A Pilot Study to Determine the Utility of Automated Tissue Dissociator for Flowcytometry Based Evaluation of Hematolymphoid Tumor Tissue Biopsies.

Routine diagnostic biopsy tissue processing, conventional histology/immunohistochemistry (IHC) method is a multi-step and time consuming practice. With the advanced tissue dissociation protocols and panel designing, flow cytometric immunophenotyping (FCI) can be performed on diagnostic hematolymphoid tissue samples using single cell suspensions that economize steps and the time taken. Diagnostic tissue samples from lymph node, mediastinal mass, testicular biopsies and similar sites were dissociated using gentle MACS Octo-dissociator and FCI was performed thereafter. Oral tissue biopsy samples were also processed as a validation set for the protocol. 21 prospective tissue biopsy samples with suspected involvement by a known hematolymphoid neoplasm were processed and evaluated. These included B lymphoblastic lymphoma (n = 12), T lymphoblastic lymphomas (n = 3), Burkitts lymphoma (n = 3) and one case each of granulocytic sarcoma, Hodgkin lymphoma and granulomatous disease. Tissue FCI and IHC were found concordant with identified profile FCI obtained from blood/bone marrow analyses. FCI can produce a highly sensitive and reliable report, within hours, by processing fresh tumor tissue samples from suspected hematolymphoid malignancies. This method can be considered as an effective adjunct to IHC and can be applicable in routine clinical diagnostics, especially in cases that needs quick diagnosis and immediate clinical treatment.

FxCycle™ Based Ploidy Correlates with Cytogenetic Ploidy in B-Cell Acute Lymphoblastic Leukemia and Is Able to Detect the Aneuploid Minimal Residual Disease Clone.

BACKGROUND: Flow cytometry (FCM) is a simple, sensitive, and specific technique that can potentially determine DNA ploidy in B-cell precursor ALL (BCP-ALL) and is complementary to cytogenetics. METHODS: A prospective FCM DNA ploidy analysis using FxCycle™ Violet (assay sensitivity 0.01%) was done in 125 consecutive new cases of BCP-ALL (90 cases <15 years of age) and compared with corresponding cytogenetic ploidy (karyotyping and/or FISH) data wherever available. This assay was also subsequently evaluated for detection of residual aneuploid clone in few BCP-ALL cases. RESULTS: Of the total 125 BCP-ALL cases evaluated, flow ploidy analysis revealed diploidy (DI 0.96-1.05) in 44.8% (n = 56), low-hyperdiploidy (DI 1.06 to 1.15) in 13.6% (n = 17), high-hyperdiploidy (DI 1.16-1.39) in 32.8% (n = 41) and near-tetraploidy (DI ≥ 1.80) in 2.4% (n = 3) cases. The high risk sub-group of low-hypodiploidy (DI 0.70 to 0.88)/near-triploidy (DI 1.40 to 1.79) constituted 5.6% (n = 7) cases while there was only one case with haploidy (DI 0.58). Overall, high concordance of 90.4% (n = 113) was noted between the combined cytogenetics ploidy and FCM ploidy. Of the total discordant cases (n = 12), the maximum discordance was seen in the low-hyperdiploid DI subgroup (n = 10), which included seven cases with low DNA index high hyperdiploidy (LDI-HHD). FCM DNA ploidy assay was able to detect the residual clone in all six MRD positive aneuploid cases evaluated. CONCLUSIONS: FxCycle™ based DNA ploidy ascertains strong correlation with cytogenetic profiles and yields complementary information that can be used by the cytogenetics laboratories or otherwise. © 2019 International Clinical Cytometry Society.

Spectrum and Immunophenotypic Profile of Acute Leukemia: A Tertiary Center Flow Cytometry Experience.

BACKGROUND: For diagnosis, sub-categorization and follow up of Acute Leukemia (AL), phenotypic analysis using flow cytometry is mandatory. MATERIAL AND METHODS: We retrospectively analyzed immunophenotypic data along with cytogenetics/molecular genetics data (wherever available) from 631 consecutive cases of AL diagnosed at our flow cytometry laboratory from January 2014 to August 2017. RESULTS: Of the total 631 cases, 52.9% (n=334) were acute lymphoblastic leukemia (ALL), 43.9% (n=277) acute myeloid leukemia (AML), 2.2% (n=14) mixed phenotypic acute leukemia (MPAL), 0.5% (n=3) acute undifferentiated leukemia (AUL) and 0.5% (n=3) chronic myeloid leukemia in blast crisis (CML-BC). ALL cases comprised of 81.7% (n=273/334) B-cell ALLs (95.2%, n=260/273 common B-ALLs and 4.8%, n=13/273 Pro B-ALLs). CD13 was the commonest cross lineage antigen, expressed in B-ALL (25.6%, n=70/273), followed by CD33 (17.9%, n=49) and combined CD13/CD33 (11.3%, n=31/273) expression. T-ALLs constituted 18.3% (n=61/334) of total ALLs and included 27.9% (n=17/61) cortical T- ALLs. CD13 was commonest (32.7%, n=20/61) aberrantly expressed antigen in T-ALLs, followed by CD117 (19.1%, n=9/47). AML cases included 32.1% (n=89/277) AML with recurrent genetic abnormalities, 9.0% (n=25/277) with FLT3/NPM1c mutation and 58.9% (n=163/277) AML NOS including 14.7% (n=24/163) AML M4/M5, 1.8% (n=3/163) AML M6 and 3.7% (n=6/163) AML M7. In AMLs, CD19 aberrancy was the most common (20.2%, n=56/277) followed by CD56 (15.8%, n=42/265). CONCLUSIONS: In this study, we document the spectrum, correlate the immunophenotype with genetic data of all leukemias, especially concerning T-ALL where the data from India is scarce.