Blood test helps predict relapse in patients with autoimmune disease affecting the kidneys

In patients with an autoimmune disease that often involves the kidneys, monitoring the blood for autoantibodies may help doctors predict the chance of relapse, according to a study appearing in the Journal of the American Society of Nephrology (JASN).

Patients with an autoimmune disorder called anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis produce antibodies that damage blood vessels in the body. Relapses of the disorder can cause severe and permanent damage to organs and other parts of the body. Jan Willem Cohen Tervaert, MD, PhD, Michael Kemna (Maastricht University, The Netherlands), and their colleagues wondered whether blood levels of ANCA autoantibodies could be used to predict a patient’s risk of relapse.

The researchers followed 166 patients with ANCA-associated vasculitis, 104 of whom had kidney problems associated with their disease and 62 of whom did not. During an average follow-up of 49 months and 18 ANCA measurements, 89 ANCA increases and 74 relapses were recorded. Among patients with kidney involvement, ANCA increases were linked with an 11-fold increased risk of relapse. Among patients without kidney involvement, ANCA increases were associated only weakly with relapses.

“By measuring ANCA levels in patients with kidney involvement, doctors can predict which patients are going to relapse. It is expected that by using ANCAs as a guideline, severe relapses necessitating dialysis can be prevented,” said Dr. Tervaert.

In an accompanying editorial, Ulrich Specks, MD (Mayo Clinic) noted that single-center studies like this one “provide useful information that hones our awareness of the different performance of biomarkers in different patient populations, and such observations warrant validation in similar cohorts.”

Study co-authors include Jan Damoiseaux, PhD, Jos Austen, Bjorn Winkens, PhD, Jim Peters, and Pieter van Paassen, MD, PhD.

The article, entitled “ANCA as a Predictor of Relapse: Useful in Patients with Renal Involvement But Not in Patients with Nonrenal Disease,” and the editorial, entitled “Accurate Relapse Prediction in ANCA-Associated Vasculitis–the Search for the Holy Grail," appear online at http://jasn.asnjournals.org