Treatment of Schistosoma mansoni infection increases helminth-specific type 2 cytokine responses and HIV-1 loads in coinfected Ugandan adults.
BACKGROUND
Studies showing that helminths stimulate type 2 cytokine responses and influence responses to unrelated antigens suggest that helminths may accelerate human immunodeficiency virus type 1 (HIV-1) disease progression in coinfected individuals and that antihelminthic therapy may be beneficial. By the same logic, however, the increase in type 2 cytokines occurring immediately after antischistosomal treatment might increase viral replication and be detrimental.


METHODS
To assess the effect of antischistosomal therapy on immune responses and HIV-1 replication, a cohort of 163 Ugandans coinfected with Schistosoma mansoni and HIV-1 was treated with praziquantel. CD4(+) T lymphocyte counts, eosinophil counts, and plasma HIV-1 RNA concentrations were measured before treatment and 1 month and 5 months after treatment. Schistosoma mansoni- and Mycobacterium tuberculosis-specific cytokine responses and serum interleukin (IL)-10 concentrations were analyzed.


RESULTS
Transient increases in viral load and sustained decreases in CD4(+) T lymphocyte count were observed, especially in subjects with higher-intensity infections. Despite enhanced posttreatment S. mansoni-specific type 2 responses, no increase in eosinophils or in M. tuberculosis-specific type 2 responses nor any decline in M. tuberculosis-specific interferon (IFN)-gamma responses were seen. A significant decline in circulating IL-10 concentrations was observed.


CONCLUSIONS
Although the mechanisms underlying the increase in viral load after treatment with praziquantel are unclear, these results do not support the hypothesis that treating schistosomiasis is beneficial in the management of HIV-1 disease in Africa.
Brown
Michael
M
Uganda Virus Research Institute, Entebbe, Uganda. michael.brown@lshtm.ac.uk
Mawa
Patrice A
PA
Joseph
Sarah
S
Bukusuba
Joseph
J
Watera
Christine
C
Whitworth
James A G
JA
Dunne
David W
DW
Elliott
Alison M
AM
D000328:Adult; D000871:Anthelmintics / Q000009:adverse effects* / Q000627:therapeutic use; D018791:CD4 Lymphocyte Count; D015496:CD4-Positive T-Lymphocytes; D005260:Female; D015658:HIV Infections / Q000150:complications / Q000276:immunology*; D006801:Humans; D007371:Interferon-gamma / Q000097:blood*; D007378:Interleukins / Q000097:blood*; D008297:Male; D008875:Middle Aged; D011223:Praziquantel / Q000009:adverse effects* / Q000627:therapeutic use; D012367:RNA, Viral / Q000097:blood; D012555:Schistosomiasis mansoni / Q000150:complications / Q000188:drug therapy* / Q000276:immunology; D014454:Uganda; D019562:Viral Load; D014779:Virus Replication
D000871:Anthelmintics; D007378:Interleukins; D012367:RNA, Viral; D011223:Praziquantel; D007371:Interferon-gamma