Biomedical subjects

S Carrabis

Publications and source records attributed to S Carrabis.

6 recordsLinked to original sources

PubMed1992

Circulating elevated levels of soluble CD23, interleukin-4, and CD20+CD23+ lymphocytes in atopic subjects with elevated serum IgE concentrations.

Circulating IgE protein levels, leukocyte counts, lymphocyte subsets, IL-4, and soluble CD23 levels were quantitated in 43 atopic and 19 nonatopic subjects. Mean values of IgE protein levels, total eosinophil counts, CD20+CD23+ cells (B cells with low-affinity IgE receptor), IL-4 and sCD23 levels were elevated in atopic patients compared with nonatopic controls. The results suggest that sCD23, IL-4, and CD20+CD23+ lymphocytes may play a role in the increased production of IgE in atopic subjects in a manner similar to that observed by other investigators in prior in vitro studies.

Adult↗

PubMed1990

Soluble interleukin-2 receptor: elevated levels in serum and synovial fluid of patients with rheumatoid arthritis.

Soluble interleukin-2 receptor (sIL-2R) levels were quantitated in the serum and synovial fluid (SF) of patients with rheumatoid arthritis (RA) and degenerative joint disease (DJD). A sandwich immunoassay, employing two monoclonal antibodies against distinct epitopes on the IL-2R, was utilized for measurement. We found a striking elevation of sIL-2R in RA SF as compared with DJD SF (RA, 1319 +/- 135; DJD, 416 +/- 59; p less than 0.001). RA serum sIL-2R levels were also significantly elevated over DJD levels. There was no interaction between rheumatoid factor (RF) and sIL-2R. RA patients with elevated sIL-2R levels had significantly longer disease duration, higher c-reactive protein (CRP) levels in serum and SF, and higher RF levels in serum and SF. The groups were similar in regard to other laboratory variables. The presence of elevated levels of sIL-2R in RA serum and SF confirms the presence of a heightened immune reactivity and in vivo activation of lymphocytes in RA.

Arthritis, Rheumatoid↗

PubMed1990

Elevated soluble CD8 in the synovial fluid from patients with rheumatoid arthritis.

Suppressor/cytotoxic T cells express the surface marker CD8, which can be measured in a soluble form in culture supernatants of activated human lymphocytes. Using a sandwich immunoassay, we assessed the levels of soluble CD8 (sCD8) in serum from patients with rheumatoid arthritis (RA; n = 82), patients with degenerative joint disease (DJD; n = 40), and healthy controls. There were no differences in serum sCD8 levels among these groups. In contrast, the levels of soluble CD8 in the synovial fluid (SF) from patients with RA (n = 53) were significantly increased compared with the levels in 23 samples from patients with DJD (821 +/- 110 U/ml versus 213 +/- 13 U/ml, p less than 0.001). Synovial fluid sCD8 levels in the RA group were strikingly elevated, to a maximum value of 5,026 U/ml. In the majority of RA SF specimens (39 of 53), the values were significantly higher in the SF than the serum. Although the RA group had higher values of sCD8, such values were not significantly correlated with measured laboratory or clinical parameters. Current clinical and laboratory methods of evaluating patients may not be adequate in dealing with the complexity and heterogeneity of RA. Soluble CD8 values may be useful in further grouping patients with this disease.

Antibodies, Monoclonal↗

PubMed1989

Soluble CD8 during T cell activation.

The CD8 Ag has long been used as a surface marker for the identification of cytotoxic and suppressor cells. Recently CD8-positive cells have been shown to release a soluble form of the CD8 Ag. We have devised a sandwich monoclonal enzyme immunoassay for the quantitation of this released CD8. Soluble CD8 was released in response to lymphocyte activation. In vitro, PHA or anti-CD3 mAb-mediated T cell activation led to release of CD8 into the culture supernatant. In vivo, serum from patients with EBV-induced infectious mononucleosis (IM), a disease associated with intense CD8+ T cell activation, demonstrated elevations in soluble CD8 (7939 U/ml, day 0) compared to serum from normal controls (289 U/ml). Levels of soluble CD8 correlated (r = 0.82, p less than 0.001) with the increased percentage of CD8+/HLA-DR+ (activated CD8+ T cells) observed in acute IM. Sequential analysis of serum during the course of IM shows that soluble CD8 levels parallel the decline in CD8+/HLA-DR+ cells that occurs with the resolution of the disease. These data suggest that released CD8 may be of value in monitoring the involvement of CD8+ T cells in response to a pathologic event. The functional role of the released CD8 molecule will require further investigation.

Adolescent↗

PubMed1989

Increased serum CD8 antigen level in childhood Hodgkin's disease relates to advanced stage and poor treatment outcome.

Measurement of the soluble form of CD8 antigen, a surface membrane component of suppressor/cytotoxic T cells, has yielded useful information relevant to prognosis in the lymphoid malignancies of childhood. We therefore determined pretreatment levels of serum CD8 antigen in 90 children with newly diagnosed Hodgkin's disease. The findings ranged widely, from 220 to 2,585 U/mL (median, 556 U/mL). In patients with advanced disease (stage III or IV), the median serum CD8 level was significantly higher than in those with less disease extension (stage I or II): 675 v 477 U/mL, P = .003. It was also higher in children with B symptoms compared with all others: 622 v 494 U/mL, P = .005. Cases with a histologic classification of mixed cellularity had a significantly higher median level of the antigen than did those classified as nodular sclerosis: 847 v 509 U/mL, P = .005. Finally, higher serum CD8 levels (greater than 430 U/mL) were significantly associated with an increased probability of treatment failure (P = .02). In a multivariate analysis, serum CD8 level retained its impact on treatment outcome after adjustment for other potentially useful prognostic factors, including disease stage, presence of B symptoms, histology, erythrocyte sedimentation rate, sex, age, and race. The prognostic strength shown by soluble CD8 in this analysis suggests that the antigen has clinical value. We postulate that increased CD8 levels in serum indicate enhanced suppressor T-cell activity, which may compromise the host's antitumor immunity, leading to unusually aggressive disease.

Adolescent↗

PubMed1988

Serum levels of CD8 antigen in childhood lymphoid malignancies: a possible indicator of increased suppressor cell activity in poor-risk patients.

Serum concentrations of CD8 antigen were measured at diagnosis with an enzyme-linked immunoassay in children with acute lymphoblastic leukemia (n = 344) or non-Hodgkin's lymphoma (n = 65). All patients had detectable levels of the serum antigen, which in its soluble nonreduced form appeared to be a 52-Kd homodimer as compared with the 66-Kd surface membrane component on most thymocytes and on a subset of functionally distinct T cells (suppressor/cytotoxic). Increased serum levels of CD8 in leukemia patients were significantly related to recognized high-risk prognostic features: high leukocyte count, large liver and spleen size, high serum lactic dehydrogenase level, T-cell immunophenotype, presence of a mediastinal mass, pseudodiploid karyotype, DNA index less than 1.16, and chromosomal translocation. Children with serum CD8 levels greater than or equal to 450 U/mL were more likely to fail treatment than were those with lower levels (P = .002), even in the group with non-T-cell leukemia (P = .003). In a multivariate analysis, serum CD8 antigen contributed independent prognostic information beyond that conveyed by age, leukocyte count, and race (P = .02). High serum CD8 antigen levels also correlated with advanced stages of disease in children with non-Hodgkin's lymphoma or B-cell leukemia. Children with higher serum CD8 antigen levels (greater than or equal to 700 U/mL) had a poorer treatment outcome (P = .003), even after results were adjusted for disease stage and serum lactic dehydrogenase level (P = .05). Measurement of serum levels of CD8 antigen not only has important prognostic value in childhood lymphoid malignancies but also could be useful in assessing the immunoregulatory role of T cells in patients with cancer.

Adolescent↗