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Notes: As a part of a worldwide investigation on the prevalence of respiratory symptoms, we have performed a study on the relationship between the indoor environment and asthma-like symptoms in the population of a central Swedish municipality. The study comprised 88 individuals, aged 20–45 years who underwent a structured interview, spirometry, a methacholine provocation test, skin-prick tests and blood samples for measurements of serum concentrations of eosinophil cationic protein (S-ECP), blood eosinophil count and total immunoglobulin E (S-IgE). In the homes, the room temperature, air humidity, respirable dust, house dust mites (HDM) and airborne micro-organisms were measured. The relative humidity in all the homes was found to be above 33%. HDM were found in 13% of homes. In the homes of the 47 subjects with asthma related symptoms, significantly higher total levels of bacteria and mould (P〈0.05) and a higher proportion of detected HDM (OR = 5.3) was found than in subjects with no asthma related symptoms, after adjustment for age, sex, smoking, indoor temperature and air humidity. HDM were found to be an independent risk factor for asthma related symptoms (OR = 7.9) and nocturnal breathlessness (OR = 6.2) (P〈0.05), while the total level of bacteria was a risk factor for asthma related symptoms and wheezing (P〈0.05). We conclude that although HDM is relatively infrequently found in the homes of central-Sweden, the presence of HDM is related to asthmatic symptoms. A relation between levels of airborne bacteria and asthma related symptoms was also found.

Notes: Background There is evidence that atopic disorders may begin in intra-uterine life; however, studies of birth characteristics and atopy show conflicting results.Methods We wanted to investigate the association of birth weight and head circumference with serum total or specific IgE, allergic rhinitis or eczema while addressing the influence of demographic and geographical factors. In this historic prospective cohort study, data were collected from birth records for 1683 men and women born in 1947–1973, from six Nordic–Baltic populations participating in the European Community Respiratory Health Survey. Blood tests for the measurement of serum total and specific IgE were available for 1494 subjects. In multiple regression analyses, adjustments were made for birth length, gender, age, study centre, adult body mass index, level of education, parental and adult smoking.Results There was no association of birth weight (n=1230) and head circumference (n=285) with serum total IgE, specific IgE antibodies, allergic rhinitis or eczema. There were neither significant interactions by gender or age, nor heterogeneity between the study centres in the analyses of birth weight and adult atopy.Conclusion Birth size was not associated with atopy among adults in this large Nordic–Baltic population study.

Notes: Background Atopic women tend to have fewer children, although atopy may favour conception.Objective To assess whether atopy is associated with the number of new births and whether changes in parity are associated with a change in atopy in a cohort of young women.Methods Women had atopy (defined as the presence of serum-specific IgE against common aeroallergens) measured in the European Community Respiratory Health Study during the years 1991–92 (n=4580). About 9 years later, 2844 (62.1%) were recontacted and 2414 (52.7%) had atopy measured again.Results Atopic women had fewer children at baseline than non-atopic women but the association disappeared at the end of the follow-up. Atopy tended to increase parity during the follow-up, but in a non-statistically significant way (relative risk=1.08; 0.86–1.35, after adjusting for number of children at baseline, age, length of follow-up, education or social class). Prevalence of atopy during the follow-up changed by the same magnitude whatever the birth cohort and the change in the number of children (P for interaction 〉0.7).Conclusion Atopic women did not have a significantly higher fertility rate but they may postpone having their first child compared with non-atopic women. We are unable to confirm the hypothesis that atopy in women may decrease with successive pregnancies.

Notes: The question of whether there is a preferential use of certain V genes in T cells entering an inflamed joint has hitherto been studied mainly using unfractionated cells from synovial fluid and tissue respectively, and no clear answer to the question has yet been provided. Concomitantly. evidence has been provided that the use of V genes may differ considerably between CD4+ and CD8+ T cells, and consequently that detection of biased V-gene expression within an inflammatory lesion may require separate analysis of the two T-cell subsets.In this paper we have therefore studied T-cell receptor V-gene expression in rheumatoid arthritis by means of double stainings of synovial fluid and blood for available anti-TCR monoclonal antibodies and antibodies to CD4 and CD8. respectively. Double stainings were also performed with anti-TCR antibodies and antibodies to activation markers HLA-DR and 1L-2R. A certain bias towards the preferential use of certain V genes was seen particularly in the synovial fluid samples within both the CD4+ and CD8+ T-cell populations, but no uniform pattern was evident among the 35 patients investigated.

Notes: To determine the extent of V-gene heterogeneity of blood T lymphocytes in patients suffering from Myasthenia Gravis (MG), we used eight recently available monoclonal antibodies (MoAb), directed against different Vα and Vβ gene products of the variable part of the T-cell receptor (TCR), covering approximately 25% of the α/β T cells in normal peripheral blood (PBL) of healthy individuals. Using a two-colour immunofluorescence method, we could calculate the expression of α/β V segments within the two major T-cell subsets, CD4-/CD8+ and CD4+/CD8- lymphocytes. Twenty-seven per cent (4/15) of the MG patients had T cells showing signs of abnormal expansion. Furthermore, among these expanded T cells, a restricted Vβ12 gene expansion could be seen, in three out of four patients. No correlation between TCR V-gene usage and HLA haplotypes (HLA-A, -B, -DR and -DQ) could be seen. Our data suggest that the majority of MG patients have abnormally expanded T-cell clones. The relevance of these findings is discussed.

Notes: We have previously described a monoclonal antibody (MoAb), H2, which recognized a tumour-unique antigen on a human T-cell chronic lymphatic leukaemia (T-CLL, CD3,4+). However further characterization of H2 has revealed a reactivity with the majority of T lymphocytes and a minority of B lymphocytes, some malignant T cells and a few cell lines of leukaemia or of hematopoietic tumour origin. The molecular weight of the antigen (80,000) precipitated by the MoAb H2 from the cell lines NALM-6 and Reh corresponded to that previously found. When PBL were stimulated with PHA, IL-2, or Con A a reduced reactivity of H2 could be seen. The MoAb H2 was submitted to the Fourth International Conference on Human Leucocyte Differentiation Antigens, Vienna, 1989. H2 did not cluster in any of the 78 flusters of differentiation (CD 1–78) discussed at the conference, indicating its unique reactivity. This suggests that we have defined a new antigen on lymphocytes with a possible role along the resting proliferating axis.

Notes: We have previously analysed the T-cell receptor (TCR) V-gene usage in peripheral blood T lymphocytes from a group of healthy Scandinavians, and described a biased representation (i.e. a statistically significant higher median representation) for some of the TCR V genes towards the CD4+ subpopulation. In a subsequent study the usage of the same V genes was analysed in single positive (CD4+CD8− and CD4−CD8+) human thymocytes, and a similar type of skewness was noted. These observations might be explained by an influence of the specificity of the TCR of thymocytes on the maturation into the CD4+ or the CD8+ lineage. Such a model would assume an interaction between a common determinant on the major histocompatibility complex (MHC) class I or class II molecules, or with a peptide that is preferentially presented by either of the two molecules, and the TCR on the maturing thymocyte. To investigate the possible influence of a different genetic background and environment on skewed TCR V-gene representation, we have in this study analysed the TCR V-gene usage in peripheral blood and umbilical cord blood lymphocytes obtained from Asians, with a different ethnic and environmental background from our previous Scandinavian subjects. In the umbilical cord blood lymphocytes the TCR V-gene usage was close to identical between the two different ethnic groups in both CD4+ and CD8+ subpopulations. Analysing the peripheral blood lymphocyte (PBL) TCR V-gene usage, we found that three of the four monoclonal antibodies (MoAb) with a biased reactivity towards the CD4+ subpopulation in the Scandinavian group also showed a similar skewed reactivity in this study. Thus, the majority of the TCR V genes were used in a similar way. Some minor but definite disrepancies could be detected when comparing ICR V-gene usage in adult individuals from these two different ethnic groups. These differences could be inferred to be due to selective peripheral expansion through environmental pressure of T cells utilizing a specific Vβ gene segment.We conclude that a striking preservation of biased TCR V-gene usage does exist in humans of distinctly different ethnic origin.