Human T-lymphotropic virus 1 adult T-cell lymphoma with Giardia and Strongyloides parasitism.

Abstract

A man originally from Togo, West Africa, developed a 2-month history of abdominal cramps, diarrhea, and weight loss, 4 years after immigrating to Canada. The patient was seropositive for human T-lymphotropic virus 1 (HTLV-1). No human immunodeficiency virus 1 or human immunodeficiency virus 2 antibodies were detected. The patient’s complete blood count values were within laboratory reference intervals, and there specifically was no evidence of adult T-cell leukemia. Upper endoscopy revealed only esophageal candidiasis, which was confirmed histologically. Duodenal biopsies contained clusters of lymphocytes with large pleomorphic nuclei that infiltrated mucosa, including glandular epithelium, and submucosa (Figure, large arrow). These lymphocytes stained with antibodies directed against CD45RO and showed no immunoreactivity for CD20. Adult T-cell lymphoma was diagnosed and was also found involving the stomach. In addition to the diffuse neoplastic process, Giardia lamblia (small arrow) and Strongyloides stercoralis parasites were identified in duodenal biopsies. Occasional cytomegalovirus inclusions within gastric glandular epithelium were also present. Stool examination for ova and parasites revealed S stercoralis rhabditiform larvae, eggs, and parasitic females. Giardia lamblia cysts and trophozoites were also identified. No filariform Strongyloides larvae were present. Human T-lymphotropic virus 1 is an oncogenic retrovirus with a global distribution that is endemic to Southeast Asia, southwestern Japan, the Caribbean, the southeastern United States, and West Africa.1,2 Environmental cofactors, such as Strongyloides parasitism, have been suggested as possible contributing mechanisms to HTLV-1– associated leukemogenesis.3 It is controversial whether HTLV-1 carriers are at increased risk for Strongyloides infection.1 Human T-lymphotropic virus 1–infected patients with adult T-cell leukemia/lymphoma, however, are immunocompromised and specifically have defects of cellmediated immunity.2 These patients are at increased risk for multiple opportunistic infections, including cytomegalovirus, herpes zoster, disseminated herpes simplex, Pneumocystis carinii, Cryptococcus, Candida, and enteric parasites, such as Strongyloides.2,4 Immunocompromised hosts with Strongyloides infections may develop autoinfection and disseminated strongyloidiasis as a result of direct transformation of rhabditiform larvae to filariform larvae