Absence of proteinuria good prognostic sign in IgA nephropathy

By Lauretta Ihonor, medwireNews Reporter

The presence of normal renal function and minor urinary abnormalities indicates a good long-term prognosis among Caucasian patients with immunoglobulin (Ig)A nephropathy, say Spanish researchers.

"We demonstrate that the long-term prognosis of this type of patient is excellent and that no special treatments other than those needed to lower blood pressure or treat increasing proteinuria are indicated," said lead researcher Eduardo Gutiérrez (Hospital 12 de Octubre, Madrid).

As the findings apply only to patients of Caucasian ancestry, further study will be needed to determine if these deductions extend to other populations, add Gutiérrez and co-investigators in the Journal of the American Society of Nephrology.

The team assessed renal biopsies obtained from 141 Caucasian patients, aged a mean of 23.7 years, with biopsy-proven IgA nephropathy.

All presented with microhematuria, normal renal function (mean serum creatinine of 0.8 mg/dL; estimated GFR of 111 mL/min per 1.73 m²), and a low mean proteinuria level of 0.2 g/24 hours.

Over a mean follow-up period of 9 years, no patient developed end-stage renal disease, despite no use of corticosteroid or immunosuppressant therapy among the group throughout follow up.

In all, 37.5% of patients experienced clinical remission after a mean period of 4 years.

Renal survival, defined as no more than a 50% increase in baseline blood creatinine, was common among the group.

Specifically, 96.7%, 91.9%, and 91.9% of patients had renal survival at 10, 15, and 20 years, respectively.

Gutiérrez described his team's findings as "reassuring" because they contradict IgA nephropathy's existing reputation as a progressive disease that requires treatment in all cases.

In light of the findings, the researchers say that "the performance of a diagnostic renal biopsy might be unnecessary given the excellent prognosis of our patients."

However, they recommend that IgA nephropathy patients who present with normal renal function should be regularly monitored for proteinuria increase or development of hypertension.

"In such cases, RAS [renin-angiotensin system] blockade should be prescribed," conclude Gutiérrez and colleagues.

Licensed from medwireNews with permission from Springer Healthcare Ltd. ©Springer Healthcare Ltd. All rights reserved. Neither of these parties endorse or recommend any commercial products, services, or equipment.