THE IMPACT OF ELEVATED SERUM IGA AND RACE ON PRIMARY RECIPIENT RENAL-ALLOGRAFT SURVIVAL

This study correlated overall serum IgA levels in pretransplant (preTx ) sera with graft survival, IgA levels, determined by nephelometry, we re normally distributed, with a mean level of 255+/-139 mg/dl and a me dian of 234 mg/dl in 631 adult primary kidney allograft recipients and a mean level of 213+/-123 mg/dl with a median of 196 mg/dl for 100 re transplant recipients, Improved 3-year survival was associated with a high preTx IgA serum level in primary recipients (Kaplan-Meier analysi s, P=0.01), but not in retransplant patients, After stratifying by rac e, IgA correlated with graft survival in Caucasian, Hispanic, and ''ot her'' (Middle Eastern, Indian subcontinent, and Asian) primary recipie nts (P less than or equal to 0.04), but not in African Americans, High er survival rates were not associated with IgA in primary recipients s tratified for rejection episodes, blood transfusions, or HLA-DR mismat ches, Graft survival was improved in patients with >2 HLA-AB mismatche s and serum IgA above the median, PreTx IgA level and IgA alpha-HLA ac tivity were significantly associated in preTx sera of primary renal al lograft recipients (chi(2)=7.145, P=0.01), although only 9% (12/133) o f sera tested displayed IgA anti-HLA class I reactivity, Thus, enhance d graft survival mediated by elevated serum IgA levels may due in part to competition for allograft HLA class I binding with deleterious Ig subclasses or immune effector cells, Elevated serum IgA may also refle ct an altered immunoregulatory state. The results suggest that, depend ing on the racial group, preTx serum IgA levels are a prognostic indic ator of graft survival in primary renal allograft recipients.