A case of crystalglobulin-induced nephropathy wherein M protein was identified by mass spectrometry and immunoglobulin G subclass staining.

Crystalglobulin-induced nephropathy is a rare disease that causes the deposition of crystallized monoclonal immunoglobulins into the glomerular capillary and arteriole spaces. Here, we report the case of a patient who presented with skin ulcers, urinary protein, and renal dysfunction. The patient underwent renal and skin biopsies, and the biopsy tissue samples were subjected to mass spectrometry. The patient was diagnosed with crystalglobulin-induced nephropathy. A literature review suggested that pathological examinations using electron microscopy, mass spectrometry, and immunofluorescent staining of paraffin-embedded biopsy samples treated with pronase may be useful for the diagnosis of this condition.

Long-term follow-up characteristics of patients with anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) receiving chronic hemodialysis at a single center.

BACKGROUND: The clinical characteristics and treatment of patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) after initiating chronic hemodialysis remain unknown. METHODS: We retrospectively enrolled 11 adult patients with AAV receiving chronic hemodialysis in our hospital from 2000-2016. We collected data describing each patient's clinical findings and treatment before and after initiating hemodialysis. Patients with AAV with and without post-hemodialysis AAV relapse were compared statistically. RESULTS: The average observation period was 6.8 ± 4.1 years, and the interval between diagnosis and initiating chronic hemodialysis was 1.9 ± 2.6 years. Before initiating chronic hemodialysis, five patients (45%) experienced 12 AAV relapses, with diagnoses made serologically or symptomatically. After initiating chronic hemodialysis, four patients experienced nine relapses, with no significant difference between the number of relapses and the number of patients experiencing relapse (p = 0.067 and 0.083, respectively). For patients' entire clinical courses before initiating chronic hemodialysis, the average steroid dose was 11.6 ± 6.9 g/y. Comparing before and after initiating chronic hemodialysis, the steroid dose decreased significantly to 3.3 ± 1.4 g/y after initiating chronic hemodialysis (p = 0.0012). Two of 11 patients died of serious infections after initiating chronic hemodialysis. CONCLUSIONS: Our results showed that the number of relapses tended to be lower despite a significantly different lower amount of steroid after initiating hemodialysis compared with before initiating hemodialysis, and the burn-out phenomenon specific to uremic patients was inferred. We believe that early tapering of steroids should be considered to avoid death rather than focusing only on relapse.

Primary IgA Vasculitis with Nephritis in a Patient with Rheumatoid Arthritis Diagnosed by Anti-galactose-deficient IgA1 Immunostaining.

Renal disease is a common complication of rheumatoid arthritis (RA) and can occur secondary to RA or be induced by therapeutic agents. Recently, glomerular deposition of galactose-deficient IgA1 (Gd-IgA1) was identified as a feature of primary IgA vasculitis with nephritis (IgA-VN). We herein report a case of IgA-VN in an RA patient whose disease activity was controlled by treatment with etanercept. To distinguish between primary IgA-VN and secondary IgA-VN caused by RA or etanercept, we performed immunostaining of renal biopsy sections with the Gd-IgA1-specific antibody KM55. Positive KM55 staining confirmed the diagnosis of primary IgA-VN in a patient with RA.

Late-Onset Neutropenia after Rituximab Treatment for Adult-Onset Nephrotic Syndrome.

A 41-year-old woman developed nephrotic syndrome at the age of 32 and was diagnosed with minimal change nephrotic syndrome based on a renal biopsy. Although remission was achieved with administration of prednisolone (PSL) and cyclosporine, the nephrotic syndrome recurred. She was also started on rituximab (RTX). She developed late-onset neutropenia after RTX treatment (R-LON) and improved 17 days later. Although the majority of R-LON cases undergo spontaneous remission, cases of death have been reported. This report is intended to warn about R-LON, since the use of RTX for adult-onset nephrotic syndrome is expected to increase in the future.