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Biomedical subjects

R Cauda

Publications and source records attributed to R Cauda.

At least 55 records · Page 3Linked to original sources

Bacterial pneumonia in HIV-infected patients: analysis of risk factors and prognostic indicators.

This case control study assessed risk factors and prognostic indicators of 350 episodes of bacterial pneumonia in 285 HIV-infected patients. On univariate analysis, intravenous drug abuse (i.v.DA; p < .001 versus controls), regular cigarette smoking (p < .001), cirrhosis (p = .04), and history of a previous episode of pneumonia (p = .04) were risk factors for community-acquired episodes of bacterial pneumonia, whereas length of hospitalization (p = .01) was a risk factor only for nosocomial bacterial pneumonia. The small amount of circulating T CD4+ cells (<100/ mm3) was a risk factor in both groups of pneumonia (p < .05). Stepwise logistic regression analysis revealed that i.v.DA in community-acquired episodes and low levels of circulating T CD4+ cells, both in community-acquired and hospital-acquired episodes, were independent risk factors for the development of bacterial pneumonia. The case-fatality rate observed in our study was 27%. On stepwise logistic regression analysis, T CD4+ cell counts < or = 100/mm3 (p = .02), neutropenia (p = .04), PO2 arterial level < or = 70 mm Hg (p = .01), and Karnofsky score < or = 50 (p = .04) were independent indicators of mortality. According to a personally developed prognostic score, 211 episodes of pneumonia (60%) were classified as mild, 63 (18%) as moderate, and 76 (22%) as severe. Clinicians must carefully evaluate those variables that can influence the prognosis of bacterial pneumonia to make early identification of affected patients and to promptly establish the most appropriate therapeutic strategy in each case.

AIDS-Related Opportunistic Infections↗

A new, striking morphological alteration of P-glycoprotein expression in NK cells from AIDS patients.

Natural killer cells from healthy donors express P-glycoprotein on their surface. This molecule is rearranged during the process of cell-mediated cytotoxicity and it appears to be clustered in the cell-to-cell contact regions. By contrast, in HIV-infected subjects this rearrangement is hindered. These results seem to be associated with cytoskeleton network alterations of the cell-mediated killing process occurring in AIDS patients and can contribute to the comprehension of the mechanisms of the natural killer cell deficiency found in these patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Flow cytometric detection of perforin in normal human lymphocyte subpopulations defined by expression of activation/differentiation antigens.

We investigated with three-color flow cytometry the expression of perforin (Pf) in normal human lymphocyte subpopulations identified by means of activation and differentiation-related antigens. Interestingly, Pf could be detected in a substantial subset (13 +/- 2%) of memory CD4+ CD45RO+ cells, on relevant percentages of memory (CD45RO+) and naive (CD45RA+) CD8+ cells and on virtually all CD3- CD16+, CD3- CD56+ and NKB1+ natural killer cells, as expected. The analysis of fluorescence intensity showed higher levels of Pf expression on CD8dim and NK cells compared to CD8bright and CD4+ lymphocytes, Pf and CD69, HLA-DR, CD95 and CD25 activation/differentiation-related antigens were never co-expressed. On average, 15 +/- 3% of CD3+ CD28+ cells were found to be Pf+, in line with a previously activated or memory cell type. Comparable percentages of CD8+ CD11b- (cytotoxic) and CD8+ CD11b+ (suppressor) T cells were Pf+. Multiparameter flow cytometry is a powerful tool to detect minute fractions of Pf-expressing cells in heterogeneous populations.

Biomarkers↗

Intracellular expression of P-170 glycoprotein in peripheral blood mononuclear cell subsets from healthy donors and HIV-infected patients.

BACKGROUND AND OBJECTIVE: P-glycoprotein (P-gp) is a transmembrane efflux pump that actively extrude a variety of unrelated drugs from cancer cells, leading to the so-called multidrug resistance (MDR) phenomenon. However, P-gp has also been found in normal bone marrow and peripheral blood mononuclear cells (PBMC). Recently, the presence of P-glycoprotein in PBMC from human immunodeficiency virus (HIV)-infected patients has also been investigated and a phenotype-associated P-gp expression has been detected. DESIGN AND METHODS: A total of thirty-eight HIV-1 positive patients with a mean age of 34 years (range, 24-41 years) were studied after an informed consent. Peripheral blood mononuclear cells (PBMC) were isolated by centrifugation on a Ficoll/Hypaque and P-glycoprotein expression was investigated on lymphocyte population by single and double-color immunofluorescence techniques. We investigated: i) both surface and intracellular expression of the P-gp molecule in different PBMC subsets, ii) P-gp expression modifications occurring during HIV infection, and iii) the effect of HIV-gp120 on the expression of P-gp by T lymphocyte subsets from healthy donors. RESULTS: Our experimental findings indicate that: a) P-gp glycoprotein can be detected on an intracellular level in different PBMC subpopulations (mainly CD8+ T lymphocytes, CD16+ NK cells and CD14+ monocytes); b) this intracellular expression is decreased in specific PBMC subsets (i.e. T-CD8+ and NK-CD16+) from HIV-infected patients and c) a rearrangement was obtained when CD4+ and CD8+ lymphocytes from healthy donors were exposed in vitro to the HIV-binding glycoprotein gp120. INTERPRETATION AND CONCLUSIONS: Our results indicate that P-gp glycoprotein can also be expressed intracellularly and can be rearranged in PBMC subsets from HIV-infected patients.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

Risk factors, nutritional status, and quality of life in HIV-infected patients with enteric salmonellosis.

AIMS: To define the potential risk factors, prognostic indicators, and quality of life of HIV-infected patients with enteric salmonellosis. METHODS: A five-year matched (1:2) case-control study was performed. Thirty cases and 60 matched controls were studied. RESULTS: Univariate analysis (p < 0.05) identified six risk factors for enteric salmonellosis: 1) increasing value of APACHE II score, 2) altered nutritional status, 3) previous antibiotic therapy, 4) ingestion of "risk" foods, 5) multiple (> or = 2) previous opportunistic infections, 6) stage C of HIV infection. Using the multivariate analysis, the most powerful predictors for developing an enteric salmonellosis were: increasing value of APACHE II score and altered nutritional status. The response to therapy was favourable in all episodes. Five (17%) patients suffered from one or more relapses. Multivariate analysis identified that a low number of circulating CD4+ (< 100/mm3) and a high APACHE II score (> 15) predict an increased risk of relapses. CONCLUSIONS: HIV-associated enteric salmonellosis occurs more frequently in patients with advanced stage of HIV infection and with impaired nutritional status. We stress the need for a prompt and accurate diagnosis and treatment since the possible haematogenous spread and relapses appear reduced under early and prolonged antibiotic therapy.

AIDS-Related Opportunistic Infections↗

Serum of healthy donors receiving granulocyte colony-stimulating factor induces T cell unresponsiveness.

The effects of serum from healthy donors receiving recombinant human granulocyte colony-stimulating factor (rhG-CSF) (G-serum) on blast transformation, expression of activation-related antigens, secretion of interleukin (IL)-2, and proliferation were evaluated in allogeneic lymphocytes stimulated with phytohemagglutinin. Escalating concentrations of G-serum induced 27%, 47%, and 70% suppression of lymphocyte proliferation; interestingly, CD4+ and CD8+ cells underwent blast transformation and up regulated early (CD69) and late (CD25, HLA-DR, and CD71) activation-related antigens. Negligible fractions of apoptotic cells were found after mitogenic challenge, suggesting that the strongly diminished proliferation was not attributable to extensive activation-induced programmed cell death of responding T cells. The levels of IL-2 in cultures containing G-serum were comparable to those in cultures performed without G-serum; however, high concentrations of exogenous IL-2 restored lymphocyte mitogenesis regardless of G-serum concentration. These findings--cell enlargement, upregulation of activation-related antigens, inability to proliferate after mitogenic stimulus, and restoration of cell division by exogenous IL-2--resembled those associated with "partial activation" of lymphocytes, a fundamental control mechanism of tolerance induction in T cell clones. Soluble immunoregulatory mediators infused with allogeneic hematopoietic progenitor products collected after rhG-CSF administration could induce T cell unresponsiveness in vivo, thus preventing clonal expansion and amplification of immune responses, and could account for the unexpectedly reduced incidence and severity of graft vs. host disease compared with allogeneic marrow infusion.

Adult↗

Central venous catheter-related sepsis in a cohort of 366 hospitalised patients.

Five hundred two central venous catheters inserted in 366 patients were evaluated prospectively over a one-year period to determine the frequency and risk factors associated with catheter-related sepsis. For study purposes, in cases in which catheter infection was suspected but the initial blood cultures were negative, the catheters were replaced by guidewire technique; otherwise, the catheters were routinely changed after 21 days by guidewire technique. A catheter-related infection was suspected in 190 cases (190/502, 38%). A diagnosis of catheter-related sepsis was established in 50 patients, which represents 10% of the total number of lines (502). Over a total of 6428 days of catheter use, the infection rate was 0.8 cases of sepsis per 100 catheter-days. Staphylococcus epidermidis, Staphylococcus aureus, and Candida spp. were the most frequently isolated aetiological agents of sepsis. On univariate analysis, six variables affecting the rate of catheter-related sepsis were identified: neutropenia for more than eight days (p < 0.001); AIDS (p < 0.001); haematological malignancy (p < 0.001); administration of total parenteral nutrition (p = 0.001); duration of site use (p = 0.04); and high APACHE II score (p = 0.04). The logistic regression analysis revealed that AIDS and haematological malignancies were independent risk factors of catheter-related sepsis. Catheter replacement over a guidewire was no more likely to be associated with sepsis than was percutaneous catheter insertion. In conclusion, although the incidence of established catheter infection is much lower than the incidence of suspected infection, in most cases of suspected infection it is wise to change the catheter with the guidewire technique and wait for culture of the tip, rather than to remove the catheter immediately. Such a policy may help reduce the number of unnecessary catheter removals.

APACHE↗

Comparative analysis of prognostic indicators of aspergillosis in haematological malignancies and HIV infection.

The objective of this study was to identify the prognostic factors influencing the outcome of aspergillosis in two models of immunodeficiency, namely haematological malignancies and HIV infection. The study is based on a 5 year prospective logistic regression analysis of risk factors, clinical features, radiological findings and therapy affecting the prognosis of aspergillosis in 43 patients, i.e. 27 haematological neoplastic patients (group A) and 16 HIV infected patients (group B). Univariate analysis indicated that neutropenia (P = 0.02), haemoptysis (P = 0.03) and concomitant AIDS (P = 0.02), negatively influenced the prognosis of aspergillosis. Comparing the two groups of patients, significant differences emerged in the prognostic indicators. In particular respiratory failure (P = 0.02) and radiological bilateral involvement of the lungs were associated with a poor prognosis in group A (P = 0.04) and low (2100/mm3) T CD4+ cell count in group B (P = 0.02). At variance, a better prognosis was documented in patients treated with sequential therapy (amphotericin B and itraconazole) only within the group of haematological patients (P = 0.003). On multivariate analysis sequential therapy (P = 0.01) and AIDS (P = 0.03) were independent prognostic indicators of aspergillosis. In conclusion, our prospective study indicates that aspergillosis, although an uncommon event in patients with HIV infection, has a more severe prognosis in comparison to haematological patients. Future prospective clinical trials are necessary to confirm the real importance of the sequential therapy, with amphotericin B and itraconazole, in patients with aspergillosis.

Adult↗

Gastric cryptosporidiosis complicating HIV infection: case report and review of the literature.

Gastric cryptosporidiosis is rarely reported despite the fact that Cryptosporidium has been recognized with increasing frequency as an aetiological agent of severe chronic diarrhoeal enteritis in patients with human immunodeficiency virus (HIV) infection. We report a case of gastric cryptosporidiosis that occurred in an AIDS patient. Fifteen previously reported cases of gastric cryptosporidiosis are also reviewed. The review of all cases reported in the literature, including our own, showed that 12 patients had digestive symptoms. In 14 out of 16 patients the diagnosis was achieved by biopsy of the gastric mucosa rather than by examination of the stools. Gastric localization of Cryptosporidium is a rare and severe manifestation of intestinal cryptosporidiosis in patients with AIDS, and no single drug regimen has yet been found to be effective in eradicating this organism.

AIDS-Related Opportunistic Infections↗

Fluconazole resistant oral candidiasis in HIV-infected patients.

OBJECTIVE: To evaluate the risk factors associated with the emergence of fluconazole resistant Candida spp. in HIV-infected patients with oral candidiasis. METHODS: Candida spp. were isolated from oral swabs and tested in vitro for resistance to fluconazole. The factors potentially correlated with vazole-resistent Candida spp. infections were investigated. RESULTS: Fifty-one out of 118 patients (43%) with oral candidiasis had fluconazole resistant Candida spp. The following factors were significantly associated with the development of fluconazole resistance: (1) more than five episodes of oral candidiasis in the previous year (P < 0.001); (2) fluconazole therapy in the previous 6 months (P < 0.001); (3) C3 category of HIV infection (P < 0.001); and (4) low number of TCD4+ cells (< 50 mm3, P = 0.002). According to multivariate analysis, previous therapy with fluconazole was the only risk factor that independently influenced the development of Candida spp. resistance (P = 0.003). CONCLUSIONS: The prophylaxis and therapy of mild fungal infections in HIV-infected patients, which may lead to azole resistance, should be carefully considered.

AIDS-Related Opportunistic Infections↗

Pneumothorax in HIV-infected patients: role of Pneumocystis carinii pneumonia and pulmonary tuberculosis.

Patients with acquired immune deficiency syndrome (AIDS) are at increased risk for pneumothorax, which usually occurs in the setting of Pneumocystis carinii pneumonia. The rationale of the present study was based on the hypothesis that the increased incidence of pulmonary tuberculosis in human immunodeficiency virus (HIV)-infected patients could favour the development of pneumothorax in such patients. A case-control study was performed comprising 140 HIV-infected patients grouped as follows: 35 patients with pneumothorax and 105 matched controls without pneumothorax. Univariate analysis identified four risk factors for pneumothorax: 1) previous P. carinii pneumonia (p=0.01); 2) current P. carinii pneumonia (p=0.02); 3) pulmonary tuberculosis (p=0.01); and 4) cysts, pneumatoceles or bullae on chest radiographs (p<0.001). Multivariate analysis indicated that current P. carinii pneumonia (p=0.01) and pulmonary tuberculosis (p=0.04) were both independent risk factors for pneumothorax. In conclusion, our findings demonstrate that, in addition to Pneumocystis carinii pneumonia, pulmonary tuberculosis enhances the risk of pneumothorax in patients with acquired immune deficiency syndrome.

AIDS-Related Opportunistic Infections↗

Osteoarticular bacterial infections are rare in HIV-infected patients. 14 cases found among 4,023 HIV-infected patients.

Among 4,023 HIV-infected patients admitted to a large Italian university hospital in the period 1985-1996, 14 had concomitant HIV and bacterial osteoarticular infections. Staphylococcus aureus infections were commonest and were diagnosed in 8 patients. Intravenous drug addiction was the only risk factor significantly associated with the development of osteoarticular infection (p = 0.04). In contrast, no statistical correlations were found with age, sex, absolute number of circulating T-CD4+ lymphocytes, neutrophils and stage of HIV infection. In conclusion, osteoarticular infections are uncommon in HIV-infected patients and are more directly related to parenteral drug abuse than to HIV.

Adult↗