A Review of Diagnostic Methods and Results for HIV-associated Disseminated Histoplasmosis: Shouldn’t We be Involving Pathologists More Systematically?

Abstract

Background. Disseminated histoplasmosis is a major killer of HIV-infected persons in Latin America. Antigen detection, fungal culture, or Polymerase Chain Reaction are often not available, but cytology and histology are usually present in most hospitals and may represent an important diagnostic alternative. In this study, we review 34 years of clinical experience to describe the respective place of cytology and histology to diagnose disseminated histoplasmosis.Methods. Between January 1st, 1981 and October 1st, 2014, a retrospective multicentric study was performed on 349 patients with confirmed disseminated histoplasmosis. Results. Whereas bone marrow was by far the most common sample taken, only 14.9% of samples were screened using cytopathology, the second most frequent sample taken was bonchoalveolar lavage for which 9.9% were subjected to cytopathological analysis, and finally spinal fluid for which 16.4% were subjected to cytopathological analysis. The samples most systematically sent to pathology were liver biopsies, lower digestive tract, and lymphnode biopsies and the most contributive in terms of positive results were lower digestive tract (72.9% positives), lymph node (66.1%), and liver (50.7%). 97.2% of bone marrow samples were subjected to direct examination by the mycologist, the second most frequent sample taken was bronchoalveolar lavage for which 97% were subjected to direct examination. Positive direct examination was independently associated with death (aHR=1.5 (95%CI=1-2.2), and positive pathology was associated with less mortality ((aHR=0.66 (95%CI=0.44-1). Conclusions. Opportunities for a rapid diagnosis were regularly missed, notably for bone marrow samples which could have been examined using complementary staining methods to those of mycologist.

Cytological Spectrum of Pulmonary Histoplasmosis Diagnosed by Bronchoalveolar Lavage: 12 Years of Experience in French Guiana

“…Since then, the MGG, Gomori-Grocott, Ziehl-Neelsen and Perls stains have been performed systematically in our department on all BALs regardless of the immune status of the patient. In previous studies, we have demonstrated the effectiveness of BAL in the diagnosis of pulmonary localization of histoplasmosis [12,22]. Comparing the different diagnostic methods of histoplasmosis in our institute between 1981 and 2014, direct examination and fungal cultures of BAL performed by the Mycology Laboratory were more frequent than cytopathological examination [22].…”

“…Comparing the different diagnostic methods of histoplasmosis in our institute between 1981 and 2014, direct examination and fungal cultures of BAL performed by the Mycology Laboratory were more frequent than cytopathological examination [22]. Overall, fewer than half of the specimens diagnosed as H. capsulatum had cytological or histological examination, whereas more than half of the specimens examined by the pathologist were positive [22]. Prior to 2015, within our department, fewer than 10% of these BALs received a request for cytological examination.…”

“…In previous studies, we have demonstrated the effectiveness of BAL in the diagnosis of pulmonary localization of histoplasmosis [12,22]. Comparing the different diagnostic methods of histoplasmosis in our institute between 1981 and 2014, direct examination and fungal cultures of BAL performed by the Mycology Laboratory were more frequent than cytopathological examination [22]. Overall, fewer than half of the specimens diagnosed as H. capsulatum had cytological or histological examination, whereas more than half of the specimens examined by the pathologist were positive [22].…”