Bruno De Rienzo

Discontinuation of primary prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis in human immunodeficiency virus type i-infected patients: The changes in opportunistic prophylaxis study

A multicenter open, randomized, controlled trial was conducted to determine whether primary prophylaxis for Pneumocystis carinii pneumonia and toxoplasmic encephalitis can be discontinued in patients infected with human immunodeficiency virus type 1 (HIV-1) whose CD4+ T cell counts have increased to >200 cells/mm3 (and who have remained at this level for at least 3 months) as a result of highly active antiretroviral therapy (HAART). Patients were randomized to either the discontinuation arm (i.e., those who discontinued prophylaxis; n=355) or to the continuation arm (n=353); the 2 arms of the study were similar in terms of demographic, clinical, and immunovirologic characteristics. During the median follow-ups of 6.4 months (discontinuation arm) and 6.1 months (continuation arm) and with a total of 419 patient-years, no patient developed P. carinii pneumonia or toxoplasmic encephalitis. The results of this study strongly indicate that primary prophylaxis for P. carinii pneumonia and toxoplasmic encephalitis can be safely discontinued in patients whose CD4+ T cell counts increase to >200 cells/mm3 during HAART.

Deregulation of the CD95/CD95L system in lymphocytes from patients with primary acute HIV infection

ObjectiveTo analyze the role of CD95/CD95 ligand (CD95L) expression and functionality in peripheral blood lymphocytes (PBL) during primary, acute HIV syndrome (AHS) and in the subsequent period. PatientsTwelve patients were studied during the acute phase of the viral infection and most were followed for some months. MethodsCell culture and cytotoxicity assays based upon 51Cr release and flow cytometry were used to evaluate cell killing via CD95 molecule, flow cytometry to assess surface antigens, enzyme-linked immunosorbent assay (ELISA) for the determination of soluble CD95 and CD95L plasma levels, quantitative competitive (QC) reverse transcription polymerase chain reaction (RT-PCR) with an original RNA competitor for the analysis of CD95L mRNA expression and QC RT-PCR for determining plasma viral load. ResultsThe analysis of PBL during this phase revealed that almost all cells, including CD8 T cells with a virgin phenotype, B lymphocytes and natural killer cells displayed CD95 molecules on the plasma membrane. Activation of CD95 on the surface of isolated lymphocytes by anti-CD95 monoclonal antibodies or binding to CD95L induced rapid apoptosis. However, CD95L mRNA was not expressed in PBL from these patients and was poorly inducible. Soluble CD95 was found in the plasma of all patients, but only in a few at high levels, even some months after seroconversion. In contrast, soluble CD95L was detected in only one patient, this occurring after the symptomatic period. For 10 of the 12 patients, expression of CD95 on the cell membrane or in the plasma did not correlate with the plasma viral load, which varied widely from patient to patient. Further, plasma levels of soluble CD95 were not altered by decreased lymphocyte activation or by efficient antiretroviral therapy. ConclusionsIn patients experiencing an acute, primary HIV infection, a prolonged deregulation of the CD95/CD95L system may exist, which is probably not entirely related to virus production but may contribute to the pathogenesis of the disease. The hypothesis can be put forward that a complex balance exists between proapoptotic events (increase in CD95 expression), probably triggered by the host as a method to limit viral production, and antiapoptotic events (decrease in CD95L expression) probably triggered by the virus as a way to increase its production and survival.

Phenotypic characteristics and tendency to apoptosis of peripheral blood mononuclear cells from HIV+ long term non progressors

The aim of this study was to analyze (i) phenotype, (ii) in vitro spontaneous and induced apoptosis, (iii) glutathione (GSH) intracellular content and (iv) inhibitors of apoptosis of potential therapeutical use in peripheral blood mononuclear cells (PBMC) from HIV+ long term non progressors (LTNP), in comparison with progressors (HIV+P) and seronegative controls (HIV−). Three groups of subjects were studied: 15 HIV+P (patients losing >150 CD4+/year), 9 LTNP (subjects infected by HIV for at least 7 years without clinical and immunological signs of progression, with a mean of 898 CD4+/μL) and 18 HIV−. All subjects were living in a large community for former drug addicts, and were matched for age and sex. We used flow cytometry for analyzing PBMC phenotype and apoptosis; high performance liquid chromatography for measuring intracellular GSH content. PBMC phenotype of LTNP shared characteristics with those of both HIV− and HIV+P. Indeed, LTNP showed a normal number CD4+ cells (an inclusion criteria), but significantly increased numbers of CD8+ lymphocytes, activated T cells, CD19+, CD5+ B lymphocytes and CD57+ cells, as well as a decrease in CD19+, CD5− B lymphocytes and CD16+ cells. In LTNP, spontaneous apoptosis was similar to that of HIV− and significantly lower than that of HIV+P. Adding interleukin-2 (IL-2) or nicotinamide (NAM) significantly decreased spontaneous apoptosis in LTNP and HIV+P. Pokeweed mitogen-induced apoptosis was also similar in LTNP and HIV−, but significantly lower than that of HIV+P. In HIV+P, but also in LTNP, spontaneous apoptosis was inversely correlated to the absolute number and percentage of CD4+ cells and directly correlated to the number and percentage of activated T cells present in peripheral blood. GSH intracellular content was greatly decreased in PBMC from HIV+P and slightly, but significantly, reduced in LTNP. Adding 2-deoxy-D-ribose, an agent provoking apoptosis through GSH depletion, to quiescent PBMC resulted in similar levels of massive cell death in the three groups. This phenomenon was equally prevented in the three groups by N-acetyl-cysteine but not by IL-2. A complex immunological situation seems to occur in LTNP. Indeed, PBMC from LTNP are characterized by a normal in vitro tendency to undergo apoptosis despite the presence of a strong activation of their immune system, unexpectedly similar to that of HIV+P. Our data suggest that NAM and IL-2 are possible candidates for reducing spontaneous apoptosis in HIV infection.

Lack of selective Vβ deletion in CD4+ or CD8+ T lymphocytes and functional integrity of T-cell repertoire during acute HIV syndrome

ObjectiveTo study the Vβ T-cell repertoire in peripheral blood lymphocytes (PBL) during acute HIV syndrome by using several anti-Vβ monoclonal antibodies (MAb) and to analyse its functionality by stimulating PBL with superantigens (SAg) such as Staphylococcus aureus enterotoxins. MethodsCytofluorimetric analysis of Vβ T-cell-receptor expression was performed on PBL from eight patients with symptomatic, acute HIV-1 primary infection, showing a dramatic decrease of CD4+ PBL accompanied by a marked increase in activated/memory CD8+ T cells, and on 12 age- and sex-matched healthy controls. PBL were then isolated, stimulated with different SAg, anti-CD3 MAb or phytohaemagglutinin and cultured for 3 days. PBL capability to progress through cell cycle was studied by the classic cytofluorimetric method of bromodeoxyuridine incorporation and DNA staining with propidium iodide. ResultsDespite the presence of a few expansions of some Vβ families among CD8+ T lymphocytes, no gross alterations in T-cell repertoire were present in patients with acute HIV syndrome. Its functionality was maintained overall, as PBL responsiveness to SAg was well preserved. Interestingly, all CD8+ T cells, although bearing different Vβ T-cell receptors, expressed marked signs of activation, i.e., CD45RO, CD38 and major histocompatibility complex class II molecules, and also high amounts of CD11a and CD18. ConclusionsOur data suggest, at least in the early phases and in the acute form of the infection, that HIV is not likely to act as a SAg. However, further studies are needed to analyse other sites, such as lymph nodes, where HIV could exert other, significant effects, and to study the expression of other Vβ families than those investigated here.

Differential down-regulation of CD95 or CD95L in chronically HIV-infected cells of monocytic or lymphocytic origin: Cellular studies and molecular analysis by quantitative competitive RT-PCR

We analysed the expression of CD95/CD95L in two widely used models for studying the cellular effects of chronic infection with human immunodeficiency virus type 1 (HIV‐1), i.e. ACH‐2 cells, derived from the lymphocytic cell line A301, and U1, derived from monocytic U937 cells. A301 and ACH‐2 mounted the same amount of plasma membrane CD95, while U1 had a consistent decrease in CD95 expression. Using different antibodies, we failed to detect the plasma membrane form of its ligand, CD95L, but we could see the intracellular presence of that molecule in A301 cells and, to a lesser extent, in ACH‐2 cells, but not in U937 or U1 cells. To confirm the cytofluorimetric data and quantify the expression of CD95L at the RNA level, we developed a quantitative competitive RT‐PCR assay. The HUT78 cell line had about 50 000 copies mRNA/1000 cells, three times more after induction with a phorbol ester and ionomycin. ACH‐2 expressed about 400‐ (basal) or 10‐ (induced) fold less CD95L mRNA than the parental cell line A301; U937 and U1 were below the limit of detection. In cells of lymphoid origin (ACH‐2) chronic HIV infection inhibits the expression of CD95L, the phenomenon occurring at the transcriptional level. In cells of monocytic origin (U1) the infection decreases the plasma membrane expression of CD95. This suggests that HIV could trigger different anti‐apoptotic strategies which likely depend upon the cell line which is infected. In monocytic cells which act as a viral reservoir, the expression of the molecule whose binding triggers apoptosis decreases, while in lymphoid cells, capable of exerting cytotoxicity, the expression of a molecule which induces apoptosis is reduced.

Non-typhoid salmonella subdural empyema in a patient with AIDS

In AIDS patients, non-typhoid salmonella metastatic abscesses in lung and brain due to bacteremia have been described previously. Here we present a case in which a group B Salmonella, serotype Copenhagen, caused right parietal subdural empyema. The etiologic diagnosis was based on culture of pus obtained from the lesion. The patient was treated for bacterial meningitis and made a good recovery. He is at present reasonably well and is taking ciprofloxacin as prophylaxis against salmonella relapse.

Oral Hairy Leukoplakia in AIDS Patients: An Ultrastructural Study

Hairy leukoplakia is a specific oral lesion associated with the opportunistic development of Epstein‐Barr virus in the oral epithelium. It is now considered to be an early sign of HIV‐induced immunosuppression.

Effects of Pulsed Electromagnetic Fields on the Proliferation of Lymphocytes from Aids Patients, HIV-Seropositive Subjects, and Seronegative Drug Users

The effect of the exposure of mitogen-stimulated lymphocytes from subjects infected by human immunodeficiency virus to extremely low frequency pulsed electromagnetic fields (PEMFs) was studied, by evaluating the incorporation of tritiated thymidine, the expression of IL-2 receptor, and the amount of activated T lymphocytes. Four groups of subjects were considered patients with acquired immunodeficiency syndrome (AIDS), asymptomatic seropositive subjects, seronegative drug users, and young healthy controls. PEMFs increased cell proliferation only in the group of healthy controls, as measured at the 72nd hour of culture, but an increase in the number of activated T lymphocytes was observed by cytofluorimetric analysis after 18 hrs of PEMF exposure in cultures from AIDS patients.