An analysis of the utility of bone marrow examinations carried out in an infectious disease ward

Abstract

Introduction: Human immunodeficiency virus (HIV) infection in South Africa places a large burden on the public healthcare sector. This necessitates quick and effective diagnostic decision making skills in acutely ill hospitalized patients, in order to improve patient outcome and reduce the length of hospital stay. Bone marrow aspirate and trephine examinations have long been utilized to aid with diagnosis in those patients who present diagnostic dilemmas in advanced stages of HIV infection. Aim: The aim of the study was to review the bone marrow examinations carried out in the Infectious Disease ward at the Charlotte Maxeke Johannesburg Academic Hospital between January 2012 and December 2014. Methods: A retrospective record review of bone marrow examination results from the National Health Laboratory Service database was undertaken. Individual patient records were reviewed if information was omitted from the bone marrow examination request forms. Results: A total of 327 patients underwent bone marrow examinations during this time period. Diagnoses unique to the bone marrow examination were obtained in 77 cases (23.5%). A unique diagnosis in this study was defined as any diagnosis made solely on bone marrow examination and not by any other means, or a diagnosis which was made faster on bone marrow examination as compared to other forms of investigation. In three of these cases there were two unique diagnoses obtained, resulting in a total of 80 unique diagnoses. The most common unique diagnoses obtained were mycobacterial infection (69 cases), malignant lesions (5 cases) and pure red cell aplasia (4 cases). A white cell count < 4 x 109/L was a predictor of a unique outcome on bone marrow investigation (p < 0.01). A neutrophil count of < 0.5 x 109/L was found in those with unique diagnoses; however, this was not significant. A lower platelet and white cell count as well as a lower CD4 cell count were found to be significant predictors of the diagnosis of mycobacterial infection on bone marrow examinations, either via positive bone marrow culture, observation of granulomata on histology, or Ziehl-Neelsen staining on trephine specimens. Concluding statement: Bone marrow examinations may assist in aiding diagnoses in patients in whom other less invasive investigations have not yielded positive outcomes. Those patients in whom the diagnosis of disseminated mycobacterial infection is of primary concern and who have advanced HIV infection with lower peripheral blood counts may benefit the most from this modality of investigation