[Treatment of thrombotic thrombocytopenic purpura].

The review discusses approaches to treatment of congenital thrombotic thrombocytopenic purpura (TTP) or Upshaw-Schulman syndrome. In congenital TTP, plasma transfusions are sufficient. Such treatment options as plasma exchange, administration of clotting factor VIII concentrate, recombinant ADAMTS13, are also used. Separately discussed issues of management of patients with TTP during pregnancy, and pediatric patients with TTP.

[Treatment of thrombotic thrombocytopenic purpura].

The review discusses approaches to treatment of acquired thrombotic thrombocytopenic purpuгa (aTTP). In patients with aTTP plasma exchanges, glucocorticosteroids allow to stop an acute attack of TTP, and use of rituximab allows to achieve remission. In recent years, caplacizumab has been used. Treatment options such as cyclosporin A, bortezomib, splenectomy, N-acetylcysteine, recombinant ADAMTS13 are also described. Separately discussed issues of management of patients with TTP during pregnancy, and pediatric patients with TTP.

Hematopoietic stem cell transplantation with alpha/beta T-lymphocyte depletion and short course of eculizumab in adolescents and young adults with paroxysmal nocturnal hemoglobinuria.

AIM: The main goal is to optimize hematopoietic stem cell transplantation (HSCT) approach among adolescents and young adults with paroxysmal nocturnal hemoglobinuria (PNH) by means of Graft-versus-host disease (GVHD) and post-transplant complications risk lowering. MATERIALS AND METHODS: We report our experience of HSCT from HLA-matched unrelated donors using TCR alfa/beta and CD19 depletion in 5 pts (1M/4F) with PNH, developed after successful immunosuppressive therapy (IST) of acquired aplastic anemia (AA). Median age of pts at the moment of transplantation was 17,8 years (range 14,5-22,7), median interval from IST to PNH was 4 years (5mo - 6,5 y). In all patients non-severe pancytopenia was present: granulocytes 0,8х109/l (0,8-1,8 х109/l) platelets 106 х109/l (27-143 х109/l) and Hb -78 g/l, median PNH clone size in granulocytes was 94 (range 75-99)%. One pts previously developed sinus thrombosis. Conditioning consisted of thoraco-abdominal irradiation 4-6 Gy, cyclophosphamide 100 mg/kg, fludarabine 150 mg/m2 and anti-thymocyte globulin (ATG) or alemtuzumab. Eculizumab was given from day (-7) till day (+14) (every 7 days, only 4 times). GVHD prophylaxis was tacrolimus ± methotrexate. RESULTS: Infusedgraft characteristics were: CD34+ - 8,1х106/kg, CD3TCRab·150х103/kg, CD3gd+ - 7,3х106/kg, СD19+ - 221х103/kg, NK -6,4х108/kg. Engraftment was achieved in all 5 pts with a median of 15(12-18) и 13(10-18) days for granulocytes and platelets, respectively. Skin acute GVHD grade I developed in only 1 pt, and subsided with short course of glucocorticoids. CMV reactivation occurred in 1 pt; there were no episodes of Epstein-Barr Virus (EBV) o rAdenovirus (AdV) reactivation. Full donor myeloid chimerism was established in all pts by day +30. Immune reconstitution was delayed until 6 months after transplant but no severe infections occurred. All pts are alive 1,7-5,5 years (med 4 years) after HSCT with normal hematopoiesis and immune function, full donor chimerism and no late sequelae. CONCLUSION: Transplantation of TCRalfa/beta and CD19 depleted hematopoietic cells from matched unrelated donor after immunoablative conditioning and supported with short course of eculizumab is perfectly safe and efficient technology leading to cure in young patients with PNH.

[Use of crizotinib for refractory ALK-positive lymphomas]. / Primenenie krizotiniba pri refrakternykh formakh ALK- pozitivnykh limfom.

AIM: To evaluate the safety and efficacy of crizotinib used in pediatric patients with relapsed or refractory ALK-positive anaplastic large-cell lymphoma (ALCL). SUBJECTS AND METHODS: The paper describes the experience with crizotinib used in 8 patients with refractory ALK-ALCL before and after allogeneic hematopoietic stem cell transplantation (HSCT). RESULTS: All the 8 (100%) patients treated with crizotinib were recorded to have complete responses, including complete metabolic ones (tumor disappearance as evidenced by positron emission tomography (PET)/computed tomography. CONCLUSION: Low and manageable toxicity of crizotinib and complete PET-negative responses in patients with resistant ALK lymphomas favor the need to test the drug as first-line therapy, by possibly decreasing the intensification of chemotherapy.

Tracking T-cell immune reconstitution after TCRαß/CD19-depleted hematopoietic cells transplantation in children.

αßT-cell-depleted allogeneic hematopoietic cell transplantation holds promise for the safe and accessible therapy of both malignant and non-malignant blood disorders. Here we employed molecular barcoding normalized T-cell receptor (TCR) profiling to quantitatively track T-cell immune reconstitution after TCRαß-/CD19-depleted transplantation in children. We demonstrate that seemingly early reconstitution of αßT-cell counts 2 months after transplantation is based on only several hundred rapidly expanded clones originating from non-depleted graft cells. In further months, frequency of these hyperexpanded clones declines, and after 1 year the observed T-cell counts and TCRß diversity are mostly provided by the newly produced T cells. We also demonstrate that high TCRß diversity at day 60 observed for some of the patients is determined by recipient T cells and intrathymic progenitors that survived conditioning regimen. Our results indicate that further efforts on optimization of TCRαß-/CD19-depleted transplantation protocols should be directed toward providing more efficient T-cell defense in the first months after transplantation.

[Age-related characteristics of the efficacy of different glucocorticosteroids in the therapy of acute lymphoblastic leukemia].

AIM: To determine predictors for decision-making on a differential approach to choosing glucocorticosteroids (GCS) for children and adolescents with acute lymphoblastic leukemia (ALL). SUBJECTS AND METHODS: The analysis covered 1064 primary patients aged to 1 to 18 years with ALL who had been registered at the clinics of Russia and Belorussia in April 2002 to November 2006. Before induction therapy, the patients were randomized into a dexamethasone (DEXA) 6 mg/m2 group (n=539) and a methylprednisolone (MePRED) 60 mg/m2 one (n=525). RESULTS: The entire group showed no statistically significant differences in survival rates between the patients receiving DEXA or MePRED. However, an analysis of age groups revealed the benefits of DEXA in children younger than 14 years (the event-free survival (EFS) was 76±2 and 71±2%, respectively (p=0.048); the overall survival (OS) was 81±2 and 77±2%, respectively (p=0.046); therapy-induced mortality was 6.4% (DEXA) andl 1.1% (MePRED) (p=0.01 4); the rate of isolated extramedullary relapses was 1.5% (DEXA) and 4.4% (MePRED) (p=0.009). At the same time, EFS and OS in 14-to-18-year-old adolescents were statistically significantly higher than in those who used MePRED (EFS, 65±6 and 52±6%, respectively (p=0.087); OS, 72±6 and 61±6%, respectively; (p=0.l 7). CONCLUSION: The findings suggest that it is possible that the choice of a GCS for ALL therapy must be also based on a patient's age. There is a need for further studies of this matter in prospective randomized multicenter trials in children and adolescents.

Efficacy of plerixafor in children with malignant tumors failing to mobilize a sufficient number of hematopoietic progenitors with G-CSF.

Mobilization of suitable amounts of PBSCs with granulocyte-CSF (G-CSF) can be difficult in children. We report the results of using plerixafor in pediatric patients who failed to mobilize progenitors with G-CSF-based regimens. Thirty-three patients, median age 9 years (range 1-18 years) and median weight 29 kg (range 10-85 kg) were enrolled into the study. After 4 days of G-CSF stimulation, the median CD34+ cell count in peripheral blood was 10.4 per µL (range 0.27-23.0 per µL). Plerixafor was administered subcutaneously (0.24 µg/kg in 30 patients and 0.3 µg/kg in 3 patients) 11-12 h before apheresis. At the time of apheresis, CD34+ cell counts increased to a median of 44.1 per µL (range 8.4-357.0 per µL), a median 4.4-fold increase. Two patients (6%) failed to mobilize. Thirty-one patients underwent apheresis and in 27 >2 × 10(6) CD34+ cells per kg of body weight were collected after one procedure. In total, 31 of 33 patients mobilized successfully and the median number of cryopreserved CD34+ cells was 5.6 × 10(6) /kg body weight (2.7 × 10(6)-27.4 × 10(6)). Twenty-four patients underwent transplantation. Engraftment was achieved in all but one patient, who died on day +9 after hematopoietic stem cell transplantation. The median time of neutrophil and platelet recovery was day +12 and +16, respectively. Our study confirms that plerixafor has impressive efficacy and very modest toxicity in children.

[Recurrences of acute promyelocytic leukemia in children: experience with arsenic trioxide therapy and autologous hematopoietic cell transplantation].

AIM: To analyze the specific features of recurrences of acute promyelocytic leukemia (APL) in children after standard therapy with daunorubicin, cytosine arabinoside (Ara-C), all-trans retinoic acid (ATRA) and to develop further programmed treatment policy. SUBJECTS AND METHODS: The study included 9 patients with recurrent APL. The recurrences developed significantly more frequently in a very high-risk group (patients with minimal residual disease being preserved after the intensive therapy phase). Induction used arsenic trioxide (ATO) and/or standard chemotherapy + ATRA; ATO monotherapy was in consolidation. CD34+ cells were mobilized until molecular remission was achieved with high-dose Ara-C and granulocyte colony-stimulating factor. Pretransplantation conditioning involved melfalan as a basic drug in combination with high-dose AraC (5 pts), treosulfan (1 pt) or bisulfan (1 pt). Six patients received gemtusumab ozogamicin, 3-9 mg/m2, at different stages of therapy. RESULTS: Before therapy one patient died; 8 patients achieved the second molecular remission; CD34+ cell mobilization and sampling were effective in 7 cases. Five patients were in long-term molecular remission after autologous hemopoietic stem cell transplantation (autoHSCT). Follow-up was 23-40 months. One patient is being prepared for transplantation. Following autoHSCT, another patient with a developed repeat recurrence died from complications due to related partially compatible transplantation. Visceral, including cardiological, toxicity of therapy was insignificant. In the APL-2003 protocol, overall and event-free survival rates were 93 +/- 3 and 76 +/- 6%, respectively. CONCLUSION; The application of ATO and autoHSCT in recurrent APL makes it possible to achieve and preserve the second molecular remission in case of insignificant extrahematological toxicity. Russian clinics should have access to ATO.

[Results of hematopoietic cell transplantation in the first complete remission in children with acute myeloid leukemia from an intermediate risk group].

AIM: To analyze the results of allogeneic and autologous hemopoietic cell transplantations (allo- and auto-HCT) in children with acute myeloid leukemia (AML) from an intermediate risk group, most of which were performed using lower-intensity conditioning modes. SUBJECTS AND METHODS. The study enrolled 36 children from an intermediate risk group, who had undergone auto-HCT (n = 22) or allo-HCT (n = 14) in December 1994 to December 2008. The patients' age was 0.7 to 16.6 years (median 12.8 years). Chemotherapeutic conditioning regimens were applied to all the patients. Melphalan was a basic myeloablative agent in 83.3% of cases. RESULTS: With a median follow-up of 4.6 years (1.1-13.8 years), three-year relapse-free survival (RFS) was 80.4%; overall survival (OS) was 65.6%. Recurrences were documented only in 6 (16.6%) patients from the auto-HCT. Transplantation-associated mortality (TAM) was 13.8% (five patients died). After allo-HCT versus auto-HCT, RFS, OS, and TAM were 100 and 68.7% (p = 0.03), 93.2 and 55.5% (p = 0.02), and 7.1 and 18.2%, respectively. Acute and chronic graft-versus-host reactions developed in 57.1 and 23.1%, respectively. CONCLUSION: Transplantation of allogeneic hemopoietic cells from a compatible related donor in the intermediate risk group children with AML, by using melphalan-based conditioning regimen, demonstrates a high survival rate with the minimum toxicity.

[Transplantation of the bone marrow from a HLA-compatible unrelated donor after immunoablative conditioning in children with acquired aplastic anemia unresponsive to combined immunosuppressive therapy: preliminary results].

AIM: To analyze the efficiency of transplantation of the bone marrow from a HLA-compatible unrelated donor and continued immunosuppressive therapy (IST) in children with aplastic anemia (AA) unresponsive to 2 courses of IST. SUBJECTS AND METHODS: The study enrolled 14 children aged 2-16 years (median 9 years). A control group comprised 26 patients in whom IST was continued. The median interval between the diagnosis of AA and transplantation was 26 months (9-156 months). The conditioning regimen consisted of thoracoabdominal irradiation in a dose of 2 Gy, fludarabin (Flu) 100-150 mg/m2, cyclophosphamide (Cy) 100-200 mg/kg, antithymocyte globulin (ATG) in 11 patients and Flu, Cy, and ATG in 3. A graft-versus-host reaction was prevented with mycophenolate mefetil in all the patients, tacrolimus in 11, and cyclosporin A in 3. Donors were compatible for high-resolution typing of 10/10 and 9/10 alleles in 8 and 6 patients, respectively; the source of a transplant was bone marrow in 13 patients and granulocyte colony-stimulating factor-mobilized peripheral blood precursors in one case. RESULTS: Thirteen patients achieved primary engraftment after single transplantation; one patient did after repeat transplantation. Grades I to II graft-versus-host reaction (GVHR) developed in 9 patients; postengraftment life-threatening infections in 3, extensive chronic GVHR in 2, circumscribed GVHR in 7. All fourteen hemopoietic cell transplant recipients followed for a median 17.5 months (range 1-71 months) were survivors. CONCLUSION: The likelihood of good survival after unrelated transplantations in AA is much higher than that after continued IST: 100% versus 15 +/- 11%.

[Long-term results of combined treatment of acute promyelocytic leukemia in children and adolescents with gene therapy].

AIM: To analyse the results of treatment of children and adolescents with acute promyelocytic leukemia (APL) including polychemotherapy and ATRA (protocols APL 93, 98 and 2003). MATERIAL AND METHODS: The course of the disease, modification of the treatment protocols with reduction of anthracyclines and ATRA doses, results of molecular monitoring of PML/RARalpha transcript have been analysed for 107 APL patients. RESULTS: For prognosis of the disease important are initial characteristics of the patient and the time of the tumor regress assessed by molecular methods--establishment of molecular remission and molecular recurrence. CONCLUSIONS: In APL it is necessary to conduct molecular monitoring especially in patients at high risk and with poor prognosis in a decrease of treatment intensity for toxicity relief. Detection of molecular recurrence is indication for treatment. To raise efficacy of APL recurrence therapy it is necessary to design a special updated protocol.

[Clinico-laboratory variants of the course and results of therapy of hepatitis-associated aplastic anemias in children].

AIM: To study clinical and laboratory characteristics of hepatitides and evaluate efficacy of immunosuppressive therapy and transplantation of the bone marrow in hepatitis-associated aplastic anemia (HAAA). MATERIAL AND METHODS: A retrospective analysis of case histories of children with HAAA was made. For all the patients standard tests for detection of aquired aplastic anemia and hepatitis were conducted. Transplantation of hemopoietic stem cells (THSC) from HLA-identical donors was made in 4 patients, 25 patients were treated with combined immunosuppressive therapy (antithymocytic globulin--ATG plus cyclosporin A -CsA), one patients received monotherapy with CsA, two--prednisolone and a short course of CsA, one child was untreated. RESULTS: Of 260 children admitted to hospital from April 1989 to July 2005 for aquired aplastic anemia, 33 (12.7%) met diagnostic criteria of HAAA. Boys to girls ratio was 267. Hepatitides were severe: median of alaninaminotransferase concentration was 1215 IU/l, aspartataminotransferase--789 IU/l, bilirubin--152.5 mcmol/l. Median of the interval from hepatitis symptoms to documentation of pancytopenia was 66 days (0-204 days). All four patients after THSC are alive for 30-72 months. Probability of complete remission after the first course of ATG+CsA is 0.72 +/- 0.09, probability of survival 0.81 +/- 0.07, median of the interval to transfusion independence--50 days. CONCLUSION: HAAA prognosis is good only in administration of up-to-date therapy. After seronegative hepatitis it is necessary to control hemogram parameters and in the presence of minimal cytopenia patients should be directed to hematological hospital.

Fludarabine, low-dose busulfan and antithymocyte globulin as conditioning for Fanconi anemia patients receiving bone marrow transplantation from HLA-compatible related donors.

Allogeneic hematopoietic stem cell transplantation (SCT) from unaffected donors remains the only modality for the correction of hematological abnormalities in Fanconi anemia (FA) patients. We performed four HLA-matched related donor SCT using a novel irradiation and cyclophosphamide-free conditioning regimen. The protocol included fludarabine 150 mg/m(2), busulfan 4 mg/kg, and antithymocyte globulin 90 mg/kg. Graft-versus-host disease (GVHD) prophylaxis was cyclosporin A, MTX, and daclizumab. The engraftment and occurrence of full stable donor hemopoiesis was rapid in all cases with minimal short-term toxic complications. There were no infections or febrile episodes during the inpatient phase. Three patients developed acute GVHD grade I-II involving gut and skin and one patient progressed to extensive chronic GVHD. The preparative conditioning regimen is safe and associated with low organ toxicity and effective immunosupression for the stable engraftment in FA patients undergoing SCT with matched related donors.

Successful treatment of pure red cell aplasia with a single dose of rituximab in a child after major ABO incompatible peripheral blood allogeneic stem cell transplantation for acquired aplastic anemia.

Pure red cell aplasia (PRCA) is a well-known although infrequent hematologic complication after allogeneic bone marrow transplantation. PRCA occurs in cases of major ABO-mismatch between donor and recipient and is believed to be due to inhibition of donor erythroid progenitors by residual host isohemagglutinins. We report a 10-year-old boy with post-hepatitis aplastic anemia (AA) who developed PRCA after HLA-matched familial peripheral blood stem cell transplantation (SCT) following conditioning with Cph 200 mg/kg + ATG 90 mg/kg. Granulocyte engraftment occurred on day +18, platelet engrafted on day +40, while reticulocytopenia at 0% persisted until day +118, and erythroid precursors were totally absent from bone marrow. After a single dose of rituximab 200 mg/m(2)administered on day +118 PRCA resolved and on day +132 the reticulocytes rose to 5.7%. On day +139 the Hb reached 137 g/l and the erythroid lineage in BM increased to 21%. We conclude that due to the rapid recovery from PRCA and lack of side effects, rituximab should be tried as first-line treatment of PRCA after allo-SCT.

[Time course changes in the count of peripheral granulocytes in children with acquired aplastic anemias treated with antithymocyte globulin, cyclosporin A and granulocytic colony stimulating factor]. / Dinamika kolichestva granulotsitov v perifericheskoi krovi u detei s priobretennymi aplasticheskimi anemiiami, poluchivshikh lechenie antitimotsitarnym globulinom, tsiklosporinom A i granulotsitarnym koloniestimuliruiushchim faktorom.

AIM: To examine the pattern of changes in the count of peripheral granulocytes in children with aplastic anemias (AA), receiving a combined immunosuppressive therapy with antithymocytic globulin (ATG) and cyclosporin A in combination with granulocytic colony-stimulating factor (G-CSF). MATERIALS AND METHODS: 31 children (17 boys and 14 girls) aged 2-15 years (median 9 years) with newly diagnosed severe and very severe acquired AA took a combined immunosuppressive therapy with ATG and cyclosporin A in combination with G-CSF in an initial dose of 10 micrograms/kg a day. RESULTS: A three-linear and response was recorded in 19 (61%) children, an isolated granulocytic response was in 26 (84%). The interval median before the recovery of granulocytes to 1.5 x 10(9)/l and 5 x 10(9)/l was 19 and 38 days, respectively. CONCLUSION: Use of G-CSF may increase the count of granulocytes in the vast majority of patients with AA, without dramatic influence on the frequency of a three-linear response. Intermittent use of G-CSF may maintain the count of granulocytes long at the safe level and reduce the cost of treatment.

A successful cord blood transplant in a child with second accelerated phase chronic myeloid leukemia following lymphoid blast crisis.

We describe a 5-year-old girl with Ph(+) CML who received a cord blood transplant in a second accelerated phase after a very early lymphoid blast crisis. She was induced into CR by ALL-directed chemotherapy and then maintained with IFN-alpha2b together with weekly rotational chemotherapy. Nineteen months after diagnosis, her mother gave birth to an HLA-compatible sibling, whose cord blood was cryopreserved. The patient's second acceleration occurred 22 months after the CML diagnosis. The subsequent conditioning regimen included busulfan 16 mg/kg, Ara-C 12 g/m2 and melphalan 140 mg/m2. In order to prevent GVHD, CsA alone was administered, 3 mg/kg i.v. per day for a total of 40 days. The total number of nucleated cells infused was 0.8 x 108/kg, with CD34+ cells 1.8 x 106/kg and CFU-GM 1 x 104/kg. Engraftment occurred on day +35. Respiratory distress, severe VOD and grade II acute gastrointestinal GVHD complicated the post-transplant period. No chronic GVHD occurred. The girl is alive 23 months after transplantation with complete donor chimerism; both Ph chromosome and bcr/abl RNA are negative. Bone Marrow Transplantation (2000) 25, 213-215.

Intermediate-dose busulfan and cyclophosphamide as a conditioning regimen for bone marrow transplantation in a case of Fanconi anemia in myelodysplastic transformation.

We report an 11-year old female with myelodysplastic (refractory anemia with excess of blasts) presentation of Fanconi anemia. After failure of initial chemotherapy with low doses of 6-mercaptopurine and prednisolone she underwent allogeneic bone marrow transplantation (BMT) from her HLA-matched sibling. Busulfan 8 mg/kg and cyclophosphamide 40 mg/kg were used as conditioning. The post-transplant course was uneventful with fast trilineage engraftment and mild cutaneous acute GVHD. She is alive 17 months after BMT with full hematological reconstitution without evidence of MDS.

[Effectiveness of piperacillin/tazobactam in the treatment of fever of unknown etiology in patients with granulocytopenia]. / Effektivnost' piperatsillin/tazobaktama v lecheni likhoradki neiasnoi étiologii u bol'nykh s granulotsitopeniei.

Piperacillin/tazobactam (P/T) was used in the treatment of 14 patients at the age of 5 to 15 years: 5 patients with acute lymphoblastic leukemia, 3 with acute nonlymphoblastic leukemia, 4 with severe aplastic anemia, 1 with lymphoma and 1 with neuroblastoma. P/T was administered as intravenous infusions in a daily dose of 200-300/25-37.5 mg/kg body weight divided into 3 or 4 portions. All the patients were subjected to intestine selective antimicrobial decontamination. In 7 patients the afebrile condition was recorded before elimination of agranulocytosis without correction of the therapy i.e. without combination of P/T with some other antibiotics such as amphotericin B, vancomycin or aminoglycosides. In 5 patients the effect was stated after correction of the regimen by its supplementing with amphotericin B. 2 patients died. No side effects of P/T was observed. The afebrile condition was provided in 1 to 7 days. P/T is recommended for the treatment of fever of obscure etiology in patients with agranulocytosis and for effective control of infection in such patients.

["Cyclosporin dependence" in the treatment of severe aplastic anemia in children]. / "Tsikloporinovaia zavisimost'" pri lechenii tiazhelykh aplasticheskikh anemii u detei.

Cyclosporin A (CA) was used in the treatment of 2 patients with acquired aplastic anemia. Upon reaching hematological remission these children had recurrence consequent to dose lowering or discontinuation of CA. The remission occurred again when full-dose CA treatment was resumed. Slow 2-year decrease in CA dose led to uneventful end of CA treatment without deterioration of blood picture.