Ryouji Kobayashi

Neurological complications after stem cell transplantation in childhood

We analyzed the incidence of neurological complications in 77 patients receiving stem cell transplantation (SCT), and 12 patients (15.8%) had the following symptoms: convulsions, intracranial hemorrhage, and leukoencephalopathy. Although statistically not significant, neurological complications were seen more frequently in patients after allogeneic transplantation, and in those with acute graft-versus-host disease (GVHD) exceeding grade II. The most significant risk factor for neurological complications was identified as unrelated donor allogenic transplantation (P = 0.016). Complications were categorized into three groups, based on time of onset and symptoms: (1) convulsions during the conditioning period, (2) intracranial hemorrhage during the period of granulocyte recovery, and (3) leukoencephalopathy at around 2 months after SCT. We propose awareness of the risks of neurological complications in each period after SCT so that immediate and effective treatment of patients can be instigated.

Vascular endothelial growth factor (VEGF) is one of the cytokines causative and predictive of hepatic veno-occlusive disease (VOD) in stem cell transplantation.

Hepatic veno-occlusive disease (VOD) is one of the most serious complications in patients receiving stem cell transplantation (SCT). However, the cause of VOD remained to be elucidated. Vascular endothelial growth factor (VEGF) has been reported to have various physiological effects including neovascularization and acceleration of vasopermeability. Because we postulated that VEGF could be one of the causative factors in VOD after SCT, serum VEGF levels were measured by ELISA in 50 patients receiving SCT. Six of the patients showed typical manifestations of VOD and four of them died due to VOD. The mean maximum serum VEGF level in the six patients with VOD was markedly increased compared to that in the patients without VOD (P < 0.001) and in normal controls (P < 0.001). Moreover, the mean maximum serum VEGF level in patients with VOD before conditioning chemoradiotherapy for SCT was also high compared to patients without VOD (P = 0.0012) in the same period. Similarly, serum VEGF levels were significantly higher in patients whose plasma protein C activities decreased below 40% (P < 0.001). during the clinical course of VOD after SCT, the increase of serum VEGF synchronized fairly well with the development of VOD. Since VEGF causes the expression of tissue factor on circulating monocyte/ macrophages and results in hypercoagulability, our observation suggests that in the patients with VOD who showed high serum VEGF it might account for the development of VOD. Furthermore, this observation may indicate a novel therapeutic strategy for prevention of VOD. Bone Marrow Transplantation (2001) 27, 1173–1180.

Platelet‐specific hemophagocytosis in a patient with juvenile dermatomyositis

Juvenile dermatomyositis (DM) is an in ̄ammatory disease mainly characterized by erythematous rash and muscular weakness with vasculopathy (1). Although the prognosis of juvenile DM is fair in most cases, severe and rush cases have been reported. Interstitial pneumonia and gastrointestinal bleeding are established fatal complications in both adulthood and juvenile DM. However, reported cases with hematological complication including thrombocytopenia are limited (2). Here, we report a case of severe thrombocytopenia complicated with juvenile DM. Of interest was a ®nding that signi®cant platelet-speci®c hemophagocytosis was observed in the bone marrow.

Umbilical cord blood stem cell transplantation from unrelated HLA-matched donor in an infant with severe congenital neutropenia.

Summary:We report here a 6-month-old boy with severe congenital neutropenia (SCN) successfully treated by cord blood stem cell transplantation (CBSCT) from an unrelated donor. He had recurrent life-threatening respiratory infection due to severe neutropenia that was refractory to recombinant human granulocyte colony-stimulating factor (rhG-CSF). Because he had no HLA-matched sibling and no time to wait for unrelated donor, he received HLA-matched unrelated CBSCT as determined by DNA typing. A total of 6.4 × 107 CB nucleated cells/kg was infused after conditioning with busulfan/horse antihuman thymocyte serum/cyclophosphamide. No GVHD developed under the treatment with cyclosporin A and methyl prednisolone. The neutrophil count reached 0.5 × 109/l on day 14, reticulocyte 1% on day 13 and platelet count over 50 × 109/l on day 31. We conclude that unrelated CBSCT can be an indication for some cases of SCN, who have recurrent life-threatening infections and are refractory to rhG-CSF, and have no HLA-matched sibling.

Hyponatremia and syndrome of inappropriate antidiuretic hormone secretion complicating stem cell transplantation

Summary:Hyponatremia is a common electrolyte disorder in hospitalized patients. Although there are a few case reports of hyponatremia following stem cell transplantation (SCT), no reports concerning the incidence are currently available. We describe the occurrence of hyponatremia and the syndrome of inappropriate secretion of antidiuretic hormone (SIADH) following SCT. In a single center analysis of 140 patients, hyponatremia and SIADH were observed in 40 and 11.4% of patients, respectively, following SCT. Risk factors for SIADH included young age, transplantation from an HLA-mismatched or unrelated donor, cord blood transplantation, and graft-versus-host disease prophylaxis with methyl prednisolone. Multivariate analysis revealed that transplantation from an HLA-mismatched donor and performance of SCT in a child below 4 years of age were risk factors for SIADH. For patients who underwent SCT from an HLA-mismatched or unrelated donor, those with SIADH showed a significantly higher overall survival rate (90.9 vs 40.2%) and event-free survival rate (77.8 vs 33.8%) compared to those without SIADH. Overall, our data show that hyponatremia and SIADH are relatively common complications following SCT, especially in children below 4 years of age and after SCT from an HLA-mismatched donor.

Significance of eosinophilia after stem cell transplantation as a possible prognostic marker for favorable outcome

Summary:Although eosinophilia after stem cell transplantation (SCT) has been addressed in recent reports, the significance of eosinophilia in disease outcome after SCT has not been well studied. In this study, we investigate the frequency of eosinophilia after SCT to determine its prognostic value. The subjects were 113 patients with malignant or nonmalignant diseases who underwent SCT treatment. In these patients, eosinophilia was detected in 44 cases (38.9%), on average 67.5 days after transplantation, and the mean maximum absolute eosinophil count was 840.5 × 106/l. To study the basis of eosinophilia after SCT, various serum cytokine levels during SCT in patients both with and without eosinophilia were analyzed. Statistical analysis indicated that the overall patient survival rates improved in those with eosinophilia compared to those without eosinophilia (88.7 vs 43.0%, P=0.0034). In particular, in patients with malignant diseases, those with eosinophilia showed a higher event-free survival (81.1 vs 44.6%, P=0.0025) and a lower relapse rate (16.0 vs 43.0%, P=0.0287) than those without eosinophilia. In conclusion, we propose that eosinophilia after SCT could be a useful prognostic marker for determining favorable outcomes in patients with malignant diseases. The reasons for this good prognosis in SCT patients with eosinophilia are discussed.

Risk factor analysis of idiopathic pneumonia syndrome after allogeneic hematopoietic SCT in children

Idiopathic pneumonia syndrome (IPS) is a critical complication following allogeneic hematopoietic SCT (HSCT); however, few reports have analyzed the risk factors for IPS in children. A total of 210 consecutive pediatric patients, including 131 boys and 79 girls, with various hematologic malignancies, aplastic anemia or solid tumors who underwent allogeneic HSCT were analyzed to clarify the incidence and risk factors for IPS. Patient and transplantation characteristics after allogeneic HSCT were compared between patients with and without IPS. Cumulative incidence rates of IPS 120 days after allogeneic HSCT were 6.7% (14/210). Of 14 patients with IPS, 11 (78.6%) died after developing IPS. The presence of prior HSCT was more frequent in patients with IPS (IPS group) than in those without IPS (non-IPS group; 35.7 vs 12.8%, respectively, P=0.018). The IPS group contained more patients with acute GVHD (grade II–IV) than the non-IPS group (50.0 vs 18.9%, respectively, P=0.006). The association of these two factors with IPS was further confirmed by multivariate analysis. We should be aware of these risk factors in patients who have undergone allogeneic HSCT.

Postoperative portal and splenic vein thrombosis in children: Identification of risk factors

Postoperative portal and splenic vein thrombosis (PSVT) is a rare but potentially fatal complication after abdominal surgery. We present 2 infants with PSVT after splenectomy and total colectomy, respectively, and also provide a review of the literature. We conclude that clinicians should consider that PSVT might occur after splenectomy for a huge splenomegaly or after a total colectomy for ulcerative colitis.

Electroencephalogram abnormality and high-dose busulfan in conditioning regimens for stem cell transplantation

High-dose busulfan (BU) is widely used in combined chemotherapy before allogeneic or autologous bone marrow transplantation. Convulsions are reported as a side-effect of high-dose BU. We recorded electroencephalograms (EEGs) before and on the third day of BU administration in 22 patients. Abnormal EEGs were observed on the third day in 13 cases (59%). These patients were older (P < 0.05) and had had larger doses of bu (P < 0.025) than the nine patients with normal eegs. convulsions occurred in two of the 22 patients, one of whom was receiving prophylaxis with phenytoin. gamma aminobutyric acid (gaba), a natural mediator of defense against epileptic activity, concentrations in cerebrospinal fluid measured before and after administration of bu showed no definite changes.

Leukoencephalopathy in Childhood Acute Lymphoblastic Leukemia with T(1; 19)

To clarify the incidence of leukoencephalopathy in patients with t(1;19) and their clinical characteristics, we studied 239 acute lymphoblastic leukemia (ALL) cases. The 1;19 translocation was found in 20 (8.5%) of the 239 children with ALL. Leukoencephalopathy occurred in 2 (10%) patients with t(1;19) during the early first remission and in one case with t(1;19) at the time of central nervous system (CNS) relapse. Leukoencephalopathy was not found during the early first remission in patients lacking t(1;19), but did develop in 4 patients lacking t(1;19) at the time of CNS relapse. There were no differences in age, sex, leukocyte count, platelet count or serum lactate dehydrogenase level between t(1;19) patients with and without leukoencephalopathy. Our results suggest the incidence of leukoencephalopathy in patients with t(1;19) during the early first remission to be 10%, but we can not predict which patients will develop leukoencephalopathy.