#1701 IgA nephropathy in numbers: the experience of a single center

Abstract Background and Aims IgA nephropathy is probably the most common glomerular disease worldwide and kidney histology is recognized to significantly impact the risk of progressive kidney failure. Method This is a retrospective cohort study of adult patients diagnosed with biopsy-proven IgA nephropathy during the last decade in the nephrology department of a tertiary hospital. Results In total, 75 patients with biopsy-proven IgA nephropathy were identified and data from 53 of them were analyzed mean age 48 ± 16 [SD years, 81% males, 60% hypertensives, 19% diabetics, baseline serum creatinine 2.03 ± 1.80 mg/dl, baseline estimated glomerular filtration rate (eGFR) 60.9 ± 31.4 ml/min/1.73 m2, baseline proteinuria 2.76 ± 2.44 gr/24 h]. Eventually, 6 patients were submitted to chronic dialysis. 50% of the patients received RAAS blockers and 14% received SGLT2-inhibitors. The most frequently used immunosuppression regimens were glucocorticoids alone (33%), glucocorticoids plus cyclophosphamide and azathioprine (13%), budesonide (9%). Relapse was identified in 9% of the patients and it was treated with glucocorticoids alone or budesonide. 25% of the patients had elevated serum IgA levels. Crescents were identified in 36% of the patients and interstitial and mesangial inflammation were observed in 83% and 64% of the patients respectively. Approximately all of the patients had arterial vessels with hyalinosis or fibroelastosis. Concerning immunofluorescence, the dominant findings were IgA, IgM, c3, λ light chain, while all other components were merely found. The median duration of follow-up was 2 years and the follow-up minus baseline serum creatinine, eGFR, and proteinuria differences were 0.35 ± 1.77 mg/dl, −4.0 ± 22.2 ml/min/1.73 m2, and −1.46 ± 2.39 gr/24 h, respectively. Median follow-up minus baseline eGFR was higher for diabetics (1.5 vs 0 ml/min/1.73 m2, p = 0.04). Participants receiving treatment with glucocorticoids were found to present a reduction of serum creatinine during follow-up (follow-up minus baseline median serum creatinine −0.1 vs 0.2 mg/dl for participants receiving vs not receiving glucocorticoids, p = 0.02) and a non-reduction of eGFR (follow-up minus baseline median eGFR 0 vs −3 ml/min/1.73 m2 for participants receiving vs not receiving glucocorticoids, p = 0.01). Participants receiving treatment with SGLT2 inhibitors were also found to have stable median eGFR during follow-up (follow-up minus baseline median eGFR 0 vs −11 ml/min/1.73 m2 for participants receiving vs not receiving SGLT2 inhibitors, p = 0.01). In multivariable linear regression analysis, follow-up minus baseline serum creatinine was independently associated with baseline proteinuria (β = 0.38, p 0.01), administration of glucocorticoids (β= −1.23, p = 0.01), and the S component of MEST-c score (β = 1.27, p = 0.04), after adjustment for age, sex, baseline serum creatinine, diabetes, hypertension, MEST-c score, and percentage of interstitial fibrosis. In multivariable linear regression analysis, follow-up minus baseline eGFR was independently associated with baseline eGFR (β= −0.43, p 0.01), baseline proteinuria (β= −2.54, p 0.05), and hypertension status (β= −18.93, p = 0.02), after adjustment for age, sex, diabetes, treatment with glucocorticoids, MEST-c score, and percentage of interstitial fibrosis. Conclusion These preliminary data indicate that patients with IgA nephropathy who were treated with glucocorticoids or SGLT2 inhibitors present better course concerning the renal function, and the S component of MEST-c score was the only element of the kidney biopsy associated with the kidney outcome.