in IgG4-RD, we performed an intergroup comparison of their clinical features including disease-specific autoantibodies.

Results:

Both the patients with IgG4-RD and mimickers were relatively old (66 and 65 years) with male predominance (67% and 60%). The final diagnoses of mimickers mainly consisted of cancer, lymphoma, vasculitis, sarcoidosis, multicentric Castleman’s disease, and atherosclerotic or infectious aortic aneurysm. The classification criteria had a sensitivity of 72.8% and a specificity of 100%. Of the 44 false-negative cases, one did not fulfill the entry criteria, 20 fulfilled one exclusion criterion, and 27 did not achieve sufficient inclusion criteria points. Compared with the true-positive cases, the false-negative cases had significantly fewer affected organs, lower serum IgG4 levels, higher serum CH50 levels, and lower prevalence of salivary/lacrimal gland and renal parenchymal lesions. They were also less likely to have had biopsies (61% vs 97%). Of note, positivity of disease-specific autoantibodies including SSA/Ro antibody, ANCA, ds-DNA antibody, and ACPA was the most common exclusion criterion fulfilled in 18 patients, only 2 of whom were diagnosed with a specific autoimmune disease (rheumatoid arthritis) complicated by IgG4-RD. The remaining 16 patients had no specific clinical symptoms related to such autoantibodies. In addition, compared with IgG4-RD patients without disease-specific autoantibodies, the 18 patients with them had almost equal serum IgG4 and complement levels, number of affected organs, and histopathology and immunostaining scores despite higher serum IgG and CRP levels.

Conclusion:

The present study suggests that the 2019 ACR/EULAR classification criteria for IgG4-RD has excellent diagnostic specificity and moderate sensitivity in daily clinical practice. Positive disease-specific autoantibodies alone, which lowered the sensitivity in this study, may have little clinical significance concerning the diagnosis of IgG4-RD.

References:

[1]Wallace ZS et al. The 2019 American College of Rheumatology/European League Against Rheumatism classification criteria for IgG4-related disease. Ann Rheum Dis. 2020 Jan;79(1):77-87.

Disclosure of Interests:

None declared

Wire-loop lesion is associated with serological immune abnormality, but not renal prognosis, in lupus nephritis

BACKGROUND

Wire-loop lesion (WL) is one of the active lesions of lupus nephritis (LN). However, few reports have focused on the clinicopathological relationships of WL to serological immune abnormality and renal prognosis.

METHODS

We enrolled 126 Japanese LN patients subjected to renal biopsy in 11 hospitals from 2000 to 2018. In patients with class III or IV of the International Society of Nephrology/Renal Pathology Society classification, we retrospectively compared clinicopathological findings between those with WL (WL+ group) and without WL (WL- group) to detect factors associated with WL. Chronic kidney disease (CKD) was defined as an estimated glomerular filtration rate of <60 mL/min/1.73m² for more than three months. We also compared these findings between those with CKD (CKD+ group) and without CKD (CKD- group) at the last visit to investigate factors associated with renal prognosis.

RESULTS

Of 126 patients, 100 (79.4%) were classified as class III or IV. WL was found in 36 (36.0%) of them. Although the renal function did not differ, the WL+ group had a higher titre of serum anti-dsDNA antibodies and lower serum complement 3 levels than the WL- group. Linear regression analysis revealed a significant association only between anti-dsDNA antibodies and WL (β = 0.27, 95% confidence interval (CI) 0.001-0.100, p = 0.01). Of these patients, 69 were tracked for 59.6 ± 55.1 months. Kaplan-Meier analysis showed no difference in renal prognosis between these groups. Next, the CKD+ group included 15 (22.1%) patients. They were older and had higher frequencies of hypertension and hyperuricaemia, serum creatinine (Cr) level, glomerulosclerosis, interstitial inflammation, interstitial fibrosis and tubular atrophy than the CKD- group at the time of renal biopsy. The frequency of WL was not significantly different. Cox regression analysis revealed significant associations of CKD with hypertension, hyperuricaemia, serum Cr level at the time of renal biopsy clinically and with tubular atrophy histologically.

CONCLUSIONS

WL was associated with serum anti-dsDNA antibodies but not with renal prognosis, suggesting that WL reflects immune abnormality but is not an independent factor predictive of renal prognosis in LN.

Vero/BC-F: an efficient packaging cell line stably expressing F protein to generate single round-infectious human parainfluenza virus type 2 vector

A stable packaging cell line (Vero/BC-F) constitutively expressing fusion (F) protein of the human parainfluenza virus type 2 (hPIV2) was established for production of the F-defective and single round-infectious hPIV2 vector in a strategy for recombinant vaccine development. The F gene expression has not evoked cytostatic or cytotoxic effects on the Vero/BC-F cells and the F protein was physiologically active to induce syncytial formation with giant polykaryocytes when transfected with a plasmid expressing hPIV2 hemagglutinin-neuraminidase (HN). Transduction of the F-defective replicon RNA into the Vero/BC-F cells led to the release of the infectious particles that packaged the replicon RNA (named as hPIV2ΔF) without detectable mutations, limiting the infectivity to a single round. The maximal titer of the hPIV2ΔF was 6.0 × 10(8) median tissue culture infections dose per ml. The influenza A virus M2 gene was inserted into hPIV2ΔF, and the M2 protein was found to be highly expressed in a human lung cancer cell line after transduction. Furthermore, in vivo airway infection experiments revealed that the hPIV2ΔF was capable of delivering transgenes to hamster tracheal cells. Thus, non-transmissible or single round-infectious hPIV2 vector will be potentially applicable to human gene therapy or recombinant vaccine development.