Staphylococcal Infection-Related Glomerulonephritis With Cryoglobulinemic Features.

Area of Science:

• Nephrology
• Pathology
• Infectious Diseases

Background:

• Staphylococcal infection-related glomerulonephritis (GN) is characterized by IgA-dominant deposits.
• Commonly presents as endocapillary or mesangial proliferative GN.
• Rare cases exhibit cryoglobulin-like features, including hyaline pseudothrombi and wireloop deposits, requiring further characterization.

Purpose of the Study:

• To investigate IgA-dominant GN with cryoglobulinemic features in patients with staphylococcal infections.
• To detail the clinical and pathological characteristics of this specific GN subtype.

Main Methods:

• Retrospective review of kidney biopsy archives from January 2016 to September 2017.
• Identification of cases with IgA-dominant GN and cryoglobulinemic features.
• Analysis of clinical presentation, biopsy findings, and patient outcomes.

Main Results:

• Five cases of IgA-dominant GN with cryoglobulinemic features were identified among 1965 native kidney biopsies.
• All patients had active staphylococcal infections, acute kidney injury, proteinuria, and hematuria.
• Biopsies showed exudative GN, focal crescents in 4 cases, hyaline pseudothrombi, and IgA/C3 co-dominant staining. One patient had transiently positive cryoglobulinemia serology.

Conclusions:

• IgA-dominant GN with cryoglobulinemic features is an uncommon yet severe manifestation of staphylococcal infection.
• Crescentic GN was prevalent, with 4 of 5 patients requiring hemodialysis.
• Evaluation for active staphylococcal infection is recommended for patients presenting with IgA-dominant GN and cryoglobulinemic features.