Roger Pool

Preliminary data on microRNA expression profiles in a group of South African patients diagnosed with chronic myeloid leukaemia

Micro-ribonucleic acids (miRNAs) are small functional non-coding RNAs that downregulate gene expression at the post-transcriptional level. Abnormal expression of specific miRNAs has been recorded in chronic lymphocytic leukaemia, other non-Hodgkin B-cell lymphomas, lung cancer and chronic myeloid leukaemia (CML). The aim of this study was to compare miRNA expression profiles among patients with newly diagnosed CML, those on established therapy with imatinib mesylate, and healthy individuals. The expression of 88 miRNAs was evaluated in a total of nine samples divided into three groups: Group 1 comprised three samples collected from newly diagnosed CML patients; group 2 consisted of three samples collected from patients on therapy; the remaining three samples were collected from healthy volunteers (control group). Total RNA was extracted from whole blood and reverse transcriptase quantitative polymerase chain reaction (RT-qPCR) was performed on the LightCycler® 480 platform using Human Serum & Plasma miRNA PCR Arrays. In group 1, only SNORD44 was downregulated, while hsa-miR-372 and hsa-miR-375 were found to be significantly upregulated compared with the control group. By contrast, 49 miRNAs were significantly upregulated in group 2 compared with the control group. miRNAs hsa-miR-106b, hsa-miR-21, hsa-miR-221, hsa-miR-10a, hsa-miR-193a-5p and hsa-miR-30e were expressed in group 2. Therefore, miRNA expression profiles differed between the two patient groups.

Plasmablastic lymphoma versus diffuse large B cell lymphoma with plasmablastic differentiation: proposal for a novel diagnostic scoring system

High-grade non-Hodgkin’s lymphomas with plasmablastic differentiation are frequently encountered in HIV-positive patients. Differentiating between diffuse large B cell lymphoma (DLBCL) with plasmablastic differentiation and true cases of plasmablastic lymphoma (PBL) is sometimes challenging, particularly as a substantial overlap in immunphenotype exists between late-stage B cell neoplasms and PBL. This study sought to develop an immunohistochemical panel to more reliably distinguishing between PBL and DLBCL with plasmablastic differentiation. Thirty-nine CD20-negative, ALK-negative, HHV8-negative non-Hodgkin’s lymphomas with plasmablastic differentiation defined by their morphological features, high proliferation index and positivity for MUM1/IRF4 and PRDM/Blimp1 protein expression were compared regarding their protein expression profiles, viral status and c-MYC-gene aberrations. These lymphomas were subsequently divided in two groups utilising CD10 and Pax5. Tumours without reactivity for either of these markers exhibited higher expression of CD138 and CD117 frequently used as the plasma cell (PC) markers, whilst tumours with reactivity for one or both markers showed a significantly higher expression of CD38 and MYC-gene aberrations. A novel diagnostic scoring system which includes the immunohistochemical expression of CD10 and Pax5 is proposed to differentiate between DLBCL with plasmablastic differentiation and true cases of PBL.

Circulating neuroblastoma cells in peripheral blood

A two-year-old black African boy was referred to Ga-Rankuwa Hospital with generalized lymphadenopathy, hepatomegaly and multiple non-tender swellings over the head. A whole-body isotope [meta-iodobenzylguanidine (MIBG)] scan (left) was performed, which demonstrated a large primary tumour in the region of the left adrenal gland together with extensive skeletal metastases. A MIBG scan images the adrenal medulla and sympathetic nervous tissue, and these results, therefore, suggested metastatic neuroblastoma. A bone marrow examination was performed as part of the clinical work-up and showed extensive infiltration by neuroblastoma cells. The patient was classified as stage IV. Successive full blood counts showed pancytopenia. Microscopic examination of a peripheral blood film showed (on a single occasion) the presence of a group of closely adherent, immature cells with fibrils (right) that were very similar in appearance to the cells infiltrating the marrow. The presence of cohesive clumps of neuroblastoma cells in the peripheral blood with associated fibrillar material is very rare.

Application of the AMLprofiler Diagnostic Microarray in the South African Setting

Acute myeloid leukemia (AML) is characterized by proliferation of the myeloid lineage and accumulation of immature hematopoietic cells in the bone marrow and is typified by marked heterogeneity both in response to treatment and survival. AMLprofiler is a qualitative in vitro diagnostic microarray incorporating seven molecular biomarkers used to diagnose and predict posttherapy survival rates. In this study, we compared AMLprofiler to routine AML diagnostic methodologies employed in South Africa, focusing on consistency of the results, cost, and time to result. RNA was isolated from bone marrow and peripheral blood samples from patients with de novo AML and was processed using Affymetrix Gene Profiling Reagent kits. The results from AMLprofiler and standard methodologies were highly comparable. In addition, many samples were determined to be positive for biomarkers not routinely investigated in South Africa, namely, CEBPA double mutants, NPM1 variants, and altered expression levels of BAALC and EVI1. 38% of samples presented with no positive biomarker; AMLprofiler nonetheless enabled 26% of AML patients to be classified into either favorable or poor prognostic categories. This study highlights the comprehensive nature of the microarray. Decreased time to result and refinement of risk stratification are notable benefits.

An endometrial histomorphometric study of CD56 + natural killer cells in women with unexplained infertility

51 SAJOG • September 2017, Vol. 23, No. 2 Background. The number of peripheral blood and endometrial natural killer cells varies greatly during implantation and the first trimester of pregnancy and is thought to play a role in the maintenance of a healthy pregnancy. However, the role of endometrial CD56+ natural killer (NK) cells as an immunological mechanism in unexplained infertility is yet unknown. Objectives. The study aimed to enumerate the concentrations of CD56+ NK cells in endometrial samples, and to statistically compare these numbers between fertile and infertile women. Methods. A histomorphometric analysis was conducted using haematoxylin and eosin staining and an immunohistochemical approach was used for quantifying cell numbers. Results. Fifty samples were collected in equal parts between a study group of infertile female subjects (mean (standard deviation) age 35 (4), range 26 42 years) and a control group of multiparous fertile individuals (mean (SD) age 43.4 (6.3), range 30 55). The mean number of CD56+ NK cells present at different depths for both the study and control groups did not differ significantly. Age and group (study or control) were not significantly related to the mean number of CD56+ NK cells. However, for the late secretory phase the mean number of CD56+ NK cells was significantly higher than for the early phase. Conclusion. Our findings could not identify a statistically significant correlation between the number of CD56+ NK cells and infertility.

Guideline for the treatment of myelodysplastic syndromes (MDS) in South Africa

INTRODUCTION Myelodysplastic syndromes (MDS) encompass a heterogeneous group of clonal haematopoietic disorders characterised by chronic and progressive cytopenias resulting from ineffective haematopoiesis. Treatment is complicated by differences in disease mechanisms in different subgroups, variable clinical phenotypes and risk of progression to acute myeloid leukaemia. RATIONALE Changes in disease classification, prognostic scoring systems, the availability of novel treatment options and the absence of South African guidelines for the diagnosis and management of these complex disorders underpinned the need for the development of these recommendations. METHODS These recommendations are based on the opinion of a number of experts in the field from the laboratory as well as clinical settings and came from both the private and institutional academic environments. The most recent literature as well as available guidelines from other countries were discussed and debated at a number of different meetings held over a 2-year period. RESULTS A comprehensive set of recommendations was developed focusing on risk stratification, supportive management and specific treatment. Novel agents and their indications are discussed and recommendations are made based on best available evidence and taking into account the availability of treatments in South Africa. CONCLUSION Correct diagnosis, risk stratification and appropriate therapeutic choices are the cornerstones of success in the management of patients with myelodysplastic syndromes.