Serum erythropoietin titers in patients with chronic renal failure measured by fetal mouse liver cell assay
Acta Haematologica Japonica 44(6): 1089-1096
Despite the significant anemia, serum erythropoietin (ESF) titers in patients with chronic renal failure (CRF) cannot be accurately determined with polycythemic mouse bioassay system; it was previously thought that inappropriate production of ESF was a major cause of renal anemia. It was previously shown that serum ESF titers in patients with CRF measured by some assay systems were not always lower than that of normal controls. Serum ESF titers in patients with CRF were investigated with a new in vitro bioassay system using fetal mouse liver cells (FMLC). Patients (29) with CRF included 4 mild cases whose serum creatinine levels (sCr) were < 6.0 mg/dl, 2 predialysis cases and 2 hemodialysis cases. The hemodialysis cases consisted of 13 males and 10 females with ages ranging from 20-69 yr. Included with the cases of CRF, 5 patients suffered from chronic glomerulonephritis (CGN), 4 suffered from renal tuberculosis, 1 suffered from chronic pyelonephritis, 1 suffered from hydronephrosis and CGN and the remaining 18 were undetermined. Normal controls consisted of 8 males ranging in age from 24-35 yr. Serum ESF titers of normal controls ranged from 4.0-84.8 mU/ml, averaging 37.5 .+-. 9.8 (mean .+-. SEM). Serum ESF titers from 29 patients with CRF were variable; they were below 50 mU/ml in 6 cases, from 50-100 mU/ml in 7 cases and > 100 mU/ml in 16 cases. The levels of serum creatinine, hemoglobin and serum ESF in patients with CRF in each stage were 4.0 .+-. 0.7 mg/dl, 10.1 .+-. 0.7 g/dl, 94.5 .+-. 28.0 mU/ml in mild cases, 10.5 .+-. 0.6 mg/dl, 4.9 .+-. 1.6 g/dl, 109 .+-. 18.4 mU/ml in predialysis cases and 12.5 .+-. 0.8 mg/dl, 7.6 .+-. 0.3 g/dl, 142.1 .+-. 23.7 mU/ml in hemodialysis cases. Serum ESF titers of male dialysis cases were significantly higher than those of female dialysis cases (P < 0.01); there was a correlation between serum ESF titers and ages (r = 0.48, P < 0.05), but there was no correlation between serum ESF titers and hemoglobulin levels, periods of dialysis and serum creatinine levels. Although serum ESF titers in patients with CRF were not necessarily lower than those of normal controls, the amount of ESF is not enough. Apparently, renal anemia may partially result from an inability to produce ESF needed for the degree of anemia.