Page 314 - SAHCS HIVMed Journal Vol 20 No 1 2019

Page 3 of 7 Original Research

The major indication for performing a BME was for the the unique diagnosis obtained in 17 of the 77 cases (22.1%)
investigation of a peripheral blood cytopenia (54% of cases). with unique diagnoses and confirmed MAC comprising
Thirty-two per cent of BMEs were performed due to a clinical three of the unique diagnoses obtained (2.6%). In two of these
suspicion of MTB and 9% were performed owing to a cases, MAC was diagnosed considerably faster on BME than
suspicion of a malignant lesion with bone marrow peripheral blood culture (4 vs. 38 days and 8 vs. 26 days,
involvement. Other indications, accounting for 5% of BMEs respectively). Five patients had the diagnosis of a pure red
performed, were for the investigation of a thrombocytosis, cell aplasia made on BME. Four cases of haematological
leucocytosis or suspected disseminated cryptococcal infection. malignancies were identified. These comprised two cases of
non-Hodgkin’s lymphoma (NHL), one case of Hodgkin’s
Unique diagnoses made on bone lymphoma and one case of peripheral T cell lymphoma.
marrow examination Aplastic anaemia and disseminated cryptococcal disease

Of the 327 BMEs performed, 158 (48.3%) yielded positive were two additional unique diagnoses made on BME.
results (Table 1). Three of these cases yielded two diagnoses
each. The most common findings were the presence of Three patients had two unique diagnoses obtained on bone
granulomata on trephine examination (57 cases, 17.4%) and a marrow investigation. The patient with Hodgkin’s
positive bone marrow culture for MTB (50 cases, 15.3%). The lymphoma also had the finding of granulomata on BME
presence of granulomata together with a positive ZN stain on and was on empiric TB treatment. One patient with a
BME was found in 32 cases (9.8%). positive Parvovirus B19 PCR slide also had a positive TB
bone marrow culture. This patient was also on empiric TB
In 77 cases (23.5% of the study population), the diagnoses treatment at the time of the BME. The third patient, who
made were unique to the BME (Table 2). Confirmed MTB was was not on TB treatment at the time of the BME, had both
the diagnosis of NHL as well as a positive ZN stain together
TABLE 1: All diagnoses on bone marrow examination. with granulomata observed on BME.
Diagnosis Number of Percentage
patients of study
population (%) Of the laboratory parameters measured, a white cell count
Microbiologically confirmed MTB (WCC) ≤ 4 × 10 /L was found to be a significant predictor of
9
MTB culture positive on BME 48 14.68 a unique diagnosis on BME (OR: 2.38 and 95% confidence
MTB culture positive on BME (Rifampicin resistant) 1 0.31
MTB culture positive and TB PCR positive 1 0.31 TABLE 2: Unique diagnoses on bone marrow examination.
TB PCR positive alone 5 1.53 Mycobacterial infection Number Number of
Total 55 16.82 of patients on
patients TB treatment
Microbiologically confirmed MAC already
MAC cultured on BME 4 1.22 Microbiologically confirmed MTB
Total 4 1.22 MTB culture positive on BME only 9 3
Microbiologically proven mycobacterial infection BME MTB culture positive and granulomata observed 6 1
BME mycobacterial culture positive, organism unknown 1 0.31 BME MTB culture positive and ZN positive and 2 1
Total 1 0.31 granulomata observed
Undifferentiated mycobacterial infection Microbiologically confirmed MAC
Granulomata observed & ZN positive 32 9.79 MAC cultured on BME only 1 1
ZN positive only 2 0.61 MAC cultured on BME faster than on peripheral blood 2 0
Total 34 10.4 Total 20 6
Possible mycobacteral infection Undifferentiated or possible mycobacterial infection
Granulomata observed only 57 17.43 ZN positive with/without granuloma 12 5
Total 57 17.43 Granulomata observed only 37 24
Haematological malignancies Total 49 29
Non-Hodgkin’s lymphoma 2 0.61 Pure red cell aplasia
Hodgkin’s lymphoma 1 0.31 Parvovirus B19 PCR positive 2 -
Peripheral T cell lymphoma 1 0.31 Suspected Parvovirus B19 infection but PCR negative 1 -
Total 4 1.22 Secondary PRCA, Parvovirus PCR negative 2 -
Pure red cell aplasia Total 5 -
Parvovirus B19 PCR positive 2 0.61 Malignancies
Suspected Parvovirus B19 infection but PCR negative 1 0.31 Non-Hodgkin’s lymphoma 2 -
Secondary PRCA, Parvovirus PCR negative 2 0.61 Hodgkin’s lymphoma 1 -
Total 5 1.53 Peripheral T cell lymphoma 1 -
Other diagnoses Total 4 -
Aplastic anaemia 1 0.31 Others
PAS stain positive, cryptococcus on BME 1 0.31 PAS stain positive, cryptococcus on BME 1 -
Total 2 0.61 Aplastic anaemia 1 -
Total 158 - Total 2 -
MTB, Mycobacterium tuberculosis; ZN, Ziehl-Neelsen; BME, bone marrow examination; MAC, MTB, Mycobacterium tuberculosis; ZN, Ziehl-Neelsen; BME, bone marrow examination;
Mycobacterium avium complex; MTBR, Mycobacterium tuberculosis rifampicin resistant; PCR, MAC, Mycobacterium avium complex; MTBR, Mycobacterium tuberculosis rifampicin
polymerase chain reaction; PRCA, pure red cell aplasia; PAS, Periodic acid-schiff. resistant; PRCA, pure red cell aplasia; PAS, Periodic acid-schiff.

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