Neutropenia in 6 ethnic groups from the Caribbean and the U.S.

BACKGROUND: Low white blood cell counts (WBC) or absolute neutrophil counts (ANC) may delay or prevent the completion of appropriate chemotherapy, especially among women receiving adjuvant therapy for breast and colon cancer, and affect cancer survival. Because race/ethnicity is also associated with survival, the authors compared WBC and ANC in healthy American-born women of African descent and European descent, and women from Barbados/Trinidad-Tobago, the Dominican Republic, Haiti, and Jamaica. METHODS: Blood samples from 261 healthy women ages 20 to 70 years were tested for WBC with differential, cytokine and growth factor levels, and ancestry informative and neutrophil elastase polymorphisms. The authors analyzed the association between neutropenia and serum WBC growth factor levels, cytokine levels, and neutrophil elastase c199a polymorphism. RESULTS: The median WBC and ANC differed among the 6 groups (P < .01 for WBC and P < .0001 for ANC). Dominicans were found to have higher median WBC and ANC than all other groups (P < .03). Neutropenia (ANC < 1500 cu/mm) was observed among 2.7% to 12.5% of the groups of predominantly African descent; no other groups were found to have neutropenia (P < .05). Granulocyte-colony-stimulating factor was found to be lower in white women, but tumor necrosis factor-alpha and C-reactive protein were not found to be correlated with ethnicity. Women of African origin were more likely to have polymorphisms of African ancestry (P < .001) and c199a alleles (P < .0001), which were also associated with low ANC levels. CONCLUSIONS: In the current study, the authors observed a strong association between neutropenia and African descent among asymptomatic women from the U.S. and the Caribbean. Among women of African descent who develop a malignancy, this association may contribute to racial disparities in treatment and outcomes.

Health effects of human T-lymphotropic virus type I (HTLV-I) in a Jamaican cohort

BACKGROUND: Other than adult T-cell leukaemia (ATL) and HTLV-I associated myelopathy (HAM), the health effects of infection with human T-lymphotropic virus type I (HTLV-I) are not well defined. METHOD: A cohort of 201 confirmed HTLV-I seropositive Jamaican food service workers and 225 seronegative controls of similar age and sex from the same population was examined. A health questionnaire, physical examination, and laboratory tests were performed at enrollment into the cohort in 1987-1988. RESULTS: One of 201 HTLV-I seropositives, but no controls were diagnosed with HAM, for a prevalence of 0.5 percent (95 percent confidence interval) (CI) 0.01-2.7 percent); no cases of ATL were diagnosed. While there was no difference in current symptoms, the HTLV-I seropositive group was more likely to report a past medical history of hepatitis or jaundice (OR = 3.49, 95 percent CI: 0.93-13.08), malaria (OR = 2.13, 95 percent CI: 0.96-4.73), and dengue fever (OR = 1.37, 95 percent CI 0.82-2.29); however, these differences were of borderline statistical significance. Low income HTLV-I seropositive women had lower body weight (P , 0.01) and body mass index (P < 0.009) than their seronegative counterparts; similar differences were seen in the smaller male group. A trend toward higher prevalence of severe anaemia (haemoglobin < 10 g/dl) (12.6 percent verus 7.7 percent, P < 0.105) and a significantly lower prevalence of eosinophilia (1.0 percent verus 6.3 percent, P < 0.004) was seen among HTLV-I seropositives are asymptomatic, HAM may be diagnosed in approximately 0.5 percent of carriers. Chronic HTLV-I infection may also subtle effects on body mass and haematological parameters.(AU)

Small bowel morphology in British Indian and Afro Caribbean subjects: evidence of tropical enteropathy

Distal duodenal biopsy specimens taken from 30 white, 35 Indian, and 20 Afro-Caribbean residents of West Birmingham during routine endoscopy for dyspepsia, were assessed by disecting microscopy and morphometry. Finger-shaped villi were significantly less frequent in the Indian and Afro-Caribbean subjects than in the white subjects when assessed by disecting microscopy (p<0.005), and both immigrant groups had decreased mucosal thickness (p<0.01), villous height (p<0.001), villous:crypt ratios (p<0.01) and enterocyte height (p<0.05) compared with the white group. In the Indian subjects villous height and villous:crypt ratios correlated significantly with the time since the last visit to the Indian subcontinent (p<0.005). Serum alkaline phosphatase values were significantly higher in the Indian subjects compared with the white (p<0.02), and serum globulins were increased in both the Afro-Caribbean and Indian subjects (p<0.01). There were no correlations between morphometric indices and body habitus or biochemical or haematological indices and the long term effect of the morphological changes is not clear. (AU)

Recurrent infections in sickle cell disease: haematological and immune studies

Some haematological and immunological indices were compared in 19 children with sickle cell disease and a history of recurrent infections and in 16 children with sickle cell disease without any known infections. The recurrent infection group had significantly greater pitted red cell counts and greater absolute monocyte counts. No differences were apparent in routine haematological indices, foetal haemoglobin, immunoglobulin, or complement levels between the groups. The interpretation of these results is discussed (AU)

Mononuclear cells in sickle cell disease: subpopulations and in vitro response to mitogens

The subpopulations of mononuclear cells and the lymphocyte proliferative capacity following mitogen stimulation were studied in 22 patients with homozygous sickle cell (SS) disease and 25 controls with a normal haemoglobin (AA) genotype. The total number of lymphocytes in peripheral blood samples was higher in SS patients compared to controls. Expressed as a percentage of total lymphocytes, the number of B lymphocytes (detected by membrane immunoglobulin Fluorescence) was normal and of T lymphocytes (identified by sheep erythocyte rosetting) was slightly reduced in SS disease. Expressed in absolute numbers, both B and T lymphoctes were increased. Lymphocyte proliferation measured by tritium labelled thymidine incorporation following stimulation with phytohaemaeglutin A and concanavalin A was normal. Following pokeweed mitogen stimulation, thymidine incorporation was significantly increased in SS disease although normal when expressed as a stimualtion index. These results do not suggest a major defect in cell mediated immunity in sickle cell disease. The number of circulating monocytes was increased in SS disease and correlated inversely with the number of reticulocyytes (r= -0.58, p < 0.005) (AU)