Immunologic biomarkers for clinical and therapeutic management of psoriasis.

BACKGROUND: The therapeutic management of psoriasis includes conventional treatments as well as the new generation of highly effective TNF-α inhibitors. However, psoriasis has proven to be a complex therapeutic challenge and treatment failures are not uncommon. Thus, laboratory biomarkers of disease progression/therapeutic efficacy may greatly help in the clinical management of psoriasis. AIMS: To identify laboratory biomarkers for clinical management and therapeutic monitoring of psoriasis. METHODS: An observational study performed on 59 patients, presenting moderate to severe psoriasis, undergoing treatment with anti-TNF-α agents (etanercept, adalimumab, and infliximab). Soluble and cellular immune/inflammatory parameters were assessed at baseline and after 12 and 24 weeks of treatment. RESULTS: Clinical efficacy was achieved in 88% of the subjects at 12 weeks, reaching 90% after 24 weeks. IL-6 and IL-22, which were elevated at baseline, were significantly reduced, in association with a significant decrease of CLA+ T cells and an increase of Treg lymphocytes. T, B, and NK cell subsets and T cell response to recall antigens did not show any evidence of immune suppression. CONCLUSIONS: Immune/inflammatory parameters including IL-6 and IL-22, CLA+ T cells, and Treg lymphocytes may prove to be valuable laboratory tools for the clinical and therapeutic monitoring of psoriasis.

Parallel conduction of the phase I preventive and therapeutic trials based on the Tat vaccine candidate.

The native HIV-1 Tat protein was chosen as vaccine candidate for phase I clinical trials in both uninfected (ClinicalTrials.gov identifier: NCT00529698) and infected volunteers (ClinicalTrials.gov identifier: NCT00505401). The rationale was based on the role of Tat in the natural infection and AIDS pathogenesis, on the association of Tat-specific immune responses with the asymptomatic stage and slow-progression rate as well as on its sequence conservation among HIV clades (http://www.hiv1tat-vaccines.info/). The parallel conduction in the same clinical centers of randomized, double blind, placebo-controlled phase I studies both in healthy, immunologically competent adults and in HIV-infected, clinically asymptomatic, individuals represents a unique occasion to compare the vaccine-induced immune response in both the preventive and therapeutic setting. In both studies, the same lot of the native Tat protein was administered 5 times, every four weeks, subcute (SC) with alum adjuvant or intradermic (ID), in the absence of adjuvant, at 7.5 microg, 15 microg or 30 microg doses, respectively. The primary and secondary endpoints of these studies were the safety and immunogenicity of the vaccine candidate, respectively. The study lasted 52 weeks and monitoring was conducted for on additional 3 years. The results of both studies indicated that the Tat vaccine is safe and well tolerated both locally and systemically and it is highly immunogenic at all the dosages and by both routes of administration. Vaccination with Tat induced a balanced immune response in uninfected and infected individuals. In particular, therapeutic immunization induced functional antibodies and partially reverted the marked Th1 polarization of anti-Tat immunity seen in natural infection, and elicited a more balanced Th1/Th2 immune response. Further, the number of CD4 T cells correlated positively with anti-Tat antibody titers. Based on these results, a phase II study is ongoing in infected drug-treated individuals (http://www.hiv1tat-vaccines.info/).

Effect of coronary percutaneous revascularization on interferon-gamma and interleukin-10 producing CD4+ T cells during acute myocardial infarction.

T lymphocytes play an important role in the induction and progression of acute coronary syndromes (ACS). To gain insight into how different T cell subsets can influence ACS, we analyzed the frequencies of circulating CD4+ T cells producing either pro-inflammatory interferon(IFN)-gamma or anti-inflammatory interleukin (IL)-10 in subjects presenting with ST-elevation myocardial infarction (STEMI). The effect of coronary bare metal (BS) and paclitaxel-eluting stent (PES) on the balance between CD4+IFN-gamma+ and CD4+IL-10+ lymphocytes was also investigated. Peripheral blood mononuclear cells (PBMC) were isolated from 38 consecutive patients with STEMI before and 48 hrs or 6 days after implantation of either BS or PES. Twenty patients with no history of coronary artery disease were included as basal controls. PBMC were stimulated in vitro with anti-CD3/anti-CD28 monoclonal antibodies, and CD4+IFN- gamma+ or CD4+IL-10+ T cells were detected by flow cytometry intracellular staining. The frequency of peripheral CD4+IL-10+ T cells was significantly higher in STEMI patients as compared with controls. Conversely, the frequency of CD4+IFN-gamma+ T lymphocytes did not differ between STEMI and subjects without history of coronary artery disease. Six days after the revascularization procedure, the percentage of CD4+IL-10+ T cells was significantly decreased in BS but not in the PES group, whereas the relative percentage of CD4+IFN-gamma+ T lymphocytes were diminished in both groups as compared with baseline levels. Our data indicate that STEMI is associated with a peripheral expansion of CD4+IL-10+ T lymphocytes, and that primary coronary revascularization with implantation of either BS or PES is followed by a reduction in circulating CD4+IFN-gamma+ T lymphocytes. PES implantation, however, appears to inhibit the relative decrease of the IL-10 producing lymphocyte as observed in BS implanted patients, shifting the balance between pro-inflammatory and anti-inflammatory T cell populations in favor of the latter.

Integrin beta2-chain (CD18) over-expression on CD4+ T cells and monocytes after ischemia/reperfusion in patients undergoing primary percutaneous revascularization.

beta2-integrin subunit (CD18) plays an essential role in leukocyte recruitment and adhesion in sites of endothelial injury. We analyzed the surface expression of CD18 on T lymphocytes and monocytes in a series of patients presenting acute coronary syndrome (ACS) who underwent primary percutaneous intervention (PCI) for coronary artery revascularization. We found that basal CD18 expression on peripheral blood-derived CD4+ (but not CD8+) T lymphocytes was significantly increased in ACS patients as compared with age-matched healthy volunteers. During primary PCI, a significant increase in CD18 molecule density was detected immediately after balloon deflation (reperfusion) on both CD4+ T cells and monocytes obtained from the right atrium (RT) as compared with basal values. These data suggest that upregulation of CD18 molecules plays an important role in local recruitment of CD4+ T cells and monocytes to the site of endothelial damage after ischemia/reperfusion, therefore being responsible, at least in part, for the inflammatory-mediated complications associated with primary PCI.

The immunology of HIV-infected long-term non-progressors--a current view.

Long-term non-progressors (LTNP) are human immunodeficiency virus (HIV)-infected individuals characterized by the absence of disease, low viral loads and stable or even increasing CD4(+) T cell counts for prolonged periods of time. In these subjects, an HIV-specific immune response which is either stronger or directed against a wider array of viral epitopes than that seen in progressors, can be often detected. Here, we summarize the characteristics of HIV-specific CD4(+) and CD8(+) T cell responses in LTNP, and discuss how a highly effective T cell-mediated immune response against HIV might contribute to the establishment of this particular condition.

Apoptotic cells overexpress vinculin and induce vinculin-specific cytotoxic T-cell cross-priming.

Here we show that apoptotic cells overexpress vinculin and are ingested by dendritic cells, which subsequently cross-prime vinculin-specific cytotoxic T lymphocytes (CTLs). Successful cross-priming requires that the apoptotic cells provide maturation signals to dendritic cells through CD40-CD40 ligand (CD40L) interactions. If apoptotic cells are CD40L-, the help of a third T cell is needed for priming, indicating a regulatory role for apoptotic cells in determining priming or tolerance. Vinculin-specific CTL priming is also related to apoptosis in vivo, given that in HIV-seropositive individuals, the frequency of specific CTLs depends on the proportion of peripheral CD40L+ apoptotic cells.

Spreading of HIV-specific CD8+ T-cell repertoire in long-term nonprogressors and its role in the control of viral load and disease activity.

Long-term non-progressors (LTNP) represent a minority of human immunodeficiency virus (HIV) infected individuals characterized by stable or even increasing CD4+ T-cell count and by stronger immune responses against HIV than progressors. In this study, HIV-specific effector CD8+ T cells, as detected by both a sensitive ex vivo enzyme-linked immunospot (ELISPOT) assay and specific major histocompatibility complex (MHC) peptide tetramers, were at a low frequency in the peripheral blood of LTNP, and recognized a lower number of HIV peptides than their memory resting cell counterparts. Both factors may account for the lack of complete HIV clearance by LTNP, who could control the viral spread, and displayed a higher magnitude of cytotoxic T lymphocyte (CTL) responses than progressors. By combining cell purification and ELISPOT assays this study demonstrates that both effector and memory resting cells were confined to a CD8+ population with memory CD45RO+ phenotype, with the former being CD28- and the latter CD28+. Longitudinal studies highlighted a relatively stable HIV-specific effector repertoire, viremia, and CD4+ T-cell counts, which were all correlated with maintenance of nonprogressor status. In conclusion, the analysis of HIV-specific cellular responses in these individuals may help define clear correlates of protective immunity in HIV infection.

Virus-specific CD8(+) T cells with type 1 or type 2 cytokine profile are related to different disease activity in chronic hepatitis C virus infection.

The present study demonstrates that the quality of the virus-specific CD8(+) T cell responses, as detected by both enzyme-linked immunospot assay and specific MHC-peptide tetramers, changed in relation to the different disease activity in chronically hepatitis C virus-infected patients. Indeed, both the serum alanine transaminase and the hepatic flogosis levels were related directly to the frequencies of peripheral memory effector CD8(+) T cells producing IFN-gamma (Tc1), but inversely to the frequencies of those producing both IL-4 and IL-10 (Tc2). Longitudinal studies highlighted that Tc1 or Tc2 responses fluctuate in relation to the different phases of the disease in the same individual. Furthermore, the Tc1 or Tc2 phenotype correlates with tetramer-positive cells expressing either CXCR3 or CCR3, promoting differential tissue localization of these cells and the maintenance of T cell homeostasis. Finally, studies at the level of liver-infiltrating lymphocytes indicated that they produced both IFN-gamma and IL-4 with an evident bias towards the Tc1-like phenotype. Our studies suggest that the progressive fluctuation of Tc1 and Tc2 responses may play a fundamental role in maintaining a long-lasting low-level liver inflammation, and may constitute the basis for new therapeutic strategies of immune regulation.

Long-term follow-up of autoimmune thrombocytopenic purpura (ATP) patients submitted to splenectomy.

We studied the general outcome in 94 adult patients with autoimmune thrombocytopenic purpura (ATP) submitted to splenectomy. Of 84/94 patients who presented a complete or partial response 30 d after splenectomy, 16 (19%) showed one or more relapses. The clinical situation of the 81 patients still under observation is as follows: 13 unresponsive, 60 completely or partially responsive, without relapses during the follow-up, 8 completely or partially responsive after one or more relapses. No correlation was found between the favourable splenectomy outcome and age at splenectomy, the diagnosis-splenectomy interval and initial response to corticosteroids. The probability of disease-free survival is 83%, projected at 10 yr, while the overall survival is 93%, projected at 10 yr. PAIgG levels of the normal subjects and of responding patients were found to be similar, while in the groups of non-responding/relapsing patients, significantly higher values of PAIgG were detected, as compared to the control group.

Vulvar squamous carcinoma: prognostic role of DNA content.

DNA nuclear content was evaluated on 46 paraffin-embedded blocks of vulvar cancer by means of flow cytometry. Fifteen of 44 evaluable samples (34%) were found to have an aneuploid DNA pattern. Aneuplody showed a statistically significant relationship with tumor grading (P = 0.0004) and defined a subset of patients who have pathological characteristics of high risk, such as advanced stage of disease, deepest stromal invasion, or positive inguinal nodes. However, when a multivariate regression model was used, ploidy status did not have any prognostic role, while FIGO staging system was confirmed to be the strongest independent prognostic factor (P = 0.009). The integration of a panel of cell kinetic parameters with traditional features is worth investigating on a larger population.

Study of cell kinetics in the normal colorectal mucosa of subjects at risk of developing colorectal carcinoma.

This report examines the 3H-thymidine-labeling index (LI), the flow cytometric S-phase cell fraction, and DNA ploidy in the normal colorectal mucosa of three groups of subjects: normal subjects (group A), patients with adenomas (group B) and patients with cancer (group C). The total LI and the LI for crypt compartment were investigated. The former LI was similar in the three groups while that for crypt compartment was significantly higher in the patients with adenomas (compartment 3), and in those with cancer (compartments 3 and 4). All of the mucosas were diploid and no significant relationship was found between the LI and the flow cytometric S-phase values, considered for each group. These data suggest that an upwards expansion of the proliferative compartment seems to be an indicator of cancer risk. In contrast, the variations of the ploidy and S-phase fraction do not appear to be important risk factors in the three groups of subjects studied.