Comparison of Candida-delayed hypersensitivity skin test size with lymphocyte transformation, migration inhibitory factor production and antibody titer

Cutaneous defenses against dermatophytes and yeasts

Predispositions to the superficial mycoses include warmth and moisture, natural or iatrogenic immunosuppression, and perhaps some degree of inherited susceptibility. Some of these infections elicit a greater inflammatory response than others, and the noninflammatory ones are generally more chronic. The immune system is involved in the defense against these infections, and cell-mediated immunity appears to be particularly important. The mechanisms involved in generating immunologic reactions in the skin are complex, with epidermal Langerhans cells, other dendritic cells, lymphocytes, microvascular endothelial cells, and the keratinocytes themselves all participating in one way or another. A variety of defects in the immunologic response to the superficial mycoses have been described. In some cases the defect may be preexistent, whereas in others the infection itself may interfere with protective cell-mediated immune responses against the organisms. A number of different mechanisms may underlie these immunologic defects and lead to the development of chronic superficial fungal infection in individual patients. Although the immunologic defects appear to be involved in the chronicity of certain types of cutaneous fungal infections, treatment of these defects remains experimental at the present time.

Correlation between cell-mediated immunity and clinical forms of paracoccidioidomycosis

Cellular immune response to specific and non-specific stimulants was investigated, both in vivo and in vitro, in 29 healthy controls and in 53 previously untreated patients with the chronic isolated organic form (CIOF), the chronic mixed form (CMF) and the acute progressive form (APF) of paracoccidioidomycosis. The study included skin tests to Paracoccidioides brasiliensis antigen (PbAg) and phytohaemagglutinin (PHA), DNCB sensitization, determination of T lymphocytes and complement rosette-forming cells, lymphocyte transformation and leucocyte migration inhibition tests using PbAg and PHA. Patients displayed staggered cutaneous response to PHA and to PbAg, with marked decrease in intensity in the APF group. DNCB sensitization test and proliferative response of lymphocytes to PHA and PbAg were severely depressed in most of the patients. Leucocyte migration inhibition indices to PbAg were highly positive, while response to PHA was slightly decreased regardless of the clinical form. The number of T lymphocytes was reduced in most of patients and in them the number of complement-rosette forming cells was normal. The distribution of patients according to a suppression index, based in the results of the tests employed, revealed a tendency towards an increased degree of cellular immunosuppression from the least severe (CIOF) to the most severe (APF) clinical form of the disease. On the whole, the present study demonstrated a gamut of immunological reactivity in paracoccidioidomycosis.

Effect of levamisole on experimental paracoccidioidomycosis in the Syrian hamster: immunologic and histopathologic correlation

The effect of levamisole (LMS) was studied in hamsters inoculated with live yeast phase culture of Paracoccidioides brasiliensis by intratesticular route. One group started LMS therapy at an early stage of infection (LMS3 group), when the animals were immunocompetent, and another group was treated in a later stage, when the immune response was already depressed (LMS12 group). As control, one group was not treated. The alterations induced by levamisole were studied by immunologic and histopathologic parameters. Compared to controls, the LMS3 group presented normal levels of cellular immune response and inflammatory reaction characterized by compact epithelioid granuloma during a longer period of time. In addition, this group showed a lower incidence of amyloidosis and lower fungi proliferation in the lesions. In the LMS12 group a transient enhancement was noteworthy of cellular immune response with maintenance of the compact pattern of the epithelioid granuloma as in the LMS3 group; however, the number of fungi and incidence of amyloidosis were similar to controls. The differences between both treated groups may be accounted for by some factors such as host immune competence, timing and total dose of LMS administered. Levamisole may be of value as additional therapy in paracoccidioidomycosis.

Delayed cutaneous hypersensitivity in normals: choice of antigens and comparison to in vitro assays of cell-mediated immunity

In 81 normal subjects, ages 19 to 100 yr (mean 52), we studied the prevalence of positive 48 hr skin reactions to six antigens: fluid tetanus toxoid, Candida albicans, SK/SD, Trichophyton, PPD, and coccidioidin. Of these, C. albicans was most frequently reactive (92%); SK/SD (51%) and tetanus (49%) were less so. Each of the remaining three antigens was reactive in less than 42% of the subjects. The minimum number of antigens required to detect delayed hypersensitivity in 100% of subjects was two: C. albicans and tetanus. We found no correlation between skin reactivity at 20 min, 6 hr, and 48 hr for most of the antigens studied, suggesting different mechanisms for reactions occurring at each time. In 60 of the subjects, lymphocyte stimulation index (LSI) with tetanus toxoid and monocyte chemotaxis (MC) assays were done. The natural log of the area of induration at 48 hr after tetanus skin testing (I48) increased as a function of LSI (p less than 0.005) and MC (p less than 0.025) by multiple regression analysis. Skin testing was less sensitive than LSI as a test for cell-mediated immunity in our population. However, because of availability and correlation with LSI, delayed cutaneous hypersensitivity should be tested initially. For this purpose, tetanus toxoid appears to be a useful antigen when used in combination with C. albicans.

Delayed hypersensitivity to tetanus toxoid in man: in vivo and in vitro studies

The frequency of positive delayed hypersensitivity skin test reactions to tetanus toxoid in 47 healthy volunteers was 80%. The frequency of immediate hypersensitivity was low (8%) and there was less discomfort than with streptokinase or PPD. There was good correlation between leukocyte migration inhibition and delayed hypersensitivity skin testing, and a quantitative relationship was demonstrated between diameter of cutaneous reaction and degree of leukocyte migration inhibition. No relationship was demonstrated between any measures of immune responsiveness and the interval from the last booster immunization. It was concluded that tetanus toxoid is a valuable antigen for assessment of delayed hypersensitivity in man.

Comparison of lymphocyte transformation and macrophage migration inhibition tests in the detection of beryllium hypersensitivity

In seven patients with chronic beryllium disease (Be) the Be lymphocyte transformation test was positive in 100%, independent of steroid therapy, and was reproducible. The Be macrophage migration inhibition test was only positive in four of seven patients (57%) not on steroids, and was not reproducible. In 72 potentially exposed healthy beryllium workers the lymphocyte transformation test was negative in all subjects. The macrophage test was positive in four of 78 and again the results were not reproducible. The workers with positive results showed no differences in age, type or duration of employment from those with negative results and showed no evidence of disease. In addition, the macrophage test was positive in two of 45 non-exposed control subjects. We also confirmed the above advantages of the lymphocyte transformation technique by using tuberculin antigen (PPD). The PPD lymphocyte transformation test gave positive results in approximately 60% of healthy beryllium workers, but the PPD macrophage test was only positive in 7%. We conclude that the Be lymphocyte transformation test is the most sensitive and reproducible and advocate its use in the diagnosis of disease and in monitoring the health of potentially exposed workers.

Improvement of impaired leukocyte migration inhibition by thymosin in patients with head and neck squamous carcinoma

In a preliminary study of the effects of SK-SD and thymosin on leukocyte migration inhibition in patients with squamous carcinoma of the head and neck, the cancer patients had significantly lower leukocyte migration inhibition of SK-SD than normal subjects. Thymosin increased the inhibition to SK-SD in the cancer patients to levels similar to those in normal subjects, and decreased the inhibition in normal subjects. These results confirm and extend the results of previous studies of the effects of thymosin in vitro, which show restoration of immune reactivity in patients with impaired cellular immunity and either no effect or a decrease in immune reactivity in subjects with normal cellular immunity. These combined observations provide a rationale for determining the clinical effects of thymosin in immunoincompetent patients with head and neck cancer and suggest that immunorestorative agents such as thymosin be used with caution in patients with normal cellular immunity.

Immunodiagnosis of candida-infections. I. Sensitivity of the antigens

Attempts were made to prepare a sensitive antigen from C. albicans suitable for detecting humoral antibodies and hypersensitivity in deep-seated candidiasis, in patients at risk of invasive candidiasis and in allergic states caused by Candida. 5343 persons suffering from systemic, bronchial, vaginal candidiasis, bronchial asthma, chronic bronchitis, polyarthritis nodosa, ulcus cruris, malignancy, rhinitis pollinosa, vasomotorica, and non infected miners, farmers and blood donors were investigated on the presence of antibodies and hypersensitivity against 8 different antigen preparations. The extracellular protein and mannan- protein isolated from the cultivation medium of C. albicans proved the most sensitive for specific anticandida antibodies. The mannan, especially the mannan isolated from the cell surface of C. albicans determined best for the allergy. Comparison made of commerical Candidine showed similar activity. The whole cell C. albicans antigens as well as the mixed Candida antigen reacted much weakly. Comparison made of autoantigen, C. albicans and mixed C. albicans antigen proved the highest sensitivity of the autoantigen.

Experimental murine candidiasis: cell-mediated immunity after cutaneous challenge

Male CBA/J mice, sensitized by cutaneous inoculation with viable Candida albicans blastospores, were used to study in vivo and in vitro cellular immune responses. Three antigens of C. albicans, viz., a cell wall glycoprotein (GP), a membrane extract (ppt-HEX), and soluble cytoplasmic substances (SCS), were used in vitro in a lymphocyte stimulation assay, whereas the GP and ppt-HEX were used in vivo to detect delayed hypersensitivity by the footpad assay. Delayed hypersensitivity to GP and ppt-HEX was transferred from sensitized donors to naive recipients with peritoneal exudate cells and not with serum. Moreover, the transfer of the reactivity to ppt-HEX was abrogated by the prior treatment of the transfer suspension with anti-theta 1.2 serum and complement. The in vitro lymphocyte response to GP and ppt-HEX correlated qualitatively with the in vivo responses. SCS, a preparation shown to be ineffective in vivo previously, did stimulate lymphocytes from sensitized animals in vitro. The in vitro response to Candida antigens, as well as phytohemagglutinin, was abolished by treatment of the lymphocyte suspension with anti-thymocyte 1.2 serum before assay, whereas anti-immunoglobulin serum had less effect on these responses. The in vivo and in vitro reactivity to the Candida antigens, therefore, was dependent upon viable T-lymphocytes. Preliminary specificity studies were carried out in the lymphocyte stimulation assay, using lymphocytes from mice infected with C. albicans tested against ppt-HEX preparations extracted from two other species of Candida, C. tropicalis and C. guillermondii, and from two other pathogenic yeast forms, Histoplasma capsulatum and Blastomyces dermatitidis. Significant cross-reactivity was observed with C. tropicalis only, a species which is known to be serologically related to C. albicans.

Immunological skin testing and interpretation: a plea for uniformity

Immunological skin tests are one of the major methods used for the assessment of one's immune status. A review of the literature clearly reveals that there is no uniform methods for the administration and interpretation of skin tests. Without uniformity, it is obvious that data are not comparable. Contradictory conclusions may be reached from the same skin test data, depending upon the method of interpretation used. Precedent, rather than rationale, has often determined the method of interpretation. There are studies which suggest that slight induration or erythema, often considered negative, are significant immunologic events. The various methods of skin test administration and interpretation are reviewed. Recommendations for application and interpretation are presented so that uniformity may exist.

In vitro stimulation of bovine peripheral blood lymphocytes: comparison of round- and flat-bottom microtiter plates for detection of tuberculin hypersensitivity

Lymphocytes from Mycobacterium bovis-sensitized and normal cattle were cultured in round- and/or flat-bottom microtiter plates and stimulated with M. bovis purified protein derivative (PPD) tuberculin. Blastogenic responses of lymphocytes from M. bovis-sensitized cattle to PPD cultured in round-bottom plates were significantly greater than those of lymphocytes cultured in flat-bottom microtiter plates. Normal lymphocytes of nonsensitized cattle were not stimulated by PPD in either round- or flat-bottom microtiter plates. Kinetics of lymphocyte responses in round-bottom plates are presented.

The effects of alternate-day corticosteroid therapy on delayed hypersensitivity skin responses

Alternate-day corticosteroid therapy had been shown to have a suppressive effect on delayed hypersensitivity skin responses elicited on repeated skin testing in an asthmatic population. While the clinical meaning is not clear, it indicates that alternate-day corticosteroid therapy may have a subtle effect on cellular hypersensitivity responses.

Toluene diisocyanate (TDI) pulmonary disease: immunologic and inhalation challenge studies

Clinical and serologic effects of TDI exposure were studied in 112 occupationally exposed plant workers. Sera were obtained before and after commencement of TDI production. All subjects were skin-tested with common inhalant allergens and a TDI-HSA conjugate. Total eosinophil counts, immunoglobulin quantitations, and specific antibody assays by PCA, P-K, and radioimmunoassay were performed. Clinically "sensitive" individuals were tested by provocative inhalation challenge with from 0.005 ppm to the threshold limit value of 0.02 ppm TDI. No TDI-induced immunologic changes were noted with the exception of 3 individuals who demonstrated small positive wheal-and-erythema reactions to TDI-HSA but not to HSA alone. Inhalation challenge with TDI vapor produced airways obstruction, as measured by FEF (25-75). These responses were of the immediate, delayed, and dual type, and were provoked in some cases with levels as low as 0.005 ppm TDI.

Detection of human contact sensitivity to dinitrochlorobenzene by the migration inhibiton test

The migration inhibitory factor (MIF) production of peripheral lymphocytes following exposure to dinitrophenylated microsomes derived from both human (DNP-hy-Mic) and guinea pig (DNP-gp-Mic) epidermis was quantitated to detect human contact sensitivity to dinitrochlorobenzene (DNCB). The lymphocytes from nonsensitized subjects did not generate MIF following exposure to either antigen. With DNP-gp-Mic as the antigen, MIF production was noted in only 1 out of 6 DNCB-sensitized subjects and was not significant statistically. With DNP-hu-Mic as the antigen, highly significant MIF production was observed in all 12 sensitized subjects ( p less than 0.0005). In order to confirm MIf production by sensitized lymphocytes following stimulation by DNP-hu-Mic, the subjects were actively sensitized with DNCB and MIF production was assessed before and after sensitization. Remarkable MIf production was noted in the lymphocyte cultures after sensitization, although no significant MIF production was observed before sensitization. MIF production of the sensitized lymphocytes cultured in the presense of DNP-hu-Mic generally correlated well with the results of patch testing, but not with the intensity of the skin test.

In vivo and in virto cellular responses to cytoplasmic and cell wall antigens of Histoplasma capsulatum in artificially immunized or infected guinea pigs

Guinea pigs were infected with different doses of yeasts of Histoplasma capsulatum or artifically immunized with several concentrations of unextracted yeast cell walls, and then tested in vivo and in vitro for cell-mediated responses to various subcellular fractions of the fungus. Three types of cell-mediated responses were measured, viz., skin test activity, production of migration inhibition factor, and lymphocyte transformation. Positive cutaneous reactions were elicited in animals immunized with 100 or 1,000 mug of cell walls when such animals were skin-tested with cell wall glycoprotein of soluble cytoplasmic substances, whereas animals immunized with 2,000 mug of cell walls did not react significantly greater than unsensitized animals when skin-tested with the same antigens. Histoplasmin did not elicit cutaneous sensitivity in guinea pigs infected with the smallest inoculum, 6 X 10(5) yeast cells, or in animals immunized with cell walls, regardless of the concentration of cell walls used as immunogen. However, hypersensitivity to H. capsulatum could be detected with cytoplasmic substances in animals infected with 6X 10(5). In guinea pigs infected with larger doses, i.e., 10 X 10(7), 15 X10(7), or 20 X 10(7), hypersensitivity could be detected with histoplasmin, cell wall glycoprotein, a ribosome-rich fraction, and soluble cytoplasmic substances. Both cell wall glycoprotein and soluble cytoplasmic substances were functional in migration inhibition factor assays with peritoneal exudate cells from animals immunized with 100 or 1,000 mug of cell walls. The transformation of lymphocytes from infected and artificially immunized guinea pigs in the presence of cell wall glycoprotein and soluble cytoplasmic substances was variable and unpredictable, the lymphocytes from some animls within a given group transforming and those from other animals showing no evidence of stimulation. Moreover, the level of stimulation could not be correlated with the degree of dermal hypersensitivity. These findings suggest that cell wall glycoprotein, and the fractions containing ribosomes and soluble cytoplasmic substances, could be useful antigens in assays for cellular immunity, and warrant further investigation with respect to specificity and active components.