Utility of a column-free cell sorting system for separation of plasma cells in multiple myeloma FISH testing in clinical laboratories

Comparison of Diagnostic Yield of a FISH Panel Against Conventional Cytogenetic Studies for Hematological Malignancies: A South Indian Referral Laboratory Analysis Of 201 Cases

Objectives:

Genetic markers are crucial fort diagnostic and prognostic investigation of hematological malignancies (HM). The conventional cytogenetic study (CCS) has been the gold standard for more than five decades. However, FISH (Fluorescence in Situ Hybridization) testing has become a popular modality owing to its targeted approach and the ability to detect abnormalities in non-mitotic cells. We here aimed to compare the diagnostic yields of a FISH panel against CCS in HMs.

Methods:

Samples of bone marrow and peripheral blood for a total of 201 HMs were tested for specific gene rearrangements using multi-target FISH and the results were compared with those from CCS.

Results:

Exhibited a greater diagnostic yield with a positive result in 39.8% of the cases, as compared to 17.9% of cases detected by CCS. Cases of chronic lymphocytic leukaemia (CLL) benefited the most by FISH testing, which identified chromosomal aberrations beyond the capacity of CCS. FISH was least beneficial in myelodysplastic syndrome (MDS) where the highest concordance with CCS was exhibited. Acute lymphocytic leukaemia (ALL) demonstrated greater benefit with CCS. In addition, we found the following abnormalities to be most prevalent in HMs by FISH panel testing: RUNX1 (21q22) amplification in ALL, deletion of D13S319/LAMP1 (13q14) in CLL, CKS1B (1q21) amplification in multiple myeloma and deletion of EGR1/RPS14 (5q31/5q32) in MDS, consistent with the literature.

Conclusions:

In conclusion, FISH was found to be advantageous in only a subset of HMs and cannot completely replace CCS. Utilization of the two modalities in conjunction or independently should depend on the indicated HM for an optimal approach to detecting chromosomal aberrations.

Do circulating tumor cells, exosomes, and circulating tumor nucleic acids have clinical utility? A report of the association for molecular pathology

Diagnosing and screening for tumors through noninvasive means represent an important paradigm shift in precision medicine. In contrast to tissue biopsy, detection of circulating tumor cells (CTCs) and circulating tumor nucleic acids provides a minimally invasive method for predictive and prognostic marker detection. This allows early and serial assessment of metastatic disease, including follow-up during remission, characterization of treatment effects, and clonal evolution. Isolation and characterization of CTCs and circulating tumor DNA (ctDNA) are likely to improve cancer diagnosis, treatment, and minimal residual disease monitoring. However, more trials are required to validate the clinical utility of precise molecular markers for a variety of tumor types. This review focuses on the clinical utility of CTCs and ctDNA testing in patients with solid tumors, including somatic and epigenetic alterations that can be detected. A comparison of methods used to isolate and detect CTCs and some of the intricacies of the characterization of the ctDNA are also provided.

A limited plasma cell flow cytometry panel with reflex CD138 immunohistochemistry is an optimal workflow process for evaluating plasma cell neoplasms in bone marrow specimens

OBJECTIVES

To determine the optimal workflow combination of flow cytometry (FC) and immunohistochemistry tests for efficient and cost-effective evaluation of plasma cell (PC) neoplasms (PCNs) in bone marrow (BM) specimens.

METHODS

Various workflow combinations of immunohistochemistry and FC for 4,031 BM specimens worked up for PCNs were compared. Turnaround time (TAT), immunohistochemistry usage, technical charges, and addendum/amendment rates were compared between periods to determine the optimal workflow combination.

RESULTS

Five distinct workflow periods were identified, with varying combinations of full or limited FC panels for assessing PC clonality and CD138/κ/λ immunohistochemistry for PC quantification. Replacement of full FC with limited FC was associated with significant reductions in TAT and number of immunostains performed per case. Elimination of immunohistochemistry on cases determined to be polyclonal by FC also resulted in significant reductions in immunohistochemistry usage and significant cost savings.

CONCLUSIONS

Assessment of PC clonality using a limited FC panel followed by reflex CD138 immunohistochemistry on cases that are monoclonal by FC provides an optimal and cost-effective workflow for evaluating PCNs in BM samples.

Neoplastic plasma cell aberrant antigen expression patterns and their association with genetic abnormalities

Little is known about aberrant antigen expression patterns and their association with cytogenetic aberrations in multiple myeloma (MM). We examined the correlation between flow cytometry and florescence in situ hybridization (FISH) in 167 marrow specimens with MM. Gene expression profiling of CD56, CD117, CD52 and CD20 mRNA in plasma cells (PCs) from patients treated on Total Therapy 2 and Total Therapy 3 trials were also evaluated. Higher expression of CD56 and CD117 was associated with hyperdiploidy. High CD52 mRNA expression was associated with c-MAF and FGFR3 subgroups. Higher expression of CD56 mRNA, but lower Kit expression, were noted in association with FGFR3. In contrast, the c-MAF subgroup showed high Kit expression but lacked NCAM mRNA expression. CKS1B amplification showed positive correlation with CD52 (p=0.0065) but negative correlation with CD20 (p=0.0207). These findings indicate that phenotypic differences in MM are associated with distinct genetic subgroups, which potentially has important diagnostic and prognostic value.