Development of therapy approach in Patient with Chronic Granulocity Leukemia: Case Report

Chronic granulocytic leukemia (CGL) is a highly specific disease that is defined by strict hematologic parameters that include a pathognomonic differential leukocyte count. Usually CGL is accompanied by the presence, in bone marrow cells, of the Ph chromosome, the first chromosomal anomaly to be regularly associated with a human neoplastic disease (1). CGL is predominantly a disease of the productive middle years of life, which maximizes its adverse impact on family life and family economics. The disease is of worldwide distribution and there is a slight male preponderance. The disease is characterized by an initial chronic phase when it behaves as a differentiated neoplasm and responds very well to simple, nonintensive therapy (1,2,3).

We present male patients with whom he was diagnosed with CGL, Ph + in early chronic phase in 1992, when he was 13 years old. Clinical characteristics of the disease at the presentation were signs of anemia syndrome in the presence of organomegaly (hepatosplenomegaly). In haematological parameters, leukocytosis up to 275×109 / L was detected with the presence of all forms of white lines in the peripheral blood smear, with anemia with hemoglobin of 89 g / L and mild thrombocytosis up to 499×109 / L. Biopsy of the bone marrow confirmed the diagnosis of CGL with a chronic phase image, and cytogenetic analysis was confirmed by Ph chromosome. Introductory treatment was carried out with Hydroxiureom in a dose dependent on haematological parameters, which achieved cytoreduction, and in the next five months, the patient received recombinant IFN alpha at a dose of 9 U per week. Clinical and hematologic remission of the disease with the maintenance of the cytogenetic marker was achieved on the applied therapy. Bearing in mind the nature of the underlying disease, allogeneic haemopoietic stem cell transplant (MHH) transplantation from the family matched (in the HLA and ABO system) of the donor, born brother, was done in the future. The conditional regimen was conducted according to the myeloablative protocol in combination with oral formulation of Busulphan-Cyclophosphamide 2 with complete supportive therapy (adequate hydration, urotoprotection, prevention of mucositis and possible forms of infection). The source of the MSH was the bone marrow, with the patient on 27.12.1993 receiving a total of 1.56×108 cells with a nucleus (total nucelar cells -TNC) / kgTM in a suspension of 1170 ml of bone marrow. Prevention of graft versus host disease (GvHD) was carried out with dual immunosuppressive therapy (Cyclosporine A + Methotrexate according to the “short Seatle” protocol). The period of iatrogenic bone marrow aplasia was accompanied by oropharyngeal mucositis of grade 2. The acceptance of the allogeneic coil, measured by the parameters of the blood count (neutrophil and platelet counts), was recorded from +18. days after transplantation. Dana +40. After transplantation complete donor chimerism has been proven. No signs of acute or chronic GvHD are registered. Remission of the disease to the cytogenetic level was maintained until August 1996. During this period, relapses of the disease were confirmed on cytogenetic and then haematological level, 32 months after the primary allogeneic transplantation of the MSH. Treatment of the first relapse begins with recombinant INF alpha at a dose of 9 MU per week for three months. The therapy did not achieve the desired response at the cytogenetic level, so treatment was continued using immunoadaptive therapy, by infusion of lymphocytes taken from the same donor. The patient received three units of donor lymphocytes (DLI) on 10.12. and 30.12.1996. and February 17, 1997, in escalating doses (2.6×107, 4.1×107, 4.1×107 / kg/bw). Clinical monitoring did not record signs of acute GvHD. Hematological monitoring detects a gradual occurrence of pancytopenia, and in April 1997, bone marrow biopsy and myocardial infarction confirmed bone marrow aplasia as a potential adverse effect of DLI. Further treatment was carried out by the secondary allogeneic transplantation of the MSH from the identical family donor. In a conditioned regimen, according to bone marrow aplasia, the patient received only antitomocyte globulin (ATG - Fresenius) at a dose of 5 mg / kg/bw for four days. The MSH source was the peripheral blood of the donor after a five-day preparation of recombinant G-CSF at a dose of 5 mcg /kg/bw. Secondary transplantation was done on May 19, 1997. where the patient received 5.3×108 TNC / kgTM, i.e., 15.5×106 / kg/bw CD34 + cells). Prevention of GvHD was not applied. Acceptance of the allogeneic coil is recorded via the number of neutrophils and platelets of +15. days after transplantation, while cytogenetic and molecular analysis determine the complete remission of the disease with complete donor chiberism. Clinical monitoring did not show signs of acute or chronic GVHD. A complete remission of the disease was maintained until December 2002 (67 months after secondary allogeneic MHH transplantation). During this period, late relapses of the disease were recorded at the cytogenetic level, and the treatment continued with the first generation tyrosine kinase inhibitor (Glivec) at a dose of 400 mg per day. The desired therapeutic response (parsing of the disease at the cytogenetic level) was not achieved, and since October 2004 the preparation of the second generation TKI - Nilotinib was included in the therapy. This form of treatment achieves a complete remission of the disease down to the molecular level that has been maintained over the past 14 years.

Chronic granulocytic leukemia is a chronic myeloproliferative disease, a hematopoietic stem cell disease, characterized by a specific Phyladelphia chromosome, or reciprocal translocation between chromosomes 9 and 22 (12,3). Thanks to the significant advances in basic diagnostic procedures, CGL is one of the rare hematological diseases that has its own ID card from clinical symptoms and signs, through physical findings, haematological parameters, peripheral blood smear, bone marrow biopsy, cytogenetics to molecular markers (4). The incidence of CGL is 10–15 people per 100 000 inhabitants per year and occurs most frequently in the age between 60–65 years (5).

The disease passes through three characteristic clinical phases, chronic, phase of acceleration and blast transformation phase, which are clearly defined on the basis of clinical, hematological and cytogenetic-molecular criteria (5, 6). Over the past decades, the therapeutic approach to treating patients with CGL has been reduced and evolved along with a more precise clarification of the pathogenesis of the disease. The end of the 19th century was marked by the use of a arsenic preparation in the treatment of CGL or X radiation of enlarged spleen. The fifties of the 20th century began with the use of chemotherapy, initially Busulphanom, and then Hydroxiuree in patients with CGL. Hydroxiurea has been the most effective cytoreduction agent for this disease for decades, as was the case with our patients at the initial stage. Using various forms of cytoreductive therapy, clinical and hematologic remission of the disease in a negligible percentage of patients could be achieved, while the causative action on the disease itself was absent. In the early 1990s, patients with CGL were treated with recombinant IFN-alpha, a powerful immunomodulatory agent that opened a new era in the control of this malignant disease. Namely, for the first time, one agent acted at the cytogenetic level, bringing in the truth in a small group of patients, and a complete cytogenetic response. The next period was marked by the establishment of new cytogenetic response scales (from minimal to complete), which dictated the therapeutic approach (monotherapy with IFN alpha or combinations with other cytoreductive agents) (7). In the case of our patient, the proposed CGL treatment algorithm was followed in full according to the time period, and immunomodulatory therapy with IFN-alpha was also applied. Transplantation of stem cell hematopoiesis since 1979 (single transplantation) over the eighties and nineties of the 20th century was the standard in the treatment of patients with CGL, and this diagnosis was the most common indication for allogeneic transplantation from a related matched donor.

Based on clinical experience, the European Bone Marrow Transplantation Group(EBMT) has designed an EBMT prognostic score for predicting mortality rates in patients with CGL-treated allogeneic MSH transplantation based on a combination of a number of parameters related to patients and potential donors (7, 8,9). In the case of our patient, since the initial treatment with cytoreductive and immunomodulatory therapy has achieved clinical and hematological control of the disease, without the desired response at the cytogenetic level, an indication is given that the treatment will continue with the allogeneic transplantation of the MSH from the family fully matching donor. In accordance with the current attitudes and the fact that it is a hematopoietic stem cell disease, the preparatory regime was myeloablative, the source of the stem cells of the bone marrow, and the prevention of GvHD double immunosuppressive therapy (8, 9). In the post-transplant period, a timely engrafment was confirmed in our patient with the achievement of complete donor chimerism, and no clinicalor acute GvHD signs were recorded by clinical monitoring. Opinions regarding the monitoring of patients with CGL in whom allogeneic transplantation of the MSH occurred in the 1990s implied a three-month analysis of the cytogenetic finding, and then over the years and a molecular marker of the disease in order to timely diagnose the possible relapse of the underlying disease. In 1990, for the first time, infusion of donor lymphocytes (DLI) was used in the treatment of relapse of the disease after allogeneic transplantation (7, 10). Clinical observations have unambiguously confirmed that CGL disease is in the first place by degree of sensitivity to applied DLI, that is, that this therapeutic procedure can achieve a significant degree of secondary remission of the disease (11). The most common side effects of DLI include GvHD and bone marrow aplasia (12, 13). In our patient, three years after allogeneic transplantation, a rough relapse of the disease was diagnosed, and treatment was performed with three escalating doses of DLI from the original family donor, according to current recommendations for treatment in these situations. Newborn bone marrow aplasia with potentially fatal infectious complications can be interpreted as an adverse effect of DLI application. In this situation, the therapeutic approach for our patients was extremely limited. It is known that secondary allogeneic transplantation of the MSH in the case of leukemia relapse is an extremely complicated procedure, followed by a high degree of post-transplant morbidity and mortality, especially if one of the modalabative preparatory regimes (13, 14) is applied. In the late nineties of the last century, in order to overcome these complications, conditioned regimens of “reduced” intensity were designed primarily for secondary allogeneic transplantation of the MHH or elderly patients with associated illnesses (2, 13, 14,15). In the phase of bone marrow aplasia after DLI our patient was only prepared with ATG, and the source of the MSH from the original family donor was peripheral blood in order to achieve the “graft-versus-leukemia” (GvL) effect needed to control the minimum residual illness. No additional immunosuppressive therapy has been applied to generate GvL effects. This treatment regimen again achieved a multi-year remission condition.

Further development of the therapeutic approach in the treatment of CGL patients after the MSH transplantation and the DLI application was based on the understanding of the molecular mechanism of the disease, and implied the use of tyrosine kinase inhibitors (TKI), starting in 1998 ( 15, 16,17). The application of different generations of TKI led to the revolutionary control of CGL, concluding with the achievement of complete molecular remission of the disease (4, 10, 14). Thanks to the introduction of TKI in CGL therapy and the achievement of molecular disease control, it can rightly be said that patients with CGL have identical life expectations as well as a healthy population. After the onset of the second relapse of the disease due to secondary allogeneic transplantation, our patient was initially included in the first, and then due to the incomplete response and the second generation TKI with long-term complete control of the disease and excellent quality of life.

Current treatment of CGL over the past 130 years significantly evolved follow-up achievements in medicine and basic biological sciences. Due to a more precise view of the pathogenetic process in the onset and progression of CGL from the chronic phase to the form of acute leukemia, concurrently with molecular mechanisms, targeted drugs have been synthesized that stop the proliferation of malignant clones in this disease (TKI). The display of our patients fully supports the development of a therapeutic approach in the treatment of CGL, cytoreductive therapy, immunomodulatory agents, MHC transplantation, application of cell therapy such as DLI to first and second generation TKI.