Positive and negative intergroup contact and newcomer immigrants' psychological adjustment.

OBJECTIVES: The present research investigates the associations between immigrants' positive and negative contact with the majority group and their psychological well-being, as indicators of their psychosocial adjustment to the host society. Perceived personal discrimination and relative deprivation in comparison to the majority group are assessed as mediators of the associations between intergroup contact and psychological well-being. METHOD: We conducted a three-wave longitudinal study with newcomer African immigrants living in Italy (N = 240; 61.7% men) with age ranging from 18 to 40 years old. RESULTS: Evidence showed that, across three waves, immigrants' negative contact with Italian natives was longitudinally associated with lower well-being and positive intergroup contact. In turn, well-being was related to immigrants' lower perceptions of relative deprivation across waves. Positive contact with Italian natives was not significantly associated with immigrants' well-being, but it was associated with higher perceived relative deprivation, which was associated with lower well-being. CONCLUSIONS: Overall, the results provide insight into the links between differently valenced contact and the psychological well-being of newcomer immigrants. Furthermore, the findings address assumptions about the primacy of negative contact in undermining social attitudes and the important role of positive contact in promoting awareness of the disadvantaged group's situation. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Antecedents of positive and negative intergroup contact: Evidence from a diary study.

In our current globalised, multicultural world, understanding antecedents of reciprocal interactions between native people and people of immigrant background is a major issue, because intergroup contact plays a crucial role in building inclusive societies. In this vein, using daily diary data, we examined the relation between the number of daily positive and negative interactions of White British majority (N = 744) and Asian British minority people (N = 582) with members of the respective outgroup, with RWA, SDO, perceived ingroup norms, neighbourhood diversity and contextual deprivation. Results showed that for the majority group, ingroup norms in favour of intergroup contact were positively associated with positive intergroup encounters, whereas Right Wing Authoritarianism (RWA) was positively associated with negative intergroup contact. Neighbourhood diversity was positively associated with positive and negative intergroup encounters. Moreover, RWA moderated the relationship between neighbourhood diversity and both positive and negative contact of White British people. For the minority group, ingroup norms were positively associated with positive intergroup contact, and the relationship between ingroup norms and negative contact was moderated by SDO. Overall, different factors affect positive and negative intergroup contact of majority and minority groups. We discuss the implications of the findings for future research and interventions.

Intergroup contact in multiple adolescents' contexts: The Intergroup Contact Interactions Scale (ICIS).

In the present contribution, we aimed to test the psychometric properties of the Intergroup Contact Interactions Scale (ICIS). The ICIS is a tool that can easily be administered to assess ethnic minority and majority adolescents' positive and negative intergroup contact in both school and out-of-school contexts. Study I included 169 adolescents in Italy (40.2% ethnic minority adolescents; 51.5% female; M age = 14.41) and provided initial support for the two-factor structure (i.e., positive and negative contact) of the ICIS in both school and out-of-school contexts. Study II, conducted with a sample of 1,037 adolescents in Italy (26.5% ethnic minority adolescents; 59.7% female; M age = 14.58), indicated that the fit of the two-factor ICIS structure was excellent for both school and out-of-school contexts. Measurement invariance across ethnic minority and majority adolescents was also established. Convergent validity was also ascertained by highlighting meaningful associations of adolescents' positive and negative contact with the quantity of contact as well as with their perceptions regarding parents' positive and negative contact with outgroup members. Study III, involving a sample of 641 adolescents in Turkey (32.9% ethnic minority adolescents; 69.6% female; M age = 15.51), supported the two-factor structure, as well as convergent validity, of the ICIS in both contexts. Measurement invariance across ethnic groups was also established. Overall, these studies suggest that the ICIS is a reliable measure for studying positive and negative intergroup contact among ethnic minority and majority adolescents across school and out-of-school contexts.

Viro-immunological response of drug-naive HIV-1-infected patients starting a first-line regimen with viraemia >500,000 copies/ml in clinical practice.

BACKGROUND: Virological success (VS) and immunological reconstitution (IR) of antiretroviral-naive HIV-1-infected patients with pre-therapy viral load (VL) >500,000 copies/ml was assessed after 12 months of treatment according to initial drug-class regimens. METHODS: An observational multicentre retrospective study was performed. VS was defined as the first VL <50 copies/ml from treatment start. IR was defined as an increase of at least 150 CD4+ T-lymphocytes from treatment start. Survival analysis was used to estimate the probability and predictors of VS and IR by 12 months of therapy. RESULTS: 428 HIV-1-infected patients were analysed. Patients were grouped according to the different first-line drug-classes used: a non-nucleoside reverse transcriptase inhibitor (NNRTI) plus two nucleoside reverse transcriptase inhibitors (NRTIs; NNRTI-group; n=105 [24.5%]); a protease inhibitor (PI) plus two NRTIs (PI-group; n=260 [60.8%]); a four-drug regimen containing a PI-regimen plus an integrase inhibitor (PI+INI-group; n=63 [14.7%]). Patients in the PI-group showed the lowest probability of VS (PI-group: 72.4%; NNRTI-group: 75.5%; PI+INI-group: 81.0%; P<0.0001). By Cox regression, patients in PI+INI and NNRTI-groups showed a higher adjusted hazard ratio (95% CI) of VS compared to those in the PI-group (PI+INI-group: 1.48 [1.08, 2.03]; P=0.014; NNRTI-group: 1.37 [1.06-1.78]; P=0.015). The probability of IR was 76.2%, and was similar among groups. Patients with AIDS showed a lower adjusted hazard ratio (95% CI) of IR compared to non-AIDS presenters (0.70 [0.54, 0.90]; P=0.005). CONCLUSIONS: In this multicentre retrospective study, patients with viraemia >500,000 copies/ml who start a first-line regimen containing PI+INI or NNRTI yield a better VS compared to those receiving a PI-based regimen.

Perceiving mixed valence emotions reduces intergroup dehumanisation.

To deny others' humanity is one of the most heinous forms of intergroup prejudice. Given evidence that perceiving various forms of complexity in outgroup members reduces intergroup prejudice, we investigated across three experiments whether the novel dimension of emotional complexity, or outgroup members' joint experience of mixed-valence emotions, would also reduce their dehumanisation. Experiment 1 found that perceiving fictitious aliens' experience of the same primary emotions (e.g. sadness) presented in mixed vs. non-mixed valence pairs led to reduced prejudice via attenuated dehumanisation, i.e. attribution of uniquely human emotions. Experiment 2 confirmed these results, using an unfamiliar real-world group as an outgroup target. Experiment 3 used a familiar outgroup and found generally similar effects, reducing social distance through reduced dehumanisation. These processes suggest that an alternate route to reduced dehumanising of outgroups might involve presenting mixed valence emotions.

Humanizing Outgroups Through Multiple Categorization: The Roles of Individuation and Threat.

In three studies, we examined the impact of multiple categorization on intergroup dehumanization. Study 1 showed that perceiving members of a rival university along multiple versus simple categorical dimensions enhanced the tendency to attribute human traits to this group. Study 2 showed that multiple versus simple categorization of immigrants increased the attribution of uniquely human emotions to them. This effect was explained by the sequential mediation of increased individuation of the outgroup and reduced outgroup threat. Study 3 replicated this sequential mediation model and introduced a novel way of measuring humanization in which participants generated attributes corresponding to the outgroup in a free response format. Participants generated more uniquely human traits in the multiple versus simple categorization conditions. We discuss the theoretical implications of these findings and consider their role in informing and improving efforts to ameliorate contemporary forms of intergroup discrimination.

Meningitis Caused by Toscana Virus Is Associated with Strong Antiviral Response in the CNS and Altered Frequency of Blood Antigen-Presenting Cells.

Toscana virus (TOSV) is a Phlebotomus-transmitted RNA virus and a frequent cause of human meningitis and meningoencephalitis in Southern Europe during the summer season. While evidence for TOSV-related central nervous system (CNS) cases is increasing, little is known about the host defenses against TOSV. We evaluated innate immune response to TOSV by analyzing frequency and activation of blood antigen-presenting cells (APCs) and cytokine levels in plasma and cerebrospinal fluid (CSF) from patients with TOSV neuroinvasive infection and controls. An altered frequency of different blood APC subsets was observed in TOSV-infected patients, with signs of monocytic deactivation. Nevertheless, a proper or even increased responsiveness of toll-like receptor 3 and 7/8 was observed in blood APCs of these patients as compared to healthy controls. Systemic levels of cytokines remained low in TOSV-infected patients, while levels of anti-inflammatory and antiviral mediators were significantly higher in CSF from TOSV-infected patients as compared to patients with other infectious and noninfectious neurological diseases. Thus, the early host response to TOSV appears effective for viral clearance, by proper response to TLR3 and TLR7/8 agonists in peripheral blood and by a strong and selective antiviral and anti-inflammatory response in the CNS.

Four-drugs regimen containing raltegravir is highly effective in HIV patients starting therapy with >500,000 copies/mL viral load.

INTRODUCTION: Assessing virological response of four-drugs antiretroviral regimen that include raltegravir (RAL) in naïve patients with high viral load (>500,000 copies/mL) selected from a multicentre Italian database. METHODS: Naïve patients with HIV RNA>500,000 copies/mL, who began standard antiretroviral regimens either based on non-nucleoside reverse transcriptase inhibitors (NNRTI) or boosted-PI (PI/r), or a standard regimen plus RAL between 2008 and 2013 were analyzed. Observation was censored at 12 months and the percentage of patients who achieved a viral load below the limit of detection (BLD) was calculated. Virological failure was defined as two consecutive viral loads>40 copies/mL. RESULTS: Overall, 179 patients were included (13% with primary HIV infection (PHI), and 42.5% with AIDS diagnosis). Of them, 156 started standard three-drugs antiretroviral regimen (75.6% PI/r-based, 24.4% NNRTI-based. Among patients with PHI, 23 patients (12.8%), 6 (25%) started a four-drugs antiretroviral regimen containing both RAL and PI/r. Patients' characteristics were as follows: males 74%, median age 42 years (IQR 35-51), sexually transmission 75.1%, median CD4 count 156 cells/µL (IQR 47-368) and median HIV-RNA 6.1 log10 copies/mL (IQR 5.8-6.4). 91 of 179 patients (50.8%) reached BLD viral load during the twelve months of observation. Three patients (1.7%) who began regimens PI/r-based with three-drugs had virological rebound after reaching BLD viral load. By use of survival analysis, we show that those patients who added RAL to the standard regimen have reached the primary end point faster (mean 8.4 months (95% CI 7.2-9.6) vs 11.4 (95% CI 11.0-11.8) in PI group and 10.3 (95% CI 9.4-11.1) in NNRTI group; p<0.001, Figure 1). In the adjusted analysis, the choice of a standard regimen versus a four-drugs regimen was driven only by higher baseline viral load (OR. 9.05; 95% CI 2.41-37.41; p=0.001). CONCLUSIONS: Only half of the naïve patients who began antiretroviral therapy having >500,000 copies/mL HIV-RNA had virological success at 12 months. The success was reached faster using the RAL-containing four-drugs regimen, suggesting that strengthening the initial regimen could be an option in patients with very high viral load to improve virological response. Probability of HIV viral load below the limit of detection in naïve HIV-1 patients with viral loads >500,000 copies/mL treated with a 4-drugs regimen containing raltegravir versus standard therapy with PI/ or NNRTI.

Badly off or better off than them? The impact of relative deprivation and relative gratification on intergroup discrimination.

This research examines for the 1st time the effects of relative deprivation and relative gratification, based on social comparison, on implicit and overt forms of discrimination toward the outgroup in a minimal group setting. Study 1 showed that compared to a control condition, relative deprivation and relative gratification enhanced implicit discrimination-measured through variations of linguistic abstraction in intergroup descriptions. Whereas both relative deprivation and relative gratification produced linguistic ingroup favoritism, linguistic productions of relatively deprived groups also conveyed outgroup derogation. Study 2 showed that relatively deprived and relatively gratified groups were overtly discriminatory in intergroup allocations of negative outcomes. The effects of relative deprivation were mediated by perceived intergroup rivalry and, in part, by perceived common fate. Perceived common fate partly accounted for the effects of relative gratification. Study 3 focused on mediators of relative gratification. First, members of relatively gratified (vs. control) groups worried about losing the ingroup advantage, which together worked as sequential mediators of discrimination. Second, relatively gratified groups reported higher existential guilt, which, in turn, was related to expectations of discrimination by the relatively deprived outgroup, and these sequentially mediated the effects of relative gratification. Overall, these studies highlight that both relative deprivation and relative gratification enhance intergroup discrimination and contribute to the understanding of the underlying processes.

Attitudes toward Arab ascendance: Israeli and global perspectives.

Arab nations are decades behind many other previously colonized nations in developing stronger economies, more democratic institutions, and more autonomy and self-government, in part as a result of external interference. The year 2011 brought the potential for greater Arab autonomy through popular uprisings against autocratic governments in Tunisia, Egypt, and Yemen, and through the Palestinian request for state recognition by the United Nations. We examined the psychology of support for Arab ascendancy among adults in 14 nations in the Balkans, the Middle East, Asia, Oceania, Europe, and North America. We predicted and found that people low on social dominance orientation endorsed forming an independent Palestinian state and desired that the Arab uprisings succeed. Rejection of ideologies that legitimize outside interference with Arabs mediated this support. Measures and model results were robust across world regions. We discuss theoretical implications regarding the advent of new ideologies and extending social dominance theory to address international relations.

Imported rickettsioses in Italy.

BACKGROUND: In Italy few cases of rickettsioses have been reported in travellers and autochthonous cases are attributed predominantly to Rickettsia conorii, the agent of Mediterranean spotted fever. METHOD: The purpose of this study was to investigate some epidemiological and clinical features of tick-borne spotted fever group rickettsiosis acquired abroad or in Italy. Serum specimens collected prospectively from patients with suspected rickettsioses were tested by immunofluorescence assay. A definitive diagnosis was made on the basis of positive serological test results at the WHO collaborative centre for rickettsial diseases, Marseille, France. We compared the clinical features of patients with confirmed rickettsioses and those showing typical clinical symptoms/signs without definitive diagnose. RESULTS: Eight of 26 patients suspected cases had confirmed rickettsioses. All patients were travellers returning from southern Africa (75% Rickettsia africae). Inoculation eschars were significantly more common in patients with confirmed rickettsioses (p = 0.004). CONCLUSIONS: Our study demonstrates that R. africae is the most frequent rickettsia observed in Italian travellers. Prior to receiving the laboratory results, physicians should start empirical treatment on the basis of epidemiologic data (e.g., travel history to Africa), and clinical findings compatible with rickettsioses (e.g., eschars).

CD4+ T-cell differentiation, regulatory T cells and gag-specific T lymphocytes are unaffected by CD4-guided treatment interruption and therapy resumption.

OBJECTIVES: Despite limiting exposure to antiretroviral drugs, structured treatment interruptions can influence multiple aspects of T-cell immunity, particularly those regarding CD4(+) T lymphocytes. We evaluated the impact of CD4-guided treatment interruption (CD4-GTI) and treatment resumption on regulatory T cells (Tregs), T-lymphocyte activation, differentiation and polyfunctional gag-specific response. METHODS: Patients were analyzed just prior to treatment interruption, at 2 and 6 months after treatment interruption, just prior to treatment resumption and at 2 and 6 months after treatment resumption. Thawed peripheral blood mononuclear cells were stained immediately for phenotype analysis or stimulated with HIV-gag peptides and analyzed by polychromatic flow cytometry. RESULTS: Treatment interruption resulted in a CD4(+) cell count decrease and plasma viral load (pVL) increase, but did not preclude a good immune reconstitution and a complete suppression of pVL after treatment resumption. Treatment interruption did not influence CD4(+) T-cell differentiation and Treg subsets. During treatment interruption, gag-specific CD4(+) T cells were not lost, although the frequency of HIV-specific CD8(+) cells increased. Most gag-specific CD4(+) T cells were potentially cytotoxic (CD107a(+)) and were not influenced by pVL or by HAART. Most helper (CD154(+)) gag-specific CD4(+) T lymphocytes did not produce interferon-γ or interleukin-2. CONCLUSION: CD4-GTI did not cause depletion of memory cells, Tregs or HIV-specific CD4(+) cells and, on the contrary, could induce HIV-specific responses. If guided by CD4(+) T-cell count, treatment interruption does not provoke irreversible immune damages.

NK-cell phenotype at interruption underlies widely divergent duration of CD4+-guided antiretroviral treatment interruption.

Long-term side effects may represent a relevant burden of antiretroviral treatment (ART) in HIV-infected patients with good CD4 immune reconstitution over extended time spans. CD4-guided treatment interruption (TI) has been evaluated to address this point and may result in a wide spectrum of time off ART in different patient cohorts. We studied whether differences in innate immune responses, in particular NK cells, are associated to patterns of longer (LoTI) or a shorter (ShTI) TI. Clinical cohort parameters were analyzed on a group of patients widely diverging for TI duration (<9 versus >18 months) on samples before TI, including NK-cell analysis and function by natural cytotoxicity receptor (NCR)-triggered γ-IFN production. Although persistently reduced NCR expression (NKp30) and function were observed in both LoTI and ShTI patients on ART compared with healthy donors, relevant differences were observed at baseline TI in those patients who subsequently developed LoTI course. Lower expression of NKG2D and NKp46 on NK cells. This also translates in reduced γ-IFN production in redirected functional assays. Thus, differences in innate immune balance exist during ART, may be associated to differential control of HIV infection and their understanding could explain clinical differences in individual patients that are not reflected by CD4(+) cell counts alone.

Cytotoxic granule release dominates gag-specific CD4+ T-cell response in different phases of HIV infection.

BACKGROUND: The activity of virus-specific T lymphocytes, among which those capable of a polyfunctional response against the viral protein gag, is crucial to control HIV infection. OBJECTIVE: The objective of this study is to investigate the polyfunctionality of gag-specific T cells in different phases of HIV infection, analyzing markers related to T-helper cell 1 (Th1) and degranulation/cytotoxicity, and the production of Th1 cytokines in peripheral blood lymphocytes from patients experiencing an acute primary infection, long-term nonprogressors, patients naive for antiretroviral drugs, and patients taking HAART. MATERIALS AND METHODS: Cells were stimulated with a pool of gag-derived peptides or with a superantigen (staphylococcal enterotoxin B). Using eight-color polychromatic flow cytometry, we analyzed the expression of interleukin-2, interferon-gamma, CD154, and CD107a by CD4 and CD8 T cells. RESULTS: The main finding was that in all HIV-positive patients, about half gag-specific CD4 T cells were CD107a, that is, able to degranulate. CD4CD154 cells unable to produce Th1 cytokines were the second most represented population. Truly polyfunctional CD4 T cells were very rare and present only in a few long-term nonprogressors. Superantigen stimulation showed that CD4 T lymphocytes from all patients displayed a typical Th response, including interleukin-2 and interferon-gamma production, lacking CD107a expression. CONCLUSION: In all the aforementioned phases of HIV infection, the large majority of gag-specific CD4 T lymphocytes cannot be identified by the sole expression of interleukin-2 and interferon-gamma, which is early impaired. Degranulation and helper functions other than Th1 cytokine production are the predominant features of HIV-specific CD4 lymphocytes.

Transmitted HIV Type 1 drug resistance and Non-B subtypes prevalence among seroconverters and newly diagnosed patients from 1992 to 2005 in Italy.

The patterns of transmitted drug-resistant (TDR) HIV-1 variants, non-B subtype spread, and epidemiological trends were evaluated either in seroconverters or in newly diagnosed individuals in Italy over a 13-year period. We analyzed 119 seroconverters, enrolled from 1992 to 2003 for the CASCADE study, and 271 newly diagnosed individuals of the SPREAD study (2002-2005), of whom 42 had a known seroconversion date. Overall, TDR was 15.1% in the CASCADE and 12.2% in the SPREAD study. In the 1992-2003 period, men having sex with men (MSMs) and heterosexuals (HEs) were 48.7% and 36.8%, respectively; TDR was found to be higher in MSMs compared to HEs (78.9% vs. 21%, p = 0.006). The same groups were 39.1% and 53.3% in the SPREAD study; however, no association was detected between modality of infection and TDR. Overall, 9.2% and 22.1% of individuals harbored a non-B clade virus in the CASCADE and SPREAD study, respectively. As evidence of onward transmission, 40% (24/60) of non-B variants were carried by European individuals in the latter study; among these patients the F1 subtype was highly prevalent (p = 0.00001). One of every eight patients who received a diagnosis of HIV-1 in recent years harbored a resistant variant, reinforcing the arguments for baseline resistance testing to customize first-line therapy in newly infected individuals. The spread of non-B clades may act as a dilution factor of TDR concealing the proportion of TDR in seroconverters and MSMs.

Performance of tests for latent tuberculosis in different groups of immunocompromised patients.

BACKGROUND: Immunocompromised persons infected with Mycobacterium tuberculosis (MTB) have increased risk of tuberculosis (TB) reactivation, but their management is hampered by the occurrence of false-negative results of the tuberculin skin test (TST). The T-cell interferon (IFN)-gamma release blood assays T-SPOT.TB (TS.TB) [Oxford Immunotec; Abingdon, UK] and QuantiFERON-TB Gold In-Tube (QFT-IT) [Cellestis Ltd; Carnegie, VIC, Australia] might improve diagnostic accuracy for latent TB infection (LTBI) in high-risk persons, although their performance in different groups of immunocompromised patients is largely unknown. METHODS AND RESULTS: Over a 1-year period, we prospectively enrolled patients in three different immunosuppressed groups, as follows: 120 liver transplantation candidates (LTCs); 116 chronically HIV-infected persons; and 95 patients with hematologic malignancies (HMs). TST, TS.TB, and QFT-IT were simultaneously performed, their results were compared, and intertest agreement was evaluated. Overall, TST provided fewer positive results (10.9%) than TS.TB (18.4%; p < 0.001) and QFT-IT (15.1%; p = 0.033). Significantly fewer HIV-infected individuals had at least one positive test (9.5%) compared with LTCs (35.8%; p < 0.001) and patients with HMs (29.5%; p < 0.001). Diagnostic agreement between tests was moderate (kappa = 0.40 to 0.65) and decreased in the HIV-infected group when the results of the TS.TB were compared with either TST (kappa = 0.16) or QFT-IT (kappa = 0.19). Indeterminate blood test results due to low positive control values were significantly more frequent with QFT-IT (7.2%) than with TS.TB (0.6%; p < 0.001). CONCLUSIONS: Blood tests identified significantly more patients as being infected with MTB than TST, although diagnostic agreement varied across groups. Based on these results, we recommend tailoring application of the new blood IFN-gamma assays for LTBI in different high-risk groups and advise caution in their current use in immunosuppressed patients.

HIV coinfection and antiretroviral therapy enhances liver steatosis in patients with hepatitis C, but only in those infected by HCV genotype other than 3.

BACKGROUND: Liver steatosis is a common finding in hepatitis C virus (HCV) infection and is associated with an increased progression of the disease. However, HCV genotype 3 steatosis presents a peculiar and virus-induced pathogenesis. We analysed the effect of HIV coinfection and antiretroviral therapy on hepatic steatosis and the effect of the steatosis on fibrosis in patients with or without HCV genotype 3 infection. METHODS: All consecutive HIV-infected and uninfected patients who had undergone a liver biopsy for evaluation of HCV infection at the Infectious Diseases Clinic (Modena, Italy) were included in this study. Primary outcomes were the presence or absence of steatosis or the presence of moderate or advanced fibrosis. RESULTS: A total of 284 patients were enrolled: 187 infected by HCV and 97 coinfected with HIV and HCV. In HCV genotype 3 patients, only HCV-related variables, such as plasma HCV RNA levels (odds ratio [OR] per log10 1.68, P < 0.001) and estimated duration of HCV infection (OR per year 1.17, P = 0.004) were associated with steatosis. In patients infected with other HCV genotypes, steatosis was associated with older age (OR per 5 years 1.47, P < 0.001), with exposure to d-drugs in HIV-HCV-coinfected patients (OR 2.60, P = 0.04) and specifically exposure to stavudine (OR 2.76 HIV-HCV-coinfected versus not HIV-infected patients, P = 0.04). Steatosis was independently associated with bridging fibrosis only in patients infected by HCV genotype other than 3 (OR 4.03, P = 0.01). CONCLUSIONS: Hepatic steatosis, in both HCV-monoinfected and in HIV-HCV-coinfected patients, is strongly correlated with HCV genotype 3, probably through interactions between HCV virus and liver cells. HIV-related increase of steatosis in patients with HCV is probably related to antiretroviral drugs, especially stavudine, in patients infected by HCV genotype other than 3.

Immunophenotype of HIV+ patients during CD4 cell-monitored treatment interruption: role of the IL-7/IL-7 receptor system.

OBJECTIVE: To investigate immunological changes during CD4-guided therapy interruption in HIV(+) patients who suspended HAART. PATIENTS: Seventeen patients aged > 18 years, who had received HAART for at least 12 months, and had a pre-interruption CD4+ cell count > 500 cells/microl, interrupted treatment. Median nadir CD4(+) cell count was 288 cells/microl. HIV plasma viral load at discontinuation was < 50 or > 50 copies/ml. Criteria for restarting treatment were: a CD4(+) T-lymphocyte count < 350 cells/microl on two separate occasions, a clinical manifestation of AIDS, and the patient's desire to resume HAART. Eleven patients were still off therapy after 12 months (group A); according to the first criterion, six patients restarted therapy within 12 months (group B). METHODS: Haematological, viro-immunological, cytofluorimetic and molecular assays were performed at baseline and every 2 months following standard methods. Statistical analysis was performed under Stata 7.0. RESULTS: In the first 2 months of treatment interruption, a significant increase in viral load and CD8(+) lymphocyte activation occurred. Then such parameters decreased and remained stable. In all patients, a decrease in CD4(+) lymphocytes took place as well, that affected in a similar manner naive, central memory, effector memory and terminally differentiated cells. Group B always presented lower amounts of CD4(+) effector memory lymphocytes. The expression of CD127 was always higher in group A. CONCLUSIONS: The loss of CD4(+) lymphocytes upon viral rebound is equal among naive and memory subsets. Patients with higher expression of CD127, who are likely to exert a better capacity to utilize endogenous interleukin-7 by T cells, could remain off therapy for longer periods.