Twenty-year Follow-up of Patients With Epidemic Glomerulonephritis due to in Brazil.

Introduction: Post-streptococcal glomerulonephritis (PSGN) has a good prognosis in children, but few studies have evaluated the long-term renal outcomes in adults with PSGN.

Methods: In a follow-up study, 47 predominantly adult patients with PSGN due to group C were reassessed 20 years after an outbreak in Nova Serrana, Brazil. We evaluated clinical characteristics, renal outcomes, and the trajectory of the estimated glomerular filtration rate (eGFR) by the creatinine-based chronic kidney disease-epidemiology collaboration equation from 5 follow-up assessments. Logistic regression and mixed-effects regression were used in the analysis.

Results: After 20 years, the participants' mean age was 56.6±15.1 years. Thirty-four (72%) patients had hypertension, 21 (44.7%) had eGFR <60 ml/min per 1.73 m, 8 of 43 (18.6%) had urine protein-to-creatinine ratio >150 mg/g, and 25 (53%) had CKD (low eGFR and/or increased proteinuria). Increasing age was associated with CKD (odds ratio: 1.07; 95% confidence interval [CI]: 1.02-1.13;  = 0.011) in multivariate analysis. The mean eGFR decline in the last 11 years of follow-up was -3.2 ml/min per 1.73 m per year (95% CI: -3.7 to -2.7). Older age at baseline (coefficient -1.05 ml/min per 1.73 m per year; 95% CI -1.28 to -0.81;  < 0.001), and hypertension 5 years after the outbreak (coefficient -7.78 ml/min/1.73 m; 95% CI -14.67 to -0.78;  = 0.027) were associated with lower eGFR during the whole study period.

Conclusion: There was a marked worsening of renal function and a high prevalence of CKD and hypertension after 20 years of PSGN outbreak. Long-term follow-up is warranted after PSGN, especially among older patients.