High serum IgA levels in patients with IgG4-related disease are associated with mild inflammation, sufficient disease-specific features, and favourable responses to treatments

OBJECTIVES

Although elevated serum immunoglobulin A (IgA) levels are thought to exclude a diagnosis of IgG4-related disease (IgG4-RD), IgG4-RD has been definitively diagnosed in some patients despite elevated serum IgA levels. This study aimed to clarify the prevalence of elevated IgA levels in patients with IgG4-RD and to compare the clinical features of IgG4-RD patients with and without elevated IgA levels.

METHODS

The clinical features of 169 IgG4-RD patients were retrospectively compared among those with and without elevated serum IgA levels.

RESULTS

Of the 169 patients with IgG4-RD, 17 (10.1%) had elevated serum IgA levels. Those with elevated serum IgA levels showed higher serum C-reactive protein levels and lower prevalence of relapse than those without. Other clinical features did not differ significantly, including inclusion scores of the American College of Rheumatology/European League Against Rheumatism classification criteria. Cox regression analysis showed that elevated serum IgA levels were associated with a lower incidence of relapse. Moreover, patients with elevated serum IgA levels showed prompt improvement in response to glucocorticoids in the IgG4-RD responder index.

CONCLUSIONS

Some patients diagnosed with IgG4-RD have high serum IgA levels. These patients may form a subgroup, characterized by good response to glucocorticoids, less frequent relapse, mildly elevated serum C-reactive protein levels, and possible complications of autoimmune diseases.

De novo normotensive scleroderma renal crisis six years after living-donor renal transplantation in a patient with overlapping systemic sclerosis/systemic lupus erythematosus syndrome: a case report

BACKGROUND

Scleroderma renal crisis (SRC) is a critical kidney involvement of systemic sclerosis (SSc), often resulting in end-stage renal disease. Although the recurrence of SRC in the allograft has been reported, the development of de novo SRC after kidney transplantation has not been reported. Furthermore, normotensive SRC, which rarely occurs, makes prompt diagnosis more challenging. This fact should be recognized widely among nephrologists.

CASE PRESENTATION

We report a 37-year-old Japanese man with overlapping SSc/systemic lupus erythematous syndrome who developed normotensive SRC in the transplanted kidney shortly after glucocorticoid escalation. Six years prior to admission, he underwent an ABO-compatible living donor kidney transplantation because of lupus nephritis. He was admitted to our hospital for gradually worsening kidney dysfunction. A kidney biopsy showed idiopathic granulomatous interstitial nephritis and high-dose prednisolone was prescribed. Although renal function improved tentatively, it deteriorated again a week later. A secondary kidney biopsy revealed acute thrombotic microangiopathy, leading to the diagnosis of normotensive SRC because all other causes were excluded, and blood pressure was within normal range. Adding an angiotensin-converting enzyme inhibitor and tapering glucocorticoid slowed the speed of deterioration of his kidney function, but he finally required hemodialysis induction.

CONCLUSIONS

SRC can newly develop even in the transplanted kidney, especially when high-dose glucocorticoid is administered. Normotensive SRC makes the diagnosis challenging, so nephrologists should carefully monitor patients with SSc and transplanted kidneys to treat SRC promptly.

Long-term outcomes of lupus nephritis with low-level proteinuria: a multicenter, retrospective study

OBJECTIVES

Reportedly, patients with lupus nephritis (LN) and low-level proteinuria have favorable short-term renal outcomes. We aimed to clarify the long-term renal outcomes and overall survival of them, and the significance of renal biopsy in the early phase with low-level proteinuria.

METHODS

We included 144 Japanese patients with biopsy-proven LN from ten hospitals. Low-level proteinuria was defined by a urine protein: creatinine ratio (UPCR) of ≤ 1 g/gCr based on previous reports. The outcomes were end-stage renal disease (ESRD) and death.

RESULTS

Compared with patients with high-level proteinuria (UPCR > 1), those with low-level proteinuria (n = 67 [46.5%]) had significantly improved renal function at the time of renal biopsy, and low activity index and chronicity index (CI) while the frequency of class III/IV was similar (79.1% vs 84.4%, p = 0.409). In patients with low-level proteinuria, cyclophosphamide usage was less, and the incidence of ESRD (3.0% vs 13.0%, p = 0.036) or death (3.0% vs 16.9%, p = 0.006) during the total observation period (median, 72 months) were low. Kaplan-Meier analysis showed significant differences in the incidence of ESRD and death between the groups. Multivariate Cox regression analysis revealed that the significant risk factors for ESRD were high CI and hypertension, whereas those for death were increased age and high-level proteinuria.

CONCLUSION

Patients with LN and low-level proteinuria had favorable long-term renal and life outcomes. As these patients have substantial active pathological lesions, renal biopsy in the early phase with low-level proteinuria could enable early diagnosis and treatment and thus improve prognosis.

Clues to mortality trends and their related factors in IgG4-related disease: A Japanese single-centre retrospective study

OBJECTIVES

This study aimed to clarify mortality trends and their related factors in immunoglobulin G4-related disease (IgG4-RD) with various organ involvement.

METHODS

We retrospectively reviewed the medical records of patients with IgG4-RD at a single rheumatology centre in Japan. We calculated the standardized mortality ratio using Japanese national mortality statistics. Cox regression analyses were also performed to assess mortality-related factors.

RESULTS

A total of 179 patients with IgG4-RD were included with a median follow-up period of 47 months. The standardized mortality ratio in our cohort was 0.86 (95% confidence interval 0.41-1.59). Univariate Cox regression analyses indicated that the number of affected organs at diagnosis (hazard ratio 1.45, 95% confidence interval 1.02-2.05), estimated glomerular infiltration rate <45 ml/min/1.73 m2 at diagnosis (vs. ≥45, hazard ratio 8.48, 95% confidence interval 2.42-29.79), and the presence of malignancy during the clinical course (hazard ratio 5.85, 95% confidence interval 1.62-21.15) had a significant impact on the time to death.

CONCLUSIONS

Our findings suggest that in the rheumatology department, IgG4-RD does not significantly affect long-term patient survival. However, multi-organ involvement, renal dysfunction, and malignancy may be associated with higher mortality trends in IgG4-RD. Early detection and appropriate management of risk factors may improve the long-term prognosis of patients with IgG4-RD.

Case report: Rosai-Dorfman disease with rare extranodal lesions in the pelvis, heart, liver and skin

Rosai-Dorfman disease (RDD), a rare form of non-Langerhans cell histiocytosis, can involve systemic extranodal lesions. Skin lesions are the most common, whereas intrapelvic, cardiac, and hepatic lesions are infrequent. The present study describes a 74-year-old woman with multiple extranodal lesions in the pelvis, heart, liver, and skin that were successfully treated with glucocorticoid therapy. She had experienced fever and persistent inflammation without cervical lymphadenopathy for several months and ¹⁸F-fluorodeoxyglucose (FDG) positron emission tomography (PET) showed abnormal FDG uptake in the left cheek; cervical, axillary, inguinal lymph nodes; periatrium; and pelvis. She was diagnosed with RDD based on skin and pelvic biopsies. Although this was an atypical case without bilateral cervical lymphadenopathy, the FDG-PET detection of inflammatory lesions led to selection of suitable biopsy sites, and pathological examination led to a correct diagnosis. Findings in this patient indicate that RDD can present with an atypical distribution of infrequent extranodal lesions, with attention required to prevent a delayed diagnosis.

Development of IgG4-related pancreatitis and kidney disease 7 years after the onset of undiagnosed lymphadenopathy: A case report

This report describes a patient diagnosed with immunoglobulin G4 (IgG4)-related pancreatitis and kidney disease 7 years after the onset of undiagnosed lymphadenopathy. A 48-year-old Japanese woman presented with fatigue and leg oedema. Computed tomography showed perigastric lymphadenopathy, for which she underwent a laparoscopic biopsy of the perigastric lymph nodes. Although histopathological examination of the lymph nodes did not lead to a definitive diagnosis, serological tests revealed elevated serum IgG4 levels (558 mg/dl) and IgG4 immunostaining of the lymph nodes showed IgG4-positive plasma cell infiltration, leading to the suspicion of IgG4-related disease. Further workup revealed no organ lesion other than lymphadenopathy. At age 55 years, despite having no subjective symptoms, contrast-enhanced computed tomography showed low-density lesions in the tail of the pancreas and the left kidney. Histopathological examination showed lymphocyte infiltration, consisting of a mixture of plasma cells and eosinophils, in both organs and obliterative phlebitis in the pancreas. IgG4 immunostaining of the kidney specimens showed 160 IgG4-positive cells per high-powered field, with the IgG4+/IgG+ cell ratio being almost 100%, leading to a diagnosis of IgG4-related pancreatitis and kidney disease. Treatment with prednisolone for 2 months resulted in lesion improvement. Although the diagnosis of IgG4-related lymphadenopathy is often challenging in patients with lymphadenopathy alone, findings in the present patient emphasise the importance of long-term follow-up, as it may allow early detection of involvement of other organs by IgG4-related disease.

Evaluating tubulointerstitial compartments in renal biopsy specimens using a deep learning-based approach for classifying normal and abnormal tubules

Renal pathology is essential for diagnosing and assessing the severity and prognosis of kidney diseases. Deep learning-based approaches have developed rapidly and have been applied in renal pathology. However, methods for the automated classification of normal and abnormal renal tubules remain scarce. Using a deep learning-based method, we aimed to classify normal and abnormal renal tubules, thereby assisting renal pathologists in the evaluation of renal biopsy specimens. Consequently, we developed a U-Net-based segmentation model using randomly selected regions obtained from 21 renal biopsy specimens. Further, we verified its performance in multiclass segmentation by calculating the Dice coefficients (DCs). We used 15 cases of tubulointerstitial nephritis to assess its applicability in aiding routine diagnoses conducted by renal pathologists and calculated the agreement ratio between diagnoses conducted by two renal pathologists and the time taken for evaluation. We also determined whether such diagnoses were improved when the output of segmentation was considered. The glomeruli and interstitium had the highest DCs, whereas the normal and abnormal renal tubules had intermediate DCs. Following the detailed evaluation of the tubulointerstitial compartments, the proximal, distal, atrophied, and degenerated tubules had intermediate DCs, whereas the arteries and inflamed tubules had low DCs. The annotation and output areas involving normal and abnormal tubules were strongly correlated in each class. The pathological concordance for the glomerular count, t, ct, and ci scores of the Banff classification of renal allograft pathology remained high with or without the segmented images. However, in terms of time consumption, the quantitative assessment of tubulitis, tubular atrophy, degenerated tubules, and the interstitium was improved significantly when renal pathologists considered the segmentation output. Deep learning algorithms can assist renal pathologists in the classification of normal and abnormal tubules in renal biopsy specimens, thereby facilitating the enhancement of renal pathology and ensuring appropriate clinical decisions.

Central fibrous area in the glomerular vascular pole consists of fibrous collagens and is associated with advanced age: a cross-sectional study

Background

For the optimal management of patients with both allograft kidneys and native kidney diseases, the recognition of the histological features associated with older age is important. This is because most pathological findings are non-specific. Central fibrous areas (CFAs) have recently been proposed to be age-related. However, the components of CFAs and whether CFAs are observed in various kidney diseases remain undetermined. This cross-sectional study was undertaken to clarify the histological features, epidemiology, and clinicopathological features of CFAs.

Methods

One hundred and one consecutive kidney needle biopsy specimens were retrospectively collected from seven facilities in the Hokuriku region and diagnosed at the Kanazawa University Hospital in 2015. First, the components of CFAs were analyzed using normal histostaining, immunostaining, and electron microscopy. Second, the patients were divided into two groups (CFA [+] or CFA [−]) according to the presence of CFA in the obtained samples. Clinical and histological features were compared between the two groups, and factors associated with CFA formation were determined using univariate and multivariate analyses. The number of CFAs per specimen was counted in the CFA (+) group. Third, the presence of myofibroblasts in CFA was examined by immunostaining.

Results

CFAs were observed in 56 of 101 patients (55.4%) with various kidney diseases. CFAs consist of fibrillar collagens (collagen I and III) in addition to non-fibrillar collagens (collagen IV and VI), as confirmed by electron microscopy. Clinically, the CFA (+) group was older and had a significantly higher prevalence of hypertension and hyperlipidemia than the CFA (−) group. Histologically, elastofibrosis of the interlobular artery, arteriolar hyalinosis, and membranous nephropathy were significantly more evident in the CFA (+) group than in the CFA (−) group. Multivariate analysis revealed that older age was the sole factor associated with CFA formation. Finally, 27 of 58 (46.6%) CFA-containing glomeruli in 26 cases included alpha-smooth muscle actin-positive cells in or adjacent to the CFA.

Conclusions

CFAs consist of fibrous collagens in addition to matrix collagens. CFA formation is associated with older age and was observed in various kidney diseases.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02835-2.

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

Successful Early Immunosuppressive Therapy for Pulmonary Arterial Hypertension Due to Takayasu arteritis: Two Case Reports and a Review of Similar Case Reports in the English Literature

The efficacy of early immunosuppressive therapy without invasive therapy, such as endovascular or surgical revascularization, for pulmonary hypertension due to Takayasu arteritis (TAK-PH) remains to be elucidated. We herein report two cases of TAK-PH due to pulmonary arteritis successfully treated with early immunosuppressive therapy. A literature review of 42 cases of TAK-PH with pulmonary artery involvement showed that the cases treated with immunosuppressive therapy early after the onset (within 12 months) had a higher erythrocyte sedimentation rate and better outcome without invasive therapy than those treated later. TAK-PH may be successfully treated with immunosuppressive therapy without invasive therapy when diagnosed early with high disease activity.

Urinary abnormality in mixed connective tissue disease predicts development of other connective tissue diseases and decrease in renal function

OBJECTIVE

To clarify the clinical significance of development of urinary abnormality in mixed connective tissue disease (MCTD).

METHODS

Forty-one patients with an initial diagnosis of MCTD, followed at five hospitals between April 1, 2000 and December 31, 2013, were included. The relationship between urinary abnormality and various clinical parameters were retrospectively analyzed. Urinary abnormality was defined as proteinuria and/or hematuria detected by urinalysis. Development of other connective tissue diseases (CTDs) was defined as satisfaction of the criteria of each respective disease.

RESULTS

Of 41 patients (34 females, 7 males, mean age at diagnosis 42.2 ± 15.2 years), 16 developed urinary abnormality (UrA(+) patients). The total incidences of development of other CTDs were higher in the UrA(+) patients than UrA(-) (62.5% versus 16.0%, p = .01). In the comparison between UrA(+) and UrA(-) patients, there were no significant differences in follow-up duration or last determined estimated glomerular filtration rate (eGFR), although eGFR decreased more significantly in the UrA(+) patients than UrA(-). (-20.2 ± 17.2 vs -6.1 ± 13.8 ml/min/1.73m2, p = .01; -21.0 ± 18.9 vs -6.7 ± 14.1%, p = .03).

CONCLUSION

Urinary abnormality during the clinical course in MCTD is predictive of a higher incidence of developing other CTDs. Furthermore, it might also predict long-term renal prognosis in patients with an initial diagnosis of MCTD.

CCR2- and CCR5-mediated macrophage infiltration contributes to glomerular endocapillary hypercellularity in antibody-induced lupus nephritis

OBJECTIVES

Lupus nephritis comprises various glomerular lesions, including endocapillary hypercellularity with macrophage infiltration. In this study, we aimed to clarify the involvement of macrophage-tropic chemokine receptors in the pathogenesis of these glomerular lesions.

METHODS

MRL/lpr mouse-derived monoclonal IgG3 antibody-producing hybridomas, 2B11.3 and B1, were injected intraperitoneally into BALB/c mice (WT) to induce endocapillary hypercellularity and wire-loop lesions, respectively. The expression of chemokine and chemokine receptors was analyzed by quantitative real time PCR and immunofluorescence. The roles of chemokine receptors in these lesions were evaluated using chemokine receptor-deficient mice or a selective CCR5 antagonist, maraviroc.

RESULTS

2B11.3 caused glomerular endocapillary hypercellularity with a significant number of glomerular CD68-positive macrophages. Further, enhanced expression of CCL2, CCL3, CCR2, CCR5, and CX3CR1 was observed in the renal cortex, compared with B1 injection, which induced wire-loop lesions. In 2B11.3-induced glomerular lesions, CD68-positive glomerular macrophages expressed CCL2, CCL3, CCR2, CCR5, and CX3CR1, while glomerular endothelial cells expressed CCL2, CCL3, CX3CL1, and CCR2. When 2B11.3 was injected, CCR2-/- and CCR5-/-, but not CX3CR1-/-, mice exhibited reduced endocapillary hypercellularity, attenuated glomerular macrophage infiltration, and improved serum blood urea nitrogen (BUN) levels. Only CCR2-/- mice developed wire-loop lesions. B1 injection caused wire-loop lesions in these chemokine receptor-deficient mice to a similar extent as WT. Maraviroc treatment reduced 2B11.3-induced endocapillary hypercellularity and improved serum BUN levels.

CONCLUSION

CCR2 and CCR5 regulate glomerular macrophage infiltration and contribute to the development of glomerular endocapillary hypercellularity in lupus nephritis. CCR5 inhibition can be a specific therapy for endocapillary hypercellularity without inducing wire-loop lesions.

Positive disease-specific autoantibodies have limited clinical significance in diagnosing IgG4-related disease in daily clinical practice

OBJECTIVES

The 2019 ACR/EULAR classification criteria for IgG4-related disease (IgG4-RD) have exclusion criteria including positive disease-specific autoantibodies, and these have been documented to have a high specificity. This study aimed to further validate these criteria as well as identify characteristics of patients showing false-negative results.

METHODS

We retrospectively analysed 162 IgG4-RD patients and 130 mimickers. The sensitivity, specificity and fulfilment rates for each criterion were calculated, and intergroup comparisons were performed to characterize the false-negative cases.

RESULTS

Both the IgG4-RD patients and mimickers were aged ≥65 years with male predominance. The final diagnoses of mimickers were mainly malignancy, vasculitis, sarcoidosis and aneurysm. The classification criteria had a sensitivity of 72.8% and specificity of 100%. Of the 44 false-negative cases, one did not fulfil the entry criteria, 20 fulfilled one exclusion criterion and 27 did not achieve sufficient inclusion criteria scores. The false-negative cases had fewer affected organs, lower serum IgG4 levels, and were less likely to have received biopsies than the true-positive cases. Notably, positive disease-specific autoantibodies were the most common exclusion criterion fulfilled in 18 patients, only two of whom were diagnosed with a specific autoimmune disease complicated by IgG4-RD. In addition, compared with the true-positive cases, the 18 had comparable serum IgG4 levels, number of affected organs, and histopathology and immunostaining scores despite higher serum IgG and CRP levels.

CONCLUSIONS

The ACR/EULAR classification criteria for IgG4-RD have an excellent diagnostic specificity in daily clinical practice. Positive disease-specific autoantibodies may have limited clinical significance for the diagnosis of IgG4-RD.

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

Factors contributing to discrepant estimated glomerular filtration values measured by creatinine and cystatin C in patients with rheumatoid arthritis

This study aimed to clarify the factors underlying the discrepancy that has been noted between estimated glomerular filtration ratio (eGFR) measured using serum creatinine (Cr) and eGFR using serum cystatin C (CysC) in patients with rheumatoid arthritis (RA) and to identify those patients whose renal function should be evaluated using CysC. We retrospectively evaluated clinical features, disease activity, Steinbrocker radiological staging, and co-morbidities (diabetes mellitus, hypertension, dyslipidemia) in 238 RA patients. eGFR using serum creatinine (eGFR-Cr) and eGFR using serum cystatin C (eGFR-CysC) were calculated using the new Japanese coefficient-modified Modification of Diet in Renal Disease study equation. To clarify the cause(s) of differences of 20% or more between the two eGFRs, we divided our RA patients into Group A (eGFR-Cr/eGFR-CysC ≥ 1.2) and Group B (eGFR-Cr/eGFR-CysC < 1.2), and searched for factors independently related to Group A. Forty-five patients (18.9%) were assigned to Group A, and 193 (81.1%) to Group B. BMI (Odds Ratio [OR] 0.820, 95% confidence interval [CI] 0.675–0.996), Hb (OR 0.633, 95% CI 0.433–0.926), CK (OR 0.773 per 10 units, 95% CI 0.644–0.933), NSAID use (OR 0.099, 95% CI 0.020–0.494), diabetes mellitus (OR 6.024, 95% CI 1.508–24.390) and stage 4 Steinbrocker radiological stage (OR 10.309, 95% CI 2.994–35.714) were identified as independent relevant factors for Group A by a multifactorial analysis. Renal function in RA patients with low BMI, diabetes, anemia and low CK may be overestimated using eGFR-Cr alone, and such patients need to be evaluated using eGFR-CysC.

Antiphospholipid antibody syndrome-associated renal thrombotic microangiopathy improved not with rivaroxaban but with warfarin in a systemic lupus erythematosus patient without lupus nephritis

A 34-year-old Japanese woman with systemic lupus erythematosus (SLE) was admitted to our hospital for exacerbation of renal dysfunction, hemolytic anemia and thrombocytopenia. Twenty-two years before admission, she was diagnosed with SLE. Eight years before, lupus anticoagulant (LAC) positivity was detected without any thrombotic findings. Fourteen months before, renal function started to worsen. Three months before, unprovoked left leg swelling appeared. She was diagnosed with deep vein thrombosis (DVT) by ultrasonography. Blood examination revealed mild anemia, thrombocytopenia, and renal dysfunction. Rivaroxaban was started after which the left leg swelling subsided. When she was referred to our hospital, LAC was positive, but hypocomplementemia nor elevation of serum anti-double-stranded DNA antibodies was detected. Renal biopsy showed acute and chronic thrombotic microangiopathy (TMA) without concurrent lupus nephritis. Brain magnetic resonance imaging showed new small multiple cerebral infarcts. Antiphospholipid antibody syndrome (APS), causing renal TMA, new cerebral infarction, and DVT was diagnosed. Rivaroxaban was changed to warfarin. Two months after admission, renal impairment improved, and the complete disappearance of DVT and brain infarcts was confirmed. This case suggests that warfarin may be more effective than direct oral anticoagulants in the treatment of APS-associated renal TMA.

Tertiary lymphoid tissue in early-stage IgG4-related tubulointerstitial nephritis incidentally detected with a tumor lesion of the ureteropelvic junction: a case report

Background

IgG4-related kidney disease causes renal impairment of unknown pathogenesis that may progress to kidney failure. Although ectopic germinal centers contribute to the pathogenesis of the head and neck lesions of IgG4-related disease, the presence of tertiary lymphoid tissue (TLT) containing germinal centers in IgG4-RKD has rarely been reported.

Case presentation

We report a 72-year-old Japanese man who had IgG4-related tubulointerstitial nephritis (TIN) with TLT formation incidentally detected in a resected kidney with mass lesion of IgG4-related ureteritis in the ureteropelvic junction. During follow-up for past surgical resection of a bladder tumor, renal dysfunction developed and a ureter mass was found in the right ureteropelvic junction, which was treated by nephroureterectomy after chemotherapy. Pathology revealed no malignancy but abundant IgG4-positive cell infiltration, obliterative phlebitis and storiform fibrosis, confirming the diagnosis of IgG4-related ureteritis. In the resected right kidney, lymphoplasmacytes infiltrated the interstitium with focal distribution in the renal subcapsule and around medium vessels without storiform fibrosis, suggesting the very early stage of IgG4-TIN. Lymphocyte aggregates were also detected at these sites and consisted of B, T, and follicular dendritic cells, indicating TLT formation. IgG4-positive cells infiltrated around TLTs.

Conclusions

Our case suggests that TLT formation is related with the development of IgG4-TIN and our analysis of distribution of TLT have possibility to elucidate IgG4-TIN pathophysiology.

Contribution of HLA-DRB1 * 09: 01 allele to development of minocycline induced antineutrophil cytoplasmic antibody (ANCA)-associated cutaneous vasculitis: report of two cases

We report two cases of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) that developed after long-term oral administration of minocycline and consider the contribution of human leukocyte antigen (HLA)-DRB 1 * 09: 01 allele to its development. Case 1; A 47-year-old man receiving minocycline for palmoplantar pustulosis for 24 months developed fever, arthralgia, and irregular livedo on the bilateral lower legs. Skin biopsy demonstrated vasculitis, while a blood test showed positivity of myeloperoxidase (MPO)-ANCA. Discontinuation of minocycline and oral administration of prednisolone relieved the symptoms promptly. Case 2; A 53-year-old woman developed reddish-brown livedo reticularis with tenderness on the bilateral lower legs after administration of minocycline to treat palmoplantar pustulosis for 24 months. Although skin biopsy did not demonstrate vasculitis, a blood test showed MPO-ANCA positivity. Cessation of minocycline resulted in rapid improvement of the cutaneous lesions and constitutional symptoms. We diagnosed both cases as having Drug-associated ANCA-associated Vasculitis (DAV) caused by minocycline according to the diagnostic criteria proposed by Cluver et al. Further examination revealed the presence of HLA-DRB1 * 09:01 allele in both cases. This allele has been implicated in the genetic background of idiopathic microscopic polyangiitis (MPA) in the Japanese population. Our finding suggests a relationship between the development of MPO-ANCA or DAV caused by minocycline and HLA-DRB1 * 09:01 allele, but will have to confirmed by further studies with larger numbers of patients.

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

Fulminant myocarditis and pulmonary cavity lesion induced by disseminated mucormycosis in a chronic hemodialysis patient: Report of an autopsied case

Mucormycosis is a rare fungal infection occurring in the immunocompromised host. It is difficult to diagnose, and its cardiac involvement is extremely rare. Here, we report a 64-year-old Japanese man with a 5-year history of hemodialysis with disseminated mucormycosis causing fulminant myocarditis and pulmonary necrosis under glucocorticoid use. Two months before, he had received an implantable cardioverter defibrillator and started to take amiodarone for recurrent ventricular arrhythmias due to hypertensive cardiomyopathy. He developed amiodarone-induced interstitial pneumonia and then received glucocorticoid therapy. Although the interstitial pneumonia partially improved, a lung cavitary lesion developed in the upper right lobe. Antibiotics had no effect, and serologic tests, blood and sputum cultures and bronchoalveolar lavage fluid were all negative for infectious pathogens. Eventually, he died of fulminant myocarditis. Autopsy revealed disseminated mucormycosis with vascular invasion and fungal thrombi, hemorrhage and infarction in lung (cavity lesion), heart (severe myocarditis), brain, thyroid and subcutaneous tissue around the implantable cardioverter defibrillator. The lung cavitary lesion was the only clinical finding suggestive of mucormycosis before autopsy. When an immunocompromised patient shows a progressive lung cavity lesion, the possibility of mucormycosis should be considered so that a broad-spectrum antifungal agent can be empirically administered in a timely fashion.

Elderly-onset Still's Disease Complicated by Macrophage Activation Syndrome: A Case Report and Review of the Literature

Adult-onset Still's disease (AOSD) usually affects young adults. Some cases of elderly-onset Still's disease (EOSD) have been reported, but its clinical features are unclear. We herein report a 74-year-old woman who developed AOSD with macrophage activation syndrome (MAS). We also reviewed 24 previous EOSD cases in patients over 70 years old and compared the findings with overall AOSD. While the clinical features were similar between the two, including the presence of MAS, disseminated intravascular coagulation was more frequent in EOSD than in AOSD. Furthermore, despite a similar frequency of glucocorticoid use, immunosuppressants and biologics were less frequently administered in EOSD than in AOSD. This report highlights the fact that typical AOSD can develop in elderly patients with some characteristic features.

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.

A Long-term Survival after Surgical Treatment for Atypical Aortic Coarctation Complicating Takayasu Arteritis with Inactive Disease at the Diagnosis: An Appropriately Treated Autopsy Case

The number of Takayasu arteritis (TAK) cases being diagnosed at an advanced age has increased, including some who develop ischemic lesions without inflammation of the involved arteries long after the onset of TAK. However, few histopathological analyses of such patients without immunosuppressive therapy have been reported. We herein report a 92-year-old woman with atypical aortic coarctation complicating TAK who underwent bypass graft surgery and survived for 23 years without immunosuppressive therapy. Microscopic findings at the autopsy revealed clear differences between the affected and unaffected arteries. This case suggests that inflammation severe enough to destroy the structure of the aorta may not inherently be sufficient to promote systemic atherosclerosis.

A case report of crystalline light chain inclusion-associated kidney disease affecting podocytes but without Fanconi syndrome: A clonal analysis of pathological monoclonal light chain

RATIONALE

Crystalline light chain inclusion-associated kidney disease affects mainly tubular epithelial cells and is often clinically manifested as Fanconi syndrome. However, only very few case reports about the crystalline deposits within the podocytes are available, and the nature of the pathogenic monoclonal light chain implicated in these cases is still unknown. We report a case of crystalline inclusion-associated kidney disease manifested as crystalline podocytopathy in which we identified the complete structure of the pathogenic monoclonal light chain as belonging to the germ-line gene of Vκ1-39.

PATIENT CONCERNS

We describe a 65-year-old woman with crystalline light chain inclusion-associated kidney disease showing mild proteinuria and renal insufficiency with monoclonal gammopathy of undetermined significance without Fanconi syndrome. She had crystalline inclusions mainly within podocytes, tubular epithelial cells and histiocytes in the kidney. Light microscopy showed vacuolation of podocytes and tubular epithelial cells, while eosin negative pale needle-like crystals were present within these cells. Electron microscopy showed accumulation of club-like crystals with high electron density in podocytes, proximal tubular epithelial cells and interstitial histiocytes. Clonal analysis revealed that a pathogenic monoclonal light chain was derived from germline gene, Vκ1-39.

DIAGNOSES

The diagnosis of crystalline light chain inclusion-associated kidney disease was made.

INTERVENTIONS AND OUTCOMES

Bortezomib and dexamethasone were started and her renal function improved to eGFR 36 mL/min/1.73 m after 9 courses of therapy.

LESSONS

Patients with light chain crystalline podocytopathy may have a similar pathogenic monoclonal light chain derived from the same germline gene, Vκ1-39, to that of patients with light chain proximal tubulopathy.