Diagnostic immunology最新文献

We analyzed several factors that might influence the ability to detect lymphocyte sensitization to a drug by the lymphocyte transformation test in a patient with erythromycin ethylsuccinate cholestatic hepatitis. Weak lymphocyte reactivity to the drug was demonstrated in standard conditions, but this could be substantially increased in the presence of a prostaglandin inhibitor, providing evidence for the presence of prostaglandin-producing suppressor cells. In contrast, no evidence for short-lived suppressor cells influencing the drug reactivity was found. Reactivity to "drug metabolite containing serum" could by recorded when reactivity to the drug itself had disappeared. Such modifications of the lymphocyte transformation test may be of help in the in vitro diagnosis of drug hypersensitivity.

A computerized tube LAI assay was used to determine the antitumor immune response in lung cancer patients. A standardized assay was established by the use of tumor antigen recovered from the spent medium of lung and colon adenocarcinoma cell lines. Furthermore, modulation of the assay by prostaglandin E2 (PGE2) was used to increase its sensitivity. Of 65 patients with epidermoid lung cancer, 34 (52.3%) had a positive nonadherence index (NAI). The NAI was inversely related to tumor burden, with 31 of 44 (70.6%) patients with lung cancer stages I and II and only 3 of 21 (14%.2%) patients with stage III having positive assays (greater than 30%). Addition of PGE2 to the as say increased the overall sensitivity so that a positive NAI was obtained in 88.6% of patients with lung cancer stages I and II, and 88.6% with stage III, respectively. Of 174 individuals from the control group, positive NAI was found in only 9 and 3.8% of patients with chronic obstructive pulmonary disease and normal controls, respectively. These results support previous observations on the specificity and sensitivity of the LAI assay in the diagnosis and study of human cancer.

Two childhood and three adult patients with acute lymphoblastic leukemia (ALL) are described. The identification of the T-cell nature of their ALL-cells was based on the positivity of their blasts with 3A1 monoclonal antibody which recognizes immature and mature T-cells. Four tested cases showed a terminal deoxynucleotidyl transferase (TdT) positivity, and four out of five were acid phosphatase (AcP)-positive. Cells from all cases were characterized with a panel of 15 monoclonal antibodies: 3A1 was constantly positive; J5, BA-1, OKT6, Leu-7, and other monoclonal antibodies reactive with T-cells (OKT3, OKT4, OKT8, OKT11, Leu-1, T65) were negative; only two cases had weak positivity with OKT11 and Leu-1, respectively; cells from all cases were surface immunoglobulin (SIg)-negative; three out of the five cases were OKT10-positive and three OKT9-positive; none of the cases reacted with OKM1 and anti-HLA-DR. Our findings indicate that the use of 3A1 monoclonal antibody was helpful in the recognition of individual cases of T-ALL otherwise considered as unclassified-ALL (U-ALL). 3A1 and an anti-common ALL Antigen (CALLA) reagent may represent the essential monoclonal antibodies to be used for screening ALL cells.

It is often difficult to obtain sufficient quantities of leukocytes from bone marrow (BM) transplant recipients for post-transplant immunological monitoring and evaluation of engraftment. We have developed a cell culture expansion technique that allows HLA-A,B, and DR typing as well as karyotyping on limited numbers (less than 10(7)) of lymphocytes. Lymphocytes from healthy control donors were allo-activated in vitro and further expanded by culturing in T-cell growth factor (TCGF). After 14 days of culture, these cells were sent for blind HLA-A,B and DR typing and for karyotyping. Surface marker studies showed that 90% of the T-cells expanded in growth factor are OK-la positive. HLA typing with these DR-bearing in vitro expanded T-cells showed excellent correlation with HLA typing on fresh unexpanded lymphocytes. Karyotyping of expanded T-cells showed normal male or female cells as expected. This technique may be especially valuable when testing pediatric or adult patients with very low lymphocyte counts.

The present study was undertaken to determine normal ranges for blood lymphocytes labeled with the monoclonal antibodies OKT3, OKT11, OKT4, and OKT8 and for the OKT4/OKT8 ratio. In addition, 26 patients with AIDS, 51 AIDS suspects, and 44 patients with infections were studied. The results of these determinations from six different study sites indicate that there is excellent intersite agreement in normal values obtained. These normal ranges may be used in clinical laboratory reporting. Data from patients indicate that a simultaneous review and comparison of OKT4+ values, OKT8+ values, and depression of the OKT4+/OKT8+ ratio is a useful indicator in clinically diagnosed AIDS patients and in AIDS suspects. These changes, moreover, cannot be attributed only to infection present in these patients, since in infection, the OKT4+/OKT8+ ratio does not exhibit the severe depression seen in AIDS. These results should provide a useful reference for further studies in diseased subjects.

Sm antibodies are a specific serum marker for the diagnosis of systemic lupus erythematosus (SLE), and a high titer of RNP antibodies in the absence of other antinuclear antibodies (ANA) is highly suggestive of the diagnosis of mixed connective tissue disease (MCTD); therefore, specificity is a very important aspect of the assays for these antibodies. Currently in the clinical laboratory, double immunodiffusion (ID) is the most specific of the assays for anti-Sm and RNP. When 74 sera from patients with various systemic rheumatic diseases were assayed by counterimmunoelectrophoresis (CIE) with ID as the reference method, three sera contained nonspecific (non-Sm) precipitin lines in the assay for anti-Sm and three sera contained nonspecific (non-RNP) precipitin lines in the assay for RNP. Precipitin lines formed by the common antinuclear antibodies are more clearly separated by ID than CIE and care must be taken to avoid false identification of precipitin lines with CIE. Indirect immunofluorescence is recommended for ANA screening, ID for definitive antibody identification, and CIE for antibody quantification.

Comparison of serum antinuclear antibody (ANA) test results on commercial HEp-2 cell culture preparations and fixed mouse kidney sections demonstrated significant differences in end-point titers and pattern production. When manufacturer's suggested screening titers are used, there is also a significant difference in qualitative results and correlation with clinical status. With individual intralaboratory establishment of screening titer levels, some of these differences become less significant, although this study suggests that mouse kidney substrate slides are more sensitive in detecting nonspecific ANA, and that HEp-2 substrate slides are more specific in detecting ANA from cases of systemic lupus erythematosus. Antinuclear antibody substrate selection must be based on classic sensitivity-specificity considerations and the clinical correlation performance desired. Comparisons of interlaboratory or follow-up ANA results are invalid without consideration of substrate variations. Regardless of substrate utilized, each laboratory should establish its own individual screening titers in relation to suitable age groupings.

A solid-phase enzymoimmunoassay (EIA) for antitetanus toxoid antibodies has been developed using activated agarose beads as the solid phase to which tetanus toxoid was covalently attached. The resulting EIA proved to be remarkably free of interference due to nonspecific absorption of reactants to the solid phase. The lower limit of detection for the assay was 0.008 U/ml of antibody. Reproducibility studies showed a satisfactory degree of consistency with coefficients of variation of 4.8% (within run) and 6.6% (run-to-run). This assay has been applied successfully to the evaluation of the humoral response to tetanus toxoid in both normal and immunocompromised individuals and it has sufficient sensitivity to determine serum levels of antitetanus antibody above the accepted protective limit of 0.01 U/ml.

Cerebrospinal fluid (CSF) specimens from 45 clinically definite MS patients were studied for the presence of oligoclonal IgG bands by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The protein bands were identified by Coomassie blue (CB) dye and silver staining. Thirteen patients showed no bands in their CSF by the CB method. Nine of these 13 patients showed presence of bands by silver staining alone. Thirty-two patients showed more than two bands in their CSF by either technique, and 28 of the 32 patients showed from one to five additional bands by silver staining compared to Coomassie blue staining. The silver staining method was thus more sensitive in identification of oligoclonal bands in CSF.