Increased risk of cardiovascular disease preceding diagnosis of incident ANCA-associated vasculitis: a Danish nationwide study

OBJECTIVE

To examine whether patients with ANCA-associated vasculitis (AAV) have an increased risk of cardiovascular disease in the months prior to diagnosis of AAV.

METHODS

Using a nested case-control framework, patients with granulomatosis with polyangiitis and microscopic polyangiitis were identified through the Danish Nationwide Registries from 1996 to 2021 and matched 1:3 with age- and sex-matched controls without AAV. Each control was assigned the same index date (date of AAV diagnosis) as their corresponding case. Conditional logistic regression was used to compute adjusted hazard ratios (HRs) for major adverse cardiovascular events (MACE), ischaemic heart disease, coronary angiogram, heart failure, venous thromboembolism, atrial fibrillation, ischaemic stroke, pericarditis and ventricular arrhythmias/implantable cardioverter defibrillator implantation/cardiac arrest (VA/ICD/CA) within 12 months, 6 months, 3 months, 2 months and 1 month before index date.

RESULTS

A total of 2371 patients with AAV (median age 63 years, 53.7% male) were matched with 7113 controls. The prevalence of any cardiovascular outcome and MACE within 12 months preceding index date were 10.3% and 2.4% for AAV, compared with 3.8% [HR 3.05 (95% CI 2.48-3.75)] and 1.3% [HR 1.98 (95% CI 1.39-2.82)] of controls. The risk of cardiovascular outcomes was similarly increased in temporal proximity to the diagnosis, with the highest HR at 1 month prior to index date: any cardiovascular outcome [HR 10.73 (95% CI 7.05-16.32)] and MACE [HR 5.78 (95% CI 2.67-12.52)]. In individual analysis, a significantly higher rate was observed for all outcomes (excluding VA/ICD/CA).

CONCLUSIONS

AAV disease is associated with an increased risk of cardiovascular disease in the months preceding diagnosis, which underlines the importance of early clinical vigilance towards cardiovascular disease.

Age- and time-dependent increases in incident anti-glomerular basement membrane disease: a nationwide cohort study

Background

Epidemiologic assessments of anti-glomerular basement membrane (GBM) disease have been challenging due to its rare occurrence. We examined changes in the incidence and outcomes from 1998 to 2018 using nationwide healthcare registries.

Methods

All patients with incident anti-GBM disease were identified using the International Classification of Diseases, 10th Revision code DM31.0A. Controls were matched 4:1 on birthyear and sex using exposure density sampling. Log link regression adjusted for time, age and sex was applied to model survival.

Results

We identified 97 patients with incident anti-GBM disease, corresponding to an incidence of 0.91 cases/million/year [standard deviation (SD) 0.6]. The incidence increased over time [1998-2004: 0.50 (SD 0.2), 2005-2011: 0.80 (SD 0.4), 2012-2018: 1.4 (SD 0.5); P = .02] and with age [0.76 (SD 0.4), 1.5 (SD 1.04) and 4.9 (SD 2.6) for patients <45, 45-75 and >75 years]. The median age was 56 years (interquartile range 46) and 51.6% were female. Dialysis was required in 58.4%, 61.9% and 62.9% of patients at day 30, 180 and 360, respectively. The 1-year kidney survival probability was 0.38 (SD 0.05) and exhibited time-dependent changes [1998-2004: 0.47 (SD 0.13), 2005-2011: 0.16 (SD 0.07), 2012-2018: 0.46 (SD 0.07); P = .035]. The 5-year mortality was 26.8% and mortality remained stable over time (P = .228). The risk of death was greater than that of the matched background population {absolute risk ratio [ARR] 5.27 [confidence interval (CI) 2.45-11.3], P < .001}, however, it was comparable to that of patients with anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) requiring renal dialysis at presentation [ARR 0.82 (CI 0.48-1.41), P = .50].

Conclusion

The incidence of anti-GBM disease increased over time, possibly related to temporal demographic changes. Mortality remained high and was comparable with an age- and sex-matched cohort of dialysis-dependent AAV patients.

Long-term cardiovascular outcomes and temporal trends in patients diagnosed with ANCA-associated vasculitis: a Danish nationwide registry study

OBJECTIVES

To examine long-term cardiovascular outcomes and temporal trends among patients with ANCA-associated vasculitis (AAV) using Danish nationwide registries.

METHODS

Using a cohort design, we examined patients with granulomatosis with polyangiitis (ICD-10: DM31.3) and microscopic polyangiitis (ICD-10: DM3.17) in Denmark from 1996-2018. Hazard ratios (HRs) of cardiovascular outcomes were compared between patients with AAV and age and gender-matched controls. Counterfactual G-estimation of HRs was performed to estimate 5-year absolute risks. Temporal trends were obtained by grouping cohorts into evenly distributed tertiles according to inclusion year.

RESULTS

A total of 2306 patients with AAV (median age: 62.9yrs, 52.6% male) were matched with 6918 controls. Median follow-up was 9.5yrs. Patients with AAV had a higher rate of ischaemic heart disease [HR 1.86 (1.62-2.15)], myocardial infarction [HR 1.62 (1.26-2.09)], coronary angiogram [HR 1.64 (1.37-1.96)], percutaneous coronary intervention [HR 1.56 (1.17-2.07)] and ventricular arrhythmias/implantable-cardioverter-defibrillator (ICD)-implantations [HR 2.04 (1.16-3.57)]. Similarly, an increased rate of heart failure [HR 2.12 (1.77-2.54)], deep vein thrombosis [HR 3.13 (2.43-4.05)], pulmonary embolism [HR 4.04 (3.07-5.32)], atrial fibrillation [HR 2.08 (1.82-2.39)], ischaemic stroke [HR 1.58 (1.31-1.90)] and in-hospital cardiac arrest [HR 2.27 (1.49-3.48)] was observed. The 5-year risk of all outcomes were significantly higher (excluding ventricular arrhythmia/ICD-implantations). For temporal trends among patients with AAV, a decreased 3-year risk of cardiovascular mortality was observed over time.

CONCLUSIONS

Patients with AAV are at increased risk of heart failure, atrial-/ventricular arrhythmias, venous thrombotic events, ischaemic stroke and myocardial infarction. Furthermore, patients with AAV were more frequently examined with coronary procedures and underwent more coronary revascularizations. No temporal changes in ischaemic cardiovascular outcomes were observed, albeit the cardiovascular mortality has decreased over time.

Validation of the Modified Fatigue Impact Scale in patients with systemic lupus erythematosus

INTRODUCTION

Patients with systemic lupus erythematosus (SLE) experience significant fatigue, a debilitating symptom associated with reduced quality of life. There has not yet been agreed on a simple and reliable method for assessing fatigue in SLE.

OBJECTIVES

To investigate the internal consistency, test-retest reliability and construct validity (convergent and discriminant validity) of the Modified Fatigue Impact Scale (MFIS) in patients with SLE. The secondary objective was to investigate the contribution of disease activity and organ damage to fatigue.

METHODS

Fatigue was assessed using the MFIS in 61 patients with SLE. Internal consistency of MFIS was assessed with Cronbach's alpha (α) and Principal Component Analysis. Test-retest reliability was evaluated using the intraclass correlation coefficient (ICC). Construct validity was studied using Spearman's rank correlation (r_s). Associations between MFIS and disease activity and organ damage were estimated with r_s.

RESULTS

Internal consistency of the MFIS was excellent with Cronbach's α = 0.97 (95% confidence interval (CI): 0.96-0.98) for the complete scale. Test-retest reliability was good with ICC = 0.89 (95% CI: 0.78-0.95, p < 0.001). Construct validity was confirmed by Spearman's correlation (VT-SF36: r_s = -0.73, p < 0.001. MH-SF36: r_s = 0.70, p < 0.001). No significant correlation was found between the MFIS and SLEDAI (r_s = 0.03, p = 0.83). There was a moderate correlation between MFIS and SLICC Damage Index (r_s = 0.43, p < 0.001).

CONCLUSION

The present study found the MFIS to be a reliable and valid instrument for assessing fatigue in SLE. Further investigations are needed to clarify if an association between measured fatigue and disease components exists.

FC059: Cardiovascular Outcomes in Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis in Denmark 1996–2018

BACKGROUND AND AIMS

Antineutrophil cytoplasmic antibody associated vasculitis (AAV) is a group of autoimmune systemic inflammatory diseases, with cardiovascular disease being the leading cause of death. However, large-scale real-world data on the risk of long-term cardiovascular outcomes associated with AAV are limited. Therefore, to understand, screen and optimize prevention of cardiovascular disease in AAV patients, we investigated the risk of long-term ischemic cardiovascular events, including ischemic heart disease, coronary angiogram (CAG), percutaneous coronary intervention (PCI) and ventricular arrhythmia/use of implantable cardioverter-defibrillator (ICD) devices. Secondary outcomes included heart failure (HF), atrial fibrillation (AF), stroke, venous thrombotic events and cardiac arrest.

METHOD

We included all incident patients with AAV diagnosed during 1996–2018. Patients were identified from the Danish nationwide healthcare registries by use of a recently validated method (positive predictive value of 97%) [1] comprising at least two consecutive hospital encounters registered as either polyangiitis with granulomatosis or microscopic polyangiitis (International Classification of Diseases, 10th Edition [ICD-10]: DM31.3 and DM31.7). Patients with AAV were matched 1:3 with controls from the general population on age and gender. We computed adjusted hazard ratios (HRs) with 95% confidence intervals (95% CIs) for each cardiovascular outcome, with all-cause mortality accounted for as a competing risk. G-computation of HRs was performed to estimate 5-year absolute risks standardized to the distribution of risk factors in the population.

RESULTS

A total of 2306 AAV patients [median age: 62.9 years (25th–75th percentile: 50.9–72.0 years), 52.6% male gender] were matched with 6918 controls. Median study follow-up was 9.5 years (25th–75th percentile: 5.3–15.8 years). Compared with controls, AAV patients had a higher rate of ischemic heart disease [HR 1.67 (95% CI 1.45–1.95)], myocardial infarction [HR 1.43 (95% CI 1.11–1.83)], CAG [HR 1.51 (95% CI 1.27–1.80)], PCI [HR 1.42 (95% CI 1.11–1.88)] and ventricular arrhythmia/ICD implantation [HR 2.03 (95% CI 1.17–3.55)]. Secondarily, AAV patients also had an increased rate of additional adverse cardiovascular events: HF [HR 1.77 (95% CI 1.48–2.11)], deep vein thrombosis [HR 2.89 (95% CI 2.24–3.72)], pulmonary embolism [HR 3.59 (95% CI 2.74–4.72)], AF [HR 1.73 (95% CI 1.51–1.98)], ischemic stroke [HR 1.34 (95% CI 1.12–1.61)] and in-hospital cardiac arrest [HR 1.97 (95% CI 1.29–2.99)]. AAV patients had a significantly increased standardized 5-year absolute risk of all outcomes except for MI, PCI and ventricular arrhythmia/ICD implantations compared with controls.

CONCLUSION

In this large nationwide registry-based follow-up study, AAV patients had a higher risk of ischemic cardiovascular events and were more likely to require revascularization therapy compared with matched control subjects. Moreover, AAV patients had a higher risk of HF, atrial- and ventricular arrhythmias as well as venous thrombotic events and ischemic stroke when compared with matched control subjects.

MO269INCREASED RISK OF DEATH IN PATIENTS WITH DOUBLE POSITIVE SEROLOGY OF ANTI-GLOMERULAR BASE MEMBRANE (ANTI-GBM) ANTIBODIES AND ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODIES (ANCA)

Background and Aims

Double positivity of anti-GBM and ANCA serology is uncommon but may represent a distinct disease entity of small vessel vasculitis. Previous research has been challenged by low disease incidence, and conflicting results pertaining to risk of death and ESRD. Accordingly, we examined incidence and outcomes based on data from multiple Danish nationwide healthcare registries.

Method

All patients with incident positive anti-GBM serology between 2013 and 2018 were identified from 3 of 4 administrative regions in Denmark. Serological positivity was defined as serum concentrations exceeding the upper reference level. Double positivity was defined by either presence of PR3-ANCA or MPO-ANCA within a margin of 30 days from inclusion. Baseline information and clinical diagnoses defined by administrative diagnoses were subsequently ascertained by cross-referencing of data from the Danish nationwide administrative registries. Risks of death or ESRD were compared based on adjusted absolute risk ratios (ARR) and cumulative incidences assessed based on the Aalen-Johansen estimator.

Results

A total of 118 patients with positive anti-GBM serology (4.4 cases/million/year) were identified. Concomitant ANCA serology was tested in 104 (88.1%), with 39 patients (37.5%) demonstrating double positivity (20 and 13 patients positive for PR3-ANCA (51.3%) and MPO-ANCA (33.3%), respectively, and 6 patients positive for all autoantibodies (5.8%)). Mean follow-up for the total study population was 1.9 (SD ±1.6) years. Compared with patients positive for anti-GBM alone, double positivity was associated with female gender (61.5%, P=0.02), and more frequent employment of plasma exchange (53.8%, P=0.04). No difference was observed with regard to age (63.2 years [SD 18.5], P=0.60), and mean anti-GBM concentration (125.5 [SD 182.4] IU/L vs. 108.9 [SD 212.7] IU/L, P=0.30). One-year mortality was 17.7% (n=14) in patients positive for anti-GBM alone, and 28.2% (n=11) in patients positive for both anti-GBM and ANCA. Double positive serology was associated with increased risk of death (ARR 2.10 [CI 1.20-3.65], P=0.009) (figure); however, there was no difference in risk of ESRD (ARR 1.28 [0.66-2.50], P=0.46).

Of all identified patients, only 32 (27%) were diagnosed with anti-GBM disease according to ICD10 code (1.2 cases/million/year). In patients with confirmatory serology and ICD-10 code, 13 (40%) had double positive serology (46.2% PR3-ANCA and 53.8% MPO-ANCA). In the subset of patients with confirmatory ICD-10 code, double positivity was associated with male gender (63.2%, P=0.07), numerical lower mean age (56.1 [SD 25.2], P=0.50), and increased mean anti-GBM concentration (333.3 [SD 278.7] vs 150.7 [SD 146.5] P= 0.026). There was no difference in risk of death or ESRD between the two groups.

Conclusion

Double positivity of anti-GBM and ANCA serology plausibly defines a distinct group of patients and is associated with a higher risk of death. While the association between an ICD10-confirmed diagnosis of anti-GBM disease and anti-GBM serology is well established, the significance of serology alone remains uncertain.

Increasing incidence and improved survival in ANCA-associated vasculitis-a Danish nationwide study

BACKGROUND

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) carries a high risk of morbidity and mortality, with outcomes modified by treatment and an incidence that may be increasing. We examined temporal changes in incidence and mortality during 2000-15 using nationwide healthcare registries.

METHODS

Patients with incident AAV were identified using International Classification of Diseases Version 10 (ICD10) codes and grouped according to inclusion year (Period 1: 2000-04, Period 2: 2005-09, Period 3: 2010-15). Log link cumulative incidence regression adjusted for age, sex, renal function, cardiovascular disease, diabetes, hypertension and advanced disease severity were used to model survival.

RESULTS

We identified 1631 patients (52% male), corresponding to an incidence of 18.5 persons/million/year (Period 1: 15.1, Period 2: 18.5, Period 3: 21.4). The slope of incident serologic ANCA testing was steeper than that of AAV (P = 0.002). Mean [standard deviation (SD)] age was 60.2 (16.7) years and mean (SD) follow-up was 6.8 (4.7) years. A total of 571 (35%) patients died (5-year mortality of 22.1%), with an absolute risk ratio (ARR) for Periods 2 and 3 compared with Period 1 of 0.80 [confidence interval (CI) 0.65-0.98, P = 0.031] and 0.39 (CI 0.31-0.50, P < 0.001). About 274 patients developed end-stage renal disease (ESRD) [16.8% (Period 1: 23.3%, Period 2: 17.6%, Period 3: 12.5%)], with ARR decreasing over time: Period 2 0.61 (CI 0.42-0.87, P = 0.007) and Period 3 0.57 (CI 0.39-0.83, P = 0.003). The overall risk of death associated with ESRD or chronic kidney disease was 1.74 (CI 1.29-2.37, P < 0.001) and 1.58 (CI 1.21-2.07, P < 0.001).

CONCLUSIONS

Incidence of ANCA testing and AAV diagnosis increased over the test period. Falls over time in mortality and ESRD risk may relate to earlier diagnosis and changes in treatment practice.

P0397OUTCOMES OF PROTEINASE 3- AND MYELOPEROXIDASE ANTI-NEUTROPHIL CYTOPLASMIC ANTIBODY ASSOCIATED VASCULITIS IN DENMARK 2014-2017

Background and Aims

Anti-neutrophil cytoplasmic antibody associated vasculitis (AAV) defines an uncommon group of autoimmune diseases with antibodies directed against proteinase 3 (PR3) or myeloperoxidase (MPO). Incidence rates of PR3- and MPO-AAV differ geographically, and current evidence based on genetic variations and cluster analyses supports discrimination of associated vasculitis based on PR3- and MPO-positivity. Such discrimination could provide insights of scope for clinical trials with ramifications for improvement of treatment. With the aim of comparing patient characteristics and outcomes between PR3- and MPO-AAV, we report on results from a nationwide retrospective cohort study.

Method

Incident patients positive for PR3- and MPO-anti-neutrophil cytoplasmic antibodies were identified in central laboratories of three of four administrative regions (covering 80% of the population) in Denmark between 1/1-2014 and 31/12-2017. Patient characteristics were identified by cross-referencing of data from multiple national health care registers. Baseline renal function was calculated based on the CKD-EPI equation using plasma creatinine measurements recorded 365 to 7 days prior to index. Incidences of all-cause mortality and end-stage renal disease stratified on baseline eGFR were computed using the Aalen-Johansen estimator. Hazard ratios for specific predictors including strata of baseline eGFR were calculated based on a multiple Cox proportional hazards model adjusted for relevant confounders.

Results

In total 770 patients were included in the study (PR3 n=399 and MPO n=371). Annual incidence rates of PR3- and MPO-AAV were 22.6 and 21.1 per million, respectively. PR3-AAV was associated with greater preponderance for male gender (54.4% vs. 42.3%, p=0.001), lower patient age (61.9 years [IQR 41.6-73.0 years] vs. 64.9 years [IQR 50.0-74.0 years], p=0.016), and greater baseline renal function (eGFR 87 ml/min [IQR 56-101 ml/min] vs. 75 ml/min [IQR 36-92 ml/min] compared with MPO-AAV. Comorbid burden was comparable; 26% of patients had history of hypertension, 15% of patients had a history of ischemic heart disease, and 12% of patients had a history of cancer.

Acute dialysis was initiated in 5.3% and 6.7%, plasmapheresis in 12.8% and 13.7%, and mechanical ventilation in 4.8% and 4.3% of patients with PR3- and MPO-AAV, respectively. Median follow-up was 564 days [234 – 932]. A total of 86 deaths and 25 end-stage renal disease endpoints were recorded during follow-up. Cumulative incidences of all-cause mortality and end-stage renal disease stratified on baseline eGFR are shown in Figure 1.

Adjusted hazard ratios for all-cause death and/or end-stage renal disease showed increased risk associated with PR3-AAV, HR 1.51 (95% CI 1.03 – 2.25, p=0.036), non-European descent, HR 3.63 (95% CI 1.29-10.25, p=0.015) and patient age, HR 1.05 (95% CI 1.03-1.07, p&lt;0.001). In both PR3- and MPO-AAV, only baseline eGFR ≤ 20ml/min/1.73m2 was associated with poorer prognosis (ref.: baseline eGFR &gt;90 ml/min/1.73m2); MPO-AAV: eGFR 51-90 ml/min/1.73m2: HR 2.34 (95% CI 0.75 – 7.34, p=0.145), eGFR 21-50 ml/min/1.73m2: HR 2.11 (95% CI 0.60 – 7.47, p=0.246), and eGFR ≤ 20ml/min/1.73m2: 5.05 (95% CI 1.55 – 16.45, p=0.007); PR3-AAV: eGFR 51-90 ml/min/1.73m2: HR 1.54 (95%CI 0.53 – 4.46, p=0.427), eGFR 21-50 ml/min/1.73m2: HR 1.70 (95% CI 0.51 – 5.64, p=0.386), and eGFR ≤ 20ml/min/1.73m2: 8.06 (95% CI 2.83 – 23.0, p=&lt;0.001).

Conclusion

In a nationwide cohort study comparing PR3- and MPO-AAV, PR3-AAV was associated with poorer 24-month outcomes in spite of superior renal function at baseline. Overall, poor prognosis was limited to patients with severe renal insufficiency (eGFR ≤20ml/min/1.73m2) at time of diagnosis in both PR3- and MPO-AAV.

Prophylactic anticoagulation in nephrotic syndrome prevents thromboembolic complications

Background

An increased incidence of thromboembolic events (TE) are reported in nephrotic syndrome (NS) leading to recommendations for prophylactic anticoagulation (PAC). However, as no randomized clinical trial has established the efficacy or risks associated with PAC, guidelines are empiric or substantiated only by estimates of risks and benefits.

This study evaluates the risk of TE and hemorrhagic complications in patients with NS treated with PAC and compares to patients not receiving PAC.

Methods

We included patients diagnosed with NS from two Danish nephrology departments with different practices for the use of PAC. Patients were included if presenting with NS from September 2006 to January 2012, a P-albumin < 30 g/L, and renal biopsy confirming non-diabetic, glomerular disease. Patients aged < 16 years, on renal replacement therapy, or administered anticoagulants at the onset of NS were excluded. Bleeding episodes and/or TE were identified from patient records. Bleeding episodes were divided into minor and major bleeding.

Results

Of the 79 patients included, 44 patients received PAC either as low or high dose low-molecular-weight heparin (LMWH) or as warfarin with or without LMWH as bridging, while 35 did not receive PAC. P-albumin was significant lower in the PAC group compared to those not receiving PAC. Significantly more TEs was observed in the non-PAC group compared to the PAC group (4 versus 0 episodes, P = 0.035). The TEs observed included one patient with pulmonary embolism (PE), one with PE and deep vein thrombosis, one with PE and renal vein thrombosis, and one with a stroke. Five patients with bleeding episodes were identified among those receiving PAC, of which two were major and three were minor, while two patients in the non-PAC group experienced a minor bleeding episode (P = 0.45 between groups). The major bleeding episodes only occurred in patients receiving PAC in combination with low dose aspirin.

Conclusions

In patients with NS the use of PAC was associated with a decreased risk of clinically significant TE, but may also be associated with more bleeding episodes although not statistically significant. Only patients treated with PAC in combination with anti-platelet therapy had major bleeding episodes.

PR3-ANCA-associated vasculitis is associated with a specific motif in the peptide-binding cleft of HLA-DP molecules

Objectives

This study aimed to characterize the association between HLA alleles and ANCA-associated vasculitis (AAV) in a genetically homogeneous population, and to analyse the contribution of specific HLA molecule amino acid sequences to the risk of AAV.

Methods

We included 187 Danish patients with AAV and 1070 healthy controls. All were HLA typed at two-field resolution. The association of HLA alleles to PR3- or MPO-AAV was analysed. The contribution of the dominant molecular motifs of the HLA-DPB1 molecule to the risk of AAV was investigated by association studies that included specific amino acid sequences of the hypervariable regions in exon 2.

Results

Ninety-four percent of patients with PR3-AAV were carriers of HLA-DPB1*04:01 while all patients with PR3-AAV were carriers of an HLA-DPB1*04 allele, and 85% were homozygous. This was significantly more than in the control group (P < 0.0001). The association was even stronger when HLA-DPB1*04:02 and -DPB1*23:01 were included. HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01 share amino acids in positions 8–9, 69, 76 and 84–87 within the hypervariable regions, but only positions 69 and 84–87 contributed significantly to the disease risk. HLA-DRB1*15 was associated with an increased risk of developing PR3-AAV, while HLA-DRB1*04, -DRB1*07 and -DQB1*03 were associated with a reduced risk of kidney involvement in PR3-AAV. MPO-AAV was only weakly associated with HLA class I alleles.

Conclusion

PR3-AAV is strongly associated with the HLA-DPB1 alleles HLA-DPB1*04:01, -DPB1*04:02 and -DPB1*23:01, which share amino acid sequences crucial for the peptide-binding groove.

Recovery of renal function succeeding stem cell transplant: a case of C3 Glomerulonephiritis secondary to monoclonal gammopathy

Membranoproliferative glomerulonephritis (MPGN) and C3 glomerulonephritis (C3 GN) can be secondary to monoclonal gammopathy and multiple myeloma. MPGN Type 1 is caused by activation of the classical pathway by immune complex formation, and C3 GN results from abnormalities in the alternative pathway of complement. In previously reported cases of MPGN and C3 GN secondary to monoclonal gammopathy/multiple myeloma, renal outcome has been poor. Here, we present the first patient, to our knowledge, who showed full renal recovery and normalization of the complement system after chemotherapy and stem cell transplantation.

Rituximab for ANCA-associated vasculitis in the setting of severe infection

OBJECTIVES

The combination of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitis (AAV) and severe infection presents a challenge because current therapies with high-dose glucocorticoids and cyclophosphamide (CYC) are immunosuppressive and increase the risk of infection. Thus, coincident infection delays and complicates the introduction of treatment. Rituximab (RTX) is an alternative to CYC in AAV and may be preferable in the setting of severe infection.

METHOD

From 2005 to July 2011, 100 patients with AAV were treated with RTX at our institution and those who received RTX instead of CYC because of concomitant infection were studied.

RESULTS

Eight patients were identified. The mean follow-up was 12 months (range 6-30 months). All patients achieved remission by 6 months that was sustained to the end of follow-up. There were no deaths or further severe infections.

CONCLUSIONS

RTX can be considered for patients with generalized AAV and concomitant severe infection.

[Immunoglobulin G4-related disease is a newly recognized inflammatory disease]

IgG4-related disease is a newly recognized inflammatory disease characterized by tissue infiltrates of IgG4 positive plasma cells. The disease was first recognized in pancreas but has now been described in nearly every organ. The diagnosis is based on the presence of dense lymphoplasmocytic infiltrates rich in IgG4 positive plasma cells. We describe a case of a 76-year-old man with IgG4-related disease involving the kidneys.

Humanized animal models for autoimmune diseases

The development of transgenic mice expressing human DR and DQ major histocompatibility complex (MHC) class II molecules has been of value in studying the immunopathology of human MHC class II-associated autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, insulin-dependent diabetes mellitus and celiac disease. Such mice have been used to identify the target antigens that are involved in the initiation of these diseases. Many of the mice develop aspects of the human diseases, either spontaneously or following immunization with the relevant antigen, thus providing an in vivo disease model, which may be used as a tool for further understanding the disease mechanisms and testing novel immunotherapies.

Acetaminophen-induced toxic epidermal necrolysis in a child

Toxic epidermal necrolysis (TEN) is a severe, life-threatening disorder that usually affects adults. It is often drug induced. We report an instance of a severe case of TEN in a 6-year-old boy, probably induced by acetaminophen, and less likely by codeine. A lymphocyte stimulation test could not identify the culprit drug. Treatment with intravenous immunoglobulin seemed to halt the disease progression.