The diagnostic utility of bone marrow examination in an infectious disease ward

Detection of Mycobacterial DNA in Human Bone Marrow

Bone marrow is a cell-rich tissue of the reticuloendothelial system essential in the homeostasis and accurate functioning of hematopoiesis and of the immune system; moreover, it is also rich in lipids because it contains marrow adipocytes. This work aimed to evaluate the detection of mycobacterial DNA in human bone marrow as a tool to understand the complex pathology caused by the main pathogen Mycobacterium tuberculosis (Mtb). Formalin-fixed paraffin-embedded human bone marrow samples were studied using both conventional PCR + hybridization and in situ PCR to figure out the cell distribution of the targeted DNA. Samples were retrospectively collected from HIV+ patients with microbiologically proved mycobacterial infection and from subjects without evidence of infection. Mycobacterium avium (Mav) as well as Mtb DNA was detected in both settings, including tissues with and without granulomas. We detected DNA from both mycobacterial species, using in situ PCR, inside bone marrow macrophages. Other cell types, including adipocytes, showed positive signals only for Mtb DNA. This result suggested, for the first time, that marrow adipocytes could constitute an ideal reservoir for the persistence of Mtb, allowing the bacilli to establish long-lasting latent infection within a suitable lipid environment. This fact might differentiate pathogenic behavior of non-specialized pathogens such as Mav from that of specialized pathogens such as Mtb.

The value of bone marrow examinations performed in the investigation of HIV infected patients with cytopenias

INTRODUCTION

Bone marrow examination (BME) is a reliable and effective tool in the diagnosis of many haematological and non-haematological diseases and may be used to investigate unexplained cytopenia in human immunodeficiency virus (HIV) infected patients. The objective of this study was to determine the diagnoses made, diagnostic yield and unique diagnostic yield of BMEs performed to investigate cytopenias in HIV infected patients.

METHOD

A retrospective cross-sectional descriptive study was performed involving all BMEs performed on HIV-infected adult patients with the main indication of unexplained cytopenia over a period of 5 years and 4 months. Data was extracted from the National Health Laboratory Service's laboratory information system and clinicians' BME request forms.

RESULTS

The study included 128 BMEs, performed on 124 patients. The diagnostic yield was 32% and the unique diagnostic yield was 30.5%. The most common diagnosis was pure red cell aplasia (10.9%), followed by immune thrombocytopenic purpura (ITP) (7%), iron deficiency anaemia (6.3%), malignancy (4.7%) and disseminated infection (3.9%).

CONCLUSION

BME is a useful investigation for unexplained cytopenia in HIV-infected patients. Less invasive investigations to exclude haematinic deficiencies, haemolysis and sepsis are recommended on an individualised basis prior to BME. In HIV-infected patients with therapy refractory ITP or ITP with atypical clinicopathological findings, BME is strongly recommended. As Mycobacterial and other infections are common in this group of patients, staining and culture of specimens are advised if BME is undertaken.

Indications and diagnostic value of bone marrow examination in HIV-positive individuals: A 3-year review at Tygerberg Hospital

Background

Bone marrow examination is a useful diagnostic tool in human immunodeficiency virus (HIV)-positive patients presenting with cytopenias and fever. However, its role in the afebrile and asymptomatic patient presenting with an isolated cytopenia is not well established. This study was conducted to determine the indications for bone marrow examination and its diagnostic yield, in HIV-positive patients at Tygerberg Hospital.

Methods

A retrospective, cross-sectional descriptive study was performed over a 3-year period from 01 September 2015 to 31 August 2018. The bone marrow examination reports for the HIV-positive patients who had a bone marrow examination during the study period were retrieved. Clinical and laboratory information was captured.

Results

Altogether 374 bone marrow reports for HIV-positive patients were found. The indication of the bone marrow examination included investigation of unexplained cytopenias, suspected haematological malignancies, follow-up examination for patients with known haematological diseases, staging of haematological or non-haematological malignancies and investigation of suspected disseminated infection. The patients' median age was 43 years and the interquartile range was 27-60 years. There was a slight female predominance with females 51% and males 49%. The diagnostic yield was 33.7%. Acute leukaemia and lymphoma were the most common diagnoses. Haematinic deficiency and pure red cell aplasia were found in the majority of cases with isolated anaemia. All cases with isolated thrombocytopenia were due to immune thrombocytopenia.

Conclusion

Bone marrow examination is a useful investigation for HIV-positive patients with cytopenias, suspected haematological malignancy and lymphoma staging. However, its early use in patients with isolated anaemia and isolated thrombocytopenia is questionable.

HIV-positive patients presenting with peripheral blood cytopenias: is bone marrow assessment a priority?

Introduction

Hematologic abnormalities are frequent among persons living with HIV (PLWH). The bone marrow aspirate (BMA) and biopsy (BMB) are commonly performed in the diagnostic approach of patients with unexplained cytopenias. Changes in antiretrovirals, supportive therapy and increased life expectancy have modified the distribution and etiology of cytopenias, questioning their use. Our aim was to analyze the diagnostic yield of BMA, BMB and marrow cultures for the evaluation of cytopenias in PLWH.

Methods

This was a retrospective cohort of ≥ 18-year-old PLWH undergoing bone marrow assessment (MA) for the evaluation of cytopenias between January 2002 and December 2015.

Results

A total of 236 cytopenic events were analyzed, 47.9% being PLWH who had a longstanding diagnosis (≥ 1 year). Adherence to antiretrovirals was 63.5%. Anemia was seen in 91.9% and pancytopenia in 39%. Common presentations included fever (52.1%), weight loss (42.8%) and adenopathies (28.8%). Median days from detection to MA was 5 (0 – 63 days). Most common etiologies were non-HIV infectious diseases (31.4%) and benign/malignant hematologic diseases (26.3%). The diagnostic yield was 16.1% for BMA, 20.3% for BMB, 30.5% for both and 35.6% when cultures were added. Patients most likely to have conclusive MA were those with moderate/severe thrombocytopenia (p = 0.007). Fever, splenomegaly, and low CD4+ counts were associated with infectious etiologies, while hematologic diagnoses were related to the presence of adenopathies.

Conclusion

As a minimally invasive intervention, the MA has a high yield for identifying the etiology of cytopenic events in PLWH, being conclusive in one in three patients. Early performance could lead to prompt diagnosis and timely therapy initiation.