Clinical Profile, Histopathology, and Outcomes in Infection-Related Glomerulonephritis - Single-Center Experience

Abstract

Background: Infection-related glomerulonephritis (IRGN) is an important source of renal morbidity with adverse outcomes in adults. Data from large centers in India is lacking on this common, yet poorly understood entity.

Materials and methods: We performed a prospective observational study of all patients diagnosed with IRGN at our center over a 3-year period between 2017 and 2019. "Typical IRGN" patients were diagnosed based on clinical and laboratory assessment; others underwent renal biopsy. Renal and patient survival outcomes were assessed in addition to factors that help predict outcomes.

Results: One hundred and twenty-five patients with a diagnosis of IRGN were included in the study, including 86 patients who underwent renal biopsy. This represented 24% of all biopsies during this time period, and IRGN was the most common nondiabetic kidney disease identified in diabetic biopsies at our center. Female preponderance and a seasonal variation were striking. Atypical sources of infection like otomycosis, tooth abscess, and dengue virus infection were noted. Male gender and diabetes were important risk factors for severe disease. Rapidly progressive glomerulonephritis (RPGN), atypical serum complement profiles, and comorbid illnesses were common in adults. Though children had more benign disease and outcomes, life-threatening complications were also noted. C3 dominance was the most striking immunofluorescence (IF) finding and was associated with poorer outcomes. Crescentic IRGN was rare, and four cases of IgA-dominant IRGN were noted. Also, 24% of the cohort required renal replacement therapy. RPGN presentation of IRGN portended worst prognosis with end-stage renal disease (ESRD) in 31% and death in 22% of patients.

Conclusion: IRGN is a common clinical entity in adults with the potential for adverse renal and survival outcomes. We have identified clinical and biopsy characteristics that are associated with ESRD and death.

Keywords: IgA-Dominant IRGN; infection-related glomerulonephritis; outcomes; renal biopsy.

Figure 1

Age distribution of IRGN cohort. IRGN = infection-related glomerulonephritis

Figure 2

Case distribution over time periods

Figure 3

Syndrome of presentation

Figure 4

Comorbidities in RPGN versus acute nephritis sub-cohort. CKD = chronic kidney disease, CLD = chronic liver disease, DM = diabetes mellitus, HTN = hypertension, RPGN = rapidly progressive glomerulonephritis

Figure 5

Laboratory evaluation

Figure 6

Infection source. GI = gastrointestinal, LRTI = lower respiratory tract infection, URTI = upper respiratory tract infection, UTI = urinary tract infection

Figure 7

Clockwise from top left. Endocapillary proliferative and exudative glomerulonephritis in hematoxylin and eosin stain (400×) and periodic acid–methenamine silver stain (400×). Electron microscopy showing subepithelial humps. Extensive granular capillary wall and mesangial staining of C3 on IF. IF = immunofluorescence

Figure 8

Outcomes. CKD = chronic kidney disease, ESRD = end-stage renal disease, ICU = intensive care unit, RPGN = rapidly progressive glomerulonephritis, RRT = renal replacement therapy.