Expression of the alpha 5 beta 1 fibronectin receptor on T lymphocytes of patients with HIV-1 infection.

AIMS: To evaluate the expression of the alpha 5 beta 1 integrin fibronectin receptor (FNR), which mediates several processes, including phagocytosis, cell motility and the immune response, on T lymphocytes of patients with HIV-1 infection. METHODS: T lymphocytes were incubated with monoclonal antibody directed against FNR and then with monoclonal antibodies, conjugated with phycoerythrin, directed against CD3, CD4 and CD8 positive cells. Expression of FNR on CD3, CD4 and CD8 positive cells was analysed using flow cytometry. RESULTS: Normal expression of FNR was observed on CD3 positive cells from asymptomatic HIV positive patients and those with AIDS. Increased expression of FNR was observed on CD8 positive cells from asymptomatic HIV positive patients and on CD4 positive cells from patients with AIDS. Increased FNR expression was observed on CD4 positive cells from patients with AIDS, particularly those with opportunistic infections caused by Pneumocystis carinii, Mycobacterium sp, Toxoplasma gondii, and Cryptococcus neoformans. CONCLUSION: Increased expression of FNR on CD8 and CD4 positive cells in asymptomatic HIV positive patients and those with AIDS, respectively, may be an epiphenomenon correlated with lymphocyte activation by HIV-1 or opportunistic infection, Further study is required to determine whether upregulation of FNR expression has a direct role in the pathogenesis of AIDS.

Levels of circulating fibronectin receptor in adult and pediatric patients with human immunodeficiency virus type 1 infection.

We found a significant increase in fibronectin receptor (FNR) levels in the sera of adult human immunodeficiency virus type 1 (HIV-1)-infected patients, especially in those with AIDS (1,026.9 +/- 583.9 ng/ml; P < 0.0001). In contrast, AIDS patients with neurologic disorders and HIV-1-seropositive patients showed normal levels of FNR in serum. In addition, HIV-1-infected children showed increased levels of FNR in serum (824.4 +/- 333.5 ng/ml; P = 0.03). We suggest that an increase of FNR levels in AIDS patients is related to enhanced expression of FNR on HIV-1-infected cells.

Effects of interleukin-8 on suppression of human lymphocyte polarization and migration by anti-LFA-1 antibody.

We investigated the role of lymphocyte function-associated antigen 1 (LFA-1) in human T cell polarization and migration assay by using monoclonal antibody specific to beta chain (CD18) and alpha chain (CD11a). T cell polarization in response to fetal calf serum (FCS) and colchicine was suppressed by the addition of CD18 and CD11a antibodies. Furthermore, T cell migration in response to lymphocyte chemotactic factor (LCF) and casein was markedly depressed by the addition of CD18 and CD11a antibodies. Additional studies to evaluate effects of interleukin 8 (IL-8) on polarization and migration of T cells preincubated with CD18 or CD11a antibody showed that IL-8 restored the capability of migration of T cells, whereas did not restore polarization activity of such cells. These studies indicate that LFA-1 plays a role in the polarization and migration of T cells and that IL-8 may positively interfer with LFA-1-adhesion molecules.

Cerebrospinal fluid concentration of fibronectin in meningitis.

Fibronectin concentrations in the cerebrospinal fluid were assessed in 20 patients with acute meningitis using a turbidimetric immunoassay. A significant increase in fibronectin concentrations was observed in patients with bacterial meningitis; decreased concentrations were observed in patients with viral meningitis. The determination of fibronectin concentration in patients with bacterial meningitis may represent a useful marker in differentiating bacterial from viral meningitis.

Plasma fibronectin concentrations in patients with human immunodeficiency virus infection.

Plasma fibronectin (PFN) concentrations were assessed in 21 patients with AIDS, in seven with AIDS-related complex (ARC), in 17 asymptomatic seropositive patients, and in 36 age and sex matched healthy control subjects. A single radial immunodiffusion technique was used to determine PFN concentration. A significant decrease in PFN concentrations was observed in patients with ARC and AIDS (especially in those patients with Pneumocystis carinii pneumonitis). On the other hand, normal PFN concentrations were observed in asymptomatic seropositive patients. The determination of PFN concentration in patients with AIDS and ARC may contribute to the diagnosis of such patients.

Total serum IgE levels in children with pertussis.

Total serum IgE levels were evaluated in 20 children with pertussis. Increased levels of serum IgE were observed in the group of children between the ages of 3 and 12 years, while normal levels of serum IgE were detected in the groups of children between birth and 24 months old and between 13 and 24 months old. A further and significant increment of serum IgE levels was also found after 10 days of hospitalization.

[The specific erythrocyte adherence method in the study of ABH antigens on normal and neoplastic bladder epithelium]. / Il metodo dell'aderenza eritrocitaria specifica (AES) per la ricerca degli antigeni ABH sull'epitelio vescicale normale e neoplastico.

The isoantigens A, B, and H, identical with those present in erythrocytes, are also present in epithelial cells of some normal tissues, included the transitional epithelium of the urinary bladder. The cell surface ABH antigens can be detected with the specific erythrocyte adherence method (SEA), but could not be detected when carcinoma developed in this tissue: with rare exceptions, the loss of demonstrable antigens paralleled morphological anaplasia. We studied retrospectively by SEA test 51 specimens of urinary bladder, including 36 primary transitional cell carcinomas at the time of initial biopsy, and 15 controls. The SEA reaction was strongly positive in normal bladder epithelium, in vascular endothelium and in erythrocytes already present in sections, while was negative in connective tissue. 21 were classified as grade 0 (papilloma): in 19 of them the ABH antigens were fully or partially preserved, and the follow up from 5 to 15 years demonstrated no recurrences; the other 2 patients with negative SEA recurred locally. The only one graded as I, with strongly positive SEA, had not recurred in at least 6 years, 5 were classified as grade II; in 2 of graded as III, the SEA reaction was weakly positive in 3, while in remaining 6 the antigens were absent. The usefulness of the detection of ABH antigens as a prognostic tool in low grade and stage bladder carcinomas is confirmed by our data establishing the correlation of antigens deletion with subsequent clinical behavior. An alteration of blood group substance synthesis occurs in malignant epithelium, but it is not known whether it causes or results from malignant changes. The SEA method resulted highly sensitive and specific; however, the test is cumbersome and time-consuming, requires special expertise and shows some limitations, particularly the frequency of the occurrence of false-negative or weakly positive results in blood group O patients.