Baker H. Al-Awamy

Relationship of haemoglobin F and alpha thalassaemia to severity of sickle-cell anaemia in the Eastern Province of Saudi Arabia.

To define the natural history of sickle cell anaemia a cord blood screening programme was initiated and during the first 3 years a total of 129 newborns with FS phenotype were detected, of whom 83 infants were followed up regularly. Forty-three of them had attained the ages of between 1 and 3 years and the analysis of their data revealed that in 21 of 43 cohort children (14 FS and 7 FS + Barts) who had almost identically raised levels of haemoglobin F, the clinical manifestations of the disease appeared to be influenced by the size of the RBC, with the microcytic group having a relatively milder clinical course as compared with the normocytics. Similar observations were made in about 50% (47/93) of non-cohort older children and adults with sickle-cell anaemia, suggesting that alpha thalassaemia in combination with increased levels of fetal haemoglobin was probably an important predictor of the clinical severity in patients with sickle-cell anaemia in the Eastern Province of Saudi Arabia.

Priapism in Association with Sickle Cell Anemia in Saudi Arabia

A questionnaire study of 42 Saudi patients with sickle cell anemia revealed that none of them had ever suffered from priapism. A comparison of hematological parameters between Jamaican priapism patients and Saudi non-priapism patients suggested that high Hb F levels and hypochromic microcytosis in Saudi patients might play an important role in preventing this complication.

877 SICKLE CELL ANEMIA IN SAUDI ARABIA: SPECULATIONS ABOUT REGIONAL VARIABILITY IN FREQUENCY AND SEVERITY

The Hb S gene is widely distributed in Saudi Arabia with a prevalence of 5% in parts of the Western (Red Sea) area and 24% in parts of the Eastern (Gulf) region. We compared hematological data of Hb SS patients from Jeddah (west) and Dammam (east).Compared to Jeddah and American patients, Dammam patients were less anemic, more microcytic, had higher HbF levels. Most retained splenic function. We speculate that the Hb S gene may have entered the southwestern Arabian peninsula from Africa in antiquity. As it progressed northeasterly it interacted with other endemic, genetic traits in isolated populations (α thal, h HPFH, etc.). These interactions ameliorated HbSS disease reducing hemozygous lethality. Reproduction by homozygotes, a high rate of consanguinity and the selective advantage of endemic falciparum malaria could have combined to produce the high prevalence of the HbS gene found in the eastern regions today.These preliminary studies indicate a wide and unique variability of sickle cell hemoglobinopathies of the Arabian Peninsula.

Stage IV non-Hodgkin's lymphoma in children

Twenty-five children with previously untreated stage IV non-Hodgkins lymphoma (NHL) were studied. At the time of evaluation 16 patients were disease-free (64%), with a median observation time of 23 months. Intensive chemotherapy for childhood NHL provides a better outlook for these patients, including those who would be considered high-risk acute lymphoblastic leukemia (ALL).

INFLUENCE OF Hb F AND α THALASSEMIA ON SEVERITY OF SICKLE CELL DISEASE IN SAUDI ARABIA

The Hb SS disease of Eastern Saudi Arabia has attracted international interest because of its comparatively “benign” course, usually attributed to high levels of Hb F found in these patients. α thalassemia, resulting in hypochromic microcytosis, is also common in this area. We determined the prevalence of Hb S and α thalassemia at birth by cord blood screening.The influence of Hb F and α thalassemia on clinical severity of Hb SS disease was assessed. 12 infants with Hb FS at birth were compared with 5 with Hb FS + Barts. At 6 and 12 months, levels of Hb F were identical in both groups. However, infants with Hb FS + Barts were microcytic and had less hepatosplenomegaly, infections and dactylitis. 8 Hb SS adults with microcytic RBC and normal Hb A2 were compared to 8 with normocytic RBC. Although Hb F levels were similar ([xmacr ] 11.9% vs 12.8%), the microcytic group had few clinical symptoms and no hospitalizations. The normocytic patients had frequent painful crises and hospitalizations. We found no relation between levels of Hb F and clinical severity in Saudi infant and adult patients with Hb SS disease. Rather, hypochromic microcytosis appeared to be a more important predictor of less severe clinical disease.