AN INVERSE RELATIONSHIP BETWEEN IMMUNOGLOBULIN G AND ALPHA-2 MACROGLOBULIN IN MINIMAL-LESION IDIOPATHIC NEPHROTIC SYNDROME

摘要

Patients with minimal-lesion nephrotic syndrome (MLNS) in relapse have hypogammaglobulinemia that is not solely explained by urinary losses, suggesting a defect in synthesis. Alpha-2 macroglobulin (alpha-2M) is elevated in MLNS (during relapse). Alpha-2M and IgG were measured by radial immunodiffusion in 18 patients with MLNS, during relapse and remission. During relapse mean (± 1 SD) alpha-2M was 896 ± 213 mg/dl; mean IgG was 218 ± 128 mg/dl. During remission mean alpha-2M was 422 ± 143 mg/dl; IgG was 493 ± 85 mg/dl. During relapse patients with the highest alpha 2-M had the lowest levels of serum IgG. 24 paired measurements were further analyzed and yielded an inverse log linear relationship. Although the mechanism for elevation of alpha-2M is unknown, we hypothesize that alpha-2M (which is known to have immunodepressant properties) specifically depresses IgG synthesis in MLNS, predisposing such patients to serious infection. Further studies of B-cell function in MLNS are in progress. The increase in alpha-2M may also account for altered T-lymphocyte function in MLNS.