High-frequency plasma exchange therapy for immunocompromised, type I crescentic glomerulonephritis complicated with IgA nephropathy: A case report and literature review.

Rationale: Anti-glomerular basement membrane (anti-GBM) disease has been reported to coexist with other immune-mediated glomerular disorders, including antineutrophil cytoplasmic autoantibody positive glomerulonephritis and membranous glomerulopathy. It is well known that anti-GBM disease often manifests as type I crescentic glomerulonephritis on renal biopsy. However, concurrent cases of both type I crescentic glomerulonephritis and IgA nephropathy are rare.

Patient Concerns: We report the case of a 40-years-old woman with microscopic hematuria, mild proteinuria and an immunocompromised status. Laboratory data revealed serum creatinine showed progressive progress, suddenly rising from the normal range to 316.2μmol/L within 4 months. The CD4 lymphocyte count was 0.274 × 109/L (reference value 0.35-1.82 × 109/L). The anti-GBM antibody titer was 192.4 IU/mL (reference range: <20 RU/mL).

Diagnoses: Renal biopsy was performed after admission. The pathological diagnosis was type I crescentic glomerulonephritis, IgA nephropathy, and clinical anti-GBM disease.

Interventions: The patient was seriously ill on admission and progressed rapidly. Combined with poor immune function, we immediately initiated high-frequency plasma exchange (PE). In addition, to avoid rebound of antibody levels, PE was performed for 5 times. Follow-up treatment was combined with standard-dose corticosteroids and cyclophosphamide.

Outcomes: The patient was followed up for 1 year. On the last visit, her serum creatinine decreased to 103.5μmol/L, anti-GBM antibody remained negative, and proteinuria and hematuria disappeared.

Lessons: This case illustrates that when crescentic nephritis or anti-GBM disease is combined with other immune diseases, especially when the immune function is extremely low, if the application of high-dose steroid shocks may induce fatal infections, to some extent high frequency PE has certain advantages.