Reference intervals of serum transferrin receptors in pre-school children in Zimbabwe.

In laboratory medicine an observed value of a biological analyte may be compared with previously observed values from an appropriate reference population. A reference range for serum transferrin receptor concentration has not been established for Zimbabwean children. We prospectively studied 208 children aged 3-60 months who were residents of Harare, a non-malaria and non-hookworm endemic area, and who attended a well-child clinic. Anthropometric measurements were calculated, complete blood counts performed and serum concentrations of ferritin and transferrin receptors determined. A final group of 83 pre-school children with no apparent illness was used to determine the serum transferrin receptor concentration reference interval after excluding individuals with abnormal clinical and laboratory investigations. The central 95 percentile interval for transferrin receptors after eliminating factors that are known to affect serum transferrin receptors was 3.9-9.5 mg/L. Children, aged < or =24 months had a lower reference range than children >24 months old. This study provides an estimate of the serum transferrin receptor reference intervals in African children using the Ramco Laboratories, Stafford, TX assay kit.

Pancytopenia in Zimbabwe.

BACKGROUND: There has been little systematic study of the clinical spectrum of pancytopenia, and the optimal diagnostic approach to pancytopenia remains undefined. METHODS: The authors studied 134 hospitalized pancytopenic patients in Zimbabwe in both consecutive and nonconsecutive fashion. RESULTS: The most common cause of pancytopenia was megaloblastic anemia, followed by aplastic anemia, acute leukemia, acquired immunodeficiency syndrome (AIDS), and hypersplenism. Severe pancytopenia was usually due to aplastic anemia. Patients with aplastic anemia and acute leukemia were usually children, whereas those with megaloblastic anemia were adults. Moderate to severe anemia was noted throughout the series, but was most striking in patients with megaloblastic anemia, aplastic anemia, and acute leukemia. The mean corpuscular volume (MCV) was elevated in most patients with megaloblastic hematopoiesis, aplastic anemia, and acute nonlymphocytic leukemia. Normal or low MCV values were noted in almost one third of patients with megaloblastic anemia. Anisocytosis, poikilocytosis, macroovalocytosis, microcytosis, fragmentation, and teardrop erythrocytes were more prominent on the blood films of patients with megaloblastic anemia. CONCLUSIONS: Megaloblastic anemia, aplastic anemia, and AIDS are the most common causes of pancytopenia in Zimbabwe. Aplasia is the most frequent cause of severe pancytopenia. The authors have formulated tentative guidelines for the evaluation of pancytopenic patients in this setting.

Vitamin B12 deficiency is the primary cause of megaloblastic anaemia in Zimbabwe.

In a study of the pathogenesis and clinical features of megaloblastic anaemia in southern Africa, we evaluated 144 consecutive Zimbabwean patients with megaloblastic haemopoiesis. Vitamin B12 deficiency was diagnosed in 86.1% of patients and was usually due to pernicious anaemia; isolated folate deficiency accounted for only 5.5% of cases. Anaemia was present in 95.8% of patients; the haemoglobin (Hb) was < or = 6 g/dl in 63.9%. Neurological dysfunction was noted in 70.2% of vitamin B12-deficient patients and was most striking in those with Hb values > 6 g/dl. Serum levels of methylmalonic acid, homocysteine, or both, were increased in 98.5% of patients. Vitamin B12 deficiency is the primary cause of megaloblastic anaemia in Zimbabwe and, contrary to textbook statements, is often due to pernicious anaemia. Isolated folate deficiency is less common. As reported in industrialized countries 75 years ago, anaemia is almost always present and often severe. Neurological dysfunction due to vitamin B12 deficiency is most prominent in patients with mild to moderate anaemia.