Biomedical subjects

H Suzuya

Publications and source records attributed to H Suzuya.

8 recordsLinked to original sources

PubMed2003

Autoimmune hepatitis following allogeneic PBSCT from an HLA-matched sibling.

A 7-year-old boy with acute lymphoblastic leukemia (ALL) in second remission received an allogeneic PBSCT from his HLA-matched sister. Acute grade II graft-versus-host disease (GVHD) resolved with corticosteroids. Chronic GVHD in the skin and oral mucosa at around day 60 responded to corticosteroids and cyclosporin A. At 6 months after the transplant, he developed hepatic dysfunction with elevated serum transaminases and gamma-globulin. Liver biopsy revealed chronic inflammation with lymphocytes and plasma cells in portal areas without destruction of bile ducts, suggesting autoimmune hepatitis. While rare, autoimmune hepatitis should be considered a potential long-term complication in patients with hepatic dysfunction in the late post-transplant phase.

Biopsy↗

PubMed2001

Intense immunosuppression followed by purified blood CD34+ cell autografting in a patient with refractory juvenile rheumatoid arthritis.

A 15-year-old boy with refractory juvenile rheumatoid arthritis (JRA) underwent intense immunosuppressive therapy followed by purified blood CD34+ cell autografting. He had been taking prednisolone (PDN) daily or every other day combined with methotrexate once a week to control the disease for 7 years. He suffered from psychological complications and a very short stature due to the adverse effects of these drugs. CD34+ cells were purified in bulk from G-CSF-mobilized PBSC using an Isolex 300. After the administration of cyclophosphamide (200 mg/kg) and anti-lymphocyte globulin (45 mg/kg), 3.6 x 10(6)/kg purified CD34+ cells were infused. His post-transplant course was uneventful except for herpes-zoster infection. He is now more than 1 year post transplant and has not taken any immunosuppressive medication. His rate of growth has increased (>10 cm/year) due to the effects of the cessation of PDN and the administration of recombinant human growth hormone (rGH), in contrast to the gain of 2 cm in the preceding 3 years with rGH treatment. Although the durability of this remission is unknown, intense immunosuppressive therapy followed by purified blood CD34+ cell autografting might be acceptable for adolescent patients with refractory JRA to achieve a drug-free period for physical and psychological maturation.

Adolescent↗

PubMed2001

Decrease in circulating hematopoietic progenitor cells by trapping in the pulmonary circulation.

BACKGROUND: When stem-cell grafts are infused into the venous circulation and stem/progenitor cells egress from BM, pulmonary capillary beds are the first microcirculation site that they encounter. This provides the potential for circulating progenitor cells to be trapped in the pulmonary circulation. METHODS: We compared the number of progenitor cells [CD34(+) cells, colony-forming unit-granulocyte-macrophage (CFU-GM), CD34(+) CD41(+) cells and CFU-megakaryocyte (CFU-meg)] and their expression of cell-adhesion molecules (CAM) in samples taken simultaneously from radial arteries and central veins of 21 patients following PBSC mobilization. RESULTS: The mean (+/- SD) frequency of progenitor cells in the radial arteries was reduced to 79% +/- 25% for CD34(+) cells, 73% +/- 27% for CFU-GM, 77% +/- 25% for CD34(+) CD41(+) cells and 70% +/- 29% for CFU-meg of the number in the central veins. This suggests that some progenitor cells might be trapped in the lung. No association between progenitor-cell expression of CAM and pulmonary trapping was observed. DISCUSSION: Our data demonstrate pulmonary trapping of PBSC during mobilization, suggesting a potential inhibitory effect on PBSC harvest and medullary trafficking following graft infusion. However, the impact associated with pulmonary PBSC trapping may be negligible in the clinical setting if sufficient cells are infused.

Antigens, CD34↗

PubMed2000

HLA-mismatched CD34-selected stem cell transplant complicated by HHV-6 reactivation in the central nervous system.

We report here a patient who suffered from PCR- confirmed human herpesvirus type 6 (HHV-6) meningoencephalitis after allogeneic purified CD34+ cell transplantation from his HLA-mismatched sibling donor, even though he had been on intense prophylaxis with i.v. ganciclovir (GCV), acyclovir (ACV) and gamma-globulin containing a specific antibody against HHV-6. Serological evaluation disclosed that both the donor and recipient had IgG antibody against HHV-6 before transplantation. His blood WBC count started to transiently increase on day 10, and all blood components had decreased by day 20. He then developed a severe headache and high blood pressure, and sporadic abnormal neurological findings including nystagmus and delirium. An analysis of cerebrospinal fluid (CSF) revealed 8 cells/microl, a glucose level of 130 mg/dl and a protein level of 201 mg/dl (normal, 50 mg/dl) on day 26. At the time, HHV-6 was detected only in CSF by a PCR-based method and he was diagnosed as having meningoencephalitis due to the local reactivation of HHV-6. Although he failed to respond to high-dose therapy with ACV (60 mg/kg/day) and gamma-globulin, the DNA of this virus disappeared from the CNS upon treatment with GCV (30 mg/kg/day) combined with the intraventricular infusion of alpha-interferon. His clinical course was further complicated with meningoencephalitis due to staphylococcus epidermidis, and he died of tentorial herniation on day 79 without the recovery of blood components. This experience may indicate that intense prophylaxis to prevent reactivation of HHV-6 in the CNS is essential for the management of such profoundly immunosuppressed patients.

Acyclovir↗

PubMed2000

Low numbers of megakaryocyte progenitors in grafts of cord blood cells may result in delayed platelet recovery after cord blood cell transplant.

Delayed platelet recovery is an inherent problem with cord blood cell transplantation (CBCT). To investigate this problem, the number of human megakaryocyte (MK) progenitor cells in cord blood (CB; n = 24) was measured and compared with that in G-CSF-mobilized peripheral blood stem cells (PBSC; n = 25). The median numbers of colony-forming units for MK (CFU-MK) that were detected by a serum-free assay system in CB and peripheral blood (PB) were 26 (range, 6-102)/10(5) nucleated cells (NC) and 37 (2-540)/10(5) mononuclear cells (MNC), respectively. The numbers of colony-forming units for granulocyte/macrophage (CFU-GM) were 88 (33-241)/10(5) NC in CB and 138 (6.3-1,250)/10(5) MNC in PB. The frequencies of CD34(+) cells in CB and PB were, respectively, 0.44% (0.10-1.07) and 0.98% (0.05-20.8). The numbers of CFU-MK in CB and PBSC were correlated with those of CD34(+) cells. The estimated number of infused CFU-MK in CBCT was 1/15 that of PBSC transplantation (PBSCT), based upon the above data and the widely used standard doses for both types of transplants. Further, the numbers of infused CFU-MK in patients who received allogeneic PBSCT at our institute were inversely correlated with the speed of platelet recovery. These data indicate that delayed platelet recovery after CBCT is simply due to the low number of CFU-MK contained in grafts.

Adolescent↗

PubMed1999

Efficacy of the mobilization of peripheral blood stem cells by granulocyte colony-stimulating factor in pediatric donors.

The advantages/disadvantages of the use of peripheral blood stem cells (PBSCs) for allogeneic transplantation still need to be clarified, particularly in children. We compared the kinetics, efficacy, and safety of PBSC mobilization by granulocyte colony-stimulating factor (G-CSF) and collection by apheresis between healthy pediatric and adult donors. A total of 19 pediatric (median age, 6 years) and 25 adult healthy donors (median age, 37 years) were given 10 micro/kg/day of G-CSF for 5 consecutive days for PBSC mobilization, which were harvested by apheresis on days 5 and/or 6. All of the donors tolerated the whole procedures. Serum trough levels of G-CSF determined by ELISA were significantly lower in the 16 pediatric donors evaluated than in adults (n = 16) on days 3 and 4 (P < 0.05). Although the WBC counts on days 4 and 5 were significantly higher in adults than in children (P = 0.006 and 0.004, respectively), the numbers of circulating CD34+ cells/unit of blood were identical. The number of blood CD34+ cells collected per unit of blood processed was identical in both donor populations. We propose that PBSCs could be effectively mobilized and collected in small children so that they could be donors for adult patients.

Adolescent↗

PubMed1998

Cerebral infarction in a patient with congenital complete heart block.

Stokes-Adams attacks are fairly common in children with congenital complete heart block, but the occurrence of cerebral infarction is quite unusual. We present the case of a 13-year-old boy with congenital heart block and an embolic stroke involving the cerebral artery. Echocardiography revealed no valvular regurgitation, hypokinetic segments, mural thrombus, or myxoma. Electrocardiographic monitoring demonstrated good response of ventricular rate to exercise and no episodes of atrial or ventricular dysrhythmia. It is assumed that embolism occurred due to bradycardia.

Adolescent↗

PubMed1998

New consecutive high-dose chemotherapy modality with fractionated blood stem cell support in the treatment of high-risk pediatric solid tumors: a feasibility study.

For the treatment of childhood solid tumors, we performed a pilot feasibility study of consecutive high-dose therapies, in which each course was followed by transplantation with granulocyte colony-stimulating factor-mobilized peripheral blood cells which had been separated into CD34-positive and -negative fractions by an Isolex system (Baxter). Positive selection of CD34+ cells has been associated with inevitable cell loss. To overcome this loss, CD34+ cells that had migrated into the negative fraction were saved and used for the first transplant, which was followed by a second transplant after a 3- to 5-month interval. In this phase I feasibility study, the results in six children were evaluated for safety and engraftment. Multi-drug cytoreductive regimens using ranimustine (MCNU), melphalan, thiotepa, carboplatin, cyclophosphamide or VP-16 were comparable between the two transplant procedures in terms of their intensity. The number of CD34+ cells in the 'CD34(+) fraction' was 3.31 x 10(6)/kg (0.63-4.3 x 10(6)/kg), while this number in the 'CD34(-) fraction' could not be evaluated correctly due their scarcity (<0.1%). The median numbers of infused MNC and CFU-GM were, respectively, 4.2 x 10(6)/kg and 1.75 x 10(5)/kg in the CD34(+) fraction, and 4.8 x 10(8)/kg and 3.35 x 10(5)/kg in the CD34(-) fraction. The number of days required to achieve an ANC >0.5 x 10(9)/l and a platelet count >20 x 10(9)/l and >50 x 10(9)/l were, respectively, 14.5, 15.0 and 19.5 in the first transplant with CD34- cells, and 13.5, 18.0 and 25.0 in the second transplant with CD34+ cells, with no essential difference between the two treatments. Although the small number of patients, the variation in clinical status and treatment, and the short follow-up invalidate any evaluation of the therapeutic benefit of this strategy, the encouraging results support the feasibility of this strategy, which enables an escalation of dose intensity with an improved cost/benefit ratio.

Adolescent↗