Probability of Finding Marrow Unrelated Donor (MUD) for an Indian patient in a Multi-national Human Leukocyte Antigen (HLA) Registry

Evolution and Utility of Preimplantation Genetic Testing for Monogenic Disorders in Assisted Reproduction - A Narrative Review

Preimplantation genetic testing (PGT) for monogenic disorders and assisted reproductive technology have evolved and progressed in tandem. PGT started with single-cell polymerase chain reaction (PCR) followed by fluorescent in situ hybridisation for a limited number of chromosomes, later called 'preimplantation genetic diagnosis (PGD) version 1'. This review highlights the various molecular genetic techniques that have evolved to detect specific inherited monogenic disorders in the preimplantation embryo. Literature review in English was performed in PubMed from 1990 to 2021, using the term 'preimplantation genetic diagnosis'. With whole-genome amplification, multiple copies of embryonic DNA were created. This helped in avoiding misdiagnosis caused by allele dropout. Multiplex fluorescent PCR analysed informative short tandem repeats (STR) and detected mutations simultaneously on automated capillary electrophoresis sequencers by mini-sequencing. Comparative genomic hybridisation (CGH) and array CGH were used for 24 chromosome aneuploidy screening. Subsequently, aneuploidies were detected by next-generation sequencing using single-nucleotide polymorphism arrays, while STR markers were used for haplotyping. 'PGD version 2' included accurate marker-based diagnosis of most monogenic disorders and detection of aneuploidy of all chromosomes. Human leukocyte antigen matching of embryos has important implications in diagnosis and cure of haemoglobinopathies and immunodeficiencies in children by means of matched related haematopoietic stem cell transplantation from an unaffected 'saviour sibling' obtained by PGT.

Barriers and Support-System while Considering Hematopoietic Stem Cell Transplant (HSCT): A Qualitative Study of Pre-HSCT Acute Leukemia Patients from a Standalone Transplant Laboratory in India

Introduction Hematopoietic stem cell transplant (HSCT) is the definite treatment for acute leukemia but considering HSCT is challenging for the patients. There are many studies that have described the patients’ experience after HSCT but very few studies have reported their experience before going for HSCT and there is no published report in India on patients’ experience before HSCT.

Objective We conducted a qualitative study to understand barriers, and support-system while considering HSCT and the chances of getting matched unrelated donor (MUD) for these patients.

Materials and Methods The present study was a qualitative study. Demographic details of 514 patients who consented for the study were noted and the patients and their families were interviewed using a semistructured interview booklet before HSCT. The interview sessions were recorded, transcribed verbatim, and analyzed for emerging themes. The study data were analyzed using QDA Miner Lite 4.0 software (Provalis Research, Montreal, Canada). Descriptive statistics such as frequency and percentage were used. The chances of getting a human leukocyte antigen (HLA)-matched donor were also computed by “HLA-matching software.”

Results Acute myeloid leukemia (64.01%) was commoner than acute lymphoid leukemia (35.99%) with male: female ratio as 1.98:1. The study showed nine themes as barriers and six themes emerged in regard to the support system for HSCT decision making. The biggest barriers identified among these patients pre-HSCT were related to cost, probability of “success of transplant,” and probable “quality of life.” The family support was the biggest support system variable followed by “treating doctor.” The chances of getting a MUD for these patients were 13.22% and 5.44% in global and Indian data pool, respectively.

Conclusion Deciding upon HSCT can be challenging for patients and understanding of barriers and support-system variables among these patients would provide important insights and help design better counseling techniques for such patients of HSCT and future studies in this context.

India's First Child using PGT-M, PGT-A and HLA Matching for Helping a Sibling having β-Thalassemia Major

β-thalassemia is a common single-gene disorder in India, with hematopoietic stem cell transplantation (HSCT) being the only cure. HSCT with matched unrelated donor is less successful, whereas finding a human leukocyte antigen (HLA)-matched related donor is difficult. Preimplantation genetic testing for monogenic diseases (PGT-M) with HLA matching is a novel option to have a matched sibling for HSCT for couples having an affected child. We present the first such case report in India. A couple, both carriers of β-thalassemia and having an affected son, underwent PGT-M with HLA matching combined with preimplantation genetic testing for aneuploidies of embryos to have a β - thalassemia-free child. This resulted in birth of a 10/10 HLA-matched sibling.

Matched unrelated donor hematopoietic progenitor cell transplantation: A report based on a single registry in India

Introduction

Currently, more than 10,000 matched unrelated donor transplants (MUDT) are performed annually worldwide. India has recorded a significant increase in the number of hematopoietic progenitor cell transplantation (HPCT) centers reporting transplants. The number of HPCTs increases by approximately 10% every year, with 1878 transplants reported by Indian stem cell transplant registries in 2016. However, published outcome data of MUDT in India are scant, with reports limited to autologous and allogenic matched unrelated transplants, which motivated us to present our MUDT data.

Aims and objective

To review the operations, and more importantly, the patient outcome data of a new registry in India.

Materials and methods

We accessed an Indian HLA donor database with high-resolution HLA typing results of 7682 (until 31st July 2018) volunteer HLA donors. The typing results were uploaded to proprietary software. The search result was considered a “match” when a 10/10 potential HLA match was found. Patients who were found to be alive through mail communication and did not exhibit signs and symptoms of disease were considered to have disease-free survival (DFS).

Results

During the six years of operations of the database, 1165 searches resulted in 68 10/10 matches from the registry. Of these, 11 were MUD HPCT records. At a minimum follow-up of almost 11 months, seven recipients continue to exhibit DFS.

Conclusions

The patient DFS data prove that even a small registry with slightly more than 7000 donors can yield reasonably good patient outcomes.

A guide to organize voluntary stem cell donors recruitment drive for hematopoietic progenitor stem cell transplant

BACKGROUND:

Hematopoietic progenitor cell transplantation (HPCT) is used as a definitive treatment in hematological malignancies. For a successful HPCT, the donor and recipient should have matching human leukocyte antigens (HLAs). About 25% of patients have a chance of finding matching HLA within family, while rests 75% are dependent on voluntary stem cell donor. Globally, there are 75 stem cell registries with more than 30 million donors registered among which India represents 0.36 million. Therefore, finding a stem cell donor for Indian patient is quite difficult. The aim of the present study is to discuss the significance of voluntary stem cell donor recruitment drive and also to guide the drive organizers and their team for effectively organizing the drive to increase the database of such donors.

MATERIALS AND METHODS:

Voluntary stem cell donor recruitment drives are conducted to spread awareness among the people and motivate them to register as a donor. Once the donors have given their consent, the sample is taken and sent to laboratory for HLA typing and the result is uploaded in World Marrow Donor Association, an international association of member to find the best possible matches for patients with hematological disorders.

RESULTS:

Genebandhu has organized over 127 recruitment camps since 2012 and recruited 13,000 voluntary stem cell donors. HLA typing of 7446 donors has been completed. Out of this small number of typed donors, 11 lifesaving HPCTs have been successfully facilitated.

CONCLUSIONS:

Here, we have demonstrated guidelines along with steps to organize voluntary stem cell donors recruitment drive that is needed to increase number of donors, thus increasing significantly the chances of saving many vital lives.

Human leukocyte antigen-matched unrelated donor search experience for hematological disorder patients requiring transplant: scenario for Indian patients

Introduction: Human leukocyte antigen (HLA)-matched unrelated donor (MUD) is the source of MUD transplantation (MUDT) for about 70% of patients who do not have matched related donor. To facilitate MUD search globally, there are 75 stem cell registries with more than 28 million donors registered (as of January 2017). Out of these donors, India has an insignificant representation of approximately 0.23 million. Further, Indians express high genetic variations, making it difficult to find MUD for an Indian patient. Aims and Objectives: The aim of this study is to analyze the MUD search for hematological disorder patients requiring transplant. An attempt was made to observe the MUD scenario for Indian patients requiring MUDT from accessible stem cell registries. Methods: A total of 558 patients approached Genebandhu registry and Chimera Transplant Research Foundation for MUD search over a period of 4 years requiring MUDT were included in this study. High resolution of HLA-A, -B, -C, -DRB1, and -DQB1 was used to perform MUD search through proprietary software called Prometheus and Bone Marrow Donors Worldwide (BMDW) search tool. Results: Out of 558 patients, MUD was located only for 135 (24.19%) patients. Out of these 135 patients, 91 (16.30%) patients found an MUD in global database and only 44 (7.88%) patients within India. Conclusion: This study demonstrates that building a large Indian database will not only help in increasing the chances of finding an MUD for maximum number of patients within India but also provide cost-effective treatment, in a society where cost is a vital factor.