Idil Yenicesu

Effect of Platelet-Rich Plasma on Peripheral Nerve Regeneration

Activated platelets release various growth factors, some of which are recognized to improve nerve regeneration. This study evaluated the effect of platelet-rich plasma (PRP) in end-to-end neurorrhaphy. A total of 45 Wistar rats were used, with the initial five used for PRP preparation. The right hind limbs were used as experimental, with the left as control. The animals were treated in five groups. Group A (n = 4): The right sciatic nerve was dissected only from the sciatic notch to the bifurcation. In all other groups, the nerve was sharply transected and repaired with: group B (n = 8): two sutures; group C (n = 8): six sutures; group D (n = 10): two sutures and PRP; and group E (n = 10): six sutures and PRP. Groups D and E were compared with groups B and C, respectively. Group E had a shorter latency time in electromyography ( P < 0.01) and a thicker myelin layer in the histological evaluation ( P < 0.003) in comparison with group C. These positive effects of PRP were not detected in the nerves were repaired with two sutures. In this animal model, the application of PRP to the repair site helped to improve remyelinization of the sciatic nerve in rats when the epineural repair was done with six sutures.

Virus-associated immune thrombocytopenic purpura in childhood.

Idiopathic thrombocytopenic purpura (ITP) in children is usually a self-limiting disorder. It may follow a viral infection or immunization and is caused by an inappropriate response of the immune system. Many viruses, such as human immuno deficiency virus, cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella, rubeola, mumps, and parvovirus, have been implicated in childhood ITP. This study is a retrospective chart review of pediatric patients diagnosed with virus-associated ITP at the Hacettepe University, G hsan Do < ramaci Childrens Hospital from 1997 to end of 2000. In viral serological studies, the EBV, CMV, and rubella antibodies were investigated for all patients at diagnosis (ELISA). The proportion of children whose ITP was associated with documented acute viral infection was 13.3% in this group. In the present study, clinical manifestations and laboratory data of virus-associated or not associated groups are similar except age. Median age of the virus-associated group is younger than that of the other, but it is not statistically significant.

Clinical Importance of Serum Vascular Endothelial and Basic Fibroblast Growth Factors in Children with Acute Lymphoblastic Leukemia

The aim of this study is to evaluate, for the first time serum levels of vascular endothelial growth factor (s-VEGF), and basic fibroblast growth factor (s-b FGF) in children with acute lymphoblastic leukemia (ALL), and its relation to clinical manifestations of the disease. Although VEGF and b FGF have been suggested to be reliable prognostic indicators and important tools for treatment approach in malignant haematopoietic and solid tumours, experience in childhood ALL has been limited to only one study on angiogenesis and urine b FGF. All 31 ALL patients included in the present study at the time of diagnosis and in remission, and all 10 control children had detectable serum levels of VEGF and b FGF. The median level of s-VEGF at the time of diagnosis was significantly lower than in the control group and at the time of remission (respectively p=0,005, p=0,0001). Twenty six of 31 patients had an increasing trend of s-VEGF levels in remission reaching control values compared with the levels obtained at diagnosis. S-b FGF median levels at the time of diagnosis were the same as those of the control group, significantly lower than the median s-b FGF values in remission (p=0,001). In patients with lower platelet counts (< 50 × 109/L) growth factors (VEGF and b FGF) were lower than in patients with higher platelet counts (p=0,0009 and p=0,002 respectively). In patients with hepatosplenomegaly (longitudinal size> 3 cm) b FGF levels were higher than patients without hepatosplenomegaly (P=0,003). We concluded that the increment in both s-VEGF and s-b FGF in patients in remission may be related to the renewal of normal haematopoiesis. The increase in s-VEGF values in 26 out of 31 patients in remission compared to normal control values, may also suggest that there is clinical significance in ALL patients.

Benefit of high-dose methylprednisolone in comparison with conventional-dose prednisolone during remission induction therapy in childhood acute lymphoblastic leukemia for long-term follow-up.

Eight-year event-free survival (EFS) was evaluated in 205 patients with acute lymphoblastic leukemia (ALL), to consider the efficacy of high-dose methylprednisolone (HDMP) given during remission induction chemotherapy between 1 and 29 days. The St Jude Total XI Study protocol was used after some minor modifications in this trial. Patients were randomized into two groups. Group A (n = 108) received conventional dose (60 mg/m2/day orally) prednisolone and group B (n = 97) received HDMP (Prednol-L, 900–600 mg/m2 orally) during remission induction chemotherapy. Complete remission was obtained in 95% of the 205 patients who were followed-up for 11 years; median follow-up was 72 months (range 60–129) and 8-year EFS rate was 60% overall (53% in group A, 66% in group B). The EFS rate of group B was significantly higher than of group A (P = 0.05). The 8-year EFS rate of groups A and B in the high-risk groups was 39% vs 63% (P = 0.002). When we compared 8-year EFS rate in groups A and B in the high-risk subgroup for both ages together ⩽2 or ⩾10 years, it was 44% vs 74%, respectively. Among patients in the high-risk subgroup with a WBC count ⩾50 × 109/l, the 8-year EFS was 38% in group A vs58% in group B. During the 11-year follow-up period, a total of 64 relapses occurred in 205 patients. In group A relapses were higher (39%) than in group B (23%) (P = 0.05). These results suggest that HDMP during remission-induction chemotherapy improves the EFS rate significantly for high-risk patients in terms of the chances of cure.

Evaluation of children with myelodysplastic syndrome: importance of extramedullary disease as a presenting symptom.

Thirty-three children diagnosed with primary myelodysplastic syndrome (MDS) in a single institution over an 8 year period were evaluated with special emphasis on children who presented with extramedullary disease (EMD). EMD was present at diagnosis in 12 (36%) of the 33 children with MDS. Three patients with juvenile myelomonocytic leukemia (JMML) and 2 patients with chronic myelomonocytic leukemia (CMML) presented with pleural effusion. Pericardial effusion was present in 3 of these patients, two of whom also had thrombosis. Pyoderma gangrenosum, relapsing polychondritis were the initial findings in another two cases with JMML. Lymphadenopathy (n=1), gingival hypertrophy (n=2), orbital granulocytic sarcoma (n=1) and spinal mass (n=1) were the presenting findings in 5 patients with refractory anemia with excess of blasts in transformation. Since high-dose methylprednisolone (HDMP, 20–30 mg/kg/day) has been shown to induce differentiation and apoptosis of myeloid leukemic cells in children with different morphological subtypes of acute myeloid leukemia in vivo and in vitro, 25 children with de novo MDS were treated with combined HDMP and cytotoxic chemotherapy. Dramatic improvement of EMD and decrease in blast cells both in the peripheral blood and bone marrow were obtained following administration of short-course HDMP treatment alone as observed in children with AML. HDMP, combined with low-dose cytosine arabinoside and mitoxantrone were used for the remission induction. Remission was achieved in 8 (80%) of 10 children who presented with EMD and in 9 (60%) of 15 children without EMD. Long-term remission (>6 years) was obtained in 4 (two with JMML and two with CMML), three of whom presented with EMD. In conclusion EMD can be a presenting finding in childhood MDS as observed in adults. In addition, the beneficial effect of HDMP combined with more intensive chemotherapy should be explored as alternative therapy in children with MDS not suitable for bone marrow transplantation.

Acute parvovirus B19 infection mimicking juvenile myelomonocytic leukemia

Abstract: An 11‐month‐old patient with parvovirus infection mimicking juvenile myelomonocytic leukemia (JMML) is presented. The patients history, presenting physical and laboratory features, was suggestive of JMML and consisted of fever, hepatosplenomegaly, lymphadenopathy, desquamation of the skin, anemia, leukocytosis with monocytosis and trilineage dysplastic findings of the peripheral blood and bone marrow. However, positive IgM titers for parvovirus B19 followed by seroconversion, negative cytogenetics and the benign follow‐up of the patient suggested acute parvovirus infection as an etiologic factor for development of dysplastic features in the patient, and thus is recommended for consideration in the differential diagnosis of MDS. Although parvovirus B19 infection mimicking MDS has previously been shown in two patients with spherocytosis and one with subclinical immune deficiency; to our knowledge, the present report is the first describing the association of acute parvovirus B19 infection with dysplastic features mimicking myelodysplasia (MDS) in a child without a demonstrable underlying hematolymphoid disorder.

Impact of ABO-Incompatible Donor on Early and Late Outcome of Hematopoietic Stem Cell Transplantation

ABO incompatibility is not a barrier to allogeneic hematopoietic stem cell transplantation (HSCT). However, the impact of an ABO mismatch on the outcome of the HSCT remains controversial. We analyzed whether ABO incompatibility leads to an increased risk of early/late complications, mortality, or increased transfusion requirements. The 147 consecutive allogeneic HSCTs includes 80 ABO-identical and 25 major, 30 minor, and 12 bidirectional ABO-mismatched grafts. The four groups were balanced with respect to disease status at transplantation. Transplantation-related mortality was significantly greater (P < .01) and overall survival significantly shorter (P = 0.2) among HSCT recipients with minor ABO-mismatched grafts. The relapse rate, progression-free survival, and transfusion requirements until discharge were not different between ABO-identical and ABO-mismatched groups. Pure red cell aplasia (PRCA); (P < .0001) and delayed red blood cell (RBC) engraftment (P < .001) were more frequent in HSCT recipients with major mismatched donors. Delayed RBC engraftment was associated with posttransplantation hyperferritininemia and increased mortality risk (P = .05). The greater frequency of sinusoidal obstruction syndrome and graft-versus-host disease (GVHD) in patients with minor mismatched transplants, did not show statistical significance. In contrast severe GVHD was significantly more frequent among minor mismatched patients (P = .04). ABO-mismatched HSCT might have an unfavorable impact on transplant outcomes. Selection of ABO-compatible donors when possible, strategies to prevent and treat PRCA, modifications in transfusion practice, and effective iron chelation are among the measures that can improve transplant outcomes.

Functional and clinical impact of novel TMPRSS6 variants in iron-refractory iron-deficiency anemia patients and genotype-phenotype studies.

Iron‐refractory iron‐deficiency anemia (IRIDA) is a rare autosomal‐recessive disorder characterized by hypochromic microcytic anemia, low transferrin saturation, and inappropriate high levels of the iron hormone hepcidin. The disease is caused by variants in the transmembrane protease serine 6 (TMPRSS6) gene that encodes the type II serine protease matriptase‐2, a negative regulator of hepcidin transcription. Sequencing analysis of the TMPRSS6 gene in 21 new IRIDA patients from 16 families with different ethnic origin reveal 17 novel mutations, including the most frequent mutation in Southern Italy (p.W590R). Eight missense mutations were analyzed in vitro. All but the p.T287N variant impair matriptase‐2 autoproteotylic activation, decrease the ability to cleave membrane HJV and inhibit the HJV‐dependent hepcidin activation. Genotype–phenotype studies in IRIDA patients have been so far limited due to the relatively low number of described patients. Our genotype–phenotype correlation analysis demonstrates that patients carrying two nonsense mutations present a more severe anemia and microcytosis and higher hepcidin levels than the other patients. We confirm that TMPRSS6 mutations are spread along the gene and that mechanistically they fully or partially abrogate hepcidin inhibition. Genotyping IRIDA patients help in predicting IRIDA severity and may be useful for predicting response to iron treatment.

Differentiation of Leukemic Cells Induced by Short-Course High-Dose Methylprednisolone in Children with Different Subtypes of Acute Myeloblastic Leukemia

Differentiation of myeloid leukemic cells to mature granulocytes by high-dose methylprednisolone (HDMP, 20-30 mg/kg/day) with a favorable antileukemic effect has previously been demonstrated in children with acute promyelocytic leukemia and acute myeloblastic leukemia (AML) M4. In the present study, three children with other morphological subtypes of AML (two AML M1, one AML M2) were given methylprednisolone (30 mg/kg/day) orally in a single dose. After a short-course (3 or 7 days) of HDMP treatment alone, a striking decrease in blast cells associated with an increase in maturing and abnormally nucleated polymorphonuclear-like cells some containing Auer rods were detected in all patients in peripheral blood or bone marrow smears. During HDMP treatment, in parallel to morphological improvements, marked increases in the percentage of cells expressing granulocytic antigen (CD15) were observed. The increase of CD15 expression on myeloid cells, together with the steady expression of CD34 and CD117 antigens in Casel(AML M1) , is suggestive of aberrant CD34 + CD117 + CD15 + cells, which may indicate the leukemic origin of the maturing myeloid cells. These results suggest that HDMP treatment may induce differentiation of myeloid leukemic cells in some children with different morphological subtypes of AML, and that the differentiation-inducing effect of HDMP should be explored in other malignant diseases.

DRAMATIC RESOLUTION OF PLEURAL EFFUSION IN CHILDREN WITH CHRONIC MYELOMONOCYTIC LEUKEMIA FOLLOWING SHORT-COURSE HIGH-DOSE METHYLPREDNISOLONE

High-dose methylprednisolone (HDMP) which can induce--differentiation and -apoptosis of myeloid leukemic cells has been shown to be very effective in the treatment of extramedullary infiltration (EMI) of children with acute myeloblastic leukemia (AML). In the present study 2 children with chronic myelomonocytic leukemia (CMML) who had pleural effusions were given a single daily dose of oral methylprednisolone (20 mg/kg or 30 mg/kg). In addition to dramatic improvement of respiratory symptoms, pleural effusions disappeared in four days in both patients possibly due to apoptotic cell death induced by HDMP treatment. Further studies are needed to determine whether high-dose corticosteroids are also effective on the resolution of pleural effusions associated with other malignant disease.