Distribution of Abnormal Hemoglobins in Puerto Rico and Survival Studies of Red Blood Cells Using Cr51

Abstract

1. A survey of the incidence of abnormal hemoglobins in different racial groups distributed over the island of Puerto Rico was performed. The relation of the rate of destruction of red cells to the presence of abnormal hemoglobin patterns in the affected population was also studied. 2. The abnormal hemoglobins were classified by the difference in paper electrophoretic mobility. Fetal hemoglobin was measured by its resistance to alkaline denaturation. The red cell life span was determined by measuring the survival of erythrocytes labelled with radioactive sodium chromate. 3. A total of 2,089 inhabitants were studied. There were 1,487 white subjects and 602 Negroes. Forty-two individuals were found to harbor abnormal hemoglobins. All but one were Negroes or Negroid of African descent, and their relative numbers agreed closely with the geographical distribution of ethnic groups in the island. Abnormal hemoglobins were found in 2.01 per cent of the entire series of 2,089 persons, but in those considered Negroes or Negroids the incidence of abnormal hemoglobins was 6.8 per cent. Of the 42 persons showing abnormal hemoglobins, thirty-four or 81 per cent, had hemoglobin S; only two of these had sickle cell anemia. The incidence of the sickle cell trait among the Puerto Rican Negro population was 5.2 per cent; and the incidence of hemoglobin S disease among those harboring the trait was 5.9 per cent. Eight, or 19 per cent of the abnormal cases had hemoglobin C; only one of these had hemoglobin C disease with clinical hemolytic anemia. The incidence of the hemoglobin C trait among the Puerto Rican Negro population is 1.3 per cent; and the incidence of hemoglobin C disease among those harboring the trait may reach 12.5 per cent. 4. All 42 cases harboring abnormal hemoglobins showed very small quantities of fetal or alkali-resistant hemoglobin ranging from 0.45 per cent to 3.25 per cent, averaging 1.12 per cent. 5. The "apparent" half-life of the red blood cells was found to be 10 days in sickle cell anemia, 7 days in SC disease, 20.6 days in cases of hemoglobin SA, 18.5 days in one case of hemoglobin C disease and 21.5 days in 2 cases of the combination CA. The normal "apparent" half-life in our laboratory is 24.5 days.

The Sickle Effect: The Silent Titan Affecting Glycated Hemoglobin Reliability

“…The two earlier studies using Ashby technic showed normal results [22,23]. In one, using 51 Cr, two SCT patients had normal results [21], while in another study [20], 30 patients with SCT showed a reduced average half-life of RBCs from 24.5 days to 20.6 days.…”

“…These studies have a relatively small number of SCT participants, and the study with the highest number of SCT patients (more than the other five studies combined) showed a decrease in RBC survival, which we are more inclined to consider based on the quantity of SCT patients [20]. The studies' discrepancies are possibly due to methodology, an insufficient number of SCT participants, the inclusion of S-β thalassemia patients, and possible interference from concomitant diseases.…”

Measurement of Hemoglobin A1c in Patients With Sickle Cell Trait

“…Although data are limited, the presence of HbS is thought to result in a shorter lifespan for red blood cells, which would result in less time available for hemoglobin glycation and hence lower HbA 1c values. 2,3 The available data do not allow us to distinguish whether our findings are attributable to biological differences between those with and without SCT or analytic interference by SCT with these particular HbA 1c assays.…”

“…The methods used to measure HbA 1 c were the Tosoh 2.2 and Tosoh G7 (variant mode) ion-exchange highperformance liquid chromatography systems; the authors noted that the NGSP website lists these methods as not having clinically significant interference in those with SCT. 2 However, they acknowledged in the discussion section that the NGSP defines "clinically significant" as a relative bias exceeding plus or minus 7% and that therefore "the possibility of minor interference that could potentially explain our findings cannot be ruled out." 1 We would argue that the differences observed between patients with and without SCT are, in fact, due to analytical interference with the Tosoh 2.2 and G7 (variant mode) methods.…”

Influence of hemoglobinopathies and glucose-6-phosphate dehydrogenase deficiency on diagnosis of diabetes by HbA1c among Tanzanian adults with and without HIV: A cross-sectional study

“…Hemoglobin A (HbA) represents over 90% of hemoglobin in healthy red blood cells (RBCs) among normal individuals, but individuals with SCT have 30-40% as hemoglobin S (HbS) [5,6]. The presence of HbS may be associated with shorter RBC life span [7], which may reduce the time for hemoglobin glycation, leading to underestimation of glucose level by HbA1c tests. Few studies have investigated the suitability of HbA1c in diabetes diagnosis among individuals with SCD/SCT and results have been inconsistent.…”