HLA typing: We perform HLA typing for solid organ and bone marrow transplant recipients and donors (living and deceased) using different methods with different levels of resolution including sequence-specific primers (SSP), reverse sequence-specific oligonucleotide probes (rSSOP), and next-generation sequencing (NGS) . We also perform HLA typing for disease association and drug susceptibility studies.
HLA antibody testing: Testing for the presence of HLA antibodies is performed at different stages and using different methodologies. Pre-transplant testing is usually performed using Luminex screen and/or Luminex single antigen microarray beads. Additionally, clinicians may request other antibody tests like Luminex C1q to look for complement-binding antibodies, and Luminex PRA to confirm the nature of the antibodies detected by the other Luminex assays. Crossmatch testing by CDC and/or flow cytometry are performed during the pre-transplant work up to help with the patient’s risk assessment and direct the decision to transplant. During the post-transplant period, we use the Luminex single antigen bead assay to detect HLA antibodies and identify the presence of donor-specific HLA antibodies. Other tests like C1q and Luminex PRA can also be ordered as a part of the post-transplant monitoring.
Engraftment monitoring after BM transplant (chimerism): In patients receiving a hematopoietic stem cell/bone marrow transplant, engraftment monitoring is performed by short-tandem repeat (STR) multiplex PCR testing of 16 markers. The laboratory usually receives separate pre-transplant samples from the patient and donor to establish the individual STR profiles. After the transplant, peripheral blood and/or bone marrow aspirate samples are tested and the proportion of donor- and recipient-derived DNA is calculated based on the presence of unique alleles for the 16 markers. Samples can be separated into different cell fractions (CD3-positive, CD19-positive, CD33/66-positive cell fractions) for a more in-depth analysis of donor chimerism. Additionally, a negative fraction can also be tested in leukemia patients to detect chimerism in potentially neoplastic cells lacking the traditional cell surface markers.
Therapeutic drug monitoring and Infectious disease testing is also available as important results for patient/donor evaluation pre transplant and post-transplant monitoring. PCR based assays along with ELISA/Luminex based assays are available for infectious disease testing. Therapeutic drug monitoring is done using ultra-sensitive MassLynx/HPLC instruments.
Histopathologic evaluation of deceased donor organs: Donor kidneys and livers are sampled at the time of organ procurement and are evaluated to assess for quality. Donor biopsy tissue undergoes several quick processing steps to obtain a high-quality H&E permanent section slide for histopathologic evaluation. This preparation also allows for rapid additional stains processing when needed. We have 24/7/365 coverage by a histology technician and a pathologist.
Histopathologic evaluation of allograft biopsies (kidney, pancreas, liver, intestine, heart, and lung allografts): Two Board-Certified pathologists specialized in transplant pathology evaluate all solid organ transplants biopsies and offer same-day interpretation for all biopsies. Ancillary studies are performed as needed to support the histopathologic diagnoses.