• by Emil Salazar
  • March 8 2017

Current State of the Molecular Transplant Diagnostics Market

Current State of the Molecular Transplant Diagnostics Market

Molecular HLA Typing Diversifies to Meet Rising Demand from Bone Marrow Transplants

The global market for molecular transplant diagnostics is projected by Kalorama Information to grow in the high single digits each year through 2021. In The World Market for Molecular Diagnostics, 7th Edition, Kalorama identifies bone marrow transplants and high-resolution tissue typing methods as key drivers for the molecular diagnostics market segment. As in other molecular diagnostics areas, established molecular methods for tissue typing face mounting competition from next-generation sequencing (NGS)-based methods.

Successful solid organ and hematopoietic stem cell (HSCT) or bone marrow transplants require histocompatibility between the recipient and donor. Autologous transplantation using hematopoietic cells from the same patient is increasingly common and eliminates the need to screen for histocompatibility. However, solid organ transplants and HSCT allografts from donors in most cases require histocompatibility confirmed by human leukocyte antigen (HLA) testing. Proteins encoded by HLA system genes function as unique cell surface markers that regulate immune system recognition of foreign cells such as pathogens and tumor cells.

Molecular HLA typing methods allows more precise matching between donor and recipient critical to bone marrow or HSCT transplant outcomes. Allogenic HSCT transplantation is a relatively high growth procedure area compared to solid organ transplantation and is a leading area of application for molecular HLA typing. Polymorphism in the human major histocompatibility complex (MHC) or HLA system is exceedingly complex for serological methods and is best captured by directly assaying genetic sequence.

While solid organ transplant volumes are largely stable or have grown only marginally in most significant regional markets, allogenic bone marrow transplant volumes have grown at rates of 4% or greater in the United States, Japan and Europe in recent years. This underlying growth in the procedure volume has contributed to the robust growth of the global molecular transplant diagnostics market. Bone marrow transplants remain key to driving demand for high-resolution molecular typing.

Primer mixes for molecular HLA typing have been standardized in well-studied populations to ensure adequate allelic coverage. However, allele detection is inherently limited in SSP and SSO kits by primer and probe selection respectively. Sequence-based typing (SBT) offers unparalleled specificity to molecular HLA typing. Sequencing allows for the detection of previously unknown alleles or alleles outside of standardized PCR reagent kits. With the commercialization of clinical NGS platforms, SBT is increasingly common in HLA labs for cost-competitive high resolution or allele resolution typing, applications predominately served by SSP currently. Low to intermediate resolution typing served by SSO and other PCR methods are expected to maintain advantages over NGS in terms of cost and turnaround time (especially real-time protocols such as CareDx’s QTYPE products) over the next five years. One Lambda (Thermo Fisher Scientific) launched its SmartType real-time PCR HLA typing kits in June 2016 to maintain share in the large market outside of high-resolution products.