Chronic granulocytic leukemia in a renal transplant 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.

Hematologic abnormalities following renal transplantation

Recipients of renal allografts are surviving longer and, consequently, may experience a variety of complications related not only to the transplanted kidney, but also to the hematopoietic system. Common hematologic complications in the renal transplant patient include abnormalities of one cell line, such as post-transplantation erythrocytosis or anemia, that are often treatable with simple measures. Conversely, pathologies involving the leukocyte and platelet population often exist in the context of pancytopenia, which may be a manifestation of systemic infection (e.g., cytomegalovirus, human herpesvirus 8) or malignancy (post-transplantation lymphoproliferative disorders). Uncommon, but life-threatening, processes complicating renal transplantation include hepatosplenic gammadelta T-cell lymphoma and viral-induced hemophagocytic syndrome, both of which are associated with severe pancytopenia and, often, death. Since this patient population is often managed in a multidisciplinary fashion by nephrologists, infection specialists, transplant surgeons, hematologists, and internal medicine physicians, a succinct review of this topic is warranted.

Chronic myeloid leukemia following kidney transplantation

Immunosuppressed renal recipients are at an increased risk of developing cancer. Leukemias are less frequent than other hematopoietic tumours and development of CML after immunosuppression is rare. We describe a 37-year-old male who presented with left-shifted leukocytosis, hypercellular bone marrow 32 months after the kidney transplant. G-banding karyotype revealed 46,XY,t(9;22)(q34;q11) and the diagnosis of chronic myeloid leukemia was made. This is the 13th case of CML after kidney transplant reported. Whether this CML appeared as a random phenomenon or chemically induced is a matter of debate. Some individuals might have an increased susceptibility to the effects of azathioprine.

Chronic granulocytic leukemia and carcinoma of the cervix in situ following renal transplantation

A 26-year-old white female presented with Philadelphia chromosome positive chronic granulocytic leukemia five years after successful renal transplantation and prolonged therapy with azathioprine and prednisone. This patient represents the seventh case of the chronic granulocytic leukemia reported within the population of immunosuppressed renal transplant recipients. Of further interest in our case is the development of carcinoma in situ of the cervix two years following the transplant. Although multiple malignancies have been recognized in renal homografts, the occurrence of chronic granulocytic leukemia and carcinoma in situ in the same patient has not been previously described. A possible mechanism for the development of chronic granulocytic leukemia is the association of chromosome damage by azathioprine and immunoparalysis of the host, thus setting the stage for the emergency of a malignant clone. The importance of close follow-up of patients on prolonged immunosuppressive therapy is emphasized.

[Acute leukemia after kidney allotransplantation (author's transl)]

Four cases of acute myelogenous leukemia and six cases of chronic myelogenous leukemia after treatment with azathioprine and prednisone for renal allotransplantation have been described in the literature. We report another two cases of acute leukemia 10 and 5 years after successful renal allotransplantation. Patient 1, a 29-year-old farmer, exhibited the signs of acute lymphatic leukemia resistent to treatment with cytostatic agens. Death was due to pneumonia. Patient 2, a 47-year-old salesman, developed pancytopenia together with splenomegaly. After splenectomy an atypical subacute myeloid leukemia became apparent which was not treated due to withdrawal of the patient. He died 2 months after diagnosis. Both patients received long-term immunosuppressive therapy with azathiopine and prednisone until the leukemia was diagnosed. A relationship between long-term immunosuppression and the occurrence of leukemia is postulated.