The somnogenic T lymphocyte suppressor prostaglandin D2 is selectively elevated in cerebrospinal fluid of advanced sleeping sickness patients.

To help to elucidate the changes induced by Trypanosoma brucei gambiense in the central nervous system (CNS) in advanced sleeping sickness patients, levels of interleukin-1 (IL-1) and prostaglandins D2 (PGD2) and E2 (PGE2) were measured by radioimmunoassay in the cerebrospinal fluid (CSF) from 24 patients diagnosed on the criteria of CSF protein, leucocyte count and parasite presence as having CNS (i.e. late stage) involvement, and from 12 patients without CNS involvement. PGD2 concentrations were selectively and markedly elevated in the late stage patients. The increased PGD2 may in part account for the increased somnolence and the immunosuppression within the CNS. Measurement of PGD2 levels in CSF may be a useful criterion for CNS involvement.