Vergleich zwischen AIDS-Patienten mit zerebraler Toxoplasmose bzw. Pneumocystis-Pneumonie hinsichtlich des virologischen und immunologischen Ansprechens auf hochaktive antiretrovirale Therapie

Objectives: There is scarce data on immune reconstitution in
antiretroviral naïve AIDS-patients with toxoplasmosis. The
observation of several cases with reduced increase of CD4-cells
upon start of antiretroviral treatment (ART) prompted us to
investigate the topic in the ClinSurv cohort. Methods: 17 German
HIV treatment centers contribute to ClinSurv, a multicentre
observational cohort under the auspices of the Robert Koch
Institute. We retrospectively selected all antiretroviral-naïve
patients with toxoplasmosis (Toxo) and - as comparator group - with
pneumocystosis (PCP) between January 1999 and December 2005.
Results: A total of 257 patients were included in the analysis, 61
with Toxo and 196 with PCP. Demographic baseline data showed
differences with regard to gender, transmission group, and baseline
CD4+ counts (60.9 vs. 44.7/µl, p=0.022). After ART initiation the
increase in CD4+ lymphocytes was lower in the Toxo versus the
PCP-group in the first, second and fourth three-month-period (74.4
vs. 120.3/µl, p=0.006; 96.6 vs. 136.2/µl, p=0.021; 156.5 vs.
211.5/µl, p=0.013). Viral load (VL) was higher in the PCP-group at
baseline (4.46 log10cop/ml vs. 5.00 log10cop/ml, p=0.008), while
virological success of ART was equal. Conclusions: Our data show
for the first time that the average CD4+ T-cell increase of
patients with toxoplasmosis is slower as compared to PCP. Most
clinicians would not be prepared to discontinue follow-up
Toxo-therapy unless CD4+ counts of 200/µl are reached. Explanation
for our finding might be the myelosuppressive side effect of
pyrimethamine, possible interactions of toxoplasmosis therapy with
ART, or an unknown direct biological influence of toxoplasmosis on
immune restoration.