Increased but stable isoagglutinin titers in hemodialysis patients

Background: Prior to an ABO incompatible kidney transplantation it is important to know the recipient’s pre-transplantation anti-A and/or anti-B (isoagglutinin) titer. This study determined if pre-transplantation isoagglutinin titers remained stable, over a period of 1 year, among hemodialysis patients. Method: Blood was collected four times, every 3 months from 54 hemodialysis patients (hemodialysed trice per week ≥ 6 months), and 56 healthy volunteers. Measurement of anti-A and anti-B (IgM and IgG) titers were performed on an automated solid phase analyzer. The titers were converted to log₂ titer steps (e.g., titer 32 = titer step 5). Results: Within blood group O, mean IgG anti-A and anti-B titers were significantly higher in the hemodialysis patients (n = 22, mean titer step: anti-A: 6.4 and anti-B:4.9), compared to the healthy volunteers [n = 19, mean titer step: anti-A: 4.9 and anti-B:3.5, p = 0.02 (anti-A) and p = 0.03 (anti-B)], despite blood group O hemodialysis patients having significantly lower total plasma IgG levels (median 8.1 g/L) than healthy volunteers (11.1 g/L, p = 0.001). Neither age, nor gender determined IgG anti-A or anti-B titers. In hemodialysis patients and healthy volunteers, the upper 95% confidence limit of anti-A and anti-B titer variation (IgM and IgG) during 1 year, did not exceed 1.0 titer step in any of the ABO groups. Conclusions: Anti-A and -B titers (IgM and IgG) remained stable in both the hemodialysis patients and healthy volunteers over a period of approximately 1 year. Blood group O hemodialysis patients had, despite lower total IgG levels, significantly elevated IgG anti-A and -B titers.