Absence of bcl-2 expression by activated CD45RO+ T lymphocytes in acute infectious mononucleosis supporting their susceptibility to programmed cell death

bcl-2 proto-oncogene encodes an inner mitochondrial membrane protein that blocks programmed cell death (apoptosis). There is now increasing evidence that regulation of bcl-2 expression is a determinant of life or death in normal lymphocytes. We have recently described that activated (CD45RO+) CD4+ and CD8+ T cells in acute infectious mononucleosis (IM) undergo apoptotic cell death on culturing, indicating an activation-driven cell death of mature T cells. In this work, we examine bcl-2 expression by activated T cells in acute IM using a flow-cytometric analysis with an anti-bcl-2 monoclonal antibody (MoAb). It was consistently observed that most T cells from acute IM patients displayed only much less bcl-2, while normal T cells expressed bcl-2 relatively strongly. Multicolor analysis showed that bcl-2- lacking T cells in acute IM were restricted to the CD45RO+ (activated) populations of CD4+, as well as CD8+ T cells. In contrast, the relatively intense levels of bcl-2 were expressed in both CD45RO+ and CD45RO- T-cell populations from normal subjects. This marked difference in bcl-2 expression of CD45RO+ T cells between acute IM and normal controls was also confirmed by Western blot analysis. Activated (CD45RO+) T cells with low bcl-2 expression, but not bcl-2-expressing CD45RO- T cells, in acute IM patients were found to die easily when cultured without added growth factors. However, in normal individuals, both CD45RO+ and CD45RO- T cells were relatively stable on culturing. These findings suggest that lack of bcl-2 expression by activated (CD45RO+) T cells in acute IM might be associated with their susceptibility to programmed cell death.     

Radial augmentation index is related to cardiovascular risk in hemodialysis patients

Cardiovascular accidents related to atherosclerosis are the leading cause of death among hemodialysis patients, which makes continuous monitoring of their cardiovascular status crucial. Recently, a handy device for monitoring the augmentation index (AIx) in the radial artery was introduced in Japan, enabling the use of the AIx in addition to pulse wave velocity (PWV) in the management of hemodialysis patients. In this study the AIx, PWV, abdominal aortic calcification index (ACI), and left ventricular mass index (LVMI) were serially assessed in 108 hemodialysis patients. The radial AIx was monitored using a newly introduced tonometer (HEM-9010AI), and the interrelationships among the measured parameters and their contributions to the risk of cardiovascular accidents were evaluated. The radial AIx was significantly higher in hemodialysis patients than in healthy subjects (N = 50) and was well correlated with risk markers such as LVMI (r = 0.30, P = 0.019) and ACI (r = 0.38, P < 0.001), but not with PWV. Multiregression analysis showed that radial AIx was also significantly associated with LVMI, ACI and blood pressure; PWV was associated with other parameters such as age, blood pressure, and ACI. The AIx and ACI were both significantly increased in patients with cardiovascular complications. Although PWV was strongly increased in the hemodialysis patients, it failed to discriminate between these subgroups of high-risk patients. The radial AIx is closely associated with aortic calcification, cardiac hypertrophy, and a history of cardiovascular accidents in hemodialysis patients, and could be a useful marker for management of these patients.     

Perforin defects of primary haemophagocytic lymphohistiocytosis in Japan

The perforin gene was analysed in 15 Japanese patients with primary haemophagocytic lymphohistiocytosis (HLH). Perforin gene defects were found in two out of eight patients with familial HLH (FHL), and one out of seven without affected siblings. Four novel mutations were identified. Compound heterozygous mutations (one FHL and one sporadic HLH) and only one allele mutation (one FHL) were defined. Flow cytometry revealed no perforin expression in CD8+ or CD56+ cells from a surviving patient with a mutation. The frequency of mutation was at least 20% of FHL in Japan. Flow cytometry for intracellular perforin may be useful for the screening of FHL2.     

CD30-positive lymphoma in human T-cell leukaemia virus type 1 carrier without monoclonal integration of HTLV-1

Summary. CD30, Ki-1 antigen, an activated T-cell antigen, is a member of the nerve growth factor receptor family. This antigen is expressed on the lymphoma cells of some adult T-cell leukaemia/lymphoma (ATL/L) patients and some patients with Epstein-Barr virus infection. CD30-positive large cell cutaneous T-cell lymphomas occasionally integrate a defective HTLV-1 provirus. We describe here an HTLV-1 carrier who developed Ki-1 lymphoma with no evidence of monoclonal integration of the HTLV-1 proviral sequence.     

Acute disseminated encephalomyelitis during treatment for idiopathic thrombocytopenic purpura

A 54-year-old woman had an episode of sudden oral bleeding and generalized petechiae 1 week after a sore throat and diarrhea. On admission, the platelet count was 0.1 x 10(4)/microl, and the platelet-associated IgG level was elevated. Hyperplasia of megakaryocytes in a bone marrow specimen and aberrant Epstein-Barr virus (EBV) antibody patterns led to a diagnosis of EBV-associated idiopathic thrombocytopenic purpura (ITP). Prednisolone (PSL) promptly restored her platelet count; however, she developed disorientation and affective lability soon after PSL was tapered. Subsequently, she ran a high fever and developed convulsive seizures. T2-weighted MRI demonstrated a high signal area in the subcortical white matter, and no abnormal findings were found on examination of the cerebrospinal fluid. The diagnosis of acute disseminated encephalomyelitis (ADEM) was made and steroid pulse therapy was started, which resulted in remission of the symptoms without recurrence in the following months. This is the first reported case of ADEM following EBV infection during treatment for ITP. Administration of PSL for ITP might mask the presenting clinical picture of ADEM. The possibility of ADEM should be investigated in patients of ITP following viral infection who develop acute encephalopathy.     

Haptoglobin therapy for acute favism: a Japanese boy with glucose-6-phosphate dehydrogenase Guadalajara

Summary. We report the case of a 2-year-old Japanese boy with acute favism who was treated with human haptoglobin products. He had been exhibiting chronic nonspherocytic haemolytic anaemia until the diagnosis of glucose-6-phosphate dehydrogenase (G6PD) deficiency when 14 months old. He suffered a favic crisis at 24 months of age, when the administration of haptoglobin was effective for relieving bilirubinaemia and haemoglobinuria. Serum-free Hb rapidly decreased to normal levels despite the sustained level of serum lactate dehydrogenase. His G6PD gene was G6, Guadalajara. This is the first application of haptoglobin therapy for acute favism and the first reported case of Japanese G6PD deficiency with typical favic crisis. Haptoglobin treatment might be helpful for managing the haemolytic crisis in the disease.