Tumor necrosis factor-alfa and monocyte chemoattractant protein-1 gene polymorphisms in kidney transplant recipients.

Tumor necrosis factor-alfa (TNF-α) gene polymorphism is supposed to have a significant influence on the incidence of acute rejection in renal transplantation. The monocyte chemoattractant protein-1 (MCP-1) is another factor supposed to modulate graft rejection. We studied TNF-α and MCP-1 gene polymorphisms in 84 kidney allograft recipients with polymerase chain reaction and restriction fragment length polymorphism and their serum levels by enzyme-linked immunosorbent assay. The patients were classified into two groups based on their outcomes: Group I (n = 47) recipients with stable graft function as the control group and group II (n=37) recipients who experienced acute graft rejection episodes in the first 30 days post-transplantation. A significantly higher incidence of TNF 2 /TNF 2 genotype was observed among patients with acute graft rejection in comparison with the control group (40.5% and 19.2% respectively, P <0.05), while no statistically significant differences were observed in the TNF 1 /TNF 1 genotype between the groups (59.4% and 80.8%, respectively, P >0.05). A significant elevation of serum TNF-α levels was found in group II than group I and between TNF 2 genotype compared with that of TNF1 genotype within group II recipients. Distribution of MCP-1 genotypes in patients with and without acute rejection episodes was not significantly different (70.2% and 76.6% for MCP-1 A/A and 29.7% and 23.4% for MCP-1 G/G, respectively, P >0.05). The serum MCP-1 levels were not significantly different between the groups and between MCP-1 G/G genotype and MCP-1 A/A genotype in group II recipients. In conclusion, TNF-α gene polymorphism or its serum levels may identify patients at risk of acute rejection, where patients with TNF 2 /TNF 2 genotype or high serum TNF-α levels are more likely to have acute rejection episodes, while there was no relation between MCP-1 genotype or its serum levels and acute rejection.

Constitutively lower expressions of CD54 on primary myeloma cells and their different localizations in bone marrow.

To evaluate nuclear factor-kappaB (NF-kappaB) activity in primary myeloma cells from myeloma patients, we confirmed that the expression levels of CD54 showed a good correlation with the levels of DNA binding activity for NF-kappaB in human myeloma cell lines, and thus analyzed the expression levels of CD54 on CD38(++) plasma cell fractions as one of NF-kappaB activity. Primary myeloma cells unexpectedly showed constitutively lower expressions of CD54 than normal bone marrow (BM) plasma cells. Furthermore, the expression levels of CD54 on these plasma cells showed a significant correlation with the plasma levels of CXCL12 stromal cell-derived factor-1alpha (SDF-1alpha) in their BM aspirates, and the expressions of CXCR4, the receptor for CXCL12, decreased on primary myeloma cells compared with normal BM plasma cells. It was also confirmed that the addition of CXCL12 to the in vitro culture significantly induced the up-regulation of CD54 expression in primary myeloma cells. In addition, myeloma cells with lower expressions of CD54 were more unstable in the in vitro culture, resulting in a marked reduction of the viable cell number. In the immunohistochemical analysis of BM aspirates, myeloma cells with lower CD54 expression resided in the perivascular regions. Therefore, these data suggest that primary myeloma cells exhibit constitutively lower CD54 that might be partially regulated by CXCL12, and their localizations in the BM may be associated with the expression levels of CD54.

IL-6-induced activation of MYC is responsible for the down-regulation of CD33 expression in CD33+ myeloma cells.

Human myeloma cells from about 10% of cases with multiple myeloma expressed CD33 and had monocytoid morphology with convoluted nuclei, and all these patients had no increase in serum CRP values. In CD33(+) myeloma cells as well as myeloma cell lines, CD33 expression levels were correlated with the increased expression levels of CEBPA (C/EBPalpha). This correlation was confirmed by the finding that transfection with the CEBPA gene induced CD33 expression in a CD33(-) myeloma cell line. As suggested by the lack of an increase in serum CRP values in CD33(+) myelomas, IL-6 down-regulated the expression of CD33 in CD33(+) myeloma cell lines along with the down-regulation of CEBPA gene expression. Cucurbitacin I (STAT3 inhibitor), but not U0126 (MAPK inhibitor), could abolish the effect of IL-6. Furthermore, IL-6 up-regulated the expression of MYC via STAT3 phosphorylation and MYC bound to the promoter region of the CEBPA gene followed by the down-regulation of CEBPA expression. It was confirmed that introduction of shRNA for MYC into a CD33(+) myeloma cell line blocked the IL-6-induced down-regulation of CD33 and CEBPA expression. Therefore, these results indicate that IL-6 can reverse the expression level of CD33 by up-regulating MYC followed by the down-regulation of CEBPA expression.

Serum IL-2 and platelet-associated immunoglobulins are good prognostic markers in immune thrombocytopenic purpura.

Immune thrombocytopenic purpura (ITP) is an acquired disease in which autoantibodies to platelets cause their sequestration and destruction by mononuclear macrophages, principally in the spleen. While most children with the disease experience a relatively short and benign clinical course, ITP in adults often lasts more than 6 months (chronic ITP) and is resistant to conventional treatment (corticosteroids, intravenous immunoglobulin, or splenectomy). This work was done to study the immunological difference between acute and chronic ITP, the effect of treatment on the studied immunological parameters, and to evaluate the role of prednisone therapy in chronic ITP. The study included 49 patients, twenty-three children with acute ITP, and twenty-six with chronic ITP. After taking the history, clinical examination was performed for all patients and control subjects. Laboratory investigations included complete blood count, bone marrow aspirate examination (patients), direct and indirect Coombs' test, antinuclear antibodies, lymphocyte phenotyping, cytokine (IL-2, IFN-gamma, and IL-6) measurement, and platelet antibodies by immunofluorescence. Results showed that acute ITP is more prevalent in preschool children and its relapse is lower when steroids are used for treatment. Platelet counts were significantly elevated in both acute and chronic ITP, especially with good response to steroids. Also, CD4 and CD4/CD8 were significantly reduced in chronic ITP with good response to therapy. Both IL-2 and IFN-gamma were significantly increased in chronic ITP when compared to acute ITP or control. Platelet associated IgM was detected more in acute than in chronic ITP, while IgG was equally detectable in both cases. This work shows that IL-2 is a good prognostic factor in chronic ITP and steroids are important for its treatment. It also shows that platelet associated IgG is a good monitoring parameter for response to treatment.

CD19 expression and growth inhibition of tumours in human multiple myeloma.

Multiple myeloma (MM) is a proliferative disorder of monoclonal plasma cells which accumulate in human bone marrow (BM). CD19 is a hallmark differentiation antigen of the B cell lineage and positively regulates antigen receptor signal transduction in mature B cells. We have previously shown that malignant plasma cells (myeloma cells) isolated from the MM patients lack the CD19 expression, while non-malignant plasma cells isolated from the healthy donors do express the CD19 antigens. It is also intriguing that there exists both CD19- and CD19+ plasma cells in some cases in pre-myeloma states including monoclonal gammopathy of undetermined significance (MGUS). It indicates that MGUS is usually composed of phenotypically non-malignant (CD19+) and malignant (CD19-) plasma cells. Furthermore, we recently demonstrate that, expression of the CD19 gene markedly inhibits the proliferation of human myeloma cell lines in vitro, and exhibits the reduced tumorigenicity in vivo and no anchorage-independent growth in vitro of a tumorigenic myeloma cell line. This inhibitory effect might result from the CD19-mediated intracellular signals because it is not observed in cells expressing the mutant CD19, which lacks the cytoplasmic domain. In this review, we suggest that loss of CD19 in MM could contribute to the proliferative advantage of the malignant plasma cell clones in this disease. Furthermore, we propose the usefulness of the phenotypic analysis of plasma cells in human plasma cell dyscrasia as a new diagnostic tool, and the CD19 gene as a potential target for the gene therapy in MM.