Hemoglobin Abraham Lincoln, beta32 (B14) leucine leads to proline. An unstable variant producing severe hemolytic disease.

An unstable hemoglobin variant was identified in a Negro woman with hemolytic anemia since infancy. A splenectomy had been performed when the patient was a child. The anemia was accompanied by erythrocyte inclusion bodies and excretion of darkly pigmented urine. Neither parent of the proposita demonstrated any hematologic abnormality, and it appeared that this hemoglobin variant arose as a new mutation. Erythrocyte survival in the patient was greatly reduced: the erythrocyte t(1/2) using radiochromium as a tag was 2.4 days, and a reticulocyte survival study performed after labeling the cells with L-[(14)C]leucine indicated a t(1/2) of 7.2 days. When stroma-free hemolysates were heated at 50 degrees C, 16-20% of the hemoglobin precipitated. The thermolability was prevented by the addition of hemin, carbon monoxide, or dithionite, suggesting an abnormality of heme binding. An increased rate of methemoglobin formation was also observed after incubation of erythrocytes at 37 degrees C. The abnormal hemoglobin could not be separated from hemoglobin A by electrophoresis or chromatography, but it was possible to isolate the variant beta-chain by precipitation with p-hydroxymercuribenzoate. Purification of the beta-chain by column chromatography followed by peptide mapping and amino acid analysis demonstrated a substitution of proline for beta32 leucine. It appears likely that a major effect of this substitution is a disruption of the normal orientation of the adjacent leucine residue at beta31 to impair heme stabilization.

Acute lymphoblastic leukemia of NK-cell lineage: responses to IL-2.

Acute lymphoblastic leukemias with phenotypic characteristics of natural killer cell derived lineage are extremely uncommon. We identified an ALL with a phenotype consistent with an NK-cell of origin. The blasts underwent a proliferative response to r-IL2 in culture but showed no spontaneous or r-IL2 or gamma-INF induced cytotoxicity. With r-IL2 stimulation however, the tumor cells demonstrated a dramatic acquisition of low density CD8 surface positivity and a loss of CD11b expression after short term culture. By comparison to ALL of B or T lineage, NK ALL likely represents an early stage of bone marrow derived NK-cell precursor.

Hepatoma associated with anabolic steroid therapy.

A patient with Fanconi's anemia who developed a hepatoma after 50 months of therapy with anabolic steroids is reported. The lesion presented as a cold focal defect on a Tc99m sulfur colloid scintigram, but was avascular on dynamic scintigraphy. Both the unusual avascularity of the hepatoma, and its association with anabolic steriod therapy are discussed.