Lymphocyte transformation test in patients with paracoccidioidomycosis

Abstract

The lymphocyte transformation test (LTT) by phytohemagglutinin was carried out on lymphocyte cultures from patients with paracoccidioidomycosis, in medium with autologous plasma (from the patient) or homologous plasma (from an unaffected individual), and lymphocyte cultures from unaffected and apparently normal individuals, in medium with autologous plasma (from the individual) or homologous plasma (from a patient with paracoccidioidomycosis). Blastogenesis was evaluated morphologically by ‘blast’ percentage, and the results analyzed according to clinical form of the disease and general condition of the patient. In the medium containing autologous plasma, percentages below the lower limit of the confidence interval for the distribution of the values for apparently normal individuals were encountered more frequently among patients with diffuse extrapulmonary paracoccidioidomycosis and in poor general condition. When the lymphocytes from patients with the disease were cultured in medium containing homologous plasma, blastogenesis increased in most cases. The lymphocytes of unaffected individuals exhibited a lower response more frequently when cultured in medium containing plasma from patients with the disease than when cultured in medium containing their own plasma. These results suggest the existence of factor(s) inhibiting blastogenesis in the plasma of these patients. In addition to such factor(s), an intrinsic lymphocyte defect may also occur in some patients, which might prevent a greater response to phytohemagglutinin even in homologous plasma. Smears of lymphocytes cultured in autologous plasma and obtained from patients, especially those with diffuse extrapulmonary diasease and in regular or poor general condition, and smears from most of the controls whose lymphocytes were cultured in the plasma of these patients revealed deeply stained cells with altered morphology and considerably reduced in number. The decreased blastic transformation might be linked with these abnormalities, possibly caused by factor(s) inhibiting blastogenesis in the culture medium containing patient plasma.