CASE PRESENTATION: A 59-year-old man of Chinese ethnicity presented to our hematology unit with headache, lethargy, and exertional dyspnea for the past 1 month. He underwent an uneventful cadaveric renal transplant 20 years ago for chronic glomerulonephritis-induced end-stage renal disease. He had been on long-term immunosuppressants since then consisting of orally administered prednisolone 10 mg daily and orally administered cyclosporine A 50 mg twice daily. On examination, he was pale with a palpable liver and spleen. He had a functioning renal graft. Marrow flow cytometry confirmed T-prolymphocytic leukemia with lymphocytes expressing CD2, CD3, CD7, CD52, and TCL-1. His human T-cell lymphotropic virus and Epstein-Barr virus serology and deoxyribonucleic acid (DNA) were negative. He was treated with one cycle of cyclophosphamide, doxorubicin, vincristine, and prednisone chemotherapy to which he failed to respond. In view of his renal allograft, he was not suitable for alemtuzumab due to the risk of nephrotoxicity. He was given orally administered venetoclax but he died on day 17 due to severe auto tumor lysis syndrome.
CONCLUSION: The place of immunophenotyping in the diagnosis and treatment of this disorder is of significant importance. More research needs to be carried out to further comprehend the pathophysiology and treatment modalities for this disorder.
METHODS: We conducted a case-control study comparing 25 patients with biopsy-proven LACR against 25 stable controls matched for age group, primary diagnosis and time post-transplant. IPV was calculated using coefficient of variance (CV) and mean absolute deviation (MAD) using tacrolimus levels in the preceding 12 months. We also assessed the percentage time for tacrolimus levels
METHODOLOGY: All sera for AT1R-Ab were collected at the University Malaya Medical Centre (UMMC), Kuala Lumpur, Malaysia. The sera were centrifuged and kept refrigerated at -80 °C before being transported to the South Australian Transplantation and Immunogenetics Laboratory (SATIS). Enzyme-linked immunosorbent assay kit (One Lambda) was used for the detection of AT1R-Ab, and it was performed according to the manufacturer's instructions. The level of >17.1 U/mL was considered to be AT1R-Ab positive; 10.0-17.1 U/mL at risk, and <10.0 U/mL negative.
RESULTS: A total of 115 samples were collected from 99 patients pre and post-kidney transplant recipients. From the pre-transplant sera (n = 68) 17.7% were positive, 35.3% were at risk and 47.0% were negative. The positive AT1R-Ab cohort were relatively younger, with a mean age of 34.7 ± 8.3 years old and statistically significant, with a p-value of 0.028. Among the sera that were tested positive, 19.0% were from the Chinese ethnicity, 6.7% from Malay and 16.7% from Indian. There was no difference in the rejection episodes, persistent or de novo HLA-DSA, and graft function between the group (AT1R-Ab negative vs AT1R-Ab at risk and positive) and the results were consistent in a model adjusted for all potential confounders.
CONCLUSION: The prevalence of positive (>17.1 U/mL) pre-transplant AT1R-Ab was 17.7% and 35.3% were at risk (10.0-17.1 U/mL) in our pre-transplant cohort.