Human Immunodeficiency Virus-Associated Thrombocytopenia in Infants

ABSTRACT. Severe thrombocytopenia was the initial manifestation of human immunodeficiency virus infection in 5 infants under 15 months of age. In only 2/5 cases maternal seropositivity was previously known while in the other 3 it was discovered after the onset of the infants'thrombocytopenia. One infant died, due to intracranial hemorrhage, and the other 4 developed to disease stage IV. Human immunodeficiency virus infection must be considered in the diagnosis of thrombocytopenia.     

The relative importance of the X-linked FCP locus and β-globin haplotypes in determining haemoglobin F levels: a study of SS patients homozygous for βS haplotypes

Five factors have been hypothesized to influence the 20-fold variation in fetal haemoglobin (Hb F) levels in sickle cell anaemia (SS): age sex, α-globin gene number, β-globin haplotype, and the X-linked F-cell production locus (FCP) that regulates the production of Hb F containing erythrocytes (F cells). We analysed the association of these factors with Hb F levels in 112 SS patients living in France who are homozygous for the three common African β-globin haplotypes (Benin, Bantu or Central African Republic and Senegal). We found that: (1) FCP accounts for about 40% of the overall variation in Hb F levels, (2) when the FCP influence is removed, β-globin haplotype is associated with 14% of the remaining Hb F variation, and (3) the other factors have little influence. Comparison with our previous study of SS individuals in Jamaica leads to the following conclusions: (1) the X-linked FCP locus is a major determinant of Hb F levels in SS disease, (2) factors linked to the β-globin haplotype have only a small effect on the variation in Hb F levels, in either the homozygous or heterozygous state, and (3) approximately half of the variation in Hb F levels still remains to be explained.