Diagnostic Accuracy of Cytochemistry Taking Flow Cytometry as Gold Standard in Diagnosing Acute Leukemia.

Abstract

Background & Objective: Acute leukemia are malignant neoplastic diseases that arise when the

hematopoietic stemcells have malignant transformation into undifferentiated cells permanently. Flow

cytometry is the gold standard to diagnose acute leukemia but it is available at few laboratories among private

and public setups in Punjab and that too is very costly. Cytochemistry is an alternative and relatively cheap

option which is available at most of the setups. So this study was planned with an aim to evaluate the

diagnostic accuracy of cytochemistry using Sudan black B and Periodic Acid Schiff. stains, for acute

leukemia diagnosis in a resource-constrained laboratories.

Methods: After meeting the inclusion criteria and taking appropriate ethical review board approval ,80

patient were enrolled in this cross sectional analytical study. Detailed history and physical examination with

complete blood cells count and numerous hematological indices were obtained by using semi- automated

analyzer; SYSMEX KX-21. Slides were made by using peripheral blood / bone marrow smears, fixed by

methanol and stained for different cytochemical stains. Leukemia cell analysis was done by using the

conventional immunofluorescence method by using the monoclonal antibodies directed against cMPO,

CD2, CD5 , CD7 , CD 10 , CD11 c , CD 14 , CD 19 ,CD 20, CD33 , CD 34 , CD 45 , CD 64 , CD 79a, HLA-DR

, KAPPA, LAMBDA and TdT. The results of flow cytometry and cytochemistry were noted in a pre-designed

proforma and results were entered in SPSS for analysis.

Results: The mean age of patients included in the study was calculated to be 39.40±14.76 years, and male to

female ratio was 1.3:1. The sensitivity, specificity, positive predictive value (PPV), negative predictive value

(NPV) and diagnostic accuracy of cytochemistry using SBB stain for diagnosis of acute leukemia was

91.94%, 100%, 100%, 78.26% & 93.75% respectively taking Flow cytometry as gold standard. Similarly, the

sensitivity, specificity, PPV , NPV and diagnostic accuracy of cytochemistry using PAS stain for diagnosis of acute

leukemia was 100%, 91.94%, 78.26%, 100% & 93.75% respectively taking flow cytometry as gold standard

Conclusion: According to this study, the cytochemistry using both SBB and PAF stains showed good

accuracy for acute leukemia. Therefore, it may substitute Flow ctometry in many cases, in restricted resource

settings.