Corticosteroids in IgA nephropathy: A retrospective analysis from the VALIGA study

Current guidelines suggest treatment with corticosteroids (CS) in IgA nephropathy (IgAN) when proteinuria
is persistently $1 g/d despite 3–6 months of supportive care and when eGFR is .50 ml/min per
1.73 m2.Whether the benefits of this treatment extend to patients with an eGFR#50 ml/min per 1.73 m2,
other levels of proteinuria, or different renal pathologic lesions remains unknown. We retrospectively
studied 1147 patients with IgAN from the European Validation Study of the Oxford Classification of IgAN
(VALIGA) cohort classified according to the Oxford-MEST classification and medication used, with details
of duration but not dosing. Overall, 46% of patients received immunosuppression, of which 98% received
CS. Treated individuals presented with greater clinical and pathologic risk factors of progression. They
also received more antihypertensive medication, and a greater proportion received renin angiotensin
system blockade (RASB) compared with individuals without immunosuppressive therapy. Immunosuppression
was associated with a significant reduction in proteinuria, a slower rate of renal function decline,
and greater renal survival. Using a propensity score, we matched 184 subjects who received CS and RASB
to 184 patients with a similar risk profile of progression who received only RASB. Within this group, CS
reduced proteinuria and the rate of renal function decline and increased renal survival. These benefits
extended to those with an eGFR#50 ml/min per 1.73 m2, and the benefits increased proportionally with
the level of proteinuria. Thus, CS reduced the risk of progression regardless of initial eGFR and in direct
proportion to the extent of proteinuria in this cohort.