Objective: Alpha-thalassemia is frequently encountered in eastern Saudi Arabia. We wanted to find out laboratory based incidence and laboratory features of Hemoglobin H disease in the Dammam region.
Methods: We retrospectively analyzed the results of Hemoglobin electrophoresis carried out during the last 5 years in our laboratory. Hemoglobin electrophoresis was performed on cellulose acetate, pH 8.6 using Helena or Biomidi kits. Hemoglobin S was confirmed by sickle solubility test. Variant hemoglobin if present, was confirmed by citrate agar (pH 6.0) electrophoresis. Helena rapid electrophoresis system was used for plate densitometry. The diagnosis of Hemoglobin H disease was made on the basis of the presence of Hemoglobin H on electrophoresis supplemented by demonstration of Hemoglobin H inclusions in red blood cells.
Results: Fifteen thousand, four hundred and ninety two blood samples were analyzed by Hemoglobin electrophoresis. We found 100 cases of Hemoglobin H disease, only one case was non-Saudi. The age ranged between 45 days to 85 years. There were 51 females and 49 males. Children (less than 12 years) were 35 and of adults there were 65. There were 35 adult females and 30 adult males. The mean +/- standard deviation of Hemoglobin H in children was 13.54 +/- 7, in adult females the mean +/- standard deviation of Hemoglobin H was 12 +/- 5.4, and in adult males it was 11.99 +/- 6.4. The Hemoglobin H inclusions seen in red blood cells ranged from 2.6-80 in children and 10-80 in adults. The sickle cell trait was co-existent in 7 cases. Hemoglobin Bart's along with Hemoglobin H was seen in 32 cases. Hemoglobin F was present, beyond first year of life in 34 cases. The Hemoglobin A2 as measured by densitometry was significantly low in all of the 3 age groups as compared to corresponding controls. The complete blood count results were available for analysis in only 26 cases of Hb H disease. The mean +/- SD values of Hb (g/dl), Hct (ratio), MCV (fl), MCH (pg) MCHC (g/dl), RDW-SD (fl) and RDW-CV (%) in these patients (all age groups together) were 8.15 +/- 1,.278 +/-.04, 59.4 +/- 5.8, 17.65 +/- 2.1, 29.4 +/- 1.7, 37.8 +/- 8.7 and 25.1 +/- 4.6. The mean Hb, Hct, MCV, MCH and MCHC were significantly reduced in all 3 age groups as compared to corresponding controls. RBC counts and RDW-CV were elevated in Hb H disease compared to corresponding controls. The blood film showed typical red cell morphology.
Conclusion: Hb H disease is not infrequently encountered in the Dammam region. This condition should be kept in mind while evaluating patients for anemia. The genetic studies to determine the exact alpha-thalassemia determinants producing Hb H disease in eastern Saudi Arabia are needed.