[Immunoglobulin quantitation by latex agglutination immunoassay--new sample treatment to reduce differences in measured values by turbidimetric immunoassay].

Serum IgG, IgA, and IgM are routinely measured by turbidimetric immunoassay (TIA), nephelometric immunoassay (NIA), and latex agglutination turbidimetric immunoassay (LATIA) while IgD and IgE, which are present in low concentrations, are usually measured by LATIA and other sensitive assays. There were some differences between LATIA and TIA in the values obtained from lyophilized serum, and sera with monoclonal proteins. We successfully solved the problem by dissociated and/or aggregated immunoglobulins treated with a newly prepared reagent. The difference caused a remarkable improvement thus realizing a coincidence in the measured values on LATIA and TIA.

Correlation between acute rejection severity and CD8-positive T cells in living related liver transplantation.

The Banff schema is the most widely used standard grading system for liver allograft rejection. To investigate the relationship between the Banff rejection activity index (RAI) and the presence of lymphocyte subpopulations in allograft liver tissue, assuming these cells to probably play an important role in the mechanism of acute cellular rejection (ACR), we performed immunohistological examinations using liver tissues with various ACR severities after living related liver transplantation (LRLT). In total, 37 needle liver biopsy specimens with ACR in LRLT were examined using antibodies to CD4, CD8, and CD20. Formalin-fixed and paraffin-embedded liver tissues were used to maintain morphology. Immunohistological findings and RAI score according to the Banff schema were compared. In the results, mainly CD8-positive (CD8+), rather than CD4-positive (CD4+), cells were detected in the portal tract and were also found in bile duct epithelium and subendothelial areas of portal veins. The number of CD8+ cells increased according to ACR grade, whereas CD4+ cells tended to decrease. There were significant correlations between the presence of CD8+ cells (p = 0.0006) and CD4+ cells (p = 0.0003) and ACR severity. On the other hand, CD20-positive cells did not correlate with ACR severity (p = 0.472). The results indicate that CD8+ cells play important roles in ACR severity of LRLT, suggesting the number of CD8+ cells in liver tissue to be useful as a supplementary tool, in addition to RAI of the Banff schema, for objective evaluation of ACR severity.

Prediction of chemosensitivity for patients with acute myeloid leukemia, according to expression levels of 28 genes selected by genome-wide complementary DNA microarray analysis.

To identify genes involved in the sensitivity of acute myeloid leukemia (AML) cells to chemotherapy, we monitored gene-expression profiles of cancer cells from 76 AML patients using a cDNA microarray consisting of 23,040 genes. We identified 63 genes that were commonly overexpressed and 372 genes suppressed in AML. Because these genes represent key molecules for disclosing the molecular mechanisms of AML, they may be potential targets for drug development. We also found 28 that revealed different expression levels between good and poor responders to chemotherapy and appeared to be associated with chemosensitivity. On that basis, we developed a "Drug Response Scoring" system that was correlated well with individual sensitivity to an anticancer drug regimen. Among the 44 cases with positive drug-response scores by our definition, 40 achieved complete remission after treatment, whereas the only 3 of the 20 cases with negative scores responded well to the treatment. An ability to predict chemosensitivity should eventually lead to achievement of our goal of "personalized therapy."