Parameters of T cell mediated immunity to commensal micro-organisms in patients with chronic purulent rhinosinusitis: a comparison between delayed type hypersensitivity skin test, lymphocyte transformation test and macrophage migration inhibition factor assay.

In 75 patients with unexplained chronic purulent rhinosinusitis T cell mediated immunity to three micro-organisms frequently colonizing the human upper respiratory tract, viz. Haemophilus influenzae, streptococci and Candida albicans, was assessed. Delayed type hypersensitivity (DTH) skin test reactivity was measured in vivo, whereas the blastogenic responsiveness (lymphocyte transformation test; LTT) and lymphokine production (e.g. migration inhibition factor; MIF) of the lymphocytes upon antigen stimulation were measured in vitro. MIF was assayed with a recently developed test system using the human monocytoid cell-line U937 as indicator cells in agarose microdroplets. Two-thirds of the 75 patients tested showed a defective DTH response to one or more of the microbial antigens; this contrasted to the findings in 25 healthy subjects, of whom over 90% showed a positive DTH reaction to any of the three antigens. PHA skin tests were entirely normal in both patients and healthy controls. Microbial antigen-specific LTT responses fluctuated considerably in time from strongly positive to negative and vice versa in healthy individuals as well as in patients. In general however, blastogenic responses in patients were comparable to or even higher than those of healthy persons. In the MIF assay, lymphocytes of all healthy individuals tested showed production of MIF upon stimulation with all three antigens; this again contrasted to two-thirds of the patients, whose lymphocytes showed a defective MIF production. Fluctuations of MIF-production in time could not be established and a very good correlation existed between the data obtained in the MIF assay and those of the DTH skin tests. These results indicate that apart from skin testing, the MIF assay seems to be the most suitable parameter to assess defects in T cell reactivity towards microbial antigens. These defects exist in two-thirds of our patients suffering from chronic purulent rhinosinusitis.

T-suppressor cell defects in euthyroid nonendemic goitre.

Recently it has been suggested that a substantial number of nonendemic goitre cases can be considered as organ-specific autoimmune disorders of the thyroid. Circulating immunoglobulins, probably receptor autoantibodies, stimulating guinea pig thyroid growth in vitro (TGI) can be found in 2/3 of such patients. Defects in the regulatory balance between T-helper (Th) and T-suppressor (Ts) cells have been described in other thyroid autoimmune diseases, such as Graves' disease and Hashimoto goitre. Such defects are thought to play a role in the loss of control over thyroid autoantibody producing B cells. To investigate whether Ts cell defects can also be found in nonendemic euthyroid goitre, we studied their number and function in 15 of such patients. All patients were clinically euthyroid. Eleven were positive for TGI. Circulating T cells, Th cells and Ts/cytotoxic cells were enumerated using monoclonal antibody techniques (OKT3, Leu3a and OKT8, respectively). Suppressor cell function was assessed employing a proliferation assay in which a short-lived population of such cells was removed by a 24 h preculture. A significant difference was found between patients and controls regarding the Leu3a+/OKT8+ cell ratio: 2.74 (SD 0.94) in patients vs 1.75 (SD 0.38) in controls (P less than 0.01); the disturbed ratio was mainly due to a decrease in the percentage of OKT8+ cells. The functional Ts cell assay also showed a defect of patient lymphocytes: patient removal index (SRI) was 1.5 (SD 1.0) vs an index of 2.6 (SD 1.2) for healthy controls (P less than 0.05). A fair correlation between the numerical and functional data on Ts cells was observed.(ABSTRACT TRUNCATED AT 250 WORDS)

The use of somatic antigen of Haemophilus influenzae for the monitoring of T cell-mediated skin test reactivity in man.

To investigate its usefulness as a skin test antigen, Haemophilus influenzae somatic antigen was tested in 28 healthy individuals, both in soluble and aggregated form. All subjects were found to possess specific antibodies against H. influenzae of both IgG and IgM subclass, thus showing their previous exposure to this commensal micro-organism. The somatic antigen in solution was found to be a poor antigen for eliciting a delayed hypersensitivity skin response: only 2 out of 16 subjects reacted with a positive DTH pattern. In contrast, 25 out of 28 persons showed a positive DTH pattern when somatic antigen was used in aggregated form. Two types of DTH reaction patterns could be detected (in a ratio of approximately 3:2), viz. those with an early (24 h) and those with a late (48 h) maximal swelling. Histology of 3 early and 1 late DTH reaction showed perivascular infiltrates of mainly Thelper/Tinducer lymphocytes. Hardly any basophils were seen. One negative skin test, biopsied at 6 h, showed no signs of Arthus reactivity. It can be concluded that skin tests using the aggregated form of the somatic antigen of H. influenzae are useful for assaying specific T-cell-mediated reactivity in man.