Impairment of Host Immune Response Against Strongyloides Stercoralis by Human T Cell Lymphotropic Virus Type 1 Infection

Abstract

A large-scale study was undertaken to clarify the prevalence rate of strongyloidiasis in Okinawa, Japan and to evaluate the relationship between strongyloidiasis and infection with human T cell lymphotropic virus type 1 (HTLV-1). The prevalence rate of Strongyloides stercoralis and HTLV-1 infection were 6.3% and 14.0%, respectively. Among 2,185 patients more than 50 years of age, the rate of S. stercoralis infection was significantly higher in patients with HTLV-1 infection compared with patients without HTLV-1 infection. In 252 patients treated with ivermectin, serum IgE levels and peripheral eosinophil counts were significantly lower in HTLV-1 co-infected patients compared with patients without HTLV-1 infection. In addition, the anthelmintic effect was significantly lower in patients with HTLV-1 infection compared with patients without HTLV-1 infection. Our prospective study demonstrated a prevalence rate for strongyloidiasis and HTLV-1 infections, and clearly demonstrated that co-infection with HTLV-1 impaired the immune response against S. stercoralis.

Effect of treatment of Strongyloides infection on HTLV‐1 expression in a patient with adult T‐cell leukemia

“…Strongyloides infections have been reported in 5-20% of ATLL cases, and these infections are often more severe than in individuals who are not coinfected with HTLV-1 [13]. Okinawa, the birthplace of this patient, is endemic for both HTLV-1 and Strongyloides [4]. S. stercoralis is an intestinal nematode usually acquired transcutaneously.…”

“…The synergistic severity of disease caused by these infections has been suggested to be due to immunocompromise resulting from HTLV-1 as a result of interferon g expression, and shift from Th2 to Th1 responses, resulting in decreased levels of IL4, IL5, IL13, and IgE [4,[16][17][18][19]. Alternatively, a Strongyloides antigen has been postulated to induce a potent polyclonal T-cell mitogenic response, and reactivation of HTLV-1 expression [1,20].…”

“…This is based on epidemiologic association of Strongyloides and HTLV-1 infections in Brazil, the Caribbean Islands, and Southern Japan, and from small clinical series reporting more severe disease manifestations in the presence of both infections than with either one alone [2][3][4]. The mechanism for the synergism between these two infectious agents is unclear.…”

Strongyloidiasis – the most neglected of the neglected tropical diseases?

“…26 In contrast, human T cell lymphotropic virus type 1 infection is strongly associated with a higher S. stercoralis prevalence as well as with an increased incidence of hyperinfection. [27][28][29] Although there is a pronounced association between disseminated strongyloidiasis and suppression of the immune system, there are also a significant number of fatal cases in the literature which could not be linked to any known impairment of the immune system. 30 They have tentatively been explained by host factors of intestinal parasite control which act at the interface between the host and the parasite, i.e.…”

Clinical conditions associated withintestinal strongyloidiasis in Rio de Janeiro, Brazil

“…This association has been reported in Brazil by Furtado et al (17) . The synergistic effects of co-infection with HTLV and S. stercoralis, which have been demonstrated, suggest that co-infected patients exhibit elevated parasite burdens and HTLV-1 proviral loads (18) (19) (20) . With respect to the interaction between strongyloidiasis and acquired immunodefi ciency syndrome (AIDS), our study indicated that the frequency of HIV infection tended to be higher among S. stercoralis-positive patients than among S. stercoralisnegative patients but that this difference was not statistically signifi cant.…”