Introduction

Culture failures are a major deterrent in diagnostic cytogenetic analysis in leukemia. An important cause of culture failure is the transit time needed to reach quality cytogenetics facilities which are often limited to select premier institutes and a few standalone centers in larger cities in India. This study evaluates the utility of a novel, patented Helix leukemia transport tube (HLTT) in reducing culture failure rates. The HLTT contains distinctive cocktail mixture designed to simulate laboratory conditions and preserve cell viability during sample transportation to ensure complete chromosomal analysis.

Methodology

Study design

This was a multi-center, prospective study. We included all bone marrow/blood samples of acute leukemia patients received in the laboratory after a transit period of 24-72 hours from May 2017 to July 2024. These were grouped into 1) ‘TT’ group- samples received in a regular sodium heparin vacutainer tube and HLTT 2) ‘no-TT’ group- samples received only in the regular sodium heparin vacutainer tube.

The samples in regular sodium heparin tubes were subjected to the standard protocol of setting two types of overnight cell cultures. These were overnight (ON) and overnight with colcemid (ONC). The HLTT tube was harvested as it was received, without any culture set-up. Conventional karyotyping was performed using metaphases obtained from all the 3 methods (ON, ONC and HLTT) and reported according to international scheme of cytogenomic nomenclature (ISCN) 2020.

Outcome measures

The utility of the HLTT was compared to conventional methods (ON and ONC) based on 5 parameters; 1) metaphase index (graded as good, moderate, low and no index), 2) chromosome morphology (graded as good, moderate, poor), 3) re-dropping rates (based on number of slides used), 4) turnaround time (TAT), and 5) culture failure rates. The first 2 parameters for HLTT, ON, and ONC were compared within the TT group. The remaining 3 were compared between TT vs no TT group.

Statistical analysis

Statistical analyses were performed using Microsoft Excel and SPSS v25. The outcome measures were analyzed using Pearson chi-square and unpaired t-tests. Baseline characteristics were summarized as median and range, and continuous variables, as counts and percentages.

Results

This study included 125 patients diagnosed with acute leukemia.

Demographic details

The TT group (n=77) had mainly males (n=50,64.9%), median age of 28 years (range 1-72 years), all (n=77,100%) bone marrow samples with predominately (n=41,53.2%) acute lymphoblastic leukemia (ALL) while the no TT group (n=48) had an almost equal number of males (n=26,54.2%) as females, median age of 50 years (range 1-82 years), a small proportion of blood samples (n=4,8.3%) with predominately (n=35,72.9%) acute myeloid leukemia (AML).

Outcome measures

The analysis of metaphase index within the TT group (N=77) showed that the HLTT had a significantly higher proportion of ‘good’ index (12,15.58% vs ON (4,5.19%) vs ONC (10,12.19%)), and low proportion of ‘no’ index (17,22% vs ON (26,33.77%) vs ONC (21,27.27%)) when compared with ON (p=0.040) and the ONC (p=0.049).

The analysis of chromosome morphology within the TT group showed that the HLTT yielded a significantly higher proportion of ‘moderate’ grade (33, 42.86% vs ON (20,25.97%) vs ONC (18,23.38%)) and lower proportion of ‘poor’ grade (7,9.09% vs ON (8,10.39%) vs ONC (18,23.38%)) when compared with ON (p=0.019) and ONC (p=0.004).

The analysis of the total number of slides reflecting the re-dropping rate revealed that there was no significant difference between the mean number of slides used to reach a complete karyotype in the two groups (7.1 vs 7.7, p=0.186).

The TAT analysis demonstrated a significantly improved TAT in TT group (21 days vs 30 days, p = 0.049).

The analysis of failure rates between the two groups showed a significant lowering (0% vs 16.67%, p=0.0002) of culture failures and cases reported as incomplete karyotype (less than 20 metaphases analysed) (5.19 vs 6.25, p=0.007).

Conclusion

The study concludes that the Helix leukemia transport tube (HLTT) is a promising solution to improve the availability and effectiveness of cytogenetic analysis, particularly in remote regions of India, thus aiding in optimal care of leukemia patients.

Disclosures

No relevant conflicts of interest to declare.

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2024
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