Severe Infection in Anti-Glomerular Basement Membrane Disease: A Retrospective Multicenter French Study

Current perspective on infections and mitigation strategies in primary systemic vasculitis

PURPOSE OF REVIEW

The purpose of this review is to summarize and evaluate most recent evidence on the epidemiology of infections and associated risk factors in patients with primary systemic vasculitides (PSV), as well as discuss mitigation strategies including the risk of antibiotic prophylaxis.

RECENT FINDINGS

Infections remain one of the leading causes of mortality in patients with PSV, with rates of severe infection ranging from 16 to 40% in different cohorts. Older age, frailty, renal and pulmonary involvement, and higher burden of comorbidities have been recognized as important patient-associated risk factors. Treatments including higher cumulative doses of glucocorticoids are associated with an increased risk of infections, and recent studies show the potential benefit of interventions such as reduced-dose glucocorticoid regimens. Existing mitigation strategies include screening, vaccination, and infection prophylaxis. The latter remains particularly important for Pneumocystis jirovecii pneumonia; however, the benefit-risk ratio seems to be less clear outside of induction phase (i.e., high dose of glucocorticoids) and optimal treatment duration remains less clear. Patients with PSV are at increased risk of infections, due to disease itself, comorbidities, and treatment side effects. Awareness of the timing and types of infection, as well as mitigation strategies are imperative to ensure treatment success and survival for patients.

Epidemiology, clinical features, risk factors, and outcomes in anti-glomerular basement membrane disease: A systematic review and meta-analysis

Anti-glomerular basement membrane (GBM) disease is a small-vessel vasculitis that represents the most aggressive form of autoimmune glomerulonephritis. The study aimed to investigate the prevalence, clinical characteristics, risk factors, and outcomes of anti-GBM disease through a systematic review and meta-analysis involving 47 studies with 2830 patients. The overall incidence of anti-GBM disease ranged from 0.60 to 1.79 per million population per annum. In rapidly progressive glomerulonephritis and crescentic glomerulonephritis, the pooled incidence rates were 8.0% and 12.8%, respectively. The pooled prevalence rates of anti-GBM antibodies, antineutrophil cytoplasmic antibodies (ANCA), and lung hemorrhage were 88.8%, 27.4%, and 32.6%, respectively. Patients with combined ANCA positivity demonstrated a prognosis comparable to those patients with only anti-GBM antibodies, though with differing clinical features. The pooled one-year patient and kidney survival rates were 76.2% and 30.2%, respectively. Kidney function on diagnosis and normal glomeruli percentage were identified as strong prognostic factors. This study represents the first comprehensive meta-analysis on anti-GBM disease, providing insights into its management. However, caution is warranted in interpreting some results due to the observational nature of the included studies and high heterogeneity.

Immunity in the balance: Fatal disseminated adenovirus infection in a patient undergoing plasma exchange and immunosuppressive chemotherapy for anti-glomerular basement membrane disease

Anti-glomerular basement membrane (anti-GBM) disease (formerly known as Goodpasture's syndrome) is a rare autoinflammatory condition that affects the renal and/or pulmonary capillaries. The standard therapeutic regimen for anti-GBM disease involves therapeutic plasma exchange (TPE), cyclophosphamide, and corticosteroids to rapidly remove and inhibit autoantibody production and reduce organ inflammation. Herein we report an 82-year-old female who developed anti-GBM disease but expired despite therapy, secondary to multi-organ failure in the setting of disseminated adenovirus disease. We discuss the utility and potential adverse effect of daily TPE for a protracted course (ie, 10-14 days), the recommended TPE intensity in the 2023 American Society for Apheresis guidelines, updated from every-other-day TPE in the 2019 guidelines, despite no new data. We also highlight the potential for unusual infections to occur in these patients due to the profound immunosuppression, and discuss the importance of balancing immunosuppression to treat the disease with close surveillance of any potential opportunistic infections.

Pneumocystis pneumonia secondary to intensive immunosuppression treatment for anti-GBM disease complicated with IgA nephropathy: A case report and literature review

RATIONALE

The estimated incidence of anti-glomerular basement membrane (anti-GBM) disease complicated with immunoglobulin A (IgA) nephropathy is minimal, there have only been 15 cases (including this case) reported in the literature, and only 5 (33.33%) of them showed significant improvement in renal function after treatment. Pneumocystis pneumonia is a severe opportunistic pulmonary infection of pneumocystis jiroveci in immunocompromised patients. Here, we report a case of pneumocystis pneumonia secondary to intensive immunosuppression treatment for anti-GBM disease complicated with IgA nephropathy, with no similar reports or studies published before to our knowledge.

PATIENT CONCERNS

The patient was admitted to our hospital with a 1-week diagnosis of crescent glomerulonephritis who had been suffered from hematuria and foamy urine for more than 1 month. Before admission, the patient received pulse dose intravenous methylprednisolone and immunosuppression with rituximab, but the renal function and titer of pathogenic antibody did not improve significantly.

DIAGNOSIS

Crescentic glomerulonephritis, anti-glomerular basal membrane disease complicated with IgA nephropathy (Type I+II) was pathologically confirmed by renal biopsy. Secondary pneumocystis pneumonia was diagnosed by acute progressive respiratory failure, chest computed tomography and metagenomic next-generation sequencing of transbronchoscopic bronchoalveolar lavage fluid.

INTERVENTIONS

The key to successful treatment was to make the pathogenic antibody turn negative quickly by combining pulse dose intravenous methylprednisolone, immunosuppression with rituximab, and plasma exchange therapy. Early identification of pneumocystis pneumonia, accurate etiological identification, and active anti-infective treatment were also crucial.

OUTCOMES

The patient was discharged after 16 days of anti-infection with secondary infection controlled and dialysis catheter removed. Up to now, the patient has been followed for a period of 28 weeks, results showed renal function had been repaired even hematuria and proteinuria were basically alleviated.

LESSONS

Our case provided experience in the treatment of anti-GBM disease complicated with IgA nephropathy, further proposed the potential therapeutic effects of rituximab, also illustrated low dose hormone combined with tacrolimus can be used as sequential therapy after plasma exchange and intensive immunosuppression. Our research also suggested that resulting in severe immune suppression, a high risk of secondary pneumocystis opportunistic infection should be aware of. metagenomic next-generation sequencing might increase the detection rate of the pathogen.

Disease activity prediction and prognosis of anti-GBM nephritis based on T lymphocyte subset ratios

Introduction

Cell-mediated autoimmunity, especially the autoreactivity of T cells, is known to underlie the initiation of anti-glomerular basement membrane disease. However, the T lymphocyte subsets that determine the disease activity, renal fibrosis, and prognosis of anti-GBM disease have not been clearly elucidated.

Methods

The T lymphocyte subsets (CD4+ and CD8+) were examined on peripheral blood and renal biopsy tissues from 65 patients with biopsy proven anti-GBM disease. Patients were divided into the high ratio group and low ratio group according to the cutoff values in the receiver operating characteristic curve analysis. The correlations of T lymphocyte subsets with clinical, pathological data, and renal outcome were analyzed.

Results

By the end of follow-up, 45 patients (69.2%) developed end-stage renal disease (ESRD). In peripheral blood, the CD4+/CD8+ ratio showed a predictive ability with a sensitivity and specificity of 91.3% and 52.9%, respectively, which gave rise to a cutoff value of 0.89. There was a significant difference in the activity index between these two groups (3.91 ± 1.38 vs. 2.89 ± 1.13, p = 0.007). In the renal tissues, the CD4+/CD8+ ratio had the optimal cutoff point of 0.82 with a sensitivity of 57.8% and specificity of 85%. The renal activity index was higher for the renal tissues with high CD4+/CD8+ ratios than that of tissues with low CD4+/CD8+ ratios (4.32 ± 1.55 vs. 3.37 ± 1.41, p = 0.016). Peripheral blood CD4+/CD8+ ratios of ≥0.89 or renal tissue CD4+/CD8+ ratios of < 0.82 positively correlated with poor renal prognosis in patients with anti-GBM nephritis.

Conclusions

The CD4+/CD8+ ratio was associated with renal activity index both in peripheral blood and renal tissue and predicts the renal prognosis of patients with anti-GBM nephritis.

Clinical and immunologic characteristics of Japanese patients with anti-glomerular basement membrane disease: case reports and literature review

Background

Clinical studies of anti-glomerular basement membrane (GBM) disease were limited because of the low incidence. We aimed to report the characteristics, treatments, and outcomes of patients with anti-GBM disease at a tertiary reference medical center in Japan and review the literature of mortality in patients with anti-GBM disease.

Case presentation

Case 1 was a 72-year-old Japanese man that was referred with worsening of the serum creatinine (from 1.1 to 27.3 mg/dL). Anti-GBM disease was confirmed by renal biopsy, and treatments with oral prednisolone and plasmapheresis were initiated. Although his anti-GBM antibody decreased (from 476 to 18 units/mL) after the treatments, the patient died from lung abscess. Case 2 was a 32-year-old Japanese man that presented with fever and macroscopic hematuria. At presentation, his serum creatinine was 4.2 mg/dL, and anti-GBM antibody was 265 units/mL. Renal biopsy confirmed the diagnosis of anti-GBM disease, and intensive treatments with plasmapheresis and methyl prednisolone were started, followed by oral prednisolone. Living-donor kidney transplantation was performed because his anti-GBM antibody had remained undetectable for 1 year after diagnosis. In the main text, clinicopathological characteristics of 12 patients with anti-GBM disease at our institution were summarized.

Conclusions

We found that the 1-year survival rate of patients with anti-GBM disease was 88% in our cohort, which was comparable to previous studies. Multicenter, nationwide studies are expected to evaluate prognosis of Japanese patients with this rare entity.