The leukocyte composition of peripheral blood buffy coat.

To assist in the interpretation of buffy coat smears from leukopenic patients, we determined the composition of the buffy coat of the blood of normal volunteers. Leukocytes were concentrated by centrifugation in microhematocrit tubes. Stained smears of these cells showed minor differences in the proportions of neutrophils, lymphocytes, and monocytes when compared to unconcentrated peripheral blood. Granulocytes of greater immaturity than the metamyelocyte were not encountered, and their presence should suggest the possibility of marrow dysfunction. Occasional young monocytoid cells and "stimulated" lymphocytes were seen.

Sickle cell anemia: erythrokinetics, blood volumes, and a study of possible determinants of severity.

The variability in the clinical expression of sickle cell anemia led us to study factors which might influence the course of this disease. We examined erythrokinetics, blood volumes, and variables which influence hemoglobin function in a group of adults with sickle cell anemia of varying degrees of clinical severity. We were unable to correlate any single measurement with the clinical course; however, our patient sample was small and the data suggested areas for further study. An expansion of plasma volume noted in all patients. This made it difficult to predict red cell mass from the hemoglobin level, which consistently underestimated its magnitude. The red cell production index and iron turnover values indicated that there is often a suboptimal erythropoietic response to anemia in sickle cell disease.

Hemoglobin Hope: studies of oxygen equilibrium in heterozygotes, hemoglobin S-Hope disease, and isolated hemoglobin Hope.

Hemoglobin Hope (beta(H14)136gly leads to asp), a mildly unstable variant, was found to have decreased oxygen affinity, a normal Bohr effect and diminished cooperativity. Decreased oxygen affinity of hemoglobin Hope may explain the previous failure to find an appropriate response to hemolysis in individuals studied who were heterozygous for both hemoglobin Hope and sickle hemoglobin. Salt bridge formation between NA1 valine and H14 aspartic acid may stabilize the beta Hope subunit in its deoxy form thus producing intrinsically low oxygen affinity and reduced cooperativity.

Circulating micromegakaryocytes signaling blast transformation of chronic myeloid leukaemia.

A patient with chronic myeloid leukaemia had numerous micromegakaryocytes in the peripheral blood and bone marrow appearing coincidentally with the onset of blast crisis. These cells were initially confused with lymphocytes because of their size, configuration and scanty cytoplasm. The true identification of these cells can be suspected by careful scrutiny of well prepared Wrights stained preparations and proven electronmicroscopically. Such marked dysplasia of the megakaryocyte series appears to be a poor prognostic sign in chronic myeloid leukaemia.

Clinical, hematologic and biosynthetic studies in sickle cell-betao-thalassemia: a comparison with sickle cell anemia.

The diseases commonly confused with sickle cell anemia include sickle cell beta-thalassemia in which synthesis of betaA-chains are completely suppressed (HbS-betao-thalassemia). We obtained hematologic measurements and studied globin biosynthesis in five patients with this disorder and compared the results with those obtained in five patients with "mild" sickle cell anemia and seven individuals with sickle cell-beta-thalassemia having hemoglobin A levels of 20-30% (HbS-beta+-thalassemia). A distinction between HbS-betao-thalassemia and sickle cell anemia was not always possible on clinical, hematologic, or electrophoretic grounds. Thalassemia heterozygotes had hypochromia and microcytosis, not generally a feature of sickle cell anemia, although overlap of values did exist. The ratio of alpha to non-alpha, or alpha to betaS-chains in sickle cell anemia approximated unity, whereas patients with HbS-betao-thalassemia had a deficit of beta-chain production relative to that of the alpha-chain. The differentiation of HbS-betao-thalassemia and sickle cell anemia can be best made on the basis of family or biosynthetic study. We estimated the regional prevalence of HbS-betao-thalassemia to be 1:23,000 of the black population.

Alpha thalassaemia in adults with sickle-cell trait.

Mild forms of alpha thalassaemia are difficult to detect in adults. Since alpha thalassaemia existing with structural defects of the beta chain of haemoglobin may lead to decreased levels of the abnormal haemoglobin, we examined individuals having sickle-cell trait for the possible coexistence of alpha thalassaemia. Patients with sickle-cell trait having haemoglobin-S (Hb-S) levels less than commonly expected were compared to two control groups--one with sickle-cell trait and the usual levels of Hg S and one with normal haemoglobin. Twenty-one patients with sickle-cell trait having Hb-S concentrations below 35% had 65.8% Hb A, 31.8% Hb S, and a mean corpuscular volume of 81.6 fl. Studies of the relative rates of alpha-, betaS- and betaA-chain synthesis in 14 of these individuals showed a mean alpha:beta ratio of 0.76. In patients with normal haemoglobin as well as in sickle-cell trait with Hb-S levels above 35%, this ratio was unity. These findings are consistent with the presence of alpha thalassaemia in patients with sickle-cell trait who have lower than usual levels of Hb S and microcytosis.