Enhanced levels of CCL19 in patients with advanced acquired immune deficiency syndrome (AIDS).

Based on the ability to recruit lymphocytes and dendritic cells to lymphoid tissue and to promote inflammation, we hypothesized a role for dysregulated CCL19 and CCL21 levels in human immunodeficiency virus (HIV)-infected patients with advanced immunodeficiency, and in particular in those with accompanying Mycobacterium avium complex (MAC) infection. The hypothesis was explored by studies in HIV-infected patients with and without MAC infection, as well as in vitro, examining the ability of proteins from MAC to promote CCL19 and CCL21 responses in peripheral blood mononuclear cells (PBMC) during highly active anti-retroviral therapy (HAART). Our main findings were: (i) raised serum levels of CCL19 in HIV-infected patients with CD4(+) T cell count <50 cells/µl compared with HIV-infected patients with CD4(+) T cell count >500 cells/µl and healthy controls, with particularly high levels in those with MAC infection; (ii) elevated plasma levels of CCL19 predicted a higher mortality in acquired immune deficiency syndrome (AIDS)-patients, independent of ongoing MAC infection; and (iii) marked production of CCL19 in MAC-stimulated peripheral blood mononuclear cells (PBMC) and pronounced disturbances in MAC-induced CCL19 production in PBMC from HIV patients that was partly reversed during HAART. Our findings suggest the involvement of CCL19 in AIDS patients with advanced immunodeficiency, potentially mediating both adaptive and maladaptive responses.

Class, subclass, and allelic exclusion of membrane-bound Ig of human B lymphocytes.

Membrane-bound immunoglobulins of peripheral blood B lymphocytes and of lymphocytes from an IgG chronic lymphocytic leukemia showed restriction to one immunoglobulin class, one IgG subclass, and one Gm allotype. Certain antigens in the C-terminal part of IgG Fc were not exposed on the cell surface.

Chemokines and common variable immunodeficiency; possible contribution of CCL19, CCL21 and CCR7 to immune dysregulation.

Common variable immunodeficiency (CVID) is a heterogeneous syndrome characterized by defective immunoglobulin production and high frequency of bacterial infections, autoimmunity and manifestations of chronic inflammation. The homeostatic chemokines CCL19 and CCL21 and their receptor CCR7 are associated with modulation of inflammatory responses. CVID patients have decreased proportions of CCR7(+) T cells in peripheral blood and we hypothesized a further dysregulation of CCL19/CCL21/CCR7 in CVID. Serum levels of CCL19 and CCL21 were compared in CVID patients and controls. T cell expression of CCR7 was related to clinical characteristics in CVID patients. Spleens extirpated from CVID patients were analysed for expression of CCL19, CCL21 and CCR7. Peripheral blood mononuclear cells (PBMC) from CVID patients and controls were analysed for cytokine response on stimulation with CCL19 and CCL21. The main findings were: (i) CVID patients have raised serum levels of CCL19 and CCL21 independently of features of chronic inflammation; (ii) CCL19 and CCR7 have similar expression in spleens from CVID patients and controls, while CCL21 is variably down-regulated in spleens from patients; (iii) T cell expression of CCR7 is particularly low in patients characterized by chronic inflammation in vivo; and (iv) PBMC from CVID patients had attenuated cytokine response to stimulation with CCL19 and CCL21. CVID patients have raised circulatory levels of CCL19 and CCL21, and an attenuated cytokine response to stimulation with these chemokines. Because CCR7, CCL19 and CCL21 are key mediators balancing immunity and tolerance in the immune system, the abnormalities of these mediators might contribute to the profound immune dysregulation seen in CVID.

Homeostatic chemokines CCL19 and CCL21 promote inflammation in human immunodeficiency virus-infected patients with ongoing viral replication.

CCL19 and CCL21 and their receptor CCR7 are expressed constitutively within lymphoid organs, regulating lymphocyte homing. Recent studies suggest that these chemokines may have inflammatory properties. We hypothesized a role of CCL19/CCL21 in human immunodeficiency virus (HIV) infection by promoting inflammation. We examined the expression of CCL19 and CCL21 in mononuclear cells from peripheral blood mononuclear cells (PBMC) and bone marrow mononuclear cells (BMMC) in HIV-infected patients before and during highly active anti-retroviral therapy (HAART). We also examined the ability of CCL19/CCL21 to promote inflammatory responses in these patients. PBMC from untreated HIV-infected patients (n = 29) released enhanced levels of CCL19 spontaneously compared with cells from controls (n = 20), particularly in those with symptomatic disease (n = 15, P < 0.01 versus controls). During HAART (n = 9), there was a decrease in the spontaneous CCL19 release and an increase in the phytohaemagglutinin-stimulated CCL19 release in both PBMC (P < 0.01) and BMMC (P < 0.05). In patients with enhanced HIV replication there was an increased proportion of inflammatory CD8(+)CCR7(-)CD45RA(-) T cells in peripheral blood [P < 0.01 and P < 0.05 versus controls, untreated (n = 9) and treatment failure (n = 8), respectively]. In vitro, CCL19/CCL21 promoted an inflammatory response in PBMC when accompanied by high viral load, irrespective of HAART. The HIV-tat protein significantly boosted the inflammatory effect of CCL19/CCL21 in PBMC. These findings link a dysregulated CCL19/CCL21/CCR7 system in HIV-infected patients to persistent inflammation and HIV replication, not only in untreated HIV infection, but also in treatment failure during HAART.

CXCL16 in HIV infection - a link between inflammation and viral replication.

BACKGROUND: While some chemokines are thought to be protective in HIV-infected individuals by their ability to block HIV entry into T cells and macrophages, chemokines could also have harmful effects in HIV infection through their ability to promote inflammation. Here, we examined the regulation and the effects of CXCL16, a newly discovered chemokine of the CXC family, in HIV-infected patients. MATERIALS AND METHODS: We examined serum levels of CXCL16 in clinically well-defined subgroups of HIV-infected individuals both before (n = 62) and during HAART (n = 40) as well as in age- and sex-matched healthy controls (n = 30). We also examined the effects of CXCL16 on inflammatory and anti-inflammatory cytokines and HIV replication in peripheral blood mononuclear cells (PBMC). RESULTS: Our main and novel findings were: (i) HIV-infected patients had significant raised CXCL16 levels according to disease severity and progression. (ii) During HAART, the immunological improvement was accompanied by a modest increase in CXCL16 level. (iii) While soluble CXCL16 promoted an anti-inflammatory response in PBMC from those on successful HAART, it induced an inflammatory response and enhanced HIV replication in PBMC from those with high viral load irrespectively of ongoing HAART. (iv) Recombinant HIV-tat protein significantly increased CXCL16 release in THP-1 macrophages. CONCLUSIONS: Our findings suggest a complex interaction between CXCL16 and HIV, promoting both inflammatory and anti-inflammatory effects as well as HIV replication, partly dependent on accompanying HIV replication.

Decreased serum lipocalin-2 levels in human immunodeficiency virus-infected patients: increase during highly active anti-retroviral therapy.

Although neutrophil gelatinase-associated lipocalin (NGAL) may play a pivotal role in the innate immune response, there are currently no data on NGAL levels in human immunodeficiency virus (HIV)-infected patients. In this study we aimed to examine the regulation of NGAL in HIV infection. The regulation of NGAL in HIV infection was examined by different experimental approaches, including studies in peripheral blood and mononuclear cells (MNC) from bone marrow aspirates before and during highly active anti-retroviral therapy (HAART). We found that: before initiating HAART, HIV-infected patients (n = 37) had significantly decreased serum NGAL levels compared with healthy controls (n = 26); (ii) during HAART, there was a gradual and significant increase in NGAL concentrations reaching levels comparable to those in healthy controls after 12 months; (iii) this increase was seen primarily in virological responders to HAART (HIV RNA level <200 copies/ml after 24 months); (iv) phytohaemagglutinin-stimulated NGAL release in MNC cells from bone marrow aspirates was decreased in untreated HIV-infected patients compared with healthy controls, but increased after 26 weeks on HAART; and (v) there was a significant positive correlation between neutrophil counts and NGAL levels at all time-points during HAART. We have shown decreased NGAL levels in HIV-infected patients, potentially reflecting decreased number and function of neutrophils as well as impaired bone marrow myelopoiesis. These abnormalities were reversed by successful HAART. Our findings underscore further the involvement of neutrophils and innate immunity in HIV-related immunodeficiency.

Clopidogrel increases expression of chemokines in peripheral blood mononuclear cells in patients with coronary artery disease: results of a double-blind placebo-controlled study.

BACKGROUND: Chemokines and platelet activation are both important in atherogenesis. Platelet inhibitors are widely used in coronary artery disease (CAD), and we hypothesized that the platelet inhibitor clopidogrel could modify chemokines in CAD patients. OBJECTIVES: We sought to investigate the effect of clopidogrel on the expression of chemokines and chemokine receptors in peripheral blood mononuclear cells (PBMC) in CAD patients. PATIENTS/METHODS: Thirty-seven patients with stable angina were randomized to clopidogrel (n = 18) or placebo (n = 19). PBMC, blood platelets and plasma were collected at baseline and after 7-10 days in the patients, and in 10 healthy controls. mRNA levels of chemokines and chemokine receptors in PBMC were analyzed by ribonuclease protection assays and real-time reverse transcriptase polymerase chain reaction. Platelet activation was studied by flow cytometry. RESULTS: (i) At baseline, the gene expression of the regulated on activation normally T-cell expressed and secreted (RANTES) chemokines and macrophage inflammatory peptide (MIP)-1beta in PBMC, the expression of CD62P and CD63 on platelets and the levels of platelet-derived microparticles (PMP) were elevated in angina patients comparing healthy controls; (ii) markers of platelet activation were either reduced (CD63) or unchanged (CD62P, PMP, beta-thromboglobulin) during clopidogrel therapy; (iii) in contrast, clopidogrel significantly up-regulated the gene expression of RANTES and MIP-1beta in PBMC, while no changes were found in the placebo group; (iv) a stable adenosine 5'-diphosphate metabolite attenuated the release of MIP-1beta, but not of RANTES, from activated PBMC in vitro. CONCLUSIONS: Even if we do not argue against a beneficial role for clopidogrel in CAD, our findings may suggest potential inflammatory effects of clopidogrel in CAD.

Complement activation in patients with congestive heart failure: effect of high-dose intravenous immunoglobulin treatment.

BACKGROUND: Increasing evidence implicates innate immunity in the pathogenesis of congestive heart failure (CHF). In the present study, we examined the possible role of complement, an important part of innate immunity, in CHF. METHODS AND RESULTS: Complement activation was analyzed in systemic and coronary circulation in 39 patients with CHF and 20 healthy control subjects. In a double-blind, placebo-controlled study, we have recently reported that high-dose intravenous immunoglobulin (IVIG) improves left ventricular ejection fraction (LVEF) in these patients. To examine if this improvement was related to IVIG-induced effects on complement, we also examined complement activation during induction (first week) and maintenance therapy (6 months) with IVIG or placebo. Our main findings were: (1) We found enhanced systemic complement activation involving classic, alternative, as well as terminal pathway in patients with CHF compared with healthy control subjects. (2) Particularly enhanced complement activation was found in coronary sinus, representing venous drainage from the heart. (3) The systemic complement activation was further enhanced during IVIG but not during placebo therapy, particularly during induction therapy. (4) Although IVIG improved LVEF in patients with CHF, the degree of IVIG-mediated complement activation was negatively correlated with this improvement of LVEF. CONCLUSIONS: This study further supports the involvement of innate immunity in the pathogenesis of CHF. Our findings suggest that complement may be added to the list of possible therapeutic targets in CHF and that future studies with specific complement inhibitors may be of interest in this disorder.

Enhanced levels of soluble and membrane-bound CD40 ligand in patients with unstable angina. Possible reflection of T lymphocyte and platelet involvement in the pathogenesis of acute coronary syndromes.

BACKGROUND: The CD40 ligand (CD40L) on activated T cells and platelets may be activating matrix metalloproteinases, inducing procoagulant activity, and be involved in the pathogenesis of acute coronary syndromes by promoting plaque rupture in atheroma. METHODS AND RESULTS: To study the role of CD40L-CD40 interaction in coronary disease, we analyzed levels of soluble (s) and membrane-bound CD40L in the peripheral blood from 29 patients with stable angina, 26 with unstable angina, and 19 controls. Our main findings follow. (1) Patients with unstable angina had significantly raised serum levels of sCD40L when compared with patients with stable angina and controls. (2) Platelets could release large amounts of sCD40L when stimulated ex vivo with the thrombin receptor-agonist peptide SFLLRN in both patients and controls. (3) Platelets in patients with unstable angina were characterized ex vivo by decreased intracellular levels and decreased SFLLRN-stimulated release of sCD40L, which may possibly represent a higher percentage of degranulated platelets in these patients. (4) T cells in patients with unstable angina had enhanced surface expression of CD40L and increased release of sCD40L on anti-CD3/anti-CD28 stimulation in vitro when compared with patients with stable angina and controls. (5) Recombinant CD40L and serum from patients with unstable angina who had high sCD40L levels induced enhanced release of monocyte chemoattractant peptide-1 from mononuclear cells, a CC-chemokine involved in the pathogenesis of atherosclerosis. CONCLUSIONS: This first demonstration of enhanced levels of soluble and membrane-bound forms of CD40L in angina patients, with particularly high levels in patients with unstable angina, suggests that CD40L-CD40 interaction may play a pathogenic role in both the long-term atherosclerotic process and in the triggering and propagation of acute coronary syndromes.

Effect of high- versus low-dose angiotensin converting enzyme inhibition on cytokine levels in chronic heart failure.

OBJECTIVES: We examined the effect of long-term treatment with two doses of the angiotensin converting enzyme (ACE) inhibitor enalapril on various immunological variables in patients with chronic congestive heart failure (CHF). BACKGROUND: Immunological mediators are increasingly recognized to play a pathogenic role in the pathophysiology of CHF. Whether ACE inhibitor therapy modifies immunological variables has not previously been investigated. METHODS: Seventy-five patients (mean age 52 +/- 11 years) with CHF were randomized between low-(5 m g daily) and high-dose (40 mg daily) enalapril in a double-blind trial. Circulating levels of immunological parameters (i.e., proinflammatory cytokines, chemokines and adhesion molecules) were measured at baseline, at 10 weeks and at the end of the study (34 weeks). RESULTS: All immunological parameters, except soluble interleukin (IL)-6 receptor, were increased in CHF compared with 21 healthy controls. During the study immunoreactive IL-6 levels decreased (p < 0.05) and soluble IL-6 receptor increased (p < 0.05) during high-dose but not during low-dose enalapril therapy. Furthermore, IL-6 bioactivity decreased only during the high-dose (p < 0.001), resulting in a significant difference in change during treatment between the two dosage groups (p < 0.001). This decrease in IL-6 bioactivity was significantly associated with decreased interventricular septum thickness as assessed by echocardiography (r = 0.56, p = 0.013). No other variables changed during treatment. CONCLUSIONS: In patients with severe CHF, high-dose enalapril therapy is associated with a significant decrease in IL-6 activity. However, despite treatment with a high-dose ACE inhibitor, a persistent immune activation exists in these patients which may be of importance for the progression of CHF.

Enhanced gene expression of chemokines and their corresponding receptors in mononuclear blood cells in chronic heart failure--modulatory effect of intravenous immunoglobulin.

OBJECTIVES: We sought to study the gene expression of chemokines and their corresponding receptors in mononuclear blood cells (MNCs) from patients with chronic heart failure (CHF), both of which were cross-sectional and longitudinal studies during therapy with intravenous immunoglobulin (IVIg). BACKGROUND: We have recently demonstrated that IVIg improves left ventricular ejection fraction (LVEF) in patients with CHF. Based on the potential pathogenic role of chemokines in CHF, we hypothesized that the beneficial effect of IVIg may be related to a modulatory, effect on the expression of chemokines and their receptors in MNCs. METHODS: We examined: 1) the gene expression of C, CC and CXC chemokines and their receptors in MNCs from 20 patients with CHF and 10 healthy blood donors; and 2) the expression of these genes in MNCs from 20 patients with CHF randomized in a double-blind fashion to therapy with IVIg or placebo for 26 weeks. RESULTS: Our main findings in CHF were: 1) markedly raised gene expression of macrophage inflammatory protein (MIP)-1alpha, MIP-1beta and interleukin (IL)-8; 2) enhanced gene expression of their corresponding receptors; 3) modulation in a normal direction of this abnormal chemokine and chemokine receptor gene expression during IVIg, but not during placebo therapy; 4) down-regulation of MIP-1alpha, MIP-1beta and IL-8 during IVIg at the protein level in plasma; and 5) a correlation between down-regulation of MIP-1alpha gene expression and improved LVEF during IVIg therapy. CONCLUSIONS: Our results further support a pathogenic role for chemokines in CHF and suggest that IVIg may represent a novel therapeutic approach, with the potential to improve LVEF in patients with CHF, possibly by modulatory effects on the chemokine network.

Interaction between chemokines and oxidative stress: possible pathogenic role in acute coronary syndromes.

OBJECTIVES: We sought to study the relationships between chemokines and oxidative stress in acute coronary syndrome. BACKGROUND: In view of existing knowledge on the participation of leukocytes and oxidative stress in the pathogenesis of acute coronary syndrome, we hypothesized that chemokines may play a role in recruiting and activating leukocytes in this disorder. METHODS: The levels of chemokines and oxidative stress were studied in 38 patients with stable and 38 with unstable angina and in 20 controls. In separate in vitro experiments the effect of chemokines on reactive oxygen species in monocytes and the effect of antioxidants on chemokine levels in these cells were also studied. RESULTS: 1) Angina patients had raised serum levels of chemokines in both cross-sectional and longitudinal testing, with particularly high levels of interleukin (IL)-8, monocyte chemoattractant protein (MCP)-1 and macrophage inflammatory peptide (MIP)-1-alpha in unstable disease. 2) T cells, and particularly monocytes, seem to contribute to the raised IL-8, MCP-1 and MIP-1-alpha levels in unstable angina. 3) Concomitantly, and significantly correlated with MCP-1 and IL-8 levels, stable and particularly unstable angina patients had decreased plasma levels of antioxidants and increased lipid peroxidation, suggesting enhanced oxidative stress. 4) Monocyte chemoattractant protein-1 enhanced the generation of O2- in monocytes from unstable angina patients, and the antioxidant glutathione-monoethyl ester suppressed the production of IL-8 and MCP-1 in these cells. CONCLUSIONS: Our findings suggest an interaction between chemokines and oxidative stress in unstable angina. This interaction may represent a vicious circle involved in the pathogenesis of acute coronary syndromes.

CXC-chemokines, a new group of cytokines in congestive heart failure--possible role of platelets and monocytes.

OBJECTIVES: The purpose of the present study was to examine the circulating levels of CXC-chemokines in patients with various degree of congestive heart failure (CHF). BACKGROUND: CXC-chemokines may be important mediators in the persistent immune activation observed in CHF patients by activation of circulating neutrophils, T-cells and monocytes and possibly by the recruitment of these cells into the failing myocardium. METHODS: Levels of interleukin (IL)-8, growth-regulated oncogene (GRO) alpha and epithelial neutrophil activating peptide (ENA)-78 were measured both in serum and in platelet-free plasma by enzyme immunoassay in 47 patients with CHF and in 20 healthy controls. RESULTS: (i) CHF patients had significantly elevated levels of all the three CXC-chemokines with IL-8 and GRO alpha showing a gradual increase along with increasing NYHA class. (ii) There was an inverse correlation between IL-8 and left ventricular ejection fraction (EF) and cardiac index (CI). (iii) Both unstimulated and lipopolysaccharide (LPS)-stimulated monocytes from CHF patients released markedly elevated amounts of all three CXC-chemokines. (iv) Platelets from patients with severe CHF were characterised by decreased content of GRO alpha and ENA-78 as well as decreased release of these chemokines upon thrombin receptor stimulation. (v) Activated platelets stimulated peripheral blood mononuclear cells in vitro to enhanced release of IL-8, and neutralising antibodies against ENA-78 inhibited this interaction. CONCLUSIONS: This study demonstrates for the first time elevated levels of CXC-chemokines in CHF, which may be of importance for progression of heart failure. Our findings further suggest that activated monocytes and platelets may contribute to enhanced CXC-chemokine levels in CHF.

Myocardial expression of CC- and CXC-chemokines and their receptors in human end-stage heart failure.

OBJECTIVES: Chemokines regulate several biological processes, such as chemotaxis, collagen turnover, angiogenesis and apoptosis. Based on the persistent immune activation with elevated circulating levels of chemokines in patients with congestive heart failure (CHF), we have hypothesised a pathogenic role for chemokines in the development of CHF. The objective of this study was to examine mRNA levels and cellular localisation of chemokines and chemokine receptors in human CHF. METHODS: We examined explanted hearts from ten patients with end-stage heart failure (all chambers) and in ten organ donors using an RNase protection assays and immunohistochemical techniques. RESULTS: Our main findings were: (i) expression of eight chemokine and nine chemokine receptor genes in both failing and nonfailing myocardium, (ii) particularly high mRNA levels of monocyte chemoattractant protein (MCP)-1 and CXC-chemokine receptor 4 (CXCR4), in both chronic failing and nonfailing myocardium, (iii) decreased mRNA levels of MCP-1 and interleukin (IL)-8 in the failing left ventricles compared to failing left atria, (iv) decreased chemokine (e.g., MCP-1 and IL-8) and increased chemokine receptor (e.g., CCR2, CXCR1) mRNA levels in failing left ventricles and failing left atria compared to corresponding chambers in the nonfailing hearts and (v) immunolocalisation of MCP-1, IL-8 and CXCR4 to cardiomyocytes. CONCLUSION: The present study demonstrates for the first time chemokine and chemokine receptor gene expression and protein localisation in the human myocardium, introducing a new family of mediators with potentially important effects on the myocardium. The observation of chemokine dysregulation in human end-stage heart failure may represent a previously unknown mechanism involved in progression of chronic heart failure.

CD4+ and CD8+ lymphocytes and HIV RNA in HIV infection: high baseline counts and in particular rapid decrease of CD8+ lymphocytes predict AIDS.

OBJECTIVE: To study the progression of HIV infection in relation to immunological and virological variables with emphasis on the role of CD8+ lymphocytes. DESIGN: Prospective follow-up from October 1991 of patients observed for at least 18 months allowing nucleoside analogue monotherapy. Peripheral CD4+ and CD8+ lymphocyte counts, HIV RNA, and soluble CD8 were analysed by statistics allowing the evaluation of serial data, avoiding time points with concurrent infections. SETTING: Tertiary university clinic. PATIENTS: Forty-nine patients were followed for 52.6 months, baseline CD4+ count of 300 x 10(6)/l, sample interval of 5.9 months (medians). MAIN OUTCOME MEASURES: AIDS, death, and CDC groups B- or C-related events. RESULTS: AIDS developed in 28% of patients. Baseline CD8+ counts above the median were significantly associated with AIDS development; the best Cox model included CD8+ cells and the log10RNA/CD4 ratio. A decline in CD8+ counts relative to baseline most significantly predicted AIDS, along with higher baseline RNA and actual CD4+ counts of less than 200 x 10(6)/l. Levels of soluble CD8 in the blood relative to total CD8+ cells significantly increased in patients developing AIDS. Death occurred in 16% of the patients, and was only predicted by high CD8+ cell counts at baseline. CDC B- and C-related events occurred in 35% of the patients and were best predicted by high baseline CD8+ counts and high RNA levels. CONCLUSIONS: The serial quantitation of CD8+ lymphocytes gave highly significant predictive information on the natural progression of HIV infection in patients with moderate to severe immune deficiency. Our data suggest that the hyperactivation of CD8+ lymphocytes is an important factor leading to a numerical decrease of CD8+ lymphocytes in progressive HIV infection.

Additive effects of IL-2 and protein kinase A type I antagonist on function of T cells from HIV-infected patients on HAART.

OBJECTIVE: To explore the basis for a possible immunomodulatory combination therapy with IL-2 and agents inhibiting protein kinase A (PKA) type I. DESIGN: Highly active antiretroviral therapy (HAART) has dramatically improved HIV therapy, but fails to eradicate the virus, and the persistence of HIV-associated immunodeficiency demonstrates the need for additional immunomodulating therapies. We have previously shown that hyperactivation of PKA type I inhibits the function of HIV-infected patient T cells. The separate and combined effect of a PKA type I-selective antagonist (Rp-8-Br-cAMPS) and Interleukin (IL)-2 on the function of T cells from HIV-infected patients on HAART was examined. METHODS: The effect of Rp-8-Br-cAMPS on anti-CD3 stimulated proliferation and IL-2 production and the combined effect with exogenous IL-2 was studied in vitro with cells from 13 HIV-infected patients on HAART and six uninfected controls. RESULTS: The PKA type I-selective antagonist improved cell proliferation (median 1.5-fold, maximal 2.8-fold) and IL-2 production (median 1.5-fold, maximal 2.4-fold) in T cells from HIV-infected patients on HAART, but not in controls. The addition of IL-2 enhanced proliferation of T cells from HIV-infected patients (approximately 1.9-fold) and that of controls (approximately 1.4-fold), but IL-2 had no effect at the concentrations produced by treatment with PKA type I antagonist. However, the combined effect of IL-2 and PKA type I antagonist was additive and resulted in a further increase in T-cell proliferation (median 2.5-fold, maximal 5.8-fold), reaching levels comparable with those of uninfected controls in most of the patients. CONCLUSION: Our findings suggest a basis for a novel strategy in treatment of HIV infection by combining IL-2 therapy and treatment modalities counteracting PKA type I activity with HAART.

Severe deficiency of 1,25-dihydroxyvitamin D3 in human immunodeficiency virus infection: association with immunological hyperactivity and only minor changes in calcium homeostasis.

The serum level of 1,25-dihydroxyvitamin D3 [1,25-(OH)2D], the biologically most potent metabolite of vitamin D, is tightly regulated within narrow limits in human healthy adults. 1,25-(OH)2D deficiency is rare and is associated with disturbances in calcium and bone metabolism. We have previously reported a marked decrease in serum levels of 1,25-(OH)2D in human immunodeficiency virus (HIV)-infected patients. The present study was designed to further examine the causes and consequences of severe 1,25-(OH)2D deficiency in these patients. The design was a prospective cohort study. Fifty-four HIV-infected patients clinically classified according to the revised criteria from Centers for Disease Control and Prevention and healthy controls were studied. Parameters related to vitamin D and calcium metabolism as well as immunological and nutritional status were determined. Twenty-nine of the patients (54%) had serum levels of 1,25-(OH)2D below the lower reference limit, and 18 of these had undetectable levels. In contrast, HIV-infected patients had normal serum levels of 25-hydroxyvitamin D and vitamin D-binding protein. HIV-infected patients as a group had modestly depressed serum calcium and PTH levels. There were, however, no correlations between these parameters and serum levels of 1,25-(OH)2D. There were no differences in serum calcium or PTH levels or nutritional status when patients with severe 1,25-(OH)2D deficiency were compared to other patients, but patients with undetectable 1,25-(OH)2D had significantly elevated serum phosphate levels. Furthermore, patients with undetectable 1,25-(OH)2D levels were characterized by advanced clinical HIV infection, low CD4+ lymphocyte counts, and high serum levels of tumor necrosis factor-alpha (TNFalpha). We conclude that inadequate 1alpha-hydroxylation of 25-hydroxyvitamin D seems to be the most likely cause of 1,25-(OH)2D deficiency in HIV-infected patients, possibly induced by an inhibitory effect of TNFalpha. The low 1,25-(OH)2D and high TNFalpha levels observed may impair the immune response in HIV-infected patients both independently and in combination and may represent an important feature of the pathogenesis of HIV-related immunodeficiency. Markedly depressed 1,25-(OH)2D serum levels are also present in certain other disorders characterized by immunological hyperactivity. Thus, the findings in the present study may not only represent a previously unrecognized immune-mediated mechanism for induction of 1,25-(OH)2D deficiency in human disease, but may also reflect the importance of adequate serum levels of 1,25-(OH)2D for satisfactory performance of the immune system in man.

The insulin-like growth factor system in human immunodeficiency virus infection: relations to immunological parameters, disease progression, and antiretroviral therapy.

Endocrine dysfunctions have previously been reported in human immunodeficiency virus (HIV) infection. In this study we evaluated the relation of immunological parameters, virus load, clinical stage, and wasting to several parameters of the insulin-like growth factor (IGF) system in 76 patients with HIV infection, of whom 37 had developed acquired immune deficiency syndrome (AIDS). A subgroup of 26 untreated patients was followed during longitudinal testing, while the effects of antiretroviral therapy were evaluated in 34 patients (nucleoside analogs in 9, nucleoside analogs in combination with protease inhibitors in 25). Twenty healthy sex- and age-matched controls were analyzed for comparison. IGF-II was decreased (P = 0.03) and IGF-binding protein-2 (IGFBP-2) and IGFBP-3 protease activity were increased (P < 0.001) in AIDS patients compared with other HIV-infected individuals and controls. Plasma levels of IGFBP-2 and IGFBP-3 protease activity correlated positively to virus load (P < 0.001) and tumor necrosis factor-alpha (P < 0.025) and negatively to CD4(+) and CD8(+) cell counts (P < 0.001). AIDS patients with wasting (n = 13) had lower IGF-II levels (P = 0.001) and higher IGFBP-2 levels (P = 0.001) than other AIDS patients. Although no significant change in any of the IGF-parameters was observed in patients during antiretroviral therapy, patients with elevated IGFBP-3 protease activity before therapy (5 of 34) all had a decrease during treatment. During longitudinal testing in patients followed without antiretroviral therapy, disease progression was associated with increases in IGFBP-3 protease activity and IGFBP-2 levels. Our results reveal several alterations in the IGF system during HIV infection with decreased IGF-II levels, increased concentration of IGFBP-2, and an increased IGFBP-3 protease activity in advanced disease.

Decreased bone formative and enhanced resorptive markers in human immunodeficiency virus infection: indication of normalization of the bone-remodeling process during highly active antiretroviral therapy.

As cytokines and 1,25-dihydroxyvitamin D [1,25-(OH)2D] appear to have an important role in bone homeostasis, we examined the possibility that human immunodeficiency virus (HIV)-infected patients, characterized by enhanced levels of proinflammatory cytokines and 1,25-(OH)2D deficiency, have disturbed bone metabolism by analyzing serum markers of bone formation (osteocalcin) and bone resorption (C-telopeptide) in 73 HIV-infected patients. HIV-infected patients with advanced clinical and immunological disease and high viral load were characterized by increased C-telopeptide and particularly by markedly depressed osteocalcin levels. HIV-infected patients had enhanced activation of the TNF system. Serum concentrations of p55 and p75-TNF receptors were negatively correlated with osteocalcin, and p75-TNF receptor was positively correlated with C-telopeptide. HIV-infected patients with advanced disease also had decreased serum concentrations of 1,25-(OH)2D, but this parameter was not correlated with osteocalcin or C-telopeptide. During 24 months with highly active antiretroviral therapy there was a marked rise in serum osteolcalcin levels together with a profound fall in viral load and TNF components and a marked rise in CD4+ T cell counts. Also, there was a shift from no correlation to a significant correlation between osteocalcin and C-telopeptide levels during such therapy. The present study suggests disturbed bone formation and resorption during HIV infection. Our findings indicating synchronization of bone remodeling during highly active antiretroviral therapy may represent a previously unrecognized beneficial effect of such therapy and expand our knowledge of the interactions between cytokines and bone in the bone-remodeling process.

Elevated plasma concentration of reduced homocysteine in patients with human immunodeficiency virus infection.

Oxidative stress has been suggested to be an important factor in the immunopathogenesis of human immunodeficiency virus (HIV) infection. Reduced plasma thiols may lead to production of reactive oxygen species, thus contributing to the oxidative stress. We quantified the total, reduced, and protein-bound forms of the thiols homocysteine, cysteine, cysteinylglycine, and methionine in plasma from 21 HIV-infected patients and 15 healthy control subjects and compared the results with clinical and immunologic indexes. The HIV-infected patients had significantly higher concentrations of reduced homocysteine in plasma compared with control subjects. No significant differences in reduced homocysteine concentrations were noted when asymptomatic and symptomatic HIV-infected patients were compared, and we did not find any relation between reduced homocysteine concentrations and other markers of immunodeficiency. The HIV-infected patients had normal total homocysteine concentrations. The reduced cysteinylglycine concentration tended to be elevated in the patient group. No differences between HIV-infected patients and control subjects were found for reduced or total cysteine. Compared with control subjects, the HIV-infected patients had lower concentrations of methionine in plasma, and a significant correlation was found between low concentrations of methionine and low CD4+ lymphocyte counts in blood. Elevated concentrations of reduced homocysteine could possibly contribute to formation of reactive oxygen species, leading to accelerated immunologic deterioration and increased HIV replication.