Diagnostic and clinical immunology最新文献

Human cultured fibroblasts and Raji and peripheral blood mononuclear cells have been compared as substrates for the immunofluorescent detection of antiactin microfilament antibodies in sera from chronic liver disease. Raji and mononuclear cells, which exhibit a rich microfilament network, proved to be the most sensitive substrates for this purpose. The clinical relevance of these findings in the diagnosis of "autoimmune" chronic liver disease is discussed.

We describe a flow cytometric technique which detects the presence of antineutrophil antibodies (NABs) in human serum. The technique provides a qualitative as well as a semiquantitative screen and provides an excellent method for monitoring the presence of antineutrophil antibodies in patients with suspected autoimmune neutropenia. Using light-scatter gating, individual populations consisting of neutrophils, monocytes, and lymphocytes can be examined simultaneously for the presence of antibody. The methodology utilizes an indirect immunofluorescence technique with FITC-labeled goat antihuman F(ab')2 antibody and fixed leukocyte suspensions. Furthermore, by utilizing class-specific FITC-labeled second antibody, significant information can be ascertained regarding the class, cell specificity, and quantity of detected antibody. Formalin fixation of neutrophils prevented pinocytosis of the fluorochrome, significantly reducing background fluorescence. Twenty-five normal subjects provided baseline antibody levels for each class. Of 92 patients with suspected autoimmune neutropenia, 27 had class IgG alone and seven were positive for both IgG and IgM class NABs. During treatment, IgG levels varied. IgM NABs alone were detected in four patients. Fifty-four patients had undetectable antibody. Antibodies were detected against monocytes in several of the IgG-positive patients. Two sera contained both IgA and IgG NABs. One serum contained IgA and IgG antibodies against monocytes. No IgD antibodies were detected in any sera tested. Some sera tested contained antibodies against lymphocytes--however, only in those sera which also contained antibodies to other cell types.

The whole complement activity (CH50) and concentrations of components (C1q, C3, and C4) and C3 split product (C3d) were determined in the cord blood of 172 newborns between 16 and 42 weeks of gestation. Histological examination of their placentas revealed that the extent of complement activation was significantly higher in those with some degree of inflammation in the amnion than in those with normal amnion. The correlation between the complement levels and gestational age was higher in those with no amnionitis. In some cases the level of C3d at an early gestational age was as high as that in adults. The C3 activation system seems to be well developed even before week 25 of gestation. Among the complement components, C3d was the most sensitive indicator of placenta inflammation. As placenta inflammation may reflect intrauterine infection, the measurement of C3d levels may be of diagnostic value.

Cord blood lymphocytes obtained from ten healthy newborns and peripheral blood obtained from ten healthy adults were compared by using ultrastructural morphometric methods. Cord blood lymphocytes could be distinguished from adult lymphocytes on the basis of nuclear contour irregularity (form factor) and perimeter (P less than .001). The mean nuclear form factor (FF) value of the cord lymphocytes, as a group, was 0.603 +/- 0.034; the mean nuclear FF value of adult lymphocytes was 0.755 +/- 0.032. Lymphocyte subpopulations were quantitated by flow cytometric and immunofluorescence techniques and correlated with nuclear contour irregularity (mean FF values) by using linear regression analysis. Overall, the correlations between nuclear contour irregularity and the proportions of distinct lymphocyte subpopulations were opposite for cord and adult blood. Increased nuclear contour irregularity was associated with increased proportions of immature lymphocytes (non-T, non-B lymphocyte population) in the neonate and with increased proportions of T cells in the adult. Of the T cells, increased nuclear contour irregularity showed a better correlation with increased proportions of T helper cells compared with T suppressor cells. A plot of the distribution of FF values indicated two populations of lymphocytes having convoluted and nonconvoluted nuclei, respectively. No true Sézary cells could be identified in cord blood with ultrastructural morphometric criteria, despite the abundance of cerebriform mononuclear cells identified by visual inspection. The lymphocyte with the most irregular nuclear contour was found in an adult and had an FF value of 0.132 (13% of a circle). The contribution of this study to the diagnosis of cutaneous T cell lymphomas and the Sézary syndrome is discussed.

The derivation of an IgG1k monoclonal antibody (HSAN 1.2) recognizing a cell membrane determinant on human neuroblastoma cells is reported. The determinant was found on all 17 cultured human neuroblastoma cells that were tested, but the density of the antigen varied widely on different cell lines. The antibody also bound to fresh and cultured Wilm's tumor cells, retinoblastoma cells, and one of two Ewing's sarcoma cell lines tested, it did not bind to mouse neuroblastoma cells, normal fibroblasts, blood, or bone marrow. Tumor cells that did not stain with HSAN 1.2 included glioma, medulloblastoma, melanoma, rhabdomyosarcoma, mesenchymoma, leukemia, and lymphoma cells. The distribution of the HSAN 1.2 antigen in normal tissues was confined to brain and newborn kidney. As few as 0.1% tumor cells in bone marrow aspirates were detectable by fluorescein-conjugated HSAN 1.2 antibody and flow cytometry. This antibody should be useful for the discrimination of neuroblastoma from other pediatric malignancies, for the detection of tumor cells in metastatic sites such as bone marrow, and for selective removal of neuroblastoma cells from marrow harvested for autologous transplantation.