Recent thymic emigrants in lymphoma patients with and without human immunodeficiency virus infection candidates for autologous peripheral stem cell transplantation.

Signal joint T cell receptor excision circles (sjTRECs) have been reported as a clinical marker to measure the potential for recovery of the immune system after immunosuppressive treatments. The aim of this study was to investigate the thymic regenerative potential in 55 human immunodeficiency virus (HIV)-1 infected (HIV(+)) and non-infected (HIV(-)) lymphoma patients, candidates for autologous stem cell transplantation (ASCT). Moreover, the possible associations between sjTRECs and other immunological and clinical parameters were examined. SjTRECs levels in peripheral blood mononuclear cells (PBMCs) were quantified by real-time polymerase chain reaction and T lymphocyte subsets were analysed by flow cytometry. Our data showed that sjTRECs were reduced in lymphoma patients compared to healthy controls, although a weak significant association between low sjTRECs levels and increasing age was maintained [odds ratio (OR) = 4.00; 95% confidence interval (CI) 1.09-17.17]. We found that different chemotherapeutic treatments seem to induce similar effects on the thymic reservoir, independently from their intensity (type and number of cycles of previous chemotherapy). Results from multivariate models including adjustment for patients' sex, type of lymphoma and type of chemotherapy showed that thymic output was independent from HIV infection (OR, 0.95; 95% CI 0.20-4.48). SjTRECs levels correlated with naive T cell subsets in overall lymphoma patients and after stratification by HIV infection (r > 0.37). HIV replication should be maximally suppressed to properly evaluate thymic output by sjTREC markers. Our results suggested that de novo T cell generation is maintained partially in pretreated recurrent lymphoma patients, candidates for ASCT, and could contribute to restore the immune function after transplantation.

Effects of interleukin-2 therapy on the proliferation and differentiation of CD4/CD25 positive and CD4/CD25 negative cells in HIV+ patients.

Interleukin-2 has been widely used in HIV-1+ subjects as an immunoactivating agent. In this study, we investigated cytokine production, Ki67 antigen expression and the modulation of the surface phenotype of the CD4/CD25+ subset as compared to the reciprocal CD4/CD25- subset in IL-2-treated HIV+ patients. Our findings suggest that CD4 T cells are heterogeneous in responding to IL-2, because CD4/CD25+ cells sharply increased their "memory" phenotype, their Ki67 antigen expression and were the main in vivo targets for IL-2-dependent proliferation during therapy, while the percentages of IFN-gamma+ (terminally differentiated) cells remained unchanged at the end of therapy. Conversely, the CD4+/CD25- subpopulation showed an expansion of differentiated cells and a slight increase in the proliferation rate. The use of anti-retroviral therapy alone (HAART) reduced the proliferation and increased the differentiation of both CD4 subsets. Our data suggest that IL-2 has a moderate capacity to activate resting T cells in vivo and is probably unable to boost HIV-1 from latency to the replicative state.

Different rates of CD4+ and CD8+ T-cell proliferation in interleukin-2-treated human immunodeficiency virus-positive subjects.

BACKGROUND: Interleukin-2 (IL-2) has been used successfully to increase CD4 cell counts in patients who are human immunodeficiency virus (HIV) positive. The mechanisms involved in this phenomenon are unknown. We hypothesized that a differential proliferation rate of CD4+ compared with CD8+ lymphocytes could be related to the increase of CD4 counts and of CD4/CD8 ratios that occur in HIV+ patients during IL-2 treatment. METHODS: We enrolled in our study 14 HIV+ patients treated with IL-2 or with highly active antiretroviral therapy (HAART) during a 96-week observation period. Using flow cytometry, we measured longitudinally the expression of the Ki67 antigen in peripheral blood CD4+ and CD8+ lymphocyte subsets. RESULTS: Compared with HAART alone, IL-2 produced a rapid increase of Ki67+ proliferating CD4 cells and a concomitant increase of the CD4/CD8 ratios, whereas the corresponding CD8 proliferation increased slightly. On the contrary, HAART alone was effective in suppressing equally both CD4 and CD8 proliferation. CONCLUSIONS: Our results suggest a selective activity of IL-2 on CD4 T-cell proliferation; on the contrary, CD8-specific proliferation is affected minimally during treatment. This information may offer the potential to plan correctly immune activating regimens.

Lymphocyte subsets and viral load in patients with HIV-associated non-Hodgkin's lymphoma treated with anti-CD20 monoclonal antibody and chemotherapy.

The anti-CD20 monoclonal antibody Rituximab is a novel antitumor agent used in association with chemotherapy (CT) for the treatment of high-grade/intermediate non-Hodgkin's lymphomas (NHL) in HIV-negative populations. This therapeutic combination is currently also being explored in HIV-positive patients with NHL (HIV-NHL). The objective of our study was to determine CD4 and CD8T cell counts, HIV plasma viremia and proviral load in patients with CD20-positive HIV-NHL treated with Rituximab plus CT and highly active antiretroviral therapy (HAART). We studied eight patients with HIV-NHL treated by anti-CD20 and CT before, after three, and after six cycles of therapy; CD4, CD8 and CD19 lymphocyte subsets were measured by monoclonal antibodies and flow cytometry. HIV plasma viremia was determined by the b-DNA assay, and proviral load by a quantitative competitive PCR. CD4T cell counts remained stable after three cycles of therapy, while a significant reduction of this subset was present at the end of therapy. HIV plasma viremia was significantly reduced after the third cycle, but returned to pretreatment levels at the end of therapy; we also observed individual fluctuations of proviral load during therapy, this marker being increased in two out of three patients at the end of therapy. These observations suggest that Rituximab plus CT accelerated the rate of CD4 depletion and of HIV replication in the peripheral blood of HIV-NHL patients and that HAART may be able to delay these effects.

Long-term (12 months) treatment with an anti-oxidant drug (silymarin) is effective on hyperinsulinemia, exogenous insulin need and malondialdehyde levels in cirrhotic diabetic patients.

BACKGROUND/AIMS: Several studies have demonstrated that diabetic patients with cirrhosis require insulin treatment because of insulin resistance. As chronic alcoholic liver damage is partly due to the lipoperoxidation of hepatic cell membranes, anti-oxidizing agents may be useful in treating or preventing damage due to free radicals. The aim of this study was to ascertain whether long-term treatment with silymarin is effective in reducing lipoperoxidation and insulin resistance in diabetic patients with cirrhosis. METHODS: A 12-month open, controlled study was conducted in two well-matched groups of insulin-treated diabetics with alcoholic cirrhosis. One group (n=30) received 600 mg silymarin per day plus standard therapy, while the control group (n=30) received standard therapy alone. The efficacy parameters, measured regularly during the study, included fasting blood glucose levels, mean daily blood glucose levels, daily glucosuria levels, glycosylated hemoglobin (HbA1c) and malondialdehyde levels. RESULTS: There was a significant decrease (p<0.01) in fasting blood glucose levels, mean daily blood glucose levels, daily glucosuria and HbA1c levels already after 4 months of treatment in the silymarin group. In addition, there was a significant decrease (p<0.01) in fasting insulin levels and mean exogenous insulin requirements in the treated group, while the untreated group showed a significant increase (p<0.05) in fasting insulin levels and a stabilized insulin need. These findings are consistent with the significant decrease (p<0.01) in basal and glucagon-stimulated C-peptide levels in the treated group and the significant increase in both parameters in the control group. Another interesting finding was the significant decrease (p<0.01) in malondialdehyde/levels observed in the treated group. CONCLUSIONS: These results show that treatment with silymarin may reduce the lipoperoxidation of cell membranes and insulin resistance, significantly decreasing endogenous insulin overproduction and the need for exogenous insulin administration.

Paclitaxel as a radiosensitiser: a proposed schedule of administration based on in vitro data and pharmacokinetic calculations.

Paclitaxel is efficacious against many human cancers. Because it blocks cells at the radiosensitive G2-M interface, paclitaxel has been investigated as a radiosensitiser. The results have been equivocal and somewhat contradictory. It is impossible to obtain proper pharmacokinetic calculations, aimed at obtaining maximum cytotoxicity and/or radiosensitisation, without knowing (i) how long the drug must be in contact with the cells, (ii) how long the effect lasts after the drug is removed from the cellular environment, (iii) whether the drug acts as a radiosensitiser even when, like cis-platinum, it is added after the radiation and (iv) what the minimum quantity of drug in the cellular environment is required for both chemotoxicity and radiosensitisation. The present work addresses the above questions. Two radioresistant cell lines of human origin were used, A375 melanoma and S549 lung carcinoma, in a clonogenic assay where only colonies with 50 or more cells were counted. For the irradiation, 6 MV X-rays were used. Any G2-M block was quantified by cell cycle kinetics analysis. From the results, a simulation of pharmacokinetics was conducted to calculate the schedule of administration of paclitaxel most likely to achieve and maintain significant chemotoxocity and radiosensitisation. The minimum concentration of paclitaxel for measurable cytotoxicity was 3 nM for both cell lines, but the drug was more toxic to the A549 cells. The minimum concentration for measurable radiosensitisation was 3 nM for A375 and approximately 0.1 nM for A549, but whereas above 3 nM the radiosensitivity increased in A375, it decreased above 1 nM for A549. A minimum of 18 h incubation with the drug was necessary for measurable effects and the radiosensitising effects were lost soon after its removal. There was no radiosensitisation if paclitaxel was added after the radiation, and, at the minimum effective concentrations, it caused only a minor and transient G2-M block. The pharmacokinetic calculations predict that 15 mg/m2 paclitaxel given as a 1 h infusion 5 days/week for 3 weeks during the radiotherapy should achieve both cytotoxicity and radiosensitisation. The mechanism of radiosensitisation by paclitaxel at the concentrations suggested by our results does not appear to be via a G2-M block and is probably concentration dependent. The results imply that low-dose, daily infusions of paclitaxel for as long as possible during a course of radiotherapy are more likely to result in radiosensitisation and prolonged cytotoxicity than high-dose infusions given once a week.

CD8+ lymphocyte phenotype and cytokine production in long-term non-progressor and in progressor patients with HIV-1 infection.

In most HIV-1-infected patients, clinical and immunological progression develops within a few years. Few infected people, termed long-term non-progressors (LTNP), remain healthy and immunologically stable for a long time. The factors governing the maintenance of this condition are not well known, but it is conceivable that CD8+ lymphocytes, cells that play a central role in controlling in vitro HIV replication, may have a part in vivo in this process. The aim of this study was to characterize the phenotypic profile and the cytokine production of CD8+ cells in a group of LTNP patients who had stable CD4+ cell counts (> 500/mm3) for at least 7 years. Their CD8+ absolute numbers were similar to a control group composed of HIV-1+ patients who have a progressive decline of their CD4+ cell counts. However, our multiparameter immunofluorescence studies show that a clinical and immunologically stable condition is associated with the presence of a CD28+, CD95 strongly positive CD8+ population, while disease progression is marked by the CD28-CD95+CD8+ subset. Purified CD8+ cells from LTNP retain their ability to produce IL-2, interferon-gamma (IFN-gamma) and, to a lesser degree, to produce IL-10 and IL-4. In contrast, CD8+ cells from progressors are unable to secrete IL-2 and IL-10. Although CD8+ cytokine profile does not fit with the proposed T helper (Th)1/Th2 switch in progressive HIV infection, LTNP CD8+ T cells maintain their capacity to produce IL-2 and IL-10 (Th0-like), a pattern very similar to that observed in normal HIV healthy controls. We suggest that CD8+ cells expressing CD28, CD95 and having a Th0-like profile may be considered to be associated with long-term survival.

Serum levels of intercellular adhesion molecule 1 in patients with HIV-related Kaposi's sarcoma.

Infection with the human immunodeficiency virus type 1 (HIV-1) in man is associated with an increase in the incidence of Kaposi's sarcoma (KS). The biological and clinical characteristics of these patients differ from those of subjects with other HIV-associated diseases. Here we report that levels of serum-soluble intercellular adhesion molecule 1 (sICAM 1) are increased in HIV-1-positive patients with KS, but not in patients belonging to other CDC classification groups. KS patients with elevated levels of serum sICAM 1 had a significant lowering of CD4 cell counts during the follow-up period compared with those KS subjects whose sICAM 1 levels were only moderately higher. We suggest that increased sICAM 1 levels may have a pathogenetic role in the development of HIV-associated immunodeficiency in KS patients and may also be considered an important prognostic factor.

The expansion of CD8 lymphocytes using T cell receptor variable gene products during HIV infection.

Fresh peripheral blood was obtained from HIV-infected subjects and from age-matched healthy controls. Single-, two- and three-colour flow cytometry was performed using FITC-labelled MoAbs directed against the following TCR V beta subfamilies: V2, V3, V5a, V5b, V5c, V6, V8, V12, V13.3, V17, V19, alone or in combination with PE-labelled CD4, CD8, HLA-DR, CD28, CD38 and with Peridinin-chlorophyll A protein (PerCP)-conjugated CD8. The percentages of each V beta subfamily did not differ in HIV+ patients compared with healthy controls. However, we were able to find in four patients (one CDC group II, one group III and two group IV) an expansion of a TCR V beta subfamily (V3 in two, V5a and V19 in one patient). These cells were mainly CD8+. Three-colour flow cytometry allowed us to define that the expanded V beta+, CD8+ T lymphocytes were characterized by the low/intermediate expression of activation markers (HLA-DR, CD28, CD38). In some HIV+ patients there is an expansion of T cells expressing a TCR V beta subfamily; the nature of this expansion may be related to factors that are still unknown, such as the genetic background of each individual and the antigenic specificity of T cells. These populations may be relevant in the host response to the virus and in disease progression.

[Median-term (4 months) treatment with glibenclamide + metformin substituting for glibenclamide + fenformin lowers the lacticemia levels in type-2 diabetics (NIDDM)]. / Il trattamento a medio termine (4 mesi) con glibenclamide + metformina in sostituzione al trattamento con glibenclamide + fenformina abbatte i livelli di lattacidemia in soggetti diabetici tipo II (NIDDM).

60 NIDDM patients, mean age (68 +/- 3 years), BMI (25 +/- 5.1 kg/m2), fasting blood glucose (FG) (170 +/- 10 mg/dl), mean daily blood glucose (MDBG) (180 +/- 10 mg/dl), daily glycosuria (GLU) (15.6 +/- 9 g/24 hours), HbA1c (7.9 +/- 0.6%), basal (1.2 +/- 0.2 ng/ml) and stimulated (3.89 +/- 1.3 mg/ml) C peptide (CP) treated by ASS (7.5 +/- 75 mg), after a strict 4 months follow-up period, were assigned to G + M treatment (7.5 +/- 1.500 mg) during a 4 months period. During G+M treatment FG (171 +/- 13 at t0 to 165 +/- 11 mg/dl: p < 0.01 at t4) varied significantly. MDBG (180 +/- 10 at t0 to 175 +/- 12 mg/dl at t4:p < 0.05), GLU (16 +/- 9 at t0 to 11 + 6 g/24 hours at t4; p < 0.01), HbA1c (8.1 +/- 0.4 at t0 to 7.6 +/- 0.3% at t4; p < 0.01). Basal CP remained unchanged in G+M period and varied significantly during ASS period (1.3 +/- 0.3 ng/ml at t4; p < 0.01) and stimulated CP (unchanged during ASS) was reduced during G+M (4.19 +/- 0.4 to 4.04; p < 0.05). Highly significant variations were observed for LAC (28.4 +/- 2.1 at t0 to 14.9 +/- 0.6 mg/dl: p < 0.01 during G+M treatment). G+M therapy was found to be more effective and safer than ASS therapy in regard to glucose metabolism and lactate production in a selected group of NIDDM patients.