Role of Interphase FISH Assay on Air-Dried Smears in Identifying Specific Structural Chromosomal Abnormalities among Pediatric Patients with Acute Leukemias.

Leukemia-associated structural chromosomal abnormalities (SCA) can be identified either by karyotyping or interphase-fluorescence in-situ hybridization (i-FISH) assays. Both karyotyping and i-FISH on mononuclear cell suspension are time, resource, and manpower-consuming assays. In this study, we have compared the results of specific leukemia-associated SCAs identified by i-FISH on air-dried bone marrow (BM)/peripheral blood (PB) smears and BM karyotyping. The study was conducted among pediatric patients (age ≤ 18 years) diagnosed with acute leukemias between January 2018 to December 2022. The results of i-FISH on air-dried BM/PB smears and BM-karyotyping for our SCA of interest (BCR::ABL1, ETV6::RUNX1, TCF3::PBX1, KMT2A rearrangement, RUNX1::RUNX1T1, CBFB::MYH11, and PML::RARA) were entered in a contingency table and the agreement of results was calculated. The strength of agreement was assessed by Cramer's V test. Among 270 patients, SCA of interest was identified among 26% and 17% of patients by i-FISH on air-dried smears and karyotyping, respectively. Excluding 53 patients with metaphase failure, the remaining 217 patients had 92% agreement (Cramer's V of 0.931 with p < 0.000) between the results for specific SCAs identified by both techniques. On excluding samples with cryptic cytogenetic aberrancies, there was 99% agreement (Cramer's V of 0.953 with p < 0.000) for gross SCA identified by both techniques. In addition, i-FISH on air-dried smears identified SCA in 30% of patients with metaphase failure. I-FISH on air-dried PB/BMA smears is a less-labor and  resource-consuming assay. It can be considered an efficient alternative to conventional karyotyping for  identifying specific SCA of interest in under-resourced laboratories. Supplementary Information: The online version contains supplementary material available at 10.1007/s12288-023-01699-2.

Relevance of CD20 antigen expression among paediatric patients with B-lineage acute lymphoblastic leukaemia.

Literature regarding prognostic relevance of CD20 antigen expression among paediatric B-lineage acute lymphoblastic leukaemia (B-ALL) patients is sparse and contradictory. We analysed clinical laboratory parameters and survival characteristics pertinent to CD20 expression among 224 treatment-naïve paediatric B-ALL patients. 50% patients had CD20 expression (CD20+ B-ALL). There was no difference in the clinical & laboratory presentation and end of induction measurable residual disease (EOI-MRD) status according to CD20 expression. As compared to CD20- B-ALL patients, CD20+ B-ALL patients had two times more relapse (16% vs. 29%, p = 0.034), inferior relapse-free survival (79% vs. 66%, p = 0.025) but no difference in overall survival (75% vs. 69%, p = 0.126). Similar to high-risk NCI status and EOI-MRD positivity, CD20 expression was an independent predictor for inferior relapse-free survival (HR: 1.860, 95% CI: 1.008-3.432, p = 0.047). Compared to baseline, there was a significant increase in CD20-expressing EOI-residual blasts among CD20- B-ALL patients (5% vs. 13%, p = 0.001). EOI residual blasts of both CD20+ and CD20- patients had three times increased normalized CD20 expression intensity (nCD20), with the intensity among CD20- B-ALL patients reaching the pretreatment nCD20 of CD20+ B-ALL patients (4.9 vs. 3.6, p = 0.666). Rituximab can be considered in managing EOI-MRD-positive CD20- B-ALL patients as the residual blasts of these patients have quantitative and qualitative increases in CD20 expression.

Central nervous system involvement in multiple myeloma: Experience from a tertiary cancer center and review of literature.

BACKGROUND: Multiple myeloma (MM) results from clonal expansion of immunoglobulin secreting, heavy chain class-switched, terminally differentiated B-lymphocytes (plasma cells), resulting in radiologic or biochemical evidence of end-organ damage. Though neurological manifestations (peripheral neuropathies, spinal radiculopathies, cranial nerve palsies, and metabolic encephalopathies) can occur during the disease course, direct central nervous system (CNS) infiltration by malignant plasma cells (CNS-MM) is very rare (~1%) and has a dismal prognosis (survival of <6 months). METHODOLOGY: Clinico-laboratory profile and outcome of CNS-MM patients diagnosed and treated at a tertiary cancer care hospital were retrospectively analyzed. RESULTS: On scrutinizing 500 consecutive myeloma case records, 4 patients with CNS-MM were identified. All these patients were diagnosed during myeloma relapse, and all had deceased within 1 week and 12 months of developing CNS infiltration. Our experience with CNS-MM patients is similar to the experiences documented across major world literature. CONCLUSION: Our manuscript reinforces that CNS-MM should be considered in any myeloma patient presenting with unexplainable CNS manifestations. As there are no prospective studies to recommend optimal treatment strategies, CNS-MM still remains a dismal complication of myeloma.

Secondary Acute Myeloid Leukemia in a Chronic Myeloid Leukemia Patient in Deep Molecular Response-An Unusual Case Report.

Perumal Kalaiyarasi Jayachandran Chronic myeloid leukemia (CML) is a clonal myeloproliferative disorder that develops from the stem cell compartment. The classical translocation ( BCR-ABL1 ) is present in approximately 95% of CML patients. Through disease progression, clonal evolution with additional chromosomal abnormalities (ACAs) start appearing. Although relatively rare, chromosomal abnormalities can exist or develop in the Philadelphia (Ph)-negative clones, which may lead to the evolution of myelodysplastic syndrome (MDS) or acute myeloid leukemia (AML). We hereby present a case of AML which emerged from a Ph-negative clone in a patient with a history of CML who was in deep molecular response. The possible mechanisms of ACAs have been discussed.

Relevance of flow cytometric categorization and end-of-induction measurable residual disease assessment in pediatric and adult T-lymphoblastic leukemia patients.

Background: T-lymphoblastic leukemia (T-ALL) patients expressing myeloid/stem cell antigens are classified as early T-cell precursor lymphoblastic leukemia (ETP-ALL) or near-ETP-ALL. Methods: Clinico-laboratory profiles, flow cytometric end-of-induction measurable residual disease (EOI-MRD), and survival of treatment naïve T-ALL patients were analyzed according to their immunophenotypic subtypes. Results: Among 81 consecutive T-ALL patients diagnosed, 21% (N=17) were ETP-ALL and 19% (N=15) were near-ETP-ALL. EOI-MRD was detectable in 39% of the 59 samples tested (31.6% of pediatric samples and 52.4% of adult samples). The frequency of EOI-MRD positivity was significantly higher among ETP-ALL (75%, P=0.001) and near-ETP-ALL (71%, P=0.009) patients compared to that in conventional-T-ALL (con-T-ALL) patients (22.5%). CD8 (P=0.046) and CD38 (P=0.046) expressions were significantly upregulated in the EOI blasts of con-T-ALL and ETP-ALL samples, respectively. The 2-year rates of overall (OS), relapse-free (RFS), and event-free survival (EFS) among the T-ALL patients (pediatric vs. adult) was 79.5% vs. 39.8% (P<0.001), 84.3% vs. 60.4% (P=0.026), and 80.3% vs. 38% (P<0.001), respectively. Univariate analysis revealed that 2-year EFS and RFS of pediatric T-ALL patients was independent of T-ALL subtype and was influenced only by EOI-MRD status. However, 2-year OS, RFS, and EFS among adult T-ALL patients were EOI-MRD independent and influenced only by the near-ETP-ALL phenotype. Conclusion: Two-year survival among pediatric and adult T-ALL patients is attributed to EOI-MRD status and near-ETP-ALL phenotype, respectively.

Precursor B-lineage acute lymphoblastic leukemia patients with aberrant natural killer cell and T cell - lineage antigen expression: experience from a tertiary cancer care center

Abstract Introduction Flow cytometric immunophenotyping (FCI) plays a major role in diagnosing hematologic malignancies. In patients diagnosed with precursor B-lineage acute lymphoblastic leukemia (B-ALL), expression of certain non-lineage/cross lineage antigens is of prognostic and cytogenetic relevance. There is a paucity of studies that have comprehensively analyzed the clinical and laboratory profiles of B-ALL patients showing aberrant T/natural killer (NK) cell antigen expression. Materials and methods This is a prospective study where 152 consecutive B-ALL patients were analyzed for aberrant expression of T/NK cell antigens (CD1a, CD5, CD4, CD7, CD8 and CD56) by FCI. The clinical and laboratory profile of these T/NK-cell antigen-expressing B-ALL patients was statistically analyzed against conventional B-ALL patients. Results In our B-ALL cohort, CD5, CD7 and CD56 expression were observed in one, six and nine patients, respectively. CD56-expressing B-ALL patients were predominantly children (89%) and presented as standard clinical risk (p = 0.010) disease with frequent ETV6-RUNX1 fusion (p = 0.021) positivity. On the contrary, CD7-expressing B-ALL patients were adolescent-young adult/adult-age skewed (83%) and had an adverse cytogenetic profile (p = 0.001), especially for the frequent presence of BCR-ABL1 fusion (p = 0.004) and KMT2A rearrangement (p = 0.045). CD7-expressing B-ALL patients had inferior event-free survival (p = 0.040) than their CD56-expressing counterparts, but there was no significant difference in the overall survival (p = 0.317). Conclusion In comparison to conventional B-ALL patients, there are significant differences in the age, cytogenetic profile and event-free survival of T/NK-cell antigen-expressing B-ALL patients.

Precursor B-lineage acute lymphoblastic leukemia patients with aberrant natural killer cell and T cell - lineage antigen expression: experience from a tertiary cancer care center.

INTRODUCTION: Flow cytometric immunophenotyping (FCI) plays a major role in diagnosing hematologic malignancies. In patients diagnosed with precursor B-lineage acute lymphoblastic leukemia (B-ALL), expression of certain non-lineage/cross lineage antigens is of prognostic and cytogenetic relevance. There is a paucity of studies that have comprehensively analyzed the clinical and laboratory profiles of B-ALL patients showing aberrant T/natural killer (NK) cell antigen expression. MATERIALS AND METHODS: This is a prospective study where 152 consecutive B-ALL patients were analyzed for aberrant expression of T/NK cell antigens (CD1a, CD5, CD4, CD7, CD8 and CD56) by FCI. The clinical and laboratory profile of these T/NK-cell antigen-expressing B-ALL patients was statistically analyzed against conventional B-ALL patients. RESULTS: In our B-ALL cohort, CD5, CD7 and CD56 expression were observed in one, six and nine patients, respectively. CD56-expressing B-ALL patients were predominantly children (89%) and presented as standard clinical risk (p=0.010) disease with frequent ETV6-RUNX1 fusion (p=0.021) positivity. On the contrary, CD7-expressing B-ALL patients were adolescent-young adult/adult-age skewed (83%) and had an adverse cytogenetic profile (p=0.001), especially for the frequent presence of BCR-ABL1 fusion (p=0.004) and KMT2A rearrangement (p=0.045). CD7-expressing B-ALL patients had inferior event-free survival (p=0.040) than their CD56-expressing counterparts, but there was no significant difference in the overall survival (p=0.317). CONCLUSION: In comparison to conventional B-ALL patients, there are significant differences in the age, cytogenetic profile and event-free survival of T/NK-cell antigen-expressing B-ALL patients.

Immunophenotypic expression and immunomodulation in minimal residual disease analysis of pediatric B acute lymphoblastic leukemia by high sensitive flow cytometry.

The major challenge in minimal residual disease (MRD) detection is the antigen modulation in post treated samples restraining the use of diagnostic immunophenotypic (IP) signature of leukemic blasts for MRD detection. The IP expression of 10 antigens in 167 children diagnosed as B-acute lymphoblastic leukemia (B-ALL) in comparison to hematogones and the extent of immunomodulation in 60 post treated MRD positive cases were studied. Upregulation was the predictable shift noted in antigens like CD73, CD86, CD19, CD20 and CD45 which was statistically significant for all except CD45. Downregulation was the predictable shift noted in antigens like CD10, CD38, CD58 and CD34 and was statistically significant in all. CD123 showed no significant trend. This immunomodulation in B-ALL results in aberrant expression of antigens during follow-up compared to the diagnostic phenotypic pattern. Hence it is necessary to be aware of the immunomodulations of antigens used in primary diagnosis to avoid being misled during MRD analysis.

Cytogenetics and FISH negative cryptic acute promyelocytic leukemia with CD56 expression.

Acute promyelocytic leukemia (APL) is characterized by reciprocal translocation t(15;17)(q22;q21) and has a favorable prognosis upon immediate recognition and treatment. However, rare cases of APL show a cryptic insertion of retinoic acid receptor alpha (RARA) gene into promyelocytic leukemia (PML) gene which is negative both by fluorescence in situ hybridization (FISH) and conventional cytogenetics (CC). Morphology, cytochemistry and flow cytometry play a key role in early identification of such cases. Polymerase chain reaction (PCR) remains the most efficient diagnostic modality for detection of cryptic APL and other variants. It is important to identify these cases as they show beneficial response to retinoids and favourable prognosis. We herein present a rare case of cryptic APL negative by FISH and conventional cytogenetics but positive for PML-RARA by PCR.

Blast size-specific flowcytometric ploidy assessment using FxCycleTM Violet dye and its correlation with conventional cytogenetic ploidy in pediatric precursor B-lineage acute lymphoblastic leukemia patients.

INTRODUCTION: Numerical chromosomal abnormalities (aneuploidies), present in approximately 30%-50% of pediatric precursor B-lineage acute lymphoblastic leukemia (B-ALL) patients, are commonly identified through a laborious conventional cytogenetic (CG) technique. Flow cytometry (FCM) can identify both physical and fluorescent properties of cells together, and by using fluorescent nucleic-acid-binding dyes, FCM can identify variations in total nucleic-acid content of cells. FxCycleTM Violet dye (FxCV) is a selective DNA-binding dye which permits simultaneous multiparametric immunophenotyping and cell-cycle/ploidy assessment in a single assay. To date, only two studies have demonstrated the feasibility of FxCV-aided FCM-ploidy analysis in B-ALL patients and only one of these studies have compared their results with CG-ploidy. METHODOLOGY: Blast size-specific FCM-ploidy was prospectively analyzed using FxCV-dye in 109 pediatric B-ALL patients, and the results were compared with concurrent CG-ploidy status. RESULTS: FCM-ploidy categorization was feasible in 98% of samples tested and the results were 82% concordant with CG-ploidy status. We observed significant correlation between DNA content and blast size (r = .823, P < .001) and could demonstrate size differences between diploid vs low-hyperdiploid (P = .025), diploid vs high-hyperdiploid (P < .001) and low- vs high-hyperdiploid blasts (P = .007). CONCLUSION: FCM-ploidy assessment using FxCV dye is a reliable assay and the results closely concur with CG-based ploidy stratification and risk assessment. Using blast size-assisted DNA content analysis, the results of FCM-ploidy analysis can be further fine-tuned.

CD19 negative and dim precursor B-lineage acute lymphoblastic leukemias: real-world challenges in a targeted-immunotherapy era.

Flow cytometric diagnosis and minimal residual disease (MRD) assessment of precursor B-lineage acute lymphoblastic leukemia (B-ALL) are heavily dependent on CD19 based gating strategies. However, this approach is not optimal in the diagnosis and follow-up of CD19 negative or dim B-ALLs. Though CD19 negative B-ALLs are rare, in the current era of CD19 targeted immuno-therapy, CD19 negative B-ALL relapses are frequent. We have presented our cohort of 14 de novo CD19 negative and dim B-ALLs and have highlighted the difficulties faced during diagnosis and MRD assessment of these patients. We have also discussed the need to identify alternative B-lineage gating markers and strategies to deal with such scenarios.