Clinical study on the melarsoprol-related encephalopathic syndrome: risk factors and HLA association

Melarsoprol administration for the treatment of late-stage human African trypanosomiasis (HAT) is associated with the development of an unpredictable and badly characterized encephalopathic syndrome (ES), probably of immune origin, that kills approximately 50% of those affected. We investigated the characteristics and clinical risk factors for ES, as well as the association between the Human Leukocyte Antigen (HLA) complex and the risk for ES in a case-control study. Late-stage Gambiense HAT patients treated with melarsoprol and developing ES (69 cases) were compared to patients not suffering from the syndrome (207 controls). Patients were enrolled in six HAT treatment centres in Angola and in the Democratic Republic of Congo. Standardized clinical data was obtained from all participants before melarsoprol was initiated. Class I (HLA-A, HLA-B, HLA-Cw) and II (HLA-DR) alleles were determined by PCR-SSOP methods in 62 ES cases and 189 controls. The principal ES pattern consisted in convulsions followed by a coma, whereas ES with exclusively mental changes was not observed. Oedema, bone pain, apathy, and a depressed humour were associated with a higher risk of ES, while abdominal pain, coma, respiratory distress, and a Babinski sign were associated with higher ES-associated mortality. Haplotype C*14/B*15 was associated with an elevated risk for ES (OR: 6.64; p-value: 0.008). Haplotypes A*23/C*14, A*23/B*15 and DR*07/B*58 also showed a weaker association with ES. This result supports the hypothesis that a genetically determined peculiar type of immune response confers susceptibility for ES

Cerebrospinal fluid neopterin as marker of the meningo-encephalitic stage of Trypanosoma brucei gambiense sleeping sickness.

BACKGROUND: Sleeping sickness, or human African trypanosomiasis (HAT), is a protozoan disease that affects rural communities in sub-Saharan Africa. Determination of the disease stage, essential for correct treatment, represents a key issue in the management of patients. In the present study we evaluated the potential of CXCL10, CXCL13, ICAM-1, VCAM-1, MMP-9, B2MG, neopterin and IgM to complement current methods for staging Trypanosoma brucei gambiense patients. METHODS AND FINDINGS: Five hundred and twelve T. b. gambiense HAT patients originated from Angola, Chad and the Democratic Republic of the Congo (D.R.C.). Their classification as stage 2 (S2) was based on the number of white blood cells (WBC) (>5/µL) or presence of parasites in the cerebrospinal fluid (CSF). The CSF concentration of the eight markers was first measured on a training cohort encompassing 100 patients (44 S1 and 56 S2). IgM and neopterin were the best in discriminating between the two stages of disease with 86.4% and 84.1% specificity respectively, at 100% sensitivity. When a validation cohort (412 patients) was tested, neopterin (14.3 nmol/L) correctly classified 88% of S1 and S2 patients, confirming its high staging power. On this second cohort, neopterin also predicted both the presence of parasites, and of neurological signs, with the same ability as IgM and WBC, the current reference for staging. CONCLUSIONS: This study has demonstrated that neopterin is an excellent biomarker for staging T. b. gambiense HAT patients. A rapid diagnostic test for detecting this metabolite in CSF could help in more accurate stage determination

Human African trypanosomiasis in Angola : clinical observations, treatment, and use of PCR for stage determination of early stage of the disease

Biological and clinical observations are described for 224 patients infected by human African trypanosomiasis (HAT) in Angola in 2007 and 2008. Seven patients were initially classified in stage 1 (S1), 17 intermediate stage (IS) (WBC <20 lymphocytes/mu l with absence of trypanosomes in cerebrospinal fluid (CSF) and no neurological signs), and 200 in stage 2 (S2). Out of 224 patients, 165 (73.6%) presented one or more neurological signs. During treatment with eflornithine, six deaths of S2 patients occurred, five of which were because of an encephalopathy syndrome. Nine patients were diagnosed with a relapse or suspected treatment failure during the follow-up: eight patients after treatment with eflornithine (relapse rate 4.1%) and one patient after pentamidine (6.6%). The contribution of PCR for stage determination evaluated for S1 and IS confirms the difficulty of stage determination, as one Si patient and two IS patients were carriers of trypanosomes detected a posteriori by PCR in CSF but were treated with pentamidine while follow-up did not confirm treatment efficacy. Since 2001 in Angola, either by passive or active mode detection, approximately 80% of the new cases every year were in S2, whereas the annual number of cases has regressed, probably because the transmission of HAT is decreasing. However, stage determination and treatment remain two major issues for the chronic form of sleeping sickness