Evaluation of a new technique using artificial intelligence for quantification of plasma cells on CD138 immunohistochemistry.

INTRODUCTION: The diagnosis of plasma cell neoplasms depends on the accurate quantification of plasma cells, traditionally done by immunohistochemical CD138 staining of bone marrow biopsies. Currently, there is no fully satisfactory reference method for this quantification. In our previous study, we compared the commonly used overview estimation method (method A) with a novel method for counting plasma cells in three representative areas (method B). Results showed comparable concordance parameters between the two methods. In this follow-up study, we compared the previously evaluated methods with a digital analysis method (method C) that uses artificial intelligence in open-source software, QuPath. METHODS: Archived CD138 immunohistochemically stained trephine sections of bone marrow samples used in our previous study were used (n = 33). Reviewers selected three representative areas on each sample by taking images with a light microscope and camera. Digital analysis was performed using the positive cell detection function in QuPath. The entire process was repeated by each reviewer to test intraobserver concordance (concordance correlation coefficient [CCC]) in addition to interobserver concordance (intraclass correlation coefficient [ICC]). RESULTS: Intraobserver concordance of method C showed strong agreement for all reviewers with the lowest CCC = 0.854. Interobserver concordance for method C using ICC was 0.909 and 0.949. This showed high interobserver agreement with significant differences between method C and previously assessed method A (ICC = 0.793 and 0.713) and method B (ICC = 0.657 and 0.658). CONCLUSION: We were able to successfully count CD138-positive plasma cells in bone marrow biopsies using artificial intelligence. This method is superior to both manual counting and overview estimation, regardless of tumour load.

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.

Evaluation of an innovative new method for quantitation of plasma cells on CD138 immunohistochemistry.

AIM: To compare the frequently used CD138 immunohistochemistry-based method of plasma cell quantitation, to a proposed new method, using interobserver and intraobserver concordance parameters. METHODS: Archival CD138 immunohistochemically stained slides made from paraffin-embedded bone marrow biopsies of 33 patients with a confirmed diagnosis of multiple myeloma were used. Light microscopic examination was performed using low magnification lenses (10×) for both the overview estimation method (method A) and the new method (method B), and high magnification lenses (50×), for method B only. For method B, reviewers selected three areas with low, intermediate and high plasma cell densities using 10× lenses. Using a well-defined technique, the 50× lens was then used to count plasma cells as a percentage of all nucleated cells. After blinded relabelling of all the slides, the nine reviewers repeated the plasma cell quantitation using both methods. The plasma cell counts were obtained, and the review times were recorded. RESULTS: Overall intraobserver concordance was comparable for method A (concordance correlation coefficient (CCC)=0.840) and method B (CCC=0.733). Interobserver concordance for method A (intraclass correlation coefficient (ICC)=0.793 and 0.713) and method B (ICC=0.657 and 0.658) indicated high similarity between reviewers. Method A showed poor interobserver concordance (ICC=0.105) at low plasma cell densities. CONCLUSIONS: The new method is comparable to the frequently used overview estimation method in terms of intraobserver and interobserver concordance, and cost. The new method has superior interobserver concordance at low plasma cell densities. The new method appears more amenable to digital scanning and analysis.

Hematological findings in adult patients with SARS CoV-2 infection at Tygerberg Hospital Cape Town South Africa.

Background: Coronavirus disease 2019 (COVID-19) is associated with hematological abnormalities of variable severity. The full blood count (FBC) and leukocyte differential count (DIFF) could facilitate the prediction of disease severity and outcome in COVID-19. This study aimed to assess the hematological parameters in early severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection and their correlation with disease outcome. Methods: A retrospective cross-sectional descriptive study was performed. Adults with a FBC and positive SARS-CoV-2 polymerase chain reaction results between March 1, and June 31, 2020 were reviewed. Basic hematological parameters (FBC, DIFF) and human immunodeficiency virus (HIV) status were recorded. Outcome measures were admission to a general ward or intensive care unit (ICU), recovery or death. Results: Six hundred and eighty-five cases median age 51 years, were analyzed. Forty-four percent were males and fourteen percent were HIV-positive with no association between death and/or ICU admission (p = 0.522 and p = 0.830, respectively). Leucocytosis was predictive of ICU admission (odds ratio [OR]: 2.4, confidence interval [CI]: 1.77-3.8186) and neutrophilia, of both mortality (OR: 1.5, CI: 1.0440-2.0899) and ICU admission (OR: 4, CI: 2.5933-6.475). Median lymphocyte count was decreased and d-dimer raised, showing no significant association with outcome. Raised neutrophil-to-lymphocyte-ratio (NLR) was associated with increased odds of mortality (OR: 2.5, CI: 1.3556-3.2503) and ICU admission (OR: 4.8, CI: 2.4307-9.5430) as was monocyte-to-lymphocyte-ratio (MLR) (OR: 2, CI: 1.3132-2.9064) and (OR: 2.3, CI: 1.0608-1.9935), respectively. Hospital admission and older age were significantly associated with mortality (p = 0.0008 and p < 0.0001), respectively. Conclusion: Evidence-based interpretation of routine laboratory parameters, readily available in resource-constrained settings, may identify patients at increased risk of mortality. The FBC, DIFF, NLR, and MLR should form part of the early COVID-19 investigation.

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.