OKT3 and ganciclovir treatments are possibly related to the presence of Epstein–Barr virus in serum after liver transplantation

The development of Epstein-Barr virus (EBV) associated lymphoproliferative disorder (PTLD) is related to EBV genome numbers in serum or plasma and B-cells, and the level of immunosuppression. EBV DNA viremia, defined as presence of EBV genomes in serum or plasma, is common in immunodeficiency. This survey of EBV viremia was performed by real-time polymerase chain reaction (PCR) on consecutive serum samples of 21 patients with acute (n = 3) or chronic liver disease (n = 18) during the first year after liver transplantation (LTX). Cytomegalovirus (CMV) DNA was analyzed with PCR in serum or leukocytes. The levels of EBV and CMV viremia were related to PTLD and the effect of different anti-rejection regimens. All patients were EBV-seropositive pre-LTX. In total, 24 of 152 (16%) samples from 10 of 21 (48%) individuals were EBV positive [five of 11 cyclosporin A (CsA); five of 10 tacrolimus treated cases]. EBV viremia was demonstrated in five of seven patients with OKT3 therapy. The number of EBV DNA positive samples was highest (26%) at 14 days after LTX. In the OKT3 treated groups, the medians of EBV DNA copy numbers were 1600/ml (range 230-7200) and 380/ml (range 120-860) in the CsA and tacrolimus patients, respectively (P < 0.02). One patient developed EBV lymphoma and another one EBV hepatitis 13 months and 24 days post-LTX, respectively. Both patients had received OKT3. Their EBV genome load was not significantly different from what was found in other patients. After ganciclovir therapy, EBV DNA was eradicated from serum in four of five patients for several months. EBV DNA load was not affected by CMV infection or disease. We conclude that presence of EBV in serum is a possible marker of an active infection and an early ganciclovir therapy may be beneficial. Quantification of EBV load offers the potential to implement pre-emptive interventions.     

OKT8-binding lymphocytes in diseases of the nervous system

OKT8-binding lymphocytes, which consist mainly of suppressor-cytotoxic T cells, were demonstrated in blood and CSF by an immunochemical method. In patients with non-inflammatory diseases, the mean value was 18% in blood and 19% in CSF. In acute viral infections of the CNS, on the other hand, the percentage was significantly lower in the initial days of the disease but then increased up to the 5th week. Eleven patients suffering from multiple sclerosis had similar percentages of OKT8-binding cells, whether or not they had acute symptoms.     

A double-label flow cytometric analysis of the simultaneous expression of OKT4 and Leu2a antigens on circulating T lymphocytes in myasthenia gravis

A two-color immunofluorescence analysis of circulating abnormal T lymphocytes bearing both helper (T4) and suppressor/cytotoxic (Leu2a) T cell markers (double marker cells) was performed by means of the laser flow cytometry system. The double marker cell level was very low in 6 patients with multiple sclerosis and 12 normal controls studied. Fifteen of 31 patients with myasthenia gravis (MG) showed an elevation of double marker cells without an increase in T6-positive cells. The values were significantly higher in patients with thymoma or thymic hyperplasia than in those with a normal thymus. The double marker cell level was considered to reflect thymic abnormality in MG and to be helpful for determining the indication of thymectomy.     

Clinical features of OKT4+/OKT8+ adult T-cell leukemia

Adult T-cell leukemia (ATL) has a range of clinical characteristics. Phenotypically the leukemic cells usually express the helper/inducer associated antigen OKT4 with lack of OKT8. We have observed three patients with acute ATL cytologically indistinguishable from OKT4+/OKT8- ATL but whose neoplastic cells had the unusual phenotype, OKT3+, OKT4+, OKT6-, OKT8+ OKT9+/-, OKT11+, Tac+/-, TdT-. All patients had abnormal karyotypes and antibodies against anti-ATL associated antigens as well as proviral DNA of human T-cell leukemia virus in the leukemic cells. The clinical course was complicated by skin eruptions, hypercalcemia, pulmonary infection and disseminated intravascular coagulopathy. All died of complications shortly after diagnosis. The clinical features of these patients were similar to those of OKT4+/OKT8- ATL. However, their acute course suggests that co-expression surface antigens OKT4 and OKT8 may be a sign of aggressive nature of the disease with poor prognosis.     

Transient deficiency of peripheral blood accessory cells in supporting T cell mitogenesis in patients suffering from chronic idiopathic thrombocytopenic purpura after intravenous gammaglobulin treatment

Summary Mitogenic response of blood lymphocytes to phytohemagglutinin (PHA) and to OKT 3 monoclonal antibodies was investigated in 7 patients suffering from chronic idiopathic thrombocytopenic purpura (ITP) before, during and after high-dose intravenous (i. v.) immunogammaglobulin (IgG) infusion. The platelet count rose above the pre-treatment values during infusion therapy in all patients but one. Five out of seven patients presented elevated platelet-associated IgG (PA-IgG) levels at the time of the first infusion; four of these showed an increase in platelet count and a transient reduction or normalization of PA-IgG after IgG infusion. Five out of seven patients showed an impairement of T lymphocyte mitogenic response to PHA and OKT 3 before therapy. All patients responded to IgG therapy with a transient deficiency of FcR mediated monocytes (Mo) in supporting T cell mitogenesis induced by both mitogens during and after IgG infusion. This reduced cooperative capability of Mo disappeared at various times after the end of therapy (range 3–12 days). The transient alteration of Mo function, possibly due to a modification in the surface number or in the affinity of Fc-receptors, can explain in part, the increase in platelet count during and after IgSRK infusion.This work was supported by grants of the CNR (Progetto Finalizzato: Ematologia; Progetto Finalizzato: Trapianto d'Organo)     

Long-term outcome of the use of OKT3 to treat steroid-resistant acute renal allograft rejection

OKT3 was used to treat steroid-resistant acute renal allograft refection in 30 of 496 adult patients transplanted over a 6-year period. Rejection was reversed (defined as a fall in serum creatinine by 50% or more within 30 days of treatment with OKT3) in 40% of cases. Successful reversal was significantly more likely when rejection occurred shortly after transplantation (t ratio-2.53; P=0.019). The long-term outcome was disappointing; the actuarial graft survival at 1 year from the start of treatment with OKT3 was 42%, and no grafts have thus far survived longer than 3 years. Graft survival was horter in older patients (coefficient/standard error 2.226; P<0.05), and no other predictor of long-term outcome was identified. Patient survival at 3 years was 88%. Serious infection occurred in 33% of patients, with two deaths. Our experience suggests that treatment with OKT3 is unlikely to reverse acute renal allograft rejection in more than half of patients where rejection is resistant to steroids. Although long-term graft survival occurred in a few cases, the overall long-term outcome was disappointing, particularly in older patients. Finally, our analysis indicates the difficulty of predicting which patients will derive long-term benefit when OKT3 is used to treat steroidresistant rejection.     

抗人CD3单链抗体基因的构建及序列分析

本文在已克隆抗人ＣＤ３抗体ＶＨ和ＶＫ基因的基础上，设计并合成了ＰＣＲ引物。两个外侧引物分别含有ＥｃｏＲＩ和ＳａｌＩ酶切位点及起始码和终止码序列，４个内侧引物各含部分连肽基因序列，回收后混合退火。     

Detection of OKT6-positive cells (without visible Birbeck granules) in normal peripheral blood

The specificity of a monoclonal antibody (OKT6) for peripheral blood mononuclear cells was examined by indirect immunofluorescence and ultrastructural immunogold labelling. Some rare peripheral blood mononuclear cells (approximately 1%) expressed T6 antigen on their membrane surface, as determined by light microscopy and cytofluorometry. Electron microscopic examination of immunogold-labelled cells revealed that OKT6-positive cells were dendritic, lacking the Birbeck granules and expressed variable density of the membrane T6 antigen. The relationship of such cells with Langerhans' cells is discussed.     

OKT3＋rhIL－2激活胎儿脾细胞的研究

观察了１８～２８周龄胎儿脾单个核细胞（ＦＳＭＣ）在体外对ＯＫＴ３＋ｒｈＩＬ－２联合刺激的反应性，结果发现：ＯＫＴ３单独能活化ＦＳＭＣ，最适浓度ＯＫＴ３与ｒｈＩＬ－２联合对ＦＳＭＣ有强协同刺激作用。ＯＫＴ３刺激ＦＳＭＣ后明显促进ＩＬ－２Ｒ表达，表明ＯＫＴ３对ＦＳＭＣ的括化作用与ＩＬ－２／ＩＬ－２Ｒ途径相关。ＯＫＴ３＋ｒｈＩＬ－２协同诱导的ＦＳＭｃ能产生ＮＫ和ＬＡＫ活性，且ＬＭ活住较单用ｒｈＩＬ－２诱导者强，间接免疫荧光染色ＦＡＣＳ分析显示，ＯＫＴ３＋ｒｈｌＬ－２协同激活的ＦＳＭＣ主要是ＣＤ８￣＋Ｔ细胞。结果表明ＦＳＭＣ与成人ＰＢＭＣ－样能被ＯＫＴ３活化。     

Transient disappearance of immunologic disorders and remission after intercurrent measles infections in children with chronic idiopathic thrombocytopenic purpura

In two children with chronic idiopathic thrombocytopenic purpura (ITP) a transient remission of thrombocytopenia was observed after intercurrent measles infection. Both cases were girls who had a long history of thrombocytopenia. During acute measles infection, the delayed hypersensitivity response was suppressed. Total T lymphocytes, T-cell subsets, especially OKT4 cells, the lymphoproliferative response, and interleukin-2 (IL-2) and -interferon production were decreased accompanying normalization of the OKT4/OKT8 ratio. However, OKT4 cells remained at a reasonably low level and the lymphoproliferative response stimulated with pokeweed mitogen was still in the lower normal range. Direct immunofluorescent study demonstrated that the measles antigen was present in the mononuclear cells, especially OKT4 cells. The levels of platelet-associated IgG antibody (PAIgG) and IgG circulating immune complex (CIC) were undetectable. One month later, the OKT4/OKT8 ratio lymphoproliferative response significantly increased, IL-2 and -interferon production increased, and PAIgG and IgG CIC reappeared with the relapse of thrombocytopenia. There was also a significant increase inin vitro IgG production due to the presence of patient OKT8 cells and/or OKT4 cells. However, there was no enhancement in the presence of patient B cells. This suggests that the presence of specific OKT4 helper T cells and a defect in the suppressor function of suppressor OKT8 cells contribute to an overproduction of IgG and the appearance of PAIgG accompanied by thrombocytopenia. The transient remission associated with measles infection is probably related to the effect of the virus on the helper T cells, resulting in a decrease in specific OKT4 helper T cells and normalization of the OKT4/OKT8 ratio, suppression of IL-2 and -interferon production, and platelet-associated IgG production.