Atypical chronic myeloid leukemia following organ transplants

Chronic Myeloid Leukemia in Renal Transplantation Patients in the Era of Tyrosine Kinase Inhibitors: A Case Report and Review of the Literature

Lifelong immunosuppression, cytotoxic effects of some immunosuppressive drugs, and opportunistic oncogenic viruses increase malignancy risks in solid organ recipients. The risk of myeloid neoplasms including chronic myeloid leukemia (CML) is also increased in this patient population. Tyrosine kinase inhibitors (TKIs), the key element of CML therapy, should be used cautiously in transplantation patients as they may interact with calcineurin inhibitors. With this report, a 63-year-old female kidney transplant recipient who developed CML 9 years after kidney transplantation is presented. CML in this patient was treated with a slightly reduced dose of imatinib (300 mg) due to concerns of adverse events including its interaction with tacrolimus. Deep molecular response (DMR) was achieved at 12 months under imatinib treatment. The patient is still in DMR after 30 months of follow-up, and she did not experience any adverse events or acute rejection episodes. CML and the use of TKIs in kidney transplant patients have been discussed with an extensive literature review. In this patient population, TKIs are generally well tolerated with achievement of treatment responses and good prognosis. Graft functions are also well maintained as long as drug interactions are monitored.

Potential Leukemic Cells Engraftment After Hematopoietic Stem Cell Transplantation From Unrelated Donors With Undiagnosed Chronic Leukemia

BACKGROUND

Donor-related neoplasms are a potential complication of treatment strategies involving stem cell transplantation. Although mechanisms for detection of short-term complications after these procedures are well developed, complications with delayed onset, notably transmission of chronic diseases such as chronic myeloid leukemia (CML), have been difficult to assess. Consequently, we studied the potential of human CML cells to engraft hematopoietic tissues after intravenous implantation in mice.

METHODS

Human peripheral blood cells, collected from CML patients presenting with moderately increased white blood cells count before treatment, were transplanted into sub-lethally irradiated, immunodeficient mice. Five weeks after transplantation the nuclear cells were isolated from the murine bone marrow, spleen, and peripheral blood and were used to quantitatively detect human CD45 antigen by flow cytometry; qRT-PCR was used to detect the BCR-ABL1 fusion gene, and the human or murine beta-glucuronidase housekeeping gene was used to examine human-murine chimerism.

RESULTS

We found that all evaluated animals had donor chimerism at the selected interval after transplant and the presence of a specific BCR-ABL1 fusion gene transcript was also detected.

CONCLUSIONS

Our results suggest that the risk of neoplasm transmission cannot be eliminated during hematopoietic stem cell transplantation from undiagnosed CML donors with borderline leukocytosis. The obtained data confirms the potential of leukemic cells to viably engraft the hematopoietic organs post-transplantation in an immunosuppressed recipient.

Clinical lessons to be learned from patients developing chronic myeloid leukemia while on immunosuppressive therapy after solid organ transplantation: yet another case after orthotopic heart transplantation

Chronic myeloid leukemia developing after transplantation of solid organs and concomitant immunosuppression is a rare but still significant clinical phenomenon. We here describe an additional case of a 62-year-old male patient developing CML after orthotopic heart transplantation and medication with cyclosporine A, mofetil-mycophenolate, and steroids. Initial antileukemic therapy was imatinib at a standard dose and within 15 months of therapy a complete cytogenetic response was noted. In this report we discuss the clinical implications of these rare but biologically important cases.