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Hemoglobin (Hb) Koln-beta zero thalassemia compound heterozygosity was discovered in a young Greek patient. This gave us the unique opportunity for studying the functional properties of this unstable high-oxygen affinity hemoglobin variant in red cells containing almost pure Hb Koln. The red cells of the proposita exhibit morphological alterations and hematologic indices corresponding to the presence of an unstable Hb and beta thalassemia. Globin chain synthesis confirmed the association with a beta zero thalassemia gene. Oxygen-binding curves for these cells were biphasic, indicating the presence of both heme- saturated and of approximately 20% of non-cooperative Hb Koln. The major component exhibits an increased oxygen affinity, reduced cooperativeness, and normal alkaline Bohr effect. The 35-year-old proposita is active, has not been splenectomized, and has not been transfused in several years.

Hemoglobin variants can be successfully identified in cord blood samples. The methods most commonly used include cellulose acetate (CAC) and citrate agar (CAG) electrophoresis. Recently thin layer isoelectric focusing (TLIF) has been shown to be an excellent method for identifying hemoglobin variants. To determine the applicability of TLIF for cord blood screening, we compared the results of 835 samples obtained by TLIF with that obtained by CAC, CAG, and the combination of both CAC and CAG. In 100 of these samples we detected an abnormal hemoglobin pattern using TLIF. In contrast, we detected only 80 abnormal samples by CAC, 70 by CAG, and 80 by using the combination of CAC and CAG. Due to the increased resolution provided by TLIF, we correctly diagnosed two sickle cell trait samples by TLIF that were incorrectly suspected to be homozygous for sickle cell disease by CAC and CAG. We identified 41 samples containing Bart's hemoglobin by TLIF in contrast to only 21 using CAC and 14 using CAG. The time and cost of TLIF was comparable to that using the combination of both methods. We, therefore, conclude that TLIF is the method of choice for cord blood screening.

Total calcium content, determined by atomic absorption spectroscopy, Ca2+ influx, and cytosolic free Ca2+ concentration ([Ca]1), estimated by a method involving the incorporation of a Ca2+ chelator (Quin 2), were measured in erythrocytes from β-thalassemic (β-thal) and hemoglobin C (CC) patients. Elevation of the total calcium content was observed in the cells from all patients, particularly in CC and splenectomized β-thal. However, [Ca]1was within the normal range (-25 nmol/L) in all the pathologic cells. Ca2+ influx in CC cells and in cells from nonsplenectomized β-thal patients was also within the same range as that observed in control erythrocytes. In cells from splenectomized β-thal patients, the kinetic of 45Ca influx was biphasic, indicating the existence of two pools of exchangeable Ca2+. Density fractionation of the cells from one splenec- tomized β-thal patient showed that the rapid pool corresponded to the lightest cell fraction, which was also found to have the highest calcium content. The dense cells exhibited a normal Ca2+ influx as well as a smaller increase in total calcium content. It is suggested that, as in sickle cell anemia, the excess of Ca2+ in β-thal cells is not free in the cytoplasm but trapped within endocytic vacuoles, especially in a population of abnormal cells that are normally removed by the spleen. In CC patients, who have a functional spleen, a different mechanism could be responsible for the calcium retention. In conclusion, the present results demonstrate that in these two cases of hemolytic anemia associated with high calcium content, Ca2+ permeability and the level of cytosolic Ca2+ are normal.© 1987 by Grune & Stratton, Inc.0006-4971/87/7003-0031$3.00/0

Total calcium content, determined by atomic absorption spectroscopy, Ca2+ influx, and cytosolic free Ca2+ concentration ( [Ca]i), estimated by a method involving the incorporation of a Ca2+ chelator (Quin 2), were measured in erythrocytes from beta-thalassemic (beta-thal) and hemoglobin C (CC) patients. Elevation of the total calcium content was observed in the cells from all patients, particularly in CC and splenectomized beta-thal. However, [Ca]i was within the normal range (approximately 25 nmol/L) in all the pathologic cells. Ca2+ influx in CC cells and in cells from nonsplenectomized beta-thal patients was also within the same range as that observed in control erythrocytes. In cells from splenectomized beta-thal patients, the kinetic of 45Ca influx was biphasic, indicating the existence of two pools of exchangeable Ca2+. Density fractionation of the cells from one splenectomized beta-thal patient showed that the rapid pool corresponded to the lightest cell fraction, which was also found to have the highest calcium content. The dense cells exhibited a normal Ca2+ influx as well as a smaller increase in total calcium content. It is suggested that, as in sickle cell anemia, the excess of Ca2+ in beta- thal cells is not free in the cytoplasm but trapped within endocytic vacuoles, especially in a population of abnormal cells that are normally removed by the spleen. In CC patients, who have a functional spleen, a different mechanism could be responsible for the calcium retention. In conclusion, the present results demonstrate that in these two cases of hemolytic anemia associated with high calcium content, Ca2+ permeability and the the level of cytosolic Ca2+ are normal.

Hemoglobin (Hb) Köln-beta° thalassemia compound heterozygosity was discovered in a young Greek patient. This gave us the unique opportunity for studying the functional properties of this unstable high-oxygen affinity hemoglobin variant in red cells containing almost pure Hb Köln. The red cells of the proposita exhibit morphological alterations and hematologic indices corresponding to the presence of an unstable Hb and beta°thalassemia. Globin chain synthesis confirmed the association with a beta°thalassemia gene. Oxygen-binding curves for these cells were biphasic, indicating the presence of both heme-saturated and of approximately 20% of non-cooperative Hb Köln. The major component exhibits an increased oxygen affinity, reduced cooperativeness, and normal alkaline Bohr effect. The 35-year-old proposita is active, has not been splenectomized, and has not been transfused in several years.