Fatal cytomegalovirus myocarditis in a seronegative ALL patient

Fatal cytomegalovirus (CMV) myocarditis occurred in a 2 year old boy with acute lymphoblastic leukemia (ALL) in remission. The patient showed mild hepatic dysfunction and a rapid progress of pancytopenia after complete remission had been achieved. At the fifth week of complete remission, he presented signs of heart failure such as tachycardia, S4 gallop on auscultation and decreased ejection fraction on echocardiography. However, no significant electrocardiographic changes were recognized. In addition to the cardiac dysfunction, the patient presented a marked tachypnea and dyspnea associated with hypoxemia. These were dramatically improved by methylprednisolone pulse therapy (30 mg/kg per day, for 3 days) and CMV high titer immunoglobulin (400 mg/kg per day, for 3 days). On the sixth day after signs of respiratory failure were improved, the patient suddenly presented a paroxysmal atrial tachycardia followed by a fatal ventricular fibrillation. Although we could detect neither a specific IgM antibody, a significant increase of IgG antibody, nor CMV genome by DNA hybridization techniques during the course of the illness, microscopic examination of necropsy specimens of the heart showed a marked disruption and disintegration of muscle bands associated with cytomegalic inclusion bodies. Polymerase chain reaction (PCR) yielded a 305 bp amplification product in the heart and lung tissues, supporting the view that myocarditis was caused by CMV.     

Specific Deposition of Serum Amyloid A Protein 2 in the Mouse

The homogenates of amyloid-laden spleens prepared from CBA mice were analysed by SDS-PAGE and immunoblotting employing rat anti-murine monoclonal antibody, MSA 4-26. The results showed that the precursor of amyloid A protein (AA), serum amyloid A protein 2 (SAA2), and SAA intermediates with molecular weights of 10,000, 9000, and 8000 were contained in amyloid-laden tissues. The experiment using sonicated spleen cells and acute phase murine sera showed a delay in the degradation rate of SAA2 on cell fragments and the remains of SAA1 in supernatants. This result can explain disappearance of SAA2 from the murine serum during amyloidogenesis in vivo.     

The effects of the immunosuppressant rapamycin on the growth of rheumatoid arthritis (RA) synovial fibroblast

RA is a chronic inflammatory disease characterized by mononuclear cell infiltration and the overgrowth of synovial fibroblast. This invasive growth of synovial tissues corresponds with the progressive destruction of articular carilage and bone. Several immunosuppresive agents, such as cyclophosphamide, cyclosporin A and mizoribine, have been clinically used to control disease progresssion, though relatively little is known of their effects on rheumatoid synovium. Rapamycin exhibits a strong immunosuppressive activity by acting on T cell signalling pathways. In the present study we examined the effects of rapamycin on the growth of synovial fibroblast isolated from RA patients. Platelet-derived growth factor (PDGF) is a potent growth factor in synovial fibroblasts isolated from RA patients. PDGF and serum stimulation resulted in a rapid phosphorylation of tyrosine and activation of mitogen-activated protein kinase (MAP kinase), 70-kD-S6 kinase (P70^S6K) and 90-kD-S6 kinase (P90^rsk). Rapamycin, a macrolide immunosuppressant, inhibited completely growth factor-induced synovial fibroblast proliferation and P70^S6K activation. In contrast, tyrosine phosphorylation and activation of MAP kinases and P90^rsk were not influenced by rapamycin treatment. Our data demonstrate that growth factor-mediated P70^S6K activation is closely related to the growth of synovial fibroblast, and suggest the efficacy of rapamycin for controlling synovial hyperplasia in RA.     

Case Report: Mucin-producing cystic neoplasm of the pancreas with onset in childhood

Mucin-producing tumours of the pancreas have been recently reported with increasing frequency and most cases have occurred in middle-aged and elderly people. In the present report, a case of a 21-year-old man with mucinous cystadenoma of the pancreas is reported. He had a long history of recurrent pancreatitis from the age of 8. When he was aged 10, the first branch of the main pancreatic duct was shown to be enlarged on endoscopic retrograde pancreaticography (ERP). A series of ERP studies and computed tomography scans performed over a period of 11 years demonstrated continuing growth of this enlargement of the pancreatic duct. Pancreaticoduodenectomy was performed and the patient has been well without further episodes of acute pancreatitis and has been free of recurrent tumour for 1 year.     

Effects of rapamycin on apoptosis of rheumatoid synovial cells

In the present study, we investigated the effects of an immunosuppressant, rapamycin, on bcl-2 expression and the susceptibility of human rheumatoid synovial fibroblasts to Fas-mediated apoptosis. Rapamycin treatment down-regulated bcl-2 expression on rheumatoid synovial cells in a dose-dependent manner. In contrast, Fas antigen expression was not influenced by rapamycin treatment. Rapamycin treatment also enhanced the susceptibility of rheumatoid synovial cells to anti-Fas monoclonal antibody-mediated apoptosis. Our results suggest that rapamycin augments the sensitivity of rheumatoid synovial fibroblasts to apoptosis by down-regulating bcl-2 expression. This pharmacological alteration of sensitivity to apoptosis in the rheumatoid synovium may represent a new therapeutic approach for rheumatoid arthritis.     

Improvement of bone disease with increased dose of glucocerebrosidase in a Gaucher disease patient who had a bone lesion presenting during low-dose enzyme replacement therapy

In recent years, enzyme replacement therapy has been shown to be useful for the treatment of Gaucher disease. A 10 year old Japanese boy with Gaucher disease underwent splenectomy at the age of 5 years and received enzyme replacement therapy from the age of 6 years. He had avascular necrosis of the bilateral femoral heads, which was not seen at the beginning of the therapy, without deterioration of hematological variables during maintenance therapy. The enzyme dosage was increased from 20 to 120 IU/kg per month resulting in an improvement of the clinical symptoms and bone lesion. In enzyme replacement therapy, dose increase is considered to be essential for improvement in bone disease; however, it is important to watch for the development of bone lesion.     

Irradiated fetal thymus transplantation in a patient with combined immunodeficiency with predominant T cell defect

A 6 month old boy was diagnosed as a case of combined immunodeficiency (with predominant T cell defect by previous classification). His T cell count was decreased, his B cell count in peripheral blood was increased, his serum IgG level was decreased, his serum IgM level was normal and the thymus was not evident on CT scans and magnetic resonance imaging. Administration of the thymus hormone, thymosin, led to a partial recovery of T cell function without normalization of the T cell count. At age 26 months the patient received an irradiated thymus transplantation from a 16 week old female fetus. After the transplantation, the T cell count (mainly CD4⁺ cells) increased by 50–70%. A mild graft-versus-host reaction (GVHR) occurred and several immunosuppressants were prescribed. Chromosome analysis showed that the T cells have both 46 XY and 46 XX karyotypes while the B cells have the 46 XY karyotype alone. His cellular immunity (skin tests, DNA synthesis, mixed lymphocyte reaction, cytotoxic activity and natural killer cell function) and his serum IgG level remained low. However, being on regular r-globulin therapy and oral anti-fungal drugs, he is now living normally with almost no trouble at age 6 years and 3 months. This case showed that irradiated thymus transplantation might be a useful method when an adequate donor for bone marrow transplantation is not available. The unexpected observation that the increased T cells were mainly CD4 may be related to the mild GVHR and the clinical improvement.