Family history, BRCA mutations and breast cancer in Vietnamese women.

The purpose of this report is to estimate the proportions of familial and hereditary breast cancers among unselected cases of breast cancer in Vietnam. Two hundred and ninety-two unselected cases of incident breast cancer were recruited from the National Cancer Hospital, Hanoi, the largest cancer centre in Vietnam. Family histories were collected for 292 cases and a DNA sample was obtained for 259 cases. DNA samples were screened for mutations in the large exons of BRCA1 and BRCA2 using the protein truncation test and by allele-specific testing for 17 founder mutations which have been reported in other Asian populations. Complete gene sequencing was performed on two cases of familial breast cancer. Seven of 292 cases reported a relative with breast cancer and one patient reported a relative with ovarian cancer. A pathogenic BRCA mutation was detected in 2 of 259 cases; one BRCA1 carrier was diagnosed at age 51 and one BRCA2 carrier was diagnosed at age 42. Neither case reported a relative with breast or ovarian cancer. A family history of breast cancer is very uncommon among Vietnamese breast cancer patients. The frequency of pathogenic BRCA mutations in Vietnamese breast cancer patients is among the lowest reported worldwide.

Human double-negative T cells in systemic lupus erythematosus provide help for IgG and are restricted by CD1c.

To understand the mechanism of T cell help for IgG production in systemic lupus erythematosus (SLE) we investigated the response of CD4- and CD8-negative (double-negative (DN)) T cells because 1) DN T cells are present at unusually high frequency in patients with SLE and can induce pathogenic autoantibodies; 2) the DN T cell repertoire includes cells restricted by CD1 Ag-presenting molecules; and 3) CD1c is expressed on a population of circulating B cells. We derived DN T cell lines from SLE patients and healthy individuals. In the presence of CD1(+) APCs, DN T cell lines from SLE patients produced both IL-4 and IFN-gamma, whereas DN T cells from healthy donors produced IFN-gamma, but no IL-4. In general, cells from patients with highly active disease produced high levels of IFN-gamma; cells from those with little activity produced high IL-4. Coculture of CD1c-directly reactive T cells from healthy donors with CD1c(+) B cells elicited IgM Abs, but little or no IgG. In contrast, CD1c-directly reactive T cells from SLE patients induced isotype switching, with a striking increase in IgG production. Neutralizing Abs to CD1c inhibited the ability of DN T cells to induce IgG production from CD1c(+) B cells, further indicating that CD1c mediated the T and B cell interaction. IgG production was also inhibited by neutralizing Abs to IL-4, correlating with the cytokine pattern of DN T cells derived from these patients. The data suggest that CD1c-restricted T cells from SLE patients can provide help to CD1c(+) B cells for IgG production and could therefore promote pathogenic autoantibody responses in SLE.

Beta-thalassemia/haemoglobin E disease in Vietnam.

A clinical and haematological study of 75 patients with beta-thalassemia/haemoglobin E (HbE) in Vietnam is described. The clinical picture is similar to thalassemia major. Anemia is often severe, haemoglobin was 5.0 +/- 1.6 g/dl. Splenomegaly was almost consistently detected. Haemochromatosis was clear. Both red cell indices and morphology showed hypochromicity and microcytosis, the MCH was 23.3 +/- 2.9 pg, the MCV was 81.5 +/- 11 fl; anisocytosis, poiklocytosis, tear drop cells, leptocytosis, target cells, and polychromasia were always observed. The osmotic fragility of erythrocytes was increased. The erythrocytic lifespan was shortened, about 7-15 days and the erythrocytes were destroyed in the spleen in 63 per cent of cases. Depending on whether it was beta(+)-thalassemia/HbE or beta(0)-thalassemia/HbE, HbF ranged from 22.8 +/- 7.2 to 57 +/- 12.7 per cent; HbE from 30.1 +/- 12.2 to 42.7 +/- 13 per cent; and HbA1 was decreased down to from only 46.8 +/- 13.5 to 0 per cent.