Multi-criteria decision making to validate performance of RBC-based formulae to screen [Formula: see text]-thalassemia trait in heterogeneous haemoglobinopathies

BACKGROUND

India has the most significant number of children with thalassemia major worldwide, and about 10,000-15,000 children with the disease are born yearly. Scaling up e-health initiatives in rural areas using a cost-effective digital tool to provide healthcare access for all sections of people remains a challenge for government or semi-governmental institutions and agencies.

METHODS

We compared the performance of a recently developed formula SCS[Formula: see text] and its web application SUSOKA with 42 discrimination formulae presently available in the literature. 6,388 samples were collected from the Postgraduate Institute of Medical Education and Research, Chandigarh, in North-Western India. Performances of the formulae were evaluated by eight different measures: sensitivity, specificity, Youden's Index, AUC-ROC, accuracy, positive predictive value, negative predictive value, and false omission rate. Three multi-criteria decision-making (MCDM) methods, TOPSIS, COPRAS, and SECA, were implemented to rank formulae by ensuring a trade-off among the eight measures.

RESULTS

MCDM methods revealed that the Shine & Lal and SCS[Formula: see text] were the best-performing formulae. Further, a modification of the SCS[Formula: see text] formula was proposed, and validation was conducted with a data set containing 939 samples collected from Nil Ratan Sircar (NRS) Medical College and Hospital, Kolkata, in Eastern India. Our two-step approach emphasized the necessity of a molecular diagnosis for a lower number of the population. SCS[Formula: see text] along with the condition MCV[Formula: see text] 80 fl was recommended for a higher heterogeneous population set. It was found that SCS[Formula: see text] can classify all BTT samples with 100% sensitivity when MCV[Formula: see text] 80 fl.

CONCLUSIONS

We addressed the issue of how to integrate the higher-ranked formulae in mass screening to ensure higher performance through the MCDM approach. In real-life practice, it is sufficient for a screening algorithm to flag a particular sample as requiring or not requiring further specific confirmatory testing. Implementing discriminate functions in routine screening programs allows early identification; consequently, the cost will decrease, and the turnaround time in everyday workflows will also increase. Our proposed two-step procedure expedites such a process. It is concluded that for mass screening of BTT in a heterogeneous set of data, SCS[Formula: see text] and its web application SUSOKA can provide 100% sensitivity when MCV[Formula: see text] 80 fl.

Prognostic significance of extramedullary disease (EMD) detected on pre-transplant 18F-FDG PET/CT in patients with multiple myeloma: Results of PIPET-M trial

Background

It is difficult to prognosticate the post-Autologous Stem Cell Transplant (ASCT) responses in multiple myeloma (MM) with the currently available prognostication models. 18F-FDGPET/CT has numerous advantages to prognosticate the post-transplant responses by assessing extramedullary disease (EMD) in addition to the extent of active disease. We aimed at identifying the prognostic value of EMD in predicting progression-free survival (PFS) and overall survival (OS).

Methods

This is a single centre prospective study from western India during a study period of 2014-2022 (with a median follow-up of patients of 6 years). All ASCT patients underwent 18F-FDG-PET/CT as part of pre-transplant workup. The conditioning and treatment protocols were not modified based on PET/CT findings. EMD on PET/CT was correlated with pre-transplant biochemical markers and post-ASCT survival/ progression (as defined by revised IMWG criteria). Statistical analysis was done using SPSS ver. 20.

Results

Patients with pre-ASCT EMD had a hazard-ratio for post-transplant all-cause mortality of 5.46 (p-0.045). Pre-transplant β2M and LDH were significantly higher in patients with EMD (p-0.036). The 6-year median OS in patients with and without EMD were 57.1%, and 80.6% respectively. Kaplan-Meier analysis showed poorer OS in patients with EMD χ2 (1-0.496, p-0.481). There was no significant difference in clinical or biochemical EFS among patients with EMD.

Conclusion

EMD detected on 18F-FDG-PET/CT has a higher hazard for mortality and is significantly correlated with pre-transplant higher β2M and LDH levels. Thus, EMD by pre-transplant 18F-FDG-PET/CT has a significant prognostic role.

Hematological and genetic profiles of persons with co-inherited heterozygous β-thalassemia and supernumerary α-globin genes

INTRODUCTION

Thalassemias are common monogenic autosomal recessive hemoglobin disorders. The usually asymptomatic heterozygotes (β-thalassemia traits, βTT) may rarely develop non-transfusion-dependent-thalassemia (NTDT) due to co-inheritance of supernumerary α-globin genes. Literature on phenotypic/genotypic features of these rare combinations is limited.

MATERIALS AND METHODS

We studied the demographic, clinical, and laboratory data from 47 persons with co-inherited βTT + supernumerary α-globin genes. HBB mutations were tested for by ARMS-PCR and/or Sanger sequencing, ααα^(anti3.7) /ααα^(anti4.2) and deletional α-thalassemia testing by multiplex gap-PCRs, and Xmn1^G γ genotyping by PCR-RFLP.

RESULTS

The 47 cases comprised 0.08% of 61 010 hemoglobinopathy screenings during the study period. Mean age was 31.9 ± 14.7 years (range 5.5-83 years), with 57.4% males. Thirty (63.8%) had NTDT-phenotype, 16 (34%) were asymptomatic/minimally symptomatic, and 1 became transfusion-dependent at the age of 20 years. Anemia/pallor and jaundice were the commonest complaints (76% each); 40% had required blood transfusions. Twenty-one had splenomegaly, 14 had hepatomegaly. Mean hemoglobin was 9.0 ± 1.9 g/dl (range 4.0-13.0). HbA2 was 5.1 ± 0.7% (3.4%-6.3%) and HbF% 4.2 ± 3.2% (0.5%-18.4%). Forty-four (93.6%) had ααα^anti3.7 , while 3 (6.4%) had ααα^anti4.2 triplications. HBB:c.92+5G>C (47%), HBB:c.27_28insG (14.9%), and HBB:c.47G>A (8.5%) were the commonest β-globin mutations. One case showed HBB:c.-138C>T (β⁺⁺ ), while the rest had β⁰ or severe-β⁺ mutations. Symptomatic cases had significantly lower hemoglobins and higher HbF% than asymptomatic ones.

CONCLUSION

This largest Indian and globally second-largest study reports the βTT + ααα^4.2 state for the first time in such genotypically-complex Indian cases. Supernumerary α-genes should be suspected in all βTT with disproportionate clinical symptoms, mild-to-moderately elevated HbF, and unexplained anisopoikilocytosis.

Hematological characteristics, cytogenetic features, and post-induction measurable residual disease in thymic stromal lymphopoietin receptor (TSLPR) overexpressed B-cell acute lymphoblastic leukemia in an Indian cohort

The overexpression of cytokine receptor-like factor-2 (CRLF2) identified by anti-thymic stromal lymphopoietin receptor/TSLPR flow cytometry (FCM) has been reported as a screening tool for the identification of BCR-ABL1-like B-cell acute lymphoblastic leukemia/B-ALL with CRLF2 re-arrangement. TSLPR expression was studied prospectively in consecutive 478 B-ALLs (≤ 12 years (n = 244); 13-25 years (n = 129); > 25 years (n = 105)) and correlated with various hematological parameters and end-of-induction measurable residual disease (day 29; MRD ≥ 0.01% by 10-color FCM). TSLPR positivity in ≥ 10% leukemic cells was detected in 14.6% (n = 70) of B-ALLs. CRLF2 re-arrangement was detected in eight cases (11.4%) including P2RY8-CRLF2 (n = 6), and IgH-CRLF2 (n = 2) with a median TSLPR positivity of 48.8% and 99% leukemic cells, respectively. Recurrent gene fusions/RGF (BCR-ABL1 (17.1%); ETV6-RUNX1 (4.2%), TCF3-PBX1 (1.4%)), other BCR-ABL1-like chimeric gene fusions/CGFs (PDGFRB-rearrangement (2.9%), IgH-EPOR (1.4%)), CRLF2 extra-copies/hyperdiploidy (17.1%), and IgH translocation without a known partner (10%) were also detected in TSLPR-positive patients. CD20 positivity (52.9% vs 38.5%; p = 0.02) as well as iAMP21 (4.3% vs 0.5%; p = 0.004) was significantly more frequent in TSLPR-positive cases. TSLPR-positive patients did not show a significantly higher MRD, compared to TSLPR-negative cases (37% vs 33%). Increasing the threshold cut-off (from ≥ 10 to > 50% or > 74%) increased the specificity to 88% and 100% respectively in identifying CRLF2 translocation. TSLPR expression is not exclusive for CRLF2 translocations and can be seen with various other RGFs, necessitating their testing before its application in diagnostic algorithms. In patients with high TSLPR positivity (> 50%), the testing may be restricted to CRLF2 aberrancies, while patients with 10-50% TSLPR positivity need to be tested for both CRLF2- and non-CRLF2 BCR-ABL1-like CGFs.

Evaluation of a flow cytometric test for G6PD-deficient erythrocytes

OBJECTIVE

Glucose-6-phosphate dehydrogenase (G6PD) deficiency, an X-linked recessive disorder, is the commonest erythrocytic enzymopathy worldwide. Reliable diagnosis and severity prediction in G6PD-deficient/heterozygous females remain challenging. A recently developed flow cytometric test for G6PD deficiency has shown promise in precisely identifying deficient females. This paper presents our experiences with this test in a subtropical setting and presents a modification in flow cytometric data acquisition strategy.

METHODS

The methaemoglobin reduction + ferryl Hb generation-based flow cytometric G6PD test was compared with the screening methaemoglobin reduction test (MRT) and confirmatory G6PD enzyme activity assay (EAA) in 20 G6PD-deficient males, 22 G6PD-heterozygous/deficient females and 20 controls. Stained cells were also assessed for bright/dim G6PD activity under a fluorescent microscope.

RESULTS

Flow cytometry separated and quantified %bright cells in heterozygous/deficient females, objectively classifying them into 6 normal (>85% bright cells), 14 intermediate (10-85%) and two G6PD-deficient (<10% bright cells). Concordance with MRT was 89% (55/62 cases) and with EAA was 77% (48/62 cases). Fluorometrically predicted violet laser excitation (405-nm) with signal acquisition in the 425-475 nm region was a technical advancement noted for the first time in this paper.

CONCLUSION

Flow cytometry/fluorescence microscopy represent technically straightforward methods for the detection and quantification of G6PD-deficient erythrocytes. Based on our results, we recommend their application as a first-line investigation to screen females who are prescribed an oxidant drug like primaquine or dapsone.

A high frequency of Gilbert syndrome (UGT1A1*28/*28) and associated hyperbilirubinemia but not cholelithiasis in adolescent and adult north Indian patients with transfusion-dependent β-thalassemia

Hyperbilirubinemia and pigment gallstones are frequent complications in transfusion-dependent β-thalassemia (TDβT) patients. Bilirubin production and clearance are determined by genetic as well as environmental variables like ineffective erythropoiesis, hemolysis, infection-induced hepatic injury, and drug- or iron-related toxicities. We studied the frequency of the Gilbert syndrome (GS), a common hereditary cause of hyperbilirubinemia in 102 TDβT patients aged 13-43 years (median 26 years). Total and unconjugated hyperbilirubinemia were frequent (81.4% and 84.3% patients respectively). Twenty (19.6%) patients showed total bilirubin > 3.0 mg/dL; 53 (51.9%) had an elevation of either alanine or aspartate aminotransferase, or alkaline phosphatase liver enzymes. Nineteen (18.6% of the 92 tested) were positive for hepatitis B or C, or HIV. The mean total and unconjugated bilirubin levels and AST, ALT, and ALP levels in patients positive for hepatitis B or C were not significantly different from negative cases. Eighteen patients (17.7%) had GS: homozygous (TA)7/7 UGT1A1 promoter motif (the *28/*28 genotype), 48 (47.1%) were heterozygous (TA)6/7. Total + unconjugated bilirubin rose significantly with the (TA)7 allele dose. Fourteen (13.7%) patients had gallstones. There was no significant difference in total/unconjugated bilirubin in patients with/without gallstones and no significant differences in frequencies of gallstones within the three UGT1A1 genotypes. This largest study in Indian TDβT patients suggests that GS should be excluded in TDβT cases where jaundice remains unexplained after treatable causes like infections, chelator toxicity, or transfusion-related hemolysis are excluded. GS was not associated with gallstones, possibly due to a lower incidence of cholelithiasis overall, a younger age cohort, or other environmental factors.

Missing Hb Q-India Peak in a Triple-Heterozygous Patient with Hb D-Punjab/Hb Q-India/β-Thalassemia Trait

Interpretation of variant hemoglobins (Hbs) can pose challenges. We describe a puzzling case with multiple variant Hb peaks that was solved by family studies. A 32-year-old female with anemia and jaundice underwent cation exchange high performance liquid chromatography (HPLC), which revealed near-absence of Hb A along with variant peaks in the D- and C-windows (78.9 and 13.3%, respectively) and normal range of Hb F. As the HPLC did not fit any known pattern, family screening was performed. Her mother was heterozygous for Hb D-Punjab (HBB: c.364G>C) and Hb Q-India (HBA1: c.193G>C) with the hybrid α^Q-India/β^D-Punjab eluting in the C-window on HPLC. Her sister had β-thalassemia (β-thal) trait, while her brother was heterozygous for Hb Q-India. In view of the family study results, the index case was interpreted as a double heterozygote for Hb D-Punjab and β-thal with coinherited Hb Q-India. The Hb Q-India peak [retention time (RT) 4.7 min.] was absent on her HPLC as there were no normal β-globin chains available to bind with the α^Q-India chains. To the best of our knowledge, such an HPLC pattern with a missing Q-India peak, despite having inherited the α^Q-India variant, has not been previously reported. This case illustrates the importance of family screening as an inexpensive and rapid method to resolve difficult and unusual HPLC patterns.

Anomaly of iliac veins: a rare cause of transient hepatic attenuation difference in a child

We report a case of transient hepatic attenuation difference (THAD) in a child caused by iliac vein anomaly. Iliac vein anomaly as a cause for THAD in a child is extremely rare.