A microcalorimetric assay to measure the reactivity of antigen-stimulated mononuclear cells from Schistosoma mansoni-infected patients.

The reactivity of mononuclear cells (2 x 10(6)/ml minimum Eagle's medium, MEM) from normal subjects and from Schistosoma mansoni-infected patients was evaluated by microcalorimetry. The results which are reported as heat production (mcal for 2 x 10(6) cells in 3600 s), were 2,087 +/- 21.3 and 2,497.0 +/- 21.3 for mononuclear cells from infected patients (N = 8) under stimulation with S. mansoni soluble egg antigen (SEA) and soluble adult worm antigenic preparation (SWAP), respectively. The values for cells from normal subjects (N = 8) were 13.7 +/- 1.1 and 29.3 +/- 3.2 in the presence of the same antigens. Pre-treatment of mononuclear cells from patients with 1 mM aminophylline (a cAMP phosphodiesterase inhibitor) totally abolished heat production. Cell viability (greater than 95%) was not changed after the measurement. The microcalorimetric assay described here measures the cellular metabolic activity and we feel justified in suggesting this technique as an auxiliary diagnosis of schistosomiasis. Given the sensitivity, precision and accuracy of this microcalorimetric assay, we feel it can be used for the diagnosis of disease conditions for which a reliable diagnostic method is required.