False elevations of glycosylated hemoglobin levels are well known in situations such as chronic renal failure. hemoglobinopathy and in the administration of certain drugs. We report a case of a 67-year-old reasonably well-controlled diabetic patient who showed marked dissociation of HbA, and HbA, c levels after introduction of the anti-neoplastic agent hydroxyurea (HU) for treatment of concomitant chronic myelogenous leukemia (CML). Analysis of glycosylated hemoglobin revealed that the false elevation of HbA, level was largely due to the increased synthesis of HbF induced by HU. In addition in vitro incubation of the patient's washed erythrocytes in the presence of heated HU for 5 days caused substantial elevations of both HbA, a d-b and HbA, c levels, suggesting the possible formation of carbamylated counterparts. As HU is frequently used in the treatment of myeloproliferative disorders, it should be noted that this drug is capable of inducing false elevation of HbA, levels.
Elevated serum concentrations of ganglioside antigen CA19-9 has been often found in poorly-controlled diabetes mellitus. However, this phenomenon is not constantly observed in all cases. To analyse the mechanism of CA19-9 and CA50 elevation, eighteen poorly-controlled diabetic patients who were confirmed not to have malignancy by thorough examinations, were investigated for Lewis phenotypes (Le), because Lea has the same epitope as CA19-9. Patients were divided into three groups according to the phenotype of Lewis blood type as follows: group A (A): 6 patients with Le (a+b-); group B (B): 8 patients with Le (a-b+); and group C (C): 4 patients with Le (a-b-). Each group was similar in age range (A: 55.7+12.8, B: 46.0±15.6, C: 62.0±21.0 years old), hemoglobin Al c level (A: 12.78±0.89, B: 12.03±1.02, C: 13.58+3.21%) and serum fructosamine level (A: 5.33±0.28, B: 4.81±0.59, C: 5.45±1.46 mmol/l). The CA19-9 levels were highest in A (91.7±45.9 U/m l), moderately elevated in B (27.9±8.6 U/m/) and low in C (6.3±1.9 U/ml)(A vs B: p<0.01, A vs C and B vs C: p<0.05). The CA50 levels were highest in A (43.3±20.6 U/ml), moderately elevated in B (17.1±13.9 U/m l) and low in C (1.2±0.5 U/ml)(A vs B: p<0.01, A vs C and B vs C: p<0.05). These results indicate that elevated serum CA19-9 level in diabetic patients with poor metabolic states is closely related to Lewis phenotype and suggest that the mechanism of CA19-9 and CA50 elevation in diabetic patients is different from that in patients with neoplasms such as pancreatic cancer.