Treatment of IgG4-related disease : Current and future approaches

IgG4-related disease (IgG4-RD) is capable of causing great morbidity and even mortality if the condition remains undiagnosed or poorly treated, yet is typically a treatment-responsive disorder. Glucocorticoids have not been studied rigorously and practices with regard to dosing and duration of treatment remain largely empiric. In addition, IgG4-RD patients are often particularly susceptible to and intolerant of the deleterious effects of glucocorticoid therapy. B cell depletion with anti-CD20 monoclonal antibodies appears to be a rapid, effective means of obtaining disease control and limiting patients' glucocorticoid exposure, but this option is frequently not available. Other therapies targeting the B cell lineage may also be efficacious, and one is under study. The means by which depletion or inhibition of B cells and their progeny ameliorate IgG4-RD is coming into focus now through careful mechanistic studies of samples from treated patients. The mechanistic understanding of IgG4-RD will bring an array of specific targets for therapeutic intervention. Plasmablast-directed therapy with a CD19 monoclonal antibody is currently in clinical trials. CD4 + cytotoxic T lymphocytes and fibrosis, both observed nearly universally in the tissue of IgG4-RD patients, present two unexploited vulnerabilities in controlling and even reversing the effects of the disease. Further development of such therapies is a major goal of the next few years.

IgG4-related disease

PURPOSE OF REVIEW

Remarkable insights have been gleaned recently with regard to the pathophysiology of IgG4-related disease (IgG4-RD). These findings have direct implications for the development of targeted strategies for the treatment of this condition.

RECENT FINDINGS

Oligoclonal expansions of cells of both the B and T lymphocyte lineages are present in the blood of patients with IgG4-RD. Oligoclonal expansions of plasmablasts are a good biomarker for disease activity. An oligoclonally expanded population of CD4+ cytotoxic T lymphocytes is found not only in the peripheral blood but also at tissue sites of active disease. This cell elaborates cytokines that may drive the fibrosis characteristic of IgG4-RD. T follicular helper cells (Tfhc), particularly the Tfhc2 subset, appear to play a major role in driving the class switch to IgG4 that typifies this disease. The relationship between malignancy and IgG4-RD remains an area of interest.

SUMMARY

Advances in understanding the pathophysiology of IgG4-RD have proceeded swiftly, leading to the identification of a number of potential targeted treatment strategies. The completion of classification criteria for IgG4-RD, an effort supported jointly by the American College of Rheumatology and the European League Against Rheumatism, will further facilitate studies on this disease.

Nationwide Trends in Hospitalizations and In-Hospital Mortality in Granulomatosis With Polyangiitis (Wegener's)

OBJECTIVE

Granulomatosis with polyangiitis (Wegener's) (GPA) is a type of antineutrophil cytoplasmic antibody-associated vasculitis that often entails severe end-organ damage and treatment-related complications that frequently lead to hospitalization and death. Nationwide trends in hospitalizations and in-hospital mortality over the past 2 decades are unknown and were evaluated in this study.

METHODS

Using the National Inpatient Sample, the largest all-payer inpatient database in the US, trends in hospitalizations with a discharge diagnosis of GPA (formerly Wegener's granulomatosis; International Classification of Disease, Ninth Revision, Clinical Modification code 446.4) between 1993 and 2011 were studied. Analyses were performed using hospital-level sampling weights to obtain US national estimates.

RESULTS

From 1993 to 2011, the annual hospitalization rate for patients with a principal diagnosis of GPA increased by 24%, from 5.1 to 6.3 per 1 million US persons (P < 0.0001 for trend); however, in-hospital deaths in this group declined by 73%, from 9.1% to 2.5% (P < 0.0001 for trend), resulting in a 66% net reduction in the annual in-hospital mortality rate. The median length of stay declined by 20%, from 6.9 days in 1993 to 5.5 days in 2011 (P = 0.0002 for trend). Infection was the most common principal discharge diagnosis when GPA was a secondary diagnosis, including among those who died during hospitalization.

CONCLUSION

The findings from these nationally representative, contemporary inpatient data indicate that the in-hospital mortality of GPA has declined substantially over the past 2 decades, while the overall hospitalization rate for GPA increased slightly. Infection remains a common principal hospitalization diagnosis among GPA patients, including hospitalizations resulting in mortality.

Identification of Functional and Expression Polymorphisms Associated With Risk for Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis

Objective

To identify risk alleles relevant to the causal and biologic mechanisms of antineutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV).

Methods

A genome‐wide association study and subsequent replication study were conducted in a total cohort of 1,986 cases of AAV (patients with granulomatosis with polyangiitis [Wegener's] [GPA] or microscopic polyangiitis [MPA]) and 4,723 healthy controls. Meta‐analysis of these data sets and functional annotation of identified risk loci were performed, and candidate disease variants with unknown functional effects were investigated for their impact on gene expression and/or protein function.

Results

Among the genome‐wide significant associations identified, the largest effect on risk of AAV came from the single‐nucleotide polymorphism variants rs141530233 and rs1042169 at the HLA–DPB1 locus (odds ratio [OR] 2.99 and OR 2.82, respectively) which, together with a third variant, rs386699872, constitute a triallelic risk haplotype associated with reduced expression of the HLA–DPB1 gene and HLA–DP protein in B cells and monocytes and with increased frequency of complementary proteinase 3 (PR3)–reactive T cells relative to that in carriers of the protective haplotype. Significant associations were also observed at the SERPINA1 and PTPN22 loci, the peak signals arising from functionally relevant missense variants, and at PRTN3, in which the top‐scoring variant correlated with increased PRTN3 expression in neutrophils. Effects of individual loci on AAV risk differed between patients with GPA and those with MPA or between patients with PR3‐ANCAs and those with myeloperoxidase‐ANCAs, but the collective population attributable fraction for these variants was substantive, at 77%.

Conclusion

This study reveals the association of susceptibility to GPA and MPA with functional gene variants that explain much of the genetic etiology of AAV, could influence and possibly be predictors of the clinical presentation, and appear to alter immune cell proteins and responses likely to be key factors in the pathogenesis of AAV.

Development of a Glucocorticoid Toxicity Index (GTI) using multicriteria decision analysis

OBJECTIVES

To develop a Glucocorticoid Toxicity Index (GTI) to assess glucocorticoid (GC)-related morbidity and GC-sparing ability of other therapies.

METHODS

Nineteen experts on GC use and outcome measures from 11 subspecialties participated. Ten experts were from the USA; nine from Canada, Europe or Australia. Group consensus methods and multicriteria decision analysis (MCDA) were used. A Composite GTI and Specific List comprise the overall GTI. The Composite GTI reflects toxicity likely to change during a clinical trial. The Composite GTI toxicities occur commonly, vary with GC exposure, and are weighted and scored. Relative weights for items in the Composite GTI were derived by group consensus and MCDA. The Specific List is designed to capture GC toxicity not included in the Composite GTI. The Composite GTI was evaluated by application to paper cases by the investigators and an external group of 17 subspecialists.

RESULTS

Thirty-one toxicity items were included in the Composite GTI and 23 in the Specific List. Composite GTI evaluation showed high inter-rater agreement (investigators κ 0.88, external raters κ 0.90). To assess the degree to which the Composite GTI corresponds to expert clinical judgement, participants ranked 15 cases by clinical judgement in order of highest to lowest GC toxicity. Expert rankings were then compared with case ranking by the Composite GTI, yielding excellent agreement (investigators weighted κ 0.87, external raters weighted κ 0.77).

CONCLUSIONS

We describe the development and initial evaluation of a comprehensive instrument for the assessment of GC toxicity.

Immunoglobulin (Ig)M antibodies to proteinase 3 in granulomatosis with polyangiitis and microscopic polyangiitis

Anti-neutrophil cytoplasmic antibodies (ANCA) appear to play an important role in the pathogenesis of ANCA-associated vasculitis (AAV). However, ANCA alone are not sufficient to generate disease, and some evidence suggests that infectious triggers may serve as inciting events for AAV disease activity. Antibodies of the immunoglobulin (Ig)M isotype often serve as markers of recent infection, and IgM ANCA have been identified previously in patients with AAV, although the frequency and clinical relevance of IgM ANCA is not well established. We sought to characterize IgM ANCA more clearly by creating a novel enzyme-linked immunosorbent assay (ELISA) for IgM antibodies to proteinase 3 [IgM proteinase 3 (PR3)-ANCA], which we applied to two large, clinically well-characterized trial cohorts of patients with granulomatosis with polyangiitis and microscopic polyangiitis. In the first cohort, IgM PR3-ANCA occurred with a frequency of 15·0%, and were associated with a higher degree of disease severity and a trend towards a higher rate of alveolar haemorrhage (29·6 versus 15·7%, P = 0·10). Analysis of follow-up samples in this cohort showed that the presence of IgM PR3-ANCA was transient, but could recur. In the second cohort, IgM PR3-ANCA occurred with a frequency of 41·1%, and were also associated with a higher degree of disease severity. A higher rate of alveolar haemorrhage was observed among those with IgM PR3-ANCA (45·3 versus 15·8%; P < 0·001). The association of transient IgM PR3-ANCA with an acute respiratory manifestation of AAV suggests a possible link between an infectious trigger and AAV disease activity.

An expanded population of pathogenic regulatory T cells in giant cell arteritis is abrogated by IL-6 blockade therapy

OBJECTIVES

Randomised-controlled trials have recently proven the efficacy of the interleukin (IL)-6 receptor antagonist tocilizumab (TCZ) in giant cell arteritis (GCA). However, the mechanism of action of IL-6 blockade in this disease is unknown. Moreover, the role of regulatory T (Treg) cells in the pathogenesis of GCA remains underexplored. Given the plasticity of Tregs and the importance of IL-6 in their biology, we hypothesised that TCZ might modulate the Treg response in GCA. We therefore characterised the Treg compartment of patients with GCA treated with TCZ.

METHODS

We classified 41 patients with GCA into three groups: active disease (aGCA, n=11), disease remission on corticosteroids (rGCA-CS, n=19) and disease remission on TCZ (rGCA-TCZ, n=11). Healthy controls (HCs) were included for comparison. We determined the frequency, phenotype and function of peripheral blood Tregs.

RESULTS

Patients with aGCA demonstrated a hypoproliferating Treg compartment enriched in IL-17-secreting Tregs (IL-17⁺Tregs). Tregs in patients with aGCA disproportionally expressed a hypofunctional isoform of Foxp3 that lacks exon 2 (Foxp3Δ2). Foxp3Δ2-expressing Tregs coexpressed CD161, a marker commonly associated with the Th17 linage, significantly more often than full-length Foxp3-expressing Tregs. Compared with those of HCs, GCA-derived Tregs demonstrated impaired suppressor capacity. Treatment with TCZ, in contrast to CS therapy, corrected the Treg abnormalities observed in aGCA. In addition, TCZ treatment increased the numbers of activated Tregs (CD45RA^-Foxp3^high) and the Treg expression of markers of trafficking (CCR4) and terminal differentiation (CTLA-4).

CONCLUSIONS

TCZ may exert its therapeutic effects in GCA by increasing the proliferation and activation of Tregs, and by reverting the pathogenic Treg phenotype seen during active disease.

Deconstructing IgG4-related disease involvement of midline structures: Comparison to common mimickers

OBJECTIVE

A series of destructive and tumefactive lesions of the midline structures have been recently added to the spectrum of IgG4-related disease (IgG4-RD). We examined the clinical, serological, endoscopic, radiological, and histological features that might be of utility in distinguishing IgG4-RD from other forms of inflammatory conditions with the potential to involve the sinonasal area and the oral cavity.

METHODS

We studied 11 consecutive patients with erosive and/or tumefactive lesions of the midline structures referred to our tertiary care center. All patients underwent serum IgG4 measurement, flow cytometry for circulating plasmablast counts, nasal endoscopy, radiological studies, and histological evaluation of tissue specimens. The histological studies included immunostaining studies to assess the number of IgG4 + plasma cells/HPF for calculation of the IgG4+/IgG + plasma cell ratio.

RESULTS

Five patients with granulomatosis with polyangiitis (GPA), three with cocaine-induced midline destructive lesions (CIMDL), and three with IgG4-RD were studied. We found no clinical, endoscopic, or radiological findings specific for IgG4-RD. Increased serum IgG4 and plasmablasts levels were not specific for IgG4-RD. Rather, all 11 patients had elevated blood plasmablast concentrations, and several patients with GPA and CIMDL had elevated serum IgG4 levels. Storiform fibrosis and an IgG4+/IgG + plasma cell ratio >20% on histological examination, however, were observed only in patients with IgG4-RD.

CONCLUSIONS

Histological examination of bioptic samples from the sinonasal area and oral cavity represents the mainstay for the diagnosis of IgG4-RD involvement of the midline structures.

Antineutrophil cytoplasmic antibody positivity in IgG4-related disease: A case report and review of the literature

BACKGROUND

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition characterized by serum IgG4 elevation and tissue infiltration of IgG4-positive plasma cells. Substantial overlap between IgG4-RD and antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitides (AAV) exists in terms of organ involvement and histopathological features. A positive ANCA assay is regarded as a highly specific finding in favor of an AAV, and generally influences away from a diagnosis of IgG4-RD. Recent reports, however, have raised the possibility that some patients with IgG4-RD are ANCA positive, thus suggesting reconsideration of the role of ANCA in the diagnostic workup. In the present work, we describe the first case of concomitant biopsy-proven IgG4-RD and granulomatosis with polyangiitis (GPA), demonstrating antiproteinase 3 (PR3) ANCA of the IgG4 subclass in the patient's serum. We also review the literature in order to provide clinicians with tools for interpreting ANCA positivity in IgG4-RD patients.

CASE SUMMARY

A 51-year-old woman was referred for left exopthalmos due to lacrimal gland enlargement and increased serum IgG4 concentration. IgG4-RD was suspected and further imaging studies disclosed multiple pulmonary masses in the right lung. Histological analysis of the left lacrimal gland was diagnostic for IgG4-RD, but lung biopsy showed typical features of GPA. ANCA assay was positive for anti-PR3 antibodies. Further immunofluorescence studies demonstrated anti-PR3 antibodies of IgG1 and IgG4 subclass. Treatment with rituximab induced swift remission of both IgG4-RD and GPA manifestations. We identified 9 other reports of patients with IgG4-RD and positive ANCA in the English literature, 5 cases with biopsy-proven IgG4-RD and 4 cases in whom IgG4-RD was diagnosed presumptively. Four patients had also histological evidence of concomitant AAV.

CONCLUSION

The present work demonstrates that ANCA positivity in patients with biopsy-proven IgG4-RD should prompt the exclusion of a concomitant vasculitic process; a positive ANCA does not exclude the diagnosis of IgG4-RD; confirmation through immunoenzymatic assays of the ANCA specificity, clinical-pathological correlation, and histopathological evaluation remain crucial steps for the differential diagnosis between AAV and IgG4-RD.

Large vessel involvement by IgG4-related disease

OBJECTIVES

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect multiple organs and lead to tumefactive, tissue-destructive lesions. Reports have described inflammatory aortitis and periaortitis, the latter in the setting of retroperitoneal fibrosis (RPF), but have not distinguished adequately between these 2 manifestations. The frequency, radiologic features, and response of vascular complications to B cell depletion remain poorly defined. We describe the clinical features, radiology findings, and treatment response in a cohort of 36 patients with IgG4-RD affecting large blood vessels.

METHODS

Clinical records of all patients diagnosed with IgG4-RD in our center were reviewed. All radiologic studies were reviewed. We distinguished between primary large blood vessel inflammation and secondary vascular involvement. Primary involvement was defined as inflammation in the blood vessel wall as a principal focus of disease. Secondary vascular involvement was defined as disease caused by the effects of adjacent inflammation on the blood vessel wall.

RESULTS

Of the 160 IgG4-RD patients in this cohort, 36 (22.5%) had large-vessel involvement. The mean age at disease onset of the patients with large-vessel IgG4-RD was 54.6 years. Twenty-eight patients (78%) were male and 8 (22%) were female. Thirteen patients (36%) had primary IgG4-related vasculitis and aortitis with aneurysm formation comprised the most common manifestation. This affected 5.6% of the entire IgG4-RD cohort and was observed in the thoracic aorta in 8 patients, the abdominal aorta in 4, and both the thoracic and abdominal aorta in 3. Three of these aneurysms were complicated by aortic dissection or contained perforation. Periaortitis secondary to RPF accounted for 27 of 29 patients (93%) of secondary vascular involvement by IgG4-RD. Only 5 patients demonstrated evidence of both primary and secondary blood vessel involvement. Of those treated with rituximab, a majority responded positively.

CONCLUSIONS

IgG4-RD is a distinctive, unique, and treatable cause of large-vessel vasculitis. It can also involve blood vessels secondary to perivascular tumefactive lesions. The most common manifestation of IgG4-related vasculitis is aortitis with aneurysm formation. The most common secondary vascular manifestation is periaortitis with relative sparing of the aortic wall. Both primary vasculitis and secondary vascular involvement respond well to B cell depletion therapy.

IgG4-related disease: pathophysiologic insights drive emerging treatment approaches

IgG4-related disease (IgG4-RD) is a fibroinflammatory condition that can affect essentially any organ. The disease shows similar histopathology findings across organ systems, consisting of a lymphoplasmacytic infiltrate enriched in IgG4-positive plasma cells, storiform fibrosis, and obliterative phlebitis. IgG4 itself appears to be a reactive phenomenon rather than the primary disease driver. Recent investigations have focused on the interactions between cells of the B cell lineage and a novel CD4+ SLAMF7+ cytotoxic T cells capable of promoting fibrosis. Plasmablasts appear to play a crucial role along with B cells in the presentation of antigen to this T cell. IgG4-RD is marked by responsiveness to glucocorticoids, but frequent disease relapse, the inability to taper glucocorticoids completely, and steroid toxicity are problematic. Targeted treatment approaches against the B cell lineage appear promising, and therapeutic efforts focused upon the CD4+ SLAMF7+ cytotoxic T cell may also be feasible.

Lesional CD4+ IFN-γ+ cytotoxic T lymphocytes in IgG4-related dacryoadenitis and sialoadenitis

OBJECTIVES

IgG4-related disease (IgG4-RD) is a chronic, systemic, inflammatory condition of unknown aetiology. We have recently described clonally expanded circulating CD4⁺ cytotoxic T lymphocytes (CTLs) in IgG4-RD that infiltrate affected tissues where they secrete interleukin (IL)-1β and transforming growth factor -β1 (TGF-β1). In this study, we sought to examine the role of CD4⁺ CTLs in the pathogenesis of IgG4-related dacryoadenitis and sialoadenitis (IgG4-DS) and to determine whether these cells secrete interferon-gamma (IFN-γ) at lesional sites.

METHODS

Salivary glands of 25 patients with IgG4-DS, 22 patients with Sjögren's syndrome (SS), 12 patients with chronic sialoadenitis (CS) and 12 healthy controls were analysed in this study. Gene expression analysis was performed on submandibular glands (SMGs) from five patients with IgG4-DS, three with CS and three healthy controls. Infiltrating CD4⁺ CTLs were examined by quantitative multicolour imaging in tissue samples from 20 patients with IgG4-DS, 22 patients with SS, 9 patients with CS and 9 healthy controls.

RESULTS

In IgG4-DS tissues, nine genes associated with CD4⁺ CTLs were overexpressed. The expression of granzyme A (GZMA) mRNA was significantly higher in samples from patients with IgG4-RD compared with corresponding tissues from SS and healthy controls. Quantitative imaging showed that infiltrating CD4⁺ GZMA⁺ CTLs were more abundant in patients with IgG4-DS than in the other groups. The ratio of CD4⁺GZMA⁺ CTLs in SMGs from patients with IgG4-DS correlated with serum IgG4 concentrations and the number of affected organs. A large fraction of CD4⁺GZMA⁺ CTLs in SMGs from patients with IgG4-DS secreted IFN-γ.

CONCLUSIONS

The pathogenesis of IgG4-DS is associated with tissue infiltration by CD4⁺GZMA⁺ CTLs that secrete IFN-γ.

Using Mass Spectrometry to Quantify Rituximab and Perform Individualized Immunoglobulin Phenotyping in ANCA-Associated Vasculitis

Therapeutic monoclonal immunoglobulins (mAbs) are used to treat patients with a wide range of disorders including autoimmune diseases. As pharmaceutical companies bring more fully humanized therapeutic mAb drugs to the healthcare market analytical platforms that perform therapeutic drug monitoring (TDM) without relying on mAb specific reagents will be needed. In this study we demonstrate that liquid-chromatography-mass spectrometry (LC-MS) can be used to perform TDM of mAbs in the same manner as smaller nonbiologic drugs. The assay uses commercially available reagents combined with heavy and light chain disulfide bond reduction followed by light chain analysis by microflow-LC-electrospray ionization-quadrupole-time-of-flight mass spectrometry (ESI-Q-TOF MS). Quantification is performed using the peak areas from multiply charged mAb light chain ions using an in-house developed software package developed for TDM of mAbs. The data presented here demonstrate the ability of an LC-MS assay to quantify a therapeutic mAb in a large cohort of patients in a clinical trial. The ability to quantify any mAb in serum via the reduced light chain without the need for reagents specific for each mAb demonstrates the unique capabilities of LC-MS. This fact, coupled with the ability to phenotype a patient's polyclonal repertoire in the same analysis further shows the potential of this approach to mAb analysis.

Therapeutic approach to IgG4-related disease: A systematic review

To review the reported evidence on the therapeutic management of IgG4-related disease (IgG4-RD) in clinical practice.A systematic search of the literature was conducted. The primary outcome measured was the rate of efficacy of first-line therapeutic approaches. Secondary outcomes measured included the rate of disease relapse, the outcome of untreated patients, the rate of patients without drug therapy at the end of follow-up, the rate of side effects, and mortality. The MOOSE, AHRQ, STROBE, and GRACE recommendations/statements were followed.The results of the systematic search strategy yielded 62 studies that included a total of 3034 patients. Complete information about first-line therapeutic regimens was detailed in 1952 patients, including glucocorticoid-based regimens in 1437 (74%), drug-free regimens in 213 (11%), and other therapies in 38 (2%). No therapy (wait and see management) was reported in 264 (13%) patients. The efficacy of monotherapy with glucocorticoids was specified in 1220 patients, of whom 97% had a therapeutic response. Relapses, however, were reported in 464/1395 (33%) patients despite typically short follow-up periods. Therapeutic efficacy was reported in 219/231 (95%) of relapses treated with glucocorticoids, 56/69 (81%) of those treated with azathioprine, 16/22 (72%) of those treated with other immunosuppressive agents, and in the 9 cases treated with rituximab (100%). In 14 studies, the authors detailed the outcome of 159/246 patients with wait-and-see management; spontaneous improvement or resolution was reported in 68 (43%) cases. Wide heterogeneity was observed with respect to the first-line therapeutic approaches used for the different organ-specific disease subsets, including significant differences in the mean dose of glucocorticoids used.Nearly 70% of reported IgG4-RD patients are treated with oral glucocorticoids in monotherapy. However, the therapeutic management is heavily influenced by geographical, epidemiological, and clinical factors, especially with respect to the predominant organ affected. The frequency of glucocorticoid failure to induce sustained remissions both during and after treatment and the assessment of glucocorticoid toxicity in IgG4-RD require further study.

Clonal expansion of CD4(+) cytotoxic T lymphocytes in patients with IgG4-related disease

BACKGROUND

IgG4-related disease (IgG4-RD) is a systemic condition of unknown cause characterized by highly fibrotic lesions with dense lymphoplasmacytic infiltrates. CD4(+) T cells constitute the major inflammatory cell population in IgG4-RD lesions.

OBJECTIVE

We used an unbiased approach to characterize CD4(+) T-cell subsets in patients with IgG4-RD based on their clonal expansion and ability to infiltrate affected tissue sites.

METHODS

We used flow cytometry to identify CD4(+) effector/memory T cells in a cohort of 101 patients with IgG4-RD. These expanded cells were characterized by means of gene expression analysis and flow cytometry. Next-generation sequencing of the T-cell receptor β chain gene was performed on CD4(+)SLAMF7(+) cytotoxic T lymphocytes (CTLs) and CD4(+)GATA3(+) TH2 cells in a subset of patients to identify their clonality. Tissue infiltration by specific T cells was examined by using quantitative multicolor imaging.

RESULTS

CD4(+) effector/memory T cells with a cytolytic phenotype were expanded in patients with IgG4-RD. Next-generation sequencing revealed prominent clonal expansions of these CD4(+) CTLs but not CD4(+)GATA3(+) memory TH2 cells in patients with IgG4-RD. The dominant T cells infiltrating a range of inflamed IgG4-RD tissue sites were clonally expanded CD4(+) CTLs that expressed SLAMF7, granzyme A, IL-1β, and TGF-β1. Clinical remission induced by rituximab-mediated B-cell depletion was associated with a reduction in numbers of disease-associated CD4(+) CTLs.

CONCLUSIONS

IgG4-RD is prominently linked to clonally expanded IL-1β- and TGF-β1-secreting CD4(+) CTLs in both peripheral blood and inflammatory tissue lesions. These active, terminally differentiated, cytokine-secreting effector CD4(+) T cells are now linked to a human disease characterized by chronic inflammation and fibrosis.

A 44-year-old man with eye, kidney, and brain dysfunction

Retinal vasculopathy with cerebral leukodystrophy (RVCL) is a rare, autosomal dominant condition caused by mutations of TREX1 (3-prime repair exonuclease-1). The phenotypic expressions range from isolated retinal involvement to varying degrees of retinopathy, cerebral infarction with calcium depositions, nephropathy, and hepatopathy. We report a case of RVCL caused by a novel TREX1 mutation. This patient's multisystem presentation, retinal involvement interpreted as "retinal vasculitis," and improvement of neuroimaging abnormalities with dexamethasone led to the accepted diagnosis of a rheumatologic disorder resembling Behçet disease. Clinicians should consider RVCL in any patient with retinal capillary obliterations associated with tumefactive brain lesions or nephropathy.

Predictors of disease relapse in IgG4-related disease following rituximab

OBJECTIVE

IgG4-related disease (IgG4-RD) is a relapsing-remitting condition responsible for fibroinflammatory lesions that can lead to organ damage and life-threatening complications at nearly any anatomical site. The duration of remission following treatment varies and predictors of relapse are unclear. The objectives of this study were to review our experience with rituximab as remission induction in IgG4-RD, to clarify the duration of efficacy and to identify predictors of flare following treatment.

METHODS

In this retrospective cohort study, all patients were treated with two doses of rituximab (1 g) separated by 15 days. Clinical, radiographic and laboratory data pertaining to rituximab response and disease relapse were collected from the electronic medical record. Kaplan-Meier curves were constructed to estimate the time to disease relapse. Log-rank analyses were performed to compare times to relapse among subgroups. Potential relapse predictors were evaluated with Cox regression analysis.

RESULTS

Fifty-seven of 60 patients (95%) had clinical responses to rituximab. Forty-one patients (68%) were treated without glucocorticoids. Twenty-one patients (37%) experienced relapses following treatment at a median time from the first infusion of 244 days. Baseline concentrations of serum IgG4, IgE and circulating eosinophils predicted subsequent relapses, with hazard ratios of 6.2 (95% CI: 1.2, 32.0), 8.2 (95% CI: 1.4, 50.0) and 7.9 (95% CI: 1.8, 34.7), respectively. The higher the baseline values, the greater the risk of relapse and the shorter the time to relapse. Only 10% of the patients had elevations of all three major risk factors, underscoring the importance of measuring all three at baseline.

CONCLUSION

Baseline elevations in serum IgG4, IgE and blood eosinophil concentrations all predict IgG4-RD relapses independently.

Clinical outcomes of treatment of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis based on ANCA type

OBJECTIVE

To evaluate whether the classification of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) according to ANCA type (anti-proteinase 3 (PR3) or anti-myeloperoxidase (MPO) antibodies) predicts treatment response.

METHODS

Treatment responses were assessed among patients enrolled in the Rituximab in ANCA-associated Vasculitis trial according to both AAV diagnosis (granulomatosis with polyangiitis (GPA)/microscopic polyangiitis (MPA)) and ANCA type (PR3-AAV/MPO-AAV). Complete remission (CR) was defined as disease activity score of 0 and successful completion of the prednisone taper.

RESULTS

PR3-AAV patients treated with rituximab (RTX) achieved CR at 6 months more frequently than did those randomised to cyclophosphamide (CYC)/azathioprine (AZA) (65% vs 48%; p=0.04). The OR for CR at 6 months among PR3-AAV patients treated with RTX as opposed to CYC/AZA was 2.11 (95% CI 1.04 to 4.30) in analyses adjusted for age, sex and new-onset versus relapsing disease at baseline. PR3-AAV patients with relapsing disease achieved CR more often following RTX treatment at 6 months (OR 3.57; 95% CI 1.43 to 8.93), 12 months (OR 4.32; 95% CI 1.53 to 12.15) and 18 months (OR 3.06; 95% CI 1.05 to 8.97). No association between treatment and CR was observed in the MPO-AAV patient subset or in groups divided according to AAV diagnosis.

CONCLUSIONS

Patients with PR3-AAV respond better to RTX than to CYC/AZA. An ANCA type-based classification may guide immunosuppression in AAV.

TRIAL REGISTRATION NUMBER

NCT00104299; post-results.

IgG4-Related Disease: Clinical and Laboratory Features in One Hundred Twenty-Five Patients

OBJECTIVE

IgG4-related disease (IgG4-RD) is an immune-mediated fibroinflammatory condition that can affect nearly any organ. Prior studies have focused on individual cases of IgG4-RD or small case series. This study was undertaken to report detailed clinical and laboratory findings in a larger group of patients with IgG4-RD whose diagnosis was established by strict clinicopathologic correlation.

METHODS

The baseline features of 125 patients with biopsy-proven IgG4-RD were reviewed. The diagnosis was confirmed by pathologists' review, based on consensus diagnostic criteria and correlation with clinicopathologic features. Disease activity and damage were assessed using the IgG4-RD Responder Index (RI). Flow cytometry was used to assess levels of circulating plasmablasts.

RESULTS

Of the 125 patients, 107 had active disease and 86 were not receiving treatment for IgG4-RD. Only 51% of the patients with active disease had elevated serum IgG4 concentrations. However, patients with active disease and elevated serum IgG4 concentrations were older, had a higher IgG4-RD RI score, a greater number of organs involved, lower complement levels, higher absolute eosinophil counts, and higher IgE levels compared to those with active disease but normal serum IgG4 concentrations (P < 0.01 for all comparisons). The correlation between IgG4+ plasmablast levels and the IgG4-RD RI of disease activity (Spearman's ρ = 0.45, P = 0.003) was stronger than the correlation between total plasmablast levels and the IgG4-RD RI. Seventy-six (61%) of the patients were male, but no significant differences according to sex were observed with regard to disease severity, organ involvement, or serum IgG4 concentrations. Treatment with glucocorticoids failed to produce sustained remission in 77% of patients.

CONCLUSION

Nearly 50% of this patient cohort with biopsy-proven, clinically active IgG4-RD had normal serum IgG4 concentrations. Elevations in the serum IgG4 concentration appeared to identify a subset of patients with a more severe disease phenotype. In addition, the levels of IgG4+ plasmablasts correlated well with the extent of disease activity.

Neutrophil-Related Gene Expression and Low-Density Granulocytes Associated With Disease Activity and Response to Treatment in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis

OBJECTIVE

To discover biomarkers involved in the pathophysiology of antineutrophil cytoplasmic antibody-associated vasculitis (AAV) and to determine whether low-density granulocytes (LDGs) contribute to gene expression signatures in AAV.

METHODS

The source of clinical data and linked biologic specimens was a randomized controlled treatment trial in AAV. RNA sequencing of whole blood from patients with AAV was performed during active disease at the baseline visit and during remission 6 months later. Gene expression was compared between patients who met versus those who did not meet the primary trial outcome of clinical remission at 6 months (responders versus nonresponders). Measurement of neutrophil-related gene expression was confirmed in peripheral blood mononuclear cells (PBMCs) to validate the findings in whole blood. A negative-selection strategy isolated LDGs from PBMC fractions.

RESULTS

Differential expression between responders (n = 77) and nonresponders (n = 35) was detected in 2,346 transcripts at the baseline visit (P < 0.05). Unsupervised hierarchical clustering demonstrated a cluster of granulocyte-related genes, including myeloperoxidase (MPO) and proteinase 3 (PR3). A granulocyte multigene composite score was significantly higher in nonresponders than in responders (P < 0.01) and during active disease than during remission (P < 0.01). This signature strongly overlapped an LDG signature identified previously in lupus (false discovery rate by gene set enrichment analysis <0.01). Transcription of PR3 measured in PBMCs was associated with active disease and treatment response (P < 0.01). LDGs isolated from patients with AAV spontaneously formed neutrophil extracellular traps containing PR3 and MPO.

CONCLUSION

In AAV, increased expression of a granulocyte gene signature is associated with disease activity and decreased response to treatment. The source of this signature is likely LDGs, a potentially pathogenic cell type in AAV.

Outcomes of nonsevere relapses in antineutrophil cytoplasmic antibody-associated vasculitis treated with glucocorticoids

OBJECTIVE

Nonsevere relapses are more common than severe relapses in antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), but their clinical course and treatment outcomes remain largely unexamined. We undertook this study to analyze the outcomes of patients with nonsevere relapses in the Rituximab in ANCA-Associated Vasculitis (RAVE) trial who were treated with prednisone according to a prespecified protocol.

METHODS

RAVE was a randomized, double-blind, placebo-controlled trial comparing rituximab (RTX) to cyclophosphamide (CYC) followed by azathioprine (AZA) for induction of remission. Patients who experienced nonsevere relapses between months 1 and 18 were treated with a prednisone increase without a concomitant change in their nonglucocorticoid immunosuppressants, followed by a taper.

RESULTS

Forty-four patients with a first nonsevere relapse were analyzed. In comparison to the 71 patients who maintained relapse-free remission over 18 months, these patients were more likely to have proteinase 3-ANCAs, diagnoses of granulomatosis with polyangiitis (Wegener's), and a history of relapsing disease at baseline. A prednisone increase led to remission in 35 patients (80%). However, only 13 patients (30%) were able to maintain second remissions through the followup period (mean 12.5 months); 31 patients (70%) had a second disease relapse, 14 of them with severe disease. The mean time to second relapse was 9.4 months (4.7 months in the group treated with RTX versus 13.7 months in the group treated with CYC/AZA; P < 0.01). Patients who experienced nonsevere relapses received more glucocorticoids than those who maintained remission (6.7 grams versus 3.8 grams; P < 0.01).

CONCLUSION

Treatment of nonsevere relapses in AAV with an increase in glucocorticoids is effective in restoring temporary remission in the majority of patients, but recurrent relapses within a relatively short interval remain common. Alternative treatment approaches are needed for this important subset of patients.

Improved survival in granulomatosis with polyangiitis: A general population-based study

BACKGROUND

Granulomatosis with polyangiitis (GPA) is associated with an increased risk of mortality; however, recent mortality trends in GPA are unknown. We evaluated this issue in a general population context.

METHODS

Using data collected between 1992 and 2013 by The Health Improvement Network in the United Kingdom, we identified individuals diagnosed as incident cases of GPA and up to 10 non-GPA controls matched on sex, age, year of birth, and year of GPA diagnosis. The cohort was divided into two based on the year of diagnosis (i.e., 1992-2002 and 2003-2013) to evaluate changes in mortality. We calculated hazard ratios for death using a Cox-proportional hazards model and the rate differences using an additive hazard model, while adjusting for potential confounders.

RESULTS

We identified 465 cases of GPA (mean age: 60 years, 52% male). The early cohort (1992-2002) GPA patients had considerably higher mortality rates than the late cohort (2003-2013) (i.e., 72.0 vs. 35.7 cases per 1000 person-years), as compared with a moderate improvement in the comparison cohorts between the two periods (19.8 vs. 17.0 cases per 1000 person-years). The corresponding absolute mortality rate difference was 52.2 (95% CI: 25.1-79.2) cases and 18.7 (95% CI: 8.3-29.1) cases per 1000 person-years (p for interaction = 0.025). The resulting HRs for mortality were 4.34 (95% CI: 2.72-6.92) and 2.41 (95% CI: 1.74-3.34), respectively (p for interaction = 0.043).

CONCLUSION

This population-based study suggests that survival of GPA patients has improved considerably over the past 2 decades, affirming the benefits of recent trends in the management of GPA and its complications.

Diagnostic Approach to the Complexity of IgG4-Related Disease

IgG4-related disease (IgG4-RD) is a systemic disease characterized by the infiltration of IgG4-bearing plasma cells and, more importantly, distinctive histopathological features: storiform fibrosis, obliterative phlebitis, a lymphoplasmacytic infiltrate, and mild-to-moderate tissue eosinophilia. The diagnostic approach is complex and relies on the coexistence of various clinical, laboratory, and histopathological findings, none of which is pathognomonic in and of itself. IgG4-related disease should be suspected in patients presenting with unexplained enlargement or swelling of 1 or more organs or tissue organs. Four laboratory abnormalities often provide initial clues to the diagnosis of IgG4-RD: peripheral eosinophilia, hypergammaglobulinemia, elevated serum IgE levels, and hypocomplementemia. Elevated serum IgG4 levels provided critical information in identifying the first cases of IgG4-RD, but recent studies have reported substantial limitations to the measurement of serum IgG4 concentrations, precluding reliance on serum IgG4 concentrations for diagnostic purposes. In contrast, new studies have suggested a promising role of flow cytometry studies in the diagnosis and longitudinal management of IgG4-RD. Demonstration of the classic histopathological features of IgG4-RD remains crucial to diagnosis in most cases, and biopsy proof is preferred strongly by most disease experts before the initiation of treatment. Of note, the multiorgan nature of IgG4-RD was first established in 2003. This review intends to provide most recent knowledge about the clinical, laboratory, radiological, and pathological characteristics of IgG4-RD that may guide the physician to establish an early diagnosis. We searched PubMed and MEDLINE for relevant articles published between January 1, 2000, and November 1, 2014, using the search terms IgG4 and IgG4-related.

Peripheral CD5+ B cells in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

CD5+ B cells have been conceptualized as a possible surrogate for Breg cells. The aim of the present study was to determine the utility of CD5+ B cells as biomarkers in antineutrophil cytoplasmic antibody-associated vasculitis (AAV).

METHODS

The absolute and relative numbers (percentages) of CD5+ B cells (explanatory variables) were measured longitudinally during 18 months in 197 patients randomized to receive either rituximab (RTX) or cyclophosphamide (CYC) followed by azathioprine (AZA) for the treatment of AAV (Rituximab in ANCA-Associated Vasculitis [RAVE] trial). Outcome variables included disease activity (status of active disease versus complete remission), responsiveness to induction therapy, disease relapse, disease severity, and, in RTX-treated patients, relapse-free survival according to the percentage of CD5+ B cells detected upon B cell repopulation.

RESULTS

CD5+ B cell numbers were comparable between the treatment groups at baseline. After an initial decline, absolute CD5+ B cell numbers progressively increased in patients in the RTX treatment arm, but remained low in CYC/AZA-treated patients. In both groups, the percentage of CD5+ B cells increased during remission induction and slowly declined thereafter. During relapse, the percentage of CD5+ B cells correlated inversely with disease activity in RTX-treated patients, but not in patients who received CYC/AZA. No significant association was observed between the numbers of CD5+ B cells and induction treatment failure or disease severity. The dynamics of the CD5+ B cell compartment did not anticipate disease relapse. Following B cell repopulation, the percentage of CD5+ B cells was not predictive of time to flare in RTX-treated patients.

CONCLUSION

The percentage of peripheral CD5+ B cells might reflect disease activity in RTX-treated patients. However, sole staining for CD5 as a putative surrogate marker for Breg cells did not identify a subpopulation of B cells with clear potential for meaningful clinical use. Adequate phenotyping of Breg cells is required to further explore the value of these cells as biomarkers in AAV.

IgG4-related disease

IgG4-related disease is a protean condition that mimics many malignant, infectious, and inflammatory disorders. This multi-organ immune-mediated condition links many disorders previously regarded as isolated, single-organ diseases without any known underlying systemic condition. It was recognised as a unified entity only 10 years ago. Histopathology is the key to diagnosis. The three central pathology features of IgG4-related disease are lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. The extent of fibrosis is an important determinant of responsiveness to immunosuppressive therapies. IgG4-related disease generally responds to glucocorticoids in its inflammatory stage, but recurrent or refractory cases are common. Important mechanistic insights have been derived from studies of patients treated by B-cell depletion. Greater awareness of this disease is needed to ensure earlier diagnoses, which can prevent severe organ damage, disabling tissue fibrosis, and even death. Identification of specific antigens and T-cell clones that drive the disease will be the first steps to elucidate the pathogenesis of IgG4-related disease.

Google-driven search for big data in autoimmune geoepidemiology: analysis of 394,827 patients with systemic autoimmune diseases

Systemic autoimmune diseases (SADs) are a significant cause of morbidity and mortality worldwide, although their epidemiological profile varies significantly country by country. We explored the potential of the Google search engine to collect and merge large series (>1000 patients) of SADs reported in the Pubmed library, with the aim of obtaining a high-definition geoepidemiological picture of each disease. We collected data from 394,827 patients with SADs. Analysis showed a predominance of medical vs. administrative databases (74% vs. 26%), public health system vs. health insurance resources (88% vs. 12%) and patient-based vs. population-based designs (82% vs. 18%). The most unbalanced gender ratio was found in primary Sjögren syndrome (pSS), with nearly 10 females affected per 1 male, followed by systemic lupus erythematosus (SLE), systemic sclerosis (SSc) and antiphospholipid syndrome (APS) (ratio of nearly 5:1). Each disease predominantly affects a specific age group: children (Kawasaki disease, primary immunodeficiencies and Schonlein-Henoch disease), young people (SLE Behçet disease and sarcoidosis), middle-aged people (SSc, vasculitis and pSS) and the elderly (amyloidosis, polymyalgia rheumatica, and giant cell arteritis). We found significant differences in the geographical distribution of studies for each disease, and a higher frequency of the three SADs with available data (SLE, inflammatory myopathies and Kawasaki disease) in African-American patients. Using a "big data" approach enabled hitherto unseen connections in SADs to emerge.

Inpatient complications in patients with giant cell arteritis: decreased mortality and increased risk of thromboembolism, delirium and adrenal insufficiency

OBJECTIVE

The morbidity and mortality of hospitalized GCA patients have been unexplored. The aim of this study was to analyse inpatient complications experienced by patients with GCA.

METHODS

We used the Nationwide Inpatient Sample database to study a large group of patients admitted for pneumonia, myocardial infarction (MI), ischaemic stroke and femoral neck fracture. Patients were divided into two groups based on whether or not they had a diagnosis of GCA upon admission. Outcomes evaluated included inpatient mortality and the occurrence of adrenal insufficiency, deep vein thrombosis, pulmonary embolism and delirium.

RESULTS

From 2008 to 2011, 8 203 447 patients ≥50 years of age were discharged from US hospitals after admission with pneumonia, MI, stroke and femoral neck fracture. Among these patients, 9311 (0.11%) had GCA. Admissions for pneumonia, stroke and hip fracture were more frequent in GCA patients compared with those without GCA, accounting for 41.5% vs 39.4%, 24.9% vs 19.8% and 15.4% vs 14.2% of hospitalizations, respectively (P ≤ 0.001). Admissions for MI were more common in non-GCA patients (26.6% vs 18.2%, P < 0.001). During hospitalization, 4.1% of the GCA patients died, compared with 4.8% of those without GCA [odds ratio (OR) 0.73, P < 0.001). The GCA population suffered significantly more often from deep vein thrombosis (OR 2.08, P < 0.001), pulmonary embolism (OR 1.58, P < 0.001), delirium (OR 1.60, P < 0.001) and adrenal insufficiency (OR 4.95, P < 0.001).

CONCLUSION

Hospitalized GCA patients have lower mortality compared with the general inpatient population but greater risk of venous thromboembolism, delirium and adrenal insufficiency.

Rituximab for IgG4-related disease: a prospective, open-label trial

OBJECTIVES

To evaluate the efficacy of rituximab (RTX) in IgG4-related disease (IgG4-RD) in an open-label pilot trial.

METHODS

We treated 30 IgG4-RD patients with two doses of RTX (1000 mg each). The participants were either treated with RTX alone (n = 26; 87%) or required to discontinue baseline glucocorticoids (GC) within 2 months (n = 4; 13%). Disease activity was measured by the IgG4-RD Responder Index (IgG4-RD RI) and physician's global assessment (PGA). Disease response was defined as the improvement of the IgG4-RD RI by two points. The primary outcome, measured at 6 months, was defined as: (1) decline of the IgG4-RD RI ≥2 points compared with baseline; (2) no disease flares before month 6; and (3) no GC use between months 2 and 6. Complete remission was defined as an IgG4-RD RI score of 0 with no GC use.

RESULTS

Disease responses occurred in 97% of participants. The baseline IgG4-RD RI and PGA values, 11±7 and 63±22 mm, respectively, declined to 1±2 and 11±16 mm at 6 months (both p<0.00001). The primary outcome was achieved by 23 participants (77%). Fourteen (47%) were in complete remission at 6 months, and 12 (40%) remained in complete remission at 12  months. Among the 19 with elevated baseline serum IgG4, IgG4 concentrations declined from a mean of 911 mg/dL (range 138-4780 mg/dL) to 422 mg/dL (range 56-2410 mg/dL) at month 6 (p<0.05). However, only 8 (42%) of the 19 achieved normal values.

CONCLUSIONS

RTX appears to be an effective treatment for IgG4-RD, even without concomitant GC therapy.

TRIAL REGISTRATION NUMBER

ClinicalTrials.gov identifier: NCT01584388.

Plasmablasts as a biomarker for IgG4-related disease, independent of serum IgG4 concentrations

OBJECTIVES

We examined the utility of circulating total and IgG4+ plasmablasts as biomarkers of diagnosis and disease activity in IgG4-related disease (IgG4-RD).

MATERIALS METHODS

We evaluated patients with active, untreated, biopsy-proven IgG4-RD affecting various organs. Flow cytometry was used to measure total plasmablast and IgG4+ plasmablast counts by gating peripheral blood for CD19lowCD38+CD20-CD27+ cells and CD19lowCD38+CD20-CD27+IgG4+ cells. Serum IgG4 concentrations were measured by nephelometry. We compared 37 IgG4-RD patients to 35 controls, including healthy individuals (n=14) and patients with other inflammatory diseases before treatment (n=21).

RESULTS

The IgG4-RD patients' mean age was 59, and 68% were male. Fourteen patients (38%) had three or more organs involved. The IgG4-RD patients had substantially elevated total plasmablast counts (median 4698/mL, range 610-79524/mL) compared to both untreated disease controls (median 592/mL, range 19-4294/mL; p < 0.001) and healthy controls (median 94/mL, range 1-653/mL; p < 0.001). Thirteen IgG4-RD patients (36%) had normal serum IgG4 concentrations (mean 60 mg/dL, range 5-123 mg/dL, normal <135 mg/dL). However, the median plasmablast count was not significantly lower in that subset with normal serum IgG4 concentrations (3784/mL) compared to those with elevated serum IgG4 (5155/mL) (p = 0.242). Among the 12 rituximab (RTX)-treated patients, the median plasmablast level during disease flare was 6356/mL (range 1123-41589/mL), declining to 1419/mL (range 386/mL-4150/mL) during remission (p < 0.01).

CONCLUSIONS

Circulating plasmablasts are elevated in active IgG4-RD, even in patients with normal serum IgG4 concentrations. Plasmablast counts are a potentially useful biomarker for diagnosis, assessing response to treatment, and determining the appropriate time for re-treatment.

Rituximab versus cyclophosphamide for ANCA-associated vasculitis with renal involvement

Rituximab (RTX) is non-inferior to cyclophosphamide (CYC) followed by azathioprine (AZA) for remission-induction in severe ANCA-associated vasculitis (AAV), but renal outcomes are unknown. This is a post hoc analysis of patients enrolled in the Rituximab for ANCA-Associated Vasculitis (RAVE) Trial who had renal involvement (biopsy proven pauci-immune GN, red blood cell casts in the urine, and/or a rise in serum creatinine concentration attributed to vasculitis). Remission-induction regimens were RTX at 375 mg/m(2) × 4 or CYC at 2 mg/kg/d. CYC was replaced by AZA (2 mg/kg/d) after 3-6 months. Both groups received glucocorticoids. Complete remission (CR) was defined as Birmingham Vasculitis Activity Score/Wegener's Granulomatosis (BVAS/WG)=0 off prednisone. Fifty-two percent (102 of 197) of the patients had renal involvement at entry. Of these patients, 51 were randomized to RTX, and 51 to CYC/AZA. Mean eGFR was lower in the RTX group (41 versus 50 ml/min per 1.73 m(2); P=0.05); 61% and 75% of patients treated with RTX and 63% and 76% of patients treated with CYC/AZA achieved CR by 6 and 18 months, respectively. No differences in remission rates or increases in eGFR at 18 months were evident when analysis was stratified by ANCA type, AAV diagnosis (granulomatosis with polyangiitis versus microscopic polyangiitis), or new diagnosis (versus relapsing disease) at entry. There were no differences between treatment groups in relapses at 6, 12, or 18 months. No differences in adverse events were observed. In conclusion, patients with AAV and renal involvement respond similarly to remission induction with RTX plus glucocorticoids or CYC plus glucocorticoids.

Rituximab for the treatment of relapses in antineutrophil cytoplasmic antibody-associated vasculitis

OBJECTIVE

Disease relapses are frequent in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). This study was undertaken to evaluate outcomes in patients with AAV who are re-treated with rituximab (RTX) and prednisone for severe disease relapses.

METHODS

The Rituximab in AAV trial was a randomized, double-blind, placebo-controlled trial comparing the rates of remission induction among patients treated with RTX (n = 99) and patients treated with cyclophosphamide (CYC) followed by azathioprine (AZA) (n = 98). Prednisone was tapered to discontinuation after 5.5 months. After remission was achieved, patients who experienced a severe disease relapse between months 6 and 18 were eligible to receive RTX and prednisone on an open-label basis according to a prespecified protocol. Investigators remained blinded with regard to the original treatment assignment.

RESULTS

Twenty-six patients received RTX for disease relapse after remission had initially been achieved with their originally assigned treatment. Fifteen of these patients were initially randomized to receive RTX and 11 to receive CYC/AZA. Thirteen (87%) of the patients originally assigned to receive RTX and 10 (91%) originally assigned to receive CYC/AZA achieved remission again with open-label RTX (an overall percentage of 88%). In half of the patients treated with open-label RTX, prednisone could be discontinued entirely. Patients in this cohort experienced fewer adverse events compared to the overall study population (4.7 adverse events per patient-year versus 11.8 adverse events per patient-year).

CONCLUSION

Re-treatment of AAV relapses with RTX and glucocorticoids appears to be a safe and effective strategy, regardless of previous treatment.