SERUM AND URINE BETA-2-MICROGLOBULIN IN HEMOPHAGOCYTIC SYNDROME

Background. Previous reports suggesting a correlation between lymphopr oliferative disease and serum levels of beta-2-microglobulin (beta-2M) and in vitro data indicating a role of cytokines in the production of beta-2M prompted a study of serum and urine beta-2M concentration in patients with hemophagocytic syndrome (HPS), because no data were prev iously available for HPS, a pathologic state associated with excessive cytokines secreted from activated reactive/malignant lymphocytes and histiocytes. Methods. Serum and urine beta-2M levels were measured in six children with HPS during active and convalescent phase and in othe r diseases. Results. Serum and urine beta-2M levels during active phas e HPS were significantly high not only in serum (median, 7.5 mg/l; ran ge, 2.3-16.0 mg/l; P < 0.01), but also in urine (median, > 31,650 mu g /gram Creatinine (gCr); range, 8179-236,333 mu g/gCr; P < 0.01), compa red with levels during convalescent phase HPS (median, 2.0 mg/l; range , 0.9-2.5 mg/l in serum and median, 338 mu g/gCr; range, 223-585 mu g/ gCr in urine) and in control subjects with diseases such as acute lymp hocytic leukemia (median, 2.3 mg/l; range, 1.0-2.8 mg/l in serum and m edian, 327 mu g/gCr; range, 48-2684 mu g/gCr in urine), infectious mon onucleosis (median, 2.9 mg/l; range, 2.5-5.5 mg/l in serum and median, 348 mu g/gCr; range, 80-1325 mu g/gCr in urine), and Kawasaki disease (median, 2.8 mg/l; range, 1.5-3.3 mg/l in serum and median, 1016 mu g /gCr; range, 214-4500 mu g/gCr in urine). Noteworthy was the observati on that urine beta-2M levels correlated closely with HPS disease activ ity. Conclusions. Urine beta-2M appears to be a useful marker for asse ssing disease activity in patients with HPS.