[Visceral leishmaniasis in patients with AIDS. Description of 2 cases]

Cell-mediated immunity plays a pivotal role in the pathogenesis and in the recovery mechanisms of visceral leishmaniasis (V.L.). This disease, observed in two patients with AIDS, has peculiar anatomical and clinical characteristics and it is usually characterized by a severe clinical course. In addition, V.L. has been proposed to be included among the relevant infections for the case definition of AIDS. We describe two cases of V.L. occurred in association with AIDS. The most relevant characteristics of our cases are the followings: Diagnosis has been achieved by the identification of Leishmania donovani in the macrophages of the bone marrow in both the patients, and of the lymph node in one patient. The detection of anti-Leishmania antibodies was positive in one patients only. A significant defect of CD4+ cells was documented in both the patients. V.L. was associated in one patient with esophageal candidiasis, disseminated tuberculosis, P. carinii pneumonia; and in the other one with cerebral toxoplasmosis, pulmonary tuberculosis, esophageal candidiasis, Kaposi's sarcoma, CMV hepatitis. Specific chemotherapy has been partially or totally ineffective in both the patients. In fact, chemotherapy led to an apparent transient recovery in one patient, followed by a symptom-free period of more than one year. We think that V.L. has been the first infection occurred in this patients, beside of HIV infection. At the time of the first observation, the clinical conditions of this patient were satisfactory and there was only a slight alteration in cellular immunity. The detection of leishmania in bone marrow was coincident with the onset of fever, the development of a wasting syndrome and a dramatic decrease in cell-mediated immunity. A second cycle of specific treatment has been ineffective and the patient died. On the contrary, the second patient did not respond to the specific treatment and died. Two important anatomo-pathological characteristics were present in our cases: a) the presence of the parasite in several organs, namely bone marrow, spleen, liver. b) the absence of granulomatous lesions which indirectly indicates the defect in cell mediated immunity.