By Everard L. Napier, M.R.C.S., L.R.C.P. (Lond.). In charge Kala-azar research, Calcutta School of Tropical Medicine. Second edition. 185 pages of text with 15 charts in the text, 18 plates, and an appendix of references to literature, author index and subject index. Oxford University Press. London, Bombay, Calcutta, Madras, 1927
Wasting and secretion of the catabolic cytokines tumor necrosis factor (TNF)/cachectin and interleukin 1 (IL-1) were assessed in weanling Syrian hamsters infected with Leishmania donovani amastigotes. Whereas the mean weight of uninfected animals increased progressively over 9 weeks, the mean weight of infected animals plateaued at 4–6 weeks and then decreased progressively until death. Splenic mononuclear cells from control hamsters produced 11.3 ± 8.3 (SD) ng TNF/106 mononuclear cells/24 hr. TNF secretion in infected animals was greater than the mean ± 2 SD of controls in 1 of 3 hamsters at 2 weeks post-infection and in 8 of 9 hamsters at weeks 4–8. The mean TNF secreted by infected animals studied at weeks 4–8 was 371 (range 28–800) ng TNF/106 mononuclear cells/24 hr (P = 0.005). Control hamsters produced 7.7 ± 2.7 pg IL-1/106 mononuclear cells/24 hr. At 2 weeks, mononuclear cells from 2 of 3 infected animals secreted amounts of IL-1 greater than the mean ± 2 SD of controls. All of 8 infected hamsters secreted increased amounts of IL-1 at 4–8 weeks. The mean was 164 (range 17–370) pg IL-1/106 mononuclear cells/24 hr (P = 0.002). In comparison to infected animals, mononuclear cells from control hamsters incubated with lipopolysaccharide, 10 µg/ml, produced 175.5 ng TNF and 44.6 pg of IL-1/106 mononuclear cells/24 hr. The effect of visceral leishmaniasis on food intake was assessed in a separate group of animals housed individually in metabolic cages. Significant reductions in weight and food intake were first observed at 2 and 3 weeks of infection, respectively. By 5 weeks, the food intake of infected animals was 46% that of controls. Syrian hamsters infected with L. donovani provide an excellent model with which to study the mechanism of wasting.