Ox red blood cells sensitized with rabbit anti-ox red cell antibody adhered opsonically to freshly prepared human peripheral blood lymphocytes. When tested by a centrifugation technique 24–59% of live lymphocytes in normal individuals formed rosettes with the indicator red cells while 41–87% of the lymphocytes in chronic lymphatic leukaemia reacted. After storage at + 4 °C the lymphocytes gradually lost the operative receptor; killing the cells by freezing and thawing, by sodium azide or by fixation in formaldehyde also resulted in loss of capacity to bind the indicator cells. Pretreatment of the lymphocytes with high doses of anti-human IgM in diluted serum resulted in a definite, although incomplete, inhibition. Also, soluble antigen-antibody complexes were inhibitory, although strong inhibition was difficult to show. Undiluted, heated normal human or rabbit serum was highly inhibitory. The high incidence of lymphocytes showing antibody opsonic adherence in patients with chronic lymphatic leukaemia, together with the finding that most lymphocytes binding sensitized ox red cells did not bind unsensitized sheep red cells (a possible T-cell marker) suggests that lymphocytes showing antibody opsonic adherence represent a subpopulation of peripheral blood lymphocytes. This subpopulation might be an analogue of the B-cell population in mice.

Consumption of fatty fish species, like salmon and herring, from the Baltic Sea is an important source of human exposure to persistent organochlorine compounds, e.g. polychlorinated dioxins (PCDDs), dibenzofurans (PCDFs) and biphenyls (PCBs). Many of these compounds show immunotoxic and hepatotoxic effects in animals. We have now studied immunological competence, including lymphocyte subsets, in 23 males with a high consumption of fish from the Baltic Sea and in a control group of 20 males with virtually no fish consumption. The high consumers had lower proportions and numbers of natural killer (NK) cells, identified by the CD 56 marker, in peripheral blood than the non-consumers. Weekly intake of fatty fish correlated negatively with proportions of NK cells (rs = -0.32, P = 0.04). There were also, in a subsample of 11 subjects, significant negative correlations between numbers of NK cells and blood levels of a toxic non-ortho-PCB congener (IUPAC 126; rs = -0.68, P = 0.02) and a mono-ortho congener (IUPAC 118; rs = -0.76, P = 0.01). A similar correlation, in 12 subjects, was seen for p,p'-DDT (rs = -0.76, P = 0.01). The corresponding negative correlation, in 13 subjects, with blood levels of PCDD/Fs was not significant (rs = -0.57, P = 0.07). No significant association was seen between organic mercury in erythrocytes and NK cells. Fish consumption was not associated with levels of any other lymphocyte subset. Neither were there any correlations with plasma immunoglobulins or liver enzyme activities. Our study indicates that accumulation of persistent organochlorine compounds in high consumers of fatty fish may adversely affect NK cell levels.

Twenty-three dust-exposed shacklers in the hanging departments of four poultry slaughter-house plants were examined immediately before work on a Monday morning with a standardized interview, pulmonary function tests (VC and FEV1), and blood sampling for analysis of complement factors. The examinations were repeated immediately after work the same day. Further, the individual breathing zone levels of both total dust and endotoxins were monitored during the whole work-shift. Moreover, spot samples of airborne bacteria and fungi were collected. The mean level of total dust was 6.3 mg/m3 (range 0.4-15.3 mg/m3) and of endotoxins 0.40 micrograms/m3 (range 0.02-1.50 micrograms/m3). Total levels of 4 x 10(5)-4 x 10(6) cfu/m3 of airborne bacteria, mainly coagulase-negative staphylococcal strains, but only 500-4000 cfu/m3 of fungi were found in the hanging departments. An over-shift increase in respiratory symptoms was found, but none of the workers had experienced any symptoms indicating extrinsic allergic alveolitis (EAA) or organic dust toxic syndrome (ODTS). Further, mean over-shift decreases of VC (3.1%) and FEV1 (4.1%) were found, indicating a harmful effect on the bronchi. There were, however, no associations between these over-shift decreases and the individual time-weighted average breathing zone levels of either total dust or of endotoxins. No over-shift change in serum complement factors was observed.

Human peripheral blood lymphocytes from healthy individuals were examined to detect the presence of membrane-bound Ig and surface receptors for fixed IgG and fixed C3. These three features are thought to be characteristic of B lymphocytes and were measured by the mixed antiglobulin rosetting reaction, the antibody (Fc) rosetting reaction and complement (C3) rosetting reactions, respectively. As a reaction believed to be characteristic of T lymphocytes, the capacity to rosette with non-sensitized SRBC was also evaluated. Mean percentages of the total number of lymphocytes from 20 healthy donors ± 1 SD were: sheep red blood cell rosetting reaction 55.7 ± 9.6; mixed antiglobulin rosetting reaction 34.3 ± 9.6; Fc rosetting reaction 26.3 ± 9.9, and C3 rosetting reaction 14.7 ± 5.2. Having established a range of normal values, eleven patients with chronic lymphatic leukaemia (CLL) were examined. For all the reactions believed characteristic of B lymphocytes the mean percentage of lymphocytes rosetting was increased; mixed antiglobulin rosettes 85.8; Fc rosettes 60.4, and C3 rosettes 56.4. There was consequent reduction in the mean percentage of lymphocytes rosetting with SRBC, i.e. 11.8%. This confirms that, in the cases studied, CLL is a disorder of B lymphocytes. In normal persons and in CLL patients it was found that Fc receptors, C3 receptors and Ig determinants appeared to express themselves independently on B lymphocytes.

The lipopolysaccharide (endotoxin) content in airborne dust samples from three different poultry slaughterhouses was determined with both the chromogenic Limulus amebocyte lysate assay and gas chromatographymass spectrometry analysis of lipopolysaccharide-derived 3-hydroxy fatty acids. Gram-negative cell walls were also measured by using two-dimensional gas chromatography/electron-capture analysis of diaminopimelic acid originating from the peptidoglycan. The correlation between the results of the Limulus assay and those of gas chromatography-mass spectrometry for determination of the lipopolysaccharide content in the dust samples was poor, whereas a good correlation was obtained between lipopolysaccharide and diaminopimelic acid concentrations with the gas chromatographic methods. The results suggest that it is predominantly cellwall-dissociated lipopolysaccharides that are measured with the Limulus assay, whereas the gas chromatographic methods allow determination of total concentrations of lipopolysaccharide, including Limulus-inactive lipopolysaccharide, gram-negative cells, and cellular debris.