Th1 responses in persons with disseminated coccidioidomycosis depend on serology titer and time from diagnosis but Th17 responses are persistent
Development of a T helper lymphocyte type-1 (Th1) response characterized by release of cytokines such as interleukin-2 (IL-2) and interferon-γ (IFN-γ) has been associated with a good outcome in coccidioidomycosis. Recent data have also suggested that T lymphocytes producing the interleukin-17 (IL-17) family of cytokines (Th17) may play a role in modulating that immunity.
A cross-sectional analysis of adult subjects with coccidioidomycosis was performed. Approximately 5 mL of heparinized whole blood was obtained by venipuncture from each subject and incubated for 18 hr with 20 µg/mL of the coccidioidal antigen preparation T27K. The plasma supernatant analyzed for concentrations of IL-2, IFN-γ and IL-17.
Nineteen subjects with non-meningeal coccidioidomycosis and 6 healthy coccidioidal immune and 6 healthy non-immune donors were recruited. In those with disseminated coccidioidomycosis, levels of IL-2 and IFN-γ were equivalent to those from healthy, immune donors and significantly above healthy non-immune donors (P<0.01). However, both IL-2 and IFN-γ were significantly lower among disseminated patients if the coccidioidal serology titer was ≥1:8 compared to less than this (P<0.03). Moreover, IL-2 levels were significantly higher in those diagnosed >1 year compared to those diagnosed earlier (P=0.04). IL-17 levels were significantly higher in the disseminated group than either immune or non-immune donors (P<0.03) and did not change with either serologic titer or time from diagnosis.
These data suggest that the Th1 response in disseminated coccidioidomycosis responds to treatment and control of disease over time. However, the Th17 appears to be persistent and not dependent on either serologic response or time from diagnosis.
N. M. Ampel,
C. T. Nguyen, None
S. M. Johnson, None
D. Pappagianis, None