Comparison of PCR with direct examination of bone marrow aspiration, myeloculture, and serology for diagnosis of visceral Leishmaniasis in immunocompromised patients

Abstract

A PCR assay amplifying a repeated sequence from the Leishmania infantum genome was compared with direct examination of bone marrow aspirate, myeloculture, and serology for the diagnosis of visceral leishmaniasis in immunocompromised patients. Of 73 patients living in an area endemic for leishmaniasis and where visceral leishmaniasis was suspected by physicians, only 10 had an indisputable diagnosis of visceral leishmaniasis. None of the diagnostic tests performed in the study achieved 100% sensitivity for diagnosing visceral leishmaniasis. PCR exhibited superior sensitivity (82%) in comparison with bone marrow aspirate examination (55%) and myeloculture (55%). Our PCR assay also showed good specificity (97%), negative predictive value (97%), and positive predictive value (82%) even when all unconfirmed PCR results were scored as false positives. Serology exhibited good sensitivity (80%) and excellent specificity (100%), negative predictive value (98%), and positive predictive value (100%) in diagnosing new cases of visceral leishmaniasis but failed to diagnose relapses. We also observed consistent negative serological results using several different immunological detection methods for 2 of the 10 patients with confirmed cases of visceral leishmaniasis. This lack of serological reactivity persisted throughout the course of their infections. These results demonstrate the importance of using PCR as an aid in the diagnosis of visceral leishmaniasis in immunocompromised patients.

Leishmania infection in rodents in Greece

“…Statistical analysis was applied to the results of molecular examination, as it was considered the most reliable method of detecting the infection . Therefore, statistical analysis was used to assess the influence of different risk factors to the Leishmania spp.…”

HIV-associated visceral leishmaniasis

“…The combination of two or more serologic techniques may significantly increase the sensitivity of antibody detection, and some authorities have recommended this practice in HIV-infected patients with suspected VL. However, in a study in which several diagnostic methods were compared, 20% of co-infected patients gave negative results with all serologic techniques [39]. The functional impairment of cell-mediated immunity due to HIV infection could result in an absent antibody response to Leishmania, as for other infections.…”

Review: Molecular biological applications in the diagnosis and control of leishmaniasis and parasite identification

“…1997a). In another study, comparison of PCR on bone marrow aspirates with microscopic examination and culture for diagnosis of VL in immune‐compromised patients showed that PCR exhibited a higher sensitivity (82%) than microscopy (55%) and culture (55%) (Piarroux et al . 1994).…”