An evaluation of serum soluble CD30 levels and serum CD26 (DPPIV) enzyme activity as markers of type 2 and type 1 cytokines in HIV patients receiving highly active antiretroviral therapy

Hidradenitis Suppurativa in Patients with HIV: A Scoping Review

Hidradenitis suppurativa (HS) is a chronic, debilitating skin disease of the apocrine glands. Bibliographic search revealed few studies concerning the association between HS and human immunodeficiency virus (HIV). To assess this link, we performed a systematic review of the current knowledge through a careful analysis of the relevant and authoritative medical literature in the field. Results showed that people with HIV are particularly susceptible to developing HS with the characteristic involvement of atypical sites, such as face or thighs, due to HIV-related immunosuppression. Based on the pathogenesis of both conditions and according to our review, we suggest that HIV screening should be routinely performed in suspected cases while monitoring and integrated approach in management are mandatory in the management of HIV-positive patients with HS.

Statistical optimization of cell disruption techniques for releasing intracellular X-prolyl dipeptidyl aminopeptidase from Lactococcus lactis spp. lactis

X-prolyl dipeptidyl aminopeptidase (PepX) is an intracellular enzyme from the Gram-positive bacterium Lactococcus lactis spp. lactis NRRL B-1821, and it has commercial importance. The objective of this study was to compare the effects of several cell disruption methods on the activity of PepX. Statistical optimization methods were performed for two cavitation methods, hydrodynamic (high-pressure homogenization) and acoustic (sonication), to determine the more appropriate disruption method. Two level factorial design (2FI), with the parameters of number of cycles and pressure, and Box-Behnken design (BBD), with the parameters of cycle, sonication time, and power, were used for the optimization of the high-pressure homogenization and sonication methods, respectively. In addition, disruption methods, consisting of lysozyme, bead milling, heat treatment, freeze-thawing, liquid nitrogen, ethylenediaminetetraacetic acid (EDTA), Triton-X, sodium dodecyl sulfate (SDS), chloroform, and antibiotics, were performed and compared with the high-pressure homogenization and sonication methods. The optimized values of high-pressure homogenization were one cycle at 130 MPa providing activity of 114.47 mU ml(-1), while sonication afforded an activity of 145.09 mU ml(-1) at 28 min with 91% power and three cycles. In conclusion, sonication was the more effective disruption method, and its optimal operation parameters were manifested for the release of intracellular enzyme from a L. lactis spp. lactis strain, which is a Gram-positive bacterium.

Of bugs and joints: the relationship between infection and joints

The association between microbes and joints has existed since antiquity, and remains complex. Diagnosis is often times difficult to determine despite highly suspicious clinical characteristics for the presence of an underlying infection. Over the several past decades, considerable advances have occurred in diagnostic methodologies and therapy. However, the morbidity and mortality of septic arthritis remains high. Great advances have occurred in the diagnosis, pathogenesis, and therapeutic management of reactive arthritis, and there is evidence that when the responsible microorganism is Chlamydia trachomathis, complete remission and cure is possible. Emergent infections, especially viral, has been recognized, i.e. HIV, hepatitis C, and most recently Chikengunya virus, and in the case of HIV associated articular manifestations, the introduction of HAART has resulted in a decrease in the incidence and development of newer complications such as the immune reconstitution syndrome. The infectious etiology of rheumatoid arthritis is being strongly considered once again, and the exciting association with periodontal disease is at the forefront of intense research. The gut microbiota is also being investigated and new and most interesting data is being gathered of the potential role of commensal gut organisms and the pathogenesis of rheumatoid arthritis.

Do the initial serum level changes of sCD26 have ability to predict successful treatment with IFN-α among naïve chronic hepatitis B patients?

INTRODUCTION

Hepatitis B is a major health problem with serious consequences. In hepatitis B treatment host cellular immune responses have a determinant role and T helper cells are the main active members of immune system against virological infection. The aims of this study are to investigate response rate of patients to INF-α therapy and evaluation of sCD26 and sCD30 roles as presenters of T cells activities in predicting the outcome of therapy in chronic hepatitis B patients.

METHODS AND MATERIALS

Fifty three chronic hepatitis B patients received IFN-α 9 MU S.C three times weekly for 24 weeks, and were followed up for 24 weeks. Serum levels of sCD26 and sCD30, before, 1 and 3 months after treatment commencement were evaluated in 53 chronic hepatitis B patients and 30 healthy individuals as control group.

RESULTS

Normal level of ALT was seen in 64.1% (34/53) of patients and undetectable DNA was observed in 39.6% (21 out of 53) of them. Finally, 33.9% (18/53) of patients obtained sustain virological response. CD26 levels changes was correlated with response to treatment and significantly (p<0.001) increased during first 3 months of treatment among patients with successful response to therapy.

CONCLUSION

Interferon is an effective and safe treatment for chronic hepatitis B patients and sCD26 serum level changes might be useful in predicting the outcome of therapy in naïve chronic hepatitis B patients undergoing treatment with IFN-α, as it can help clinicians for withdrawing non-responder patients for prevention of adverse events and economical burden.

Biomarkers of immune dysfunction following combination antiretroviral therapy for HIV infection

Combination antiretroviral therapy (cART) has significantly reduced morbidity and mortality of HIV-infected patients, yet their life expectancy remains reduced compared with the general population. Most HIV-infected patients receiving cART have some persistent immune dysfunction characterized by chronic immune activation and premature aging of the immune system. Here we review biomarkers of T-cell activation (CD69, -25 and -38, HLA-DR, and soluble CD26 and -30); generalized immune activation (C-reactive protein, IL-6 and D-dimer); microbial translocation (lipopolysaccharide, 16S rDNA, lipopolysaccharide-binding protein and soluble CD14); and immune dysfunction of specific cellular subsets (T cells, natural killer cells and monocytes) in HIV-infected patients on cART and their relationship to adverse clinical outcomes including impaired CD4 T-cell recovery, as well as non-AIDS clinical events, such as cardiovascular disease.

Immunopathogenesis of immune reconstitution disease in HIV patients responding to antiretroviral therapy

PURPOSE OF REVIEW

The aim of this article is to review the most recent literature regarding the immunopathogenesis of pathogen-associated immune reconstitution disease and to discuss the role of immune activation and various effector molecules and cells such as macrophages, effector and regulatory T cells, and natural killer cells in immune reconstitution disease.

RECENT FINDINGS

Many HIV patients receiving antiretroviral treatment develop immune reconstitution disease, which is characterized by exaggerated inflammatory immune responses to replicating or dead pathogens. In the majority of these cases, immune reconstitution disease is associated with restoration of pathogen-specific cellular immune responses involving CD4 or CD8 effector T cells. The precise conditions that trigger immune reconstitution disease have not yet been identified. Immune reconstitution disease patients have overt immune activation, which may be due to poor homeostatic control after the fast initial immune recovery in patients receiving antiretroviral therapy. Poor homeostatic control in immune reconstitution disease patients may be linked to unbalanced restoration of effector and regulatory T cells.

SUMMARY

Although the precise mechanism of immune reconstitution disease is not well understood, it is probably related to rapid restoration of pathogen-specific immune responses and poor homeostatic control that promote exaggerated immunopathological responses, especially if viable pathogens or pathogen debris are present at high concentrations.

Hepatitis virus immune restoration disease of the liver

PURPOSE OF REVIEW

Co-infection of HIV with hepatitis B virus or hepatitis C virus is common. Hepatotoxicity (grade 3 or 4 transaminitis) after highly active antiretroviral therapy occurs more frequently in either hepatitis B virus or hepatitis C virus co-infection. The cause of abnormal alanine aminotransferase following the initiation of highly active antiretroviral therapy is often multifactorial, and may include immune restoration disease. Since the widespread use of highly active antiretroviral therapy, liver disease secondary to viral hepatitis has become one of the most common causes of death in HIV infected individuals. A better understanding of the immunopathogenesis, diagnosis and treatment of hepatitis immune restoration disease is urgently needed, therefore.

RECENT FINDINGS

Our current understanding of the immunopathogenesis of hepatitis immune restoration disease is limited but it is likely that hepatic damage is secondary to recruitment of both antigen-specific and nonantigen-specific mononuclear cells to the liver, possibly mediated by IFN-gamma. HIV-hepatitis B virus co-infected individuals with low CD4 T-cells and elevated hepatitis B virus DNA and alanine aminotransferase prior to initiation of highly active antiretroviral therapy are at increased risk of hepatitis B virus immune restoration disease. Risk factors for hepatitis C virus immune restoration disease are less well defined. Although clinical deterioration can occur, hepatitis immune restoration disease has also been associated with successful clearance of both hepatitis B virus and hepatitis C virus.

SUMMARY

Further randomized clinical trials are needed to develop improved management strategies for hepatitis immune restoration disease.

A prospective study of serum soluble CD30 concentration and risk of non-Hodgkin lymphoma

Prediagnostic serum concentration of soluble CD30 (sCD30), a marker for chronic B-cell stimulation, has been associated with increased risk of developing AIDS-related non-Hodgkin lymphoma (NHL) in a recent study of HIV(+) patients. To investigate among healthy persons whether serum sCD30 is associated with NHL risk, we carried out a nested case-control study within the Prostate, Lung, Colorectal and Ovarian Cancer Screening Trial. There was a strong dose-response relationship between prediagnostic sCD30 concentration and NHL risk among 234 cases and 234 individually matched controls (odds ratio [95% confidence interval] for second, third, and fourth quartiles vs first quartile: 1.4 [0.8-2.6], 2.2 [1.2-4.1], 4.1 [2.2-7.8]; P(trend) < .001), which persisted among cases diagnosed 6 to 10 years after providing a blood sample. Given that a similar relationship has been observed among HIV(+) patients, our findings suggest that chronic B-cell stimulation may be an important mechanism involved in B-cell lymphomagenesis among severely immunocompromised and healthy populations alike.

HIV infection and rheumatic diseases: the changing spectrum of clinical enigma

In this article, the authors discuss the occurrence and prevalence of rheumatic syndromes before and after highly active antiretroviral therapy became the usual mode of treatment. The immunologic, environmental, and genetic factors behind the combination of HIV infection and rheumatic manifestation contribute to the complexity of these diseases. Miscellaneous case reports are discussed in relation to HIV infection. The authors conclude that geriatric care of HIV patients is on the horizon as more people have access to newer, more effective therapy and mortality is on the decline. Younger HIV patients will be committed to a lifetime of therapy to address bone disease and other chronic problems. In the future, newer agents may steer the clinical scenario in unforeseen directions.

Plasma sCD26 and sCD30 levels in cutaneous leishmaniasis

CD26 and CD30 are surface molecules expressed on activated Th1 and Th2 cells, respectively. It is, therefore assumed that plasma levels of CD26 and CD30 (sCD26 and sCD30) correlate with Th1 and Th2 response, respectively. In this study, plasma levels of sCD26 and sCD30 in patients with non-healing form of cutaneous leishmaniasis (CL) were measured and compared with the levels of sCD26 and sCD30 in patients with healing form of CL and healthy control volunteers. The results indicate that the plasma levels of sCD26 and sCD30 are significantly (p<0.05) higher in patients with non-healing form of CL than patients with healing form of CL or healthy control. No significant difference is seen in the levels of sCD26 and sCD30 in patients with healing form of CL in comparison with healthy control group. It is concluded that sCD30 might be used as an indicator of a Th2 response in patients with non-healing form of CL.

CD26 expression on CD4+T cells in patients with cutaneous leishmaniasis

Surrogate marker(s) of protection in human leishmaniasis is not well defined. In this study, T helper 1 (Th1) and Th2 cytokine profiles and CD26 expression on CD4(+) T cells in peripheral blood mononuclear cells of patients with healing or non-healing forms of cutaneous leishmaniasis (CL) stimulated with Leishmania antigens were assessed. The level of interferon (IFN)-gamma production was significantly higher in patients with healing or non-healing forms of CL than in healthy controls, but it was not significantly different between the two patient groups. The level of interleukin-5 production was significantly higher in patients with the non-healing form of CL than in the two other groups. There was a significant increase in the level of CD26 expression on CD4(+) T cells in patients with healing (P < 0.001) or non-healing (P = 0.025) forms of CL compared with the control group, but no significant difference was seen between the two patient groups. A weak positive correlation was seen between IFN-gamma production and CD26 expression on CD4(+) T cells of patients with the healing form of lesion (r = 0.54, P = 0.008), but this correlation was not observed in patients with the non-healing form of CL (r = 0.53, P = 0.078). Surface CD26 is not correlated with the clinical manifestation of CL or IFN-gamma production. Therefore, CD26 is not a surrogate marker for IFN-gamma production in CL.

Increased serum levels of soluble CD30 in patients with common variable immunodeficiency and its clinical implications

Common variable immunodeficiency (CVID) is a heterogeneous group of disorders, characterized by hypogammaglobulinemia and increased susceptibility to recurrent pyogenic infections, autoimmunity, and malignancies. Twenty-five cases with CVID (18 male and 7 female) and 25 healthy volunteers were investigate in this study. Soluble CD30 (sCD30) serum levels of the subjects were measured and compared. Serum levels of sCD30 in the patients with CVID were significantly increased in comparison with controls (36.93 +/- 32.38 vs 5.27 +/- 1.32 U/ml, P < 0.001). The group of patients with splenomegaly and reversed ratio of CD3+CD4+ T cells/CD3+CD8+ T cells had the highest serum levels of sCD30 (66.01 +/- 43.34 U/ml) in comparison with other patients (P = 0.010). High levels of sCD30 in the CVID patients with splenomegaly and the presence of lymphoma in a patient with the highest level of sCD30 may suggest a soluble form of this marker as a prognostic tool in such diseases.

Short communication: decreasing soluble CD30 and increasing IFN-gamma plasma levels are indicators of effective highly active antiretroviral therapy

It was previously reported that without highly active antiretroviral therapy (HAART), secretion of Th1 cytokines and antiviral IFN-gamma in HIV-infected patients is decreased, whereas the production of Th2 cytokines, proinflammatory cytokines, and TNF-alpha is increased. We studied the effect of HAART on Th1-, Th2-, and monocyte-derived cytokines, and on the Th2-type immune response marker soluble (s)CD30 in HIV-1-infected hemophilia patients. Viral Load (VL), CD4+ lymphocyte counts, and plasma levels of sIL-1RA, IL-2, sIL-2R, IL-3, IL-4, IL-6, sIL-6R, IL-7, IL-10, TNF-alpha, TGF-beta2, IFN-gamma, and sCD30 were measured in 18 patients who received HAART. Nine patients were initially treatment-naive and were monitored after the initiation of HAART. sCD30 median levels were significantly higher in treatment-naive patients than in patients who were on HAART (77 vs. 30 U/ml, p = 0.005). A strong association was observed between sCD30 and VL (r = 0.85, p = 0.004). After the initiation of HAART, sCD30 levels decreased and remained low (at 1 year, 38; at 2 years, 41 U/ml; p = 0.012 and p = 0.021, respectively, as compared to baseline level) and this was accompanied by a decrease in VL and monocyte-derived IL-6 and an increase in CD4+ lymphocyte counts and Th1-derived IFN-gamma. One year after the initiation of HAART a strong inverse correlation was observed between IFN-gamma and VL (r = -0.83, p = 0.006). In contrast to sCD30 and IFN-gamma, CD4 counts and plasma IL-6 did not correlate with VL at any time. Our data suggest that decreasing sCD30 and increasing IFN-gamma plasma levels are indicators of effective HAART treatment and CD4 Th1 cell recovery in HIV-infected patients.

CXCR4 or CCR5 tropism of human immunodeficiency virus type 1 isolates does not determine the immunological milieu in patients responding to antiretroviral therapy

Here we address whether CCR5 or CXCR4 tropism of the predominant viral strain detected before or on combination antiretroviral therapy (ART) explains why some human immunodeficiency virus (HIV)-infected patients who begin ART with advanced HIV disease retain low interferon (IFN)-gamma responses, despite recovery of CD4(+) T cell counts. Tropism was determined by culture and confirmed by gp120 V3 loop sequence of multiple plasma samples in eight adult male patients who began treatment with <50 CD4(+) T cells/microL. Four patients had mixed infections, one had only R5 HIV, and three had only X4 HIV. Of these, two carried CCR5Delta32. Viral tropism was not related to CD4(+) T cell counts or HIV RNA levels. When immunological responses were monitored over several years, IFN-gamma responses to cytomegalovirus were below the median value of uninfected controls and similar in patients with R5, X4, or mixed infection. Interleukin-5 responses were low and plasma soluble CD30 levels were high at treatment onset, but resolved with control of HIV replication irrespective of HIV tropism. Levels of LAG-3 (lymphocyte activation gene-3 protein) were elevated in patients with uncontrolled HIV replication. Hence the immunological milieu did not reflect HIV tropism.

Changes of soluble CD26 and CD30 levels correlate with response to interferon plus ribavirin therapy in patients with chronic hepatitis C

BACKGROUND

Clearance of hepatitis C virus (HCV) is attributed to host cellular immune responses, in which T helper cells play a critical role. The purpose of the present paper was therefore to study the serial changes of serum soluble markers released from T helper 1 (Th1) and 2 (Th2) and their correlations with treatment responses in chronic hepatitis C patients receiving interferon-alpha plus ribavirin for 24 weeks.

METHODS

Serum markers (soluble CD26 and CD30 levels) of T helper cells were quantified before and 6 months after combination therapy in 33 chronic hepatitis C patients and in 20 healthy controls.

RESULTS

Compared to healthy controls, chronic hepatitis C patients had significantly lower serum soluble CD26 levels before (140.4 +/- 63.9 ng/mL vs 200.6 +/- 60.3 ng/mL, P < 0.0001) and after (115.9 +/- 32.9 ng/mL vs 200.6 +/- 60.3 ng/mL, P < 0.0001) combination therapy. The level was even lower in those with non-sustained virologic response (non-SVR; 139.0 +/- 50.9 ng/mL vs 117.7 +/- 40.3 ng/mL, P = 0.039). In contrast, soluble CD30 levels at 6 months after combination therapy were significantly lower in patients with SVR than those with non-SVR (6.4 +/- 3.5 U/mL vs 10.4 +/- 5.4 U/mL, P = 0.021).

CONCLUSION

Chronic hepatitis C patients have a weak Th1 response as reflected by lower soluble CD26 levels and the levels are even lower in non-sustained responders. In sharp contrast, downregulation of Th2 response with serial changes of soluble CD30 level is associated with successful treatment of HCV infection.

Therapy Insight: CNS manifestations of HIV-associated immune reconstitution inflammatory syndrome

The introduction of combination antiretroviral therapy for HIV infection has prolonged the lives of patients with AIDS. It is increasingly being recognized, however, that following initiation of this therapy some patients can develop a paradoxical neurological deterioration, despite dramatic improvements in HIV viral load and CD4+ T-cell counts. This immune reconstitution inflammatory syndrome (IRIS) in the CNS is emerging as an important neurological complication, particularly as antiretroviral therapy is now becoming readily available worldwide. Currently, there are no guidelines for prevention, diagnosis or treatment of the CNS manifestations of IRIS. Even in patients with an acute presentation, the diagnosis can be challenging. Furthermore, it is possible that more-chronic forms of the syndrome exist but remain unrecognized. Here, we review the various clinical presentations of CNS IRIS, and discuss options for their management.

Proviral load and immune markers associated with human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) in Peru

Human T-lymphotropic virus type 1 (HTLV-1) is the aetiological agent of HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP). The objective of this study is to identify which ex vivo and in vivo markers are associated independently with HAM/TSP in a Peruvian population. Eighty-one subjects (33 men/48 women) were enrolled: 35 presented with HAM/TSP, 33 were asymptomatic HTLV-1 carriers (ACs) and 13 were HTLV-1-seronegative controls (SCs). Ex vivo markers included T cell proliferation and Th1 [interferon (IFN)-gamma], Th2 [interleukin (IL)-4, IL-5], proinflammatory [tumour necrosis factor (TNF)-alpha] and anti-inflammatory (IL-10) cytokine production in non-stimulated peripheral blood mononuclear cell (PBMC) cultures. In vivo CD4(+) T cell count, markers of Th1 [interferon-inducible protein (IP)-10] and Th2 (sCD30) activity in plasma and HTLV-1 proviral load in PBMCs were also evaluated. In univariate analysis, several markers, including T cell proliferation, IFN-gamma, IP-10, sCD30 and proviral load were associated with HAM/TSP, but in a multiple logistic regression analysis only the proviral load remained associated significantly with disease manifestation [adjusted OR 9.10 (1.24-66.91)]. Our findings suggest that HAM/TSP is associated primarily with proviral load, whereas the observed association with some immune markers seems secondary.

A T2 cytokine environment may not limit T1 responses in human immunodeficiency virus patients with a favourable response to antiretroviral therapy

Low-level production of interferon-gamma (IFN-gamma) marks human immunodeficiency virus (HIV)-induced immunodeficiency and has been ascribed to a bias towards T2 cytokines. This was investigated in two cross-sectional studies of HIV patients who were immunodeficient when they began antiretroviral therapy (ART) and had stable increases in CD4 T-cell counts. Blood leucocytes were assessed unstimulated or after stimulation with cytomegalovirus (CMV), anti-CD3 or mitogen. IFN-gamma and interleukin (IL)-5 responses were initially assessed by enzyme-linked immunosorbent spot-forming cell assay (ELISPOT) and enzyme-linked immunosorbent assay (ELISA). We then adopted a sensitive reverse transcription-polymerase chain reaction (RT-PCR) system to assess IFN-gamma, IL-5, IL-4 and IL-4delta2 (an inhibitory splice variant of IL-4) mRNA. The results were correlated with putative serological markers of a T1 [lymphocyte activation gene-3 (LAG-3), CD26] or a T2 [CD30, immunoglobulin E (IgE)] cytokine environment. IL-5 production and IgE levels were elevated in patients. IgE levels did not correlate with IFN-gamma, but showed an inverse correlation with IL-5 released in culture (P = 0.05). The levels of IL-4, IFN-gamma, IL-5 and IL-4delta2 mRNA were correlated after anti-CD3 stimulation, where IL-5 was the best predictor of IFN-gamma mRNA (P = 0.006). Weak positive correlations were evident between CD30 and cytokine mRNA levels, whilst IgE correlated inversely with IL-4, IL-4delta2, IL-5 and IFN-gamma mRNA levels. These analyses provide no evidence for an inverse relationship between T1 and T2 cytokine responses in HIV patients, but suggest that the elevation of IgE marks low cytokine responses.

Immune Reconstitution Syndrome in HIV: Validating a Case Definition and Identifying Clinical Predictors in Persons Initiating Antiretroviral Therapy

BACKGROUND

Clinical deterioration after initiation of antiretroviral therapy may result from restored immunity. There is no standard clinical definition for immune reconstitution syndrome. The objectives of this study were to validate a proposed definition and to identify factors predictive of immune reconstitution syndrome.

METHODS

This was a retrospective case-control study from an academic university medical practice. Cases were matched to > or =2 control subjects by CD4+ cell count at the time of initiation of antiretroviral therapy. Cases and "mock cases" were blindly reviewed by 2 human immunodeficiency virus (HIV) experts.

RESULTS

Twenty possible cases of immune reconstitution syndrome were identified; HIV experts excluded all cases of herpes zoster (shingles), with agreement on real and mock cases of 92%. For 14 confirmed case patients (compared with 40 control subjects), immune reconstitution syndrome was associated with a higher number of prior opportunistic infections (P=.003) and higher CD8+ cell counts at baseline (P=.05) and at week 12 (P=.02). Immune reconstitution syndrome was associated with lower baseline levels of alanine aminotransferase (P=.05) and hemoglobin (P=.02). On multivariate analysis, the number of prior opportunistic infections (odds ratio, 2.7; P=.007) and lower hemoglobin level at baseline (odds ratio, 0.8; P=.003) were independently associated with development of immune reconstitution syndrome. A predictive model was defined by classification and regression tree analysis with a sensitivity and specificity of 78.57% and 87.50%, respectively, for an importance score of > or =4 (on a scale of 0.0 to 100.0), and 92.86% and 80.00%, respectively, for a score of > or =2, using the number of prior opportunistic infections, CD8+ cell count, and hemoglobin level.

CONCLUSIONS

A standard definition for immune reconstitution syndrome is possible. Patients with a greater severity of illness at initiation of antiretroviral therapy are at risk for immune reconstitution syndrome. The model defined by classification and regression tree analysis may provide a basis for risk stratification before initiation of antiretroviral therapy.

Elevated serum soluble CD30 precedes the development of AIDS-associated non-Hodgkin's B cell lymphoma

CD30, first described as the Ki antigen on malignant B cells in Hodgkin's lymphoma, is also expressed on normal activated B and T cells. It can be cleaved from the cell surface and detected in normal serum as soluble CD30 (sCD30), where it can be an indicator of levels of immune activation. In a cross-sectional study utilizing archived sera at a time point close to but preceding a diagnosis of acquired immunodeficiency syndrome (AIDS)-associated non-Hodgkin's B cell lymphoma, AIDS lymphoma subjects (n = 49) showed elevated mean levels of sCD30 compared to controls with AIDS but no malignancy (n = 44, p < 0.01), HIV-infected but relatively healthy (n = 47, p < 0.001), or HIV-seronegative controls (n = 44, p < 0.001). Serum sCD30 was significantly correlated to serum levels of the B cell cytokines interleukin-6 (IL-6), IL-10, and sCD23, but only among lymphoma subjects (p < or = 0.05). Correlations between sCD30 and other markers of immune system activation were seen among all HIV-infected subjects (sCD27, sCD44, CXCL13, p < 0.05). These observations suggest that sCD30, especially in combination with other immune system molecules, could be an important biomarker for an immune system environment conducive to B cell hyperactivation and the development of AIDS-associated B cell lymphoma.

Significant link between sCD30 changes and HIV viremia in patients treated with HAART

Elevated sCD30 levels were generally associated with poor prognosis in chronic HIV infection prior to the era of highly active antiretroviral therapy (HAART). Little information is available on sCD30 and HIV-1 viremia. In this study, the association between sCD30 and HIV-1 viremia was investigated in HIV-infected patients who underwent HAART. sCD30 was measured in 276 patients prior (T0) and 6 months after HAART (T6). Standard survival analyses were used to evaluate the prognostic value of sCD30 and sCD30 change from baseline to predict the virological response to HAART. Higher levels (>30 U/ml) of sCD30 prior to HAART were associated with relatively higher viremia (P = 0.0001) and tended to be associated with a lower chance of achieving virological success (P = 0.13). The median T6 sCD30 level in patients who concomitantly had viremia >500 copies/ml was higher than the median sCD30 level of those with viremia </=500 copies/ml (P = 0.002). Conversely, within the patients who achieved viral suppression on HAART, those who had concomitantly a larger reduction in sCD30 subsequently experienced a higher rate of virological failure (P = 0.04). A strong, but complex, link exists between sCD30 levels and HIV viremia in the era of HAART. The change in sCD30 levels from pre-therapy to the date of first viral suppression could be used to identify patients who are more likely to experience later virological rebound among those who achieve initially virological success.

Persistent HIV-1 replication does not explain low levels of T-cell interferon-gamma mRNA and elevated serum NO(2) (-)/NO(3) (-) in patients with stable CD4 T-cell responses to HAART

HIV-1 infected patients adherent to HAART and displaying stable increases in CD4 T-cell counts differ in their control of HIV replication and one might expect this to reflect depressed immune function. The importance of virological control in functional immune reconstitution was investigated in HIV-1 infected patients who maintained high or undetectable plasma HIV RNA levels over 2-4 years on HAART (discordant and complete responders, respectively). Immunocompetence and immune activation were assessed directly ex vivo and after a short period of culture, as HIV replication in cultures from viraemic patients may artificially depress responses. Expression of cytokine (interferon-gamma, interleukin-5) and chemokine receptor (CCR5, CRTH2) mRNA were determined and soluble CD30 and NO(2) (-)/NO(3) (-) were measured in sera. Unstimulated cells from all patients had low levels of IFNgamma mRNA relative to uninfected controls. Discordant responders had more IFNgamma, IL-5 and CCR5 mRNA in mitogen-stimulated PBMC than complete responders, where the difference could be attributed to CD8-T-cells. Serum NO(2) (-)/NO(3) (-) levels were significantly higher in all patients than controls, with no difference between complete and discordant responders. Serum CD30 levels were significantly higher in discordant responders. These data indicate a persistent immune deficit in immune reconstituted patients irrespective of HIV viral load and associate persistent viral replication with lymphocyte activation, probably involving CD8 T-cells.

Immune restoration inflammatory syndromes: Apparently paradoxical clinical events after the initiation of HAART

Immune reconstitution occurs after initiation of highly active antiretroviral therapy in immunodeficient HIV-positive individuals. Unexpected deterioration of inflammatory disease and atypical clinical features resembling symptoms of autoimmune disease may arise. These atypical inflammatory disorders, synonymously summarized as immune reconstitution syndrome, immune restoration disease, and immune restoration inflammatory syndrome (IRIS), are caused by augmentation of inflammation during immune reconstitution in an immunocompromised host. These disorders have to be distinguished from intercurrent infection and rheumatic disease, respectively. Treatment of IRIS consists of elements for both potential differential diagnoses (ie, anti-inflammatory and immunosuppressive drugs, such as in autoimmune disorders and antimicrobial chemotherapy, to decrease the burden of pathogen, such as in infectious disease). Therefore, awareness for IRIS is of increasing importance from a clinical point of view. However, diagnostic criteria and standards of treatment are still preliminary.

Adverse events of desirable gain in immunocompetence: the Immune Restoration Inflammatory Syndromes

Augmentation of inflammation may occur during immune reconstitution in a immunocompromised host. This phenomenon is able to cause atypical inflammatory disorders, synonymously summarized as 'Immune Reconstitution Syndrome', 'Immune Restoration Disease' and 'Immune Restoration Inflammatory Syndrome' (IRIS). Immune reconstitution occurs, if temporarily use of immunosuppressive agents was terminated or if highly active antiretroviral therapy in human immunodeficiency virus positive individuals with secondary immunodeficiency was initiated. Unexpected deterioration of inflammatory disease and atypical clinical features, resembling symptoms of autoimmune disease may arise. They have to be distinguished from intercurrent infection and rheumatic disease, respectively. Treatment of IRIS would consist of both potential differential diagnoses: use of anti-inflammatory and immunosuppressive drugs like in autoimmune disorders as well as antimicrobial chemotherapy to decrease the burden of pathogen like in infectious disease. Therefore, awareness for IRIS is of increasing importance from a clinical point of view. However, diagnostic criteria and standards of treatment still have to be defined.

Graves' disease during immune reconstitution after highly active antiretroviral therapy for HIV infection: evidence of thymic dysfunction

A patient with HIV infection who experienced immune reconstitution after highly active antiretroviral therapy (HAART) [increase in CD4 T cell count from <1/microl to >600/microl] presented with severe Graves' disease 32 months after commencing HAART. A comprehensive clinical and laboratory study demonstrated pronounced regional lymphadenopathy and thymic enlargement at presentation, and that the onset of thyrotropin receptor antibody production was associated with increased production of soluble CD30 (a marker of type 2 immune responses). Blood naive CD8 T cell counts and TREC levels in both CD4 and CD8 T cells were increased at multiple time points compared with carefully selected controls. We conclude that the Graves' disease in this patient was associated with abnormally high blood counts of thymus-derived T cells, and propose that Graves' disease after HAART in this and other HIV patients may result from failure to delete autoreactive T cell clones in the regenerating thymus.

CD30-positive atypical lymphoid cells in common non-neoplastic cutaneous infiltrates rich in neutrophils and eosinophils

CD30-positive cells characterize lymphomatoid papulosis and anaplastic large cell lymphoma but can also be found in nonneoplastic skin disorders. Purportedly, CD30 is useful in the differential diagnosis between insect bites and lymphomatoid papulosis. Recently, a subtype of neutrophil-rich CD30-positive anaplastic large cell lymphoma has been described, which may enter the differential diagnosis of cutaneous neutrophil-rich inflammatory infiltrates. We studied atypical CD30-positive lymphoid cells in five eosinophil-rich and 23 neutrophil-rich common nonneoplastic skin infiltrates. The eosinophil-rich cases included five insect bites. The neutrophil-rich cases included 9 inflammatory (hidradenitis suppurativa [n = 4], stasis ulcer [n = 2], ruptured cyst, rhynophyma, and Sweet syndrome); 12 infectious (bacterial [n = 8], viral [n = 2] and fungal [n = 2] etiologies); and 2 environmental (spider bites) cases. Atypical CD30-positive cells were found in 4 of 5 eosinophil-rich, 8 of 9 neutrophil-rich inflammatory, 6 of 12 neutrophil-rich infectious, and 2 of 2 neutrophil-rich environmental cases. Polymerase chain reaction analysis for B- and T-cell clonality and cell counts of neutrophils, eosinophils, plasma cells, B cells (using CD20), and T cells (using CD3) were performed in the cases that contained atypical CD30-positive lymphoid cells. CD30-positive cells averaged 4.8% of the cells counted in the areas where they were most concentrated. Of the 18 cases that amplified with polymerase chain reaction, all were polyclonal for T-cell receptor rearrangements; 10 were polyclonal and 8 oligoclonal for B-cell immunoglobulin rearrangements. There was no correlation between B-cell oligoclonality with CD30-positive cell counts, a particular disease, or a disease category. In conclusion, the presence of CD30-positive atypical lymphoid cells in 71.4% of the common nonneoplastic cases studied, even in the presence of clonal B-cell populations, warrants caution in the interpretation of these cells as malignant, particularly when dealing with the differential diagnosis of lymphomatoid papulosis or neutrophil-rich anaplastic large cell lymphoma.

Dipeptidyl-peptidase IV from bench to bedside: an update on structural properties, functions, and clinical aspects of the enzyme DPP IV

Dipeptidyl-peptidase IV/CD26 (DPP IV) is a cell-surface protease belonging to the prolyloligopeptidase family. It selectively removes the N-terminal dipeptide from peptides with proline or alanine in the second position. Apart from its catalytic activity, it interacts with several proteins, for instance, adenosine deaminase, the HIV gp120 protein, fibronectin, collagen, the chemokine receptor CXCR4, and the tyrosine phosphatase CD45. DPP IV is expressed on a specific set of T lymphocytes, where it is up-regulated after activation. It is also expressed in a variety of tissues, primarily on endothelial and epithelial cells. A soluble form is present in plasma and other body fluids. DPP IV has been proposed as a diagnostic or prognostic marker for various tumors, hematological malignancies, immunological, inflammatory, psychoneuroendocrine disorders, and viral infections. DPP IV truncates many bioactive peptides of medical importance. It plays a role in glucose homeostasis through proteolytic inactivation of the incretins. DPP IV inhibitors improve glucose tolerance and pancreatic islet cell function in animal models of type 2 diabetes and in diabetic patients. The role of DPP IV/ CD26 within the immune system is a combination of its exopeptidase activity and its interactions with different molecules. This enables DPP IV/CD26 to serve as a co-stimulatory molecule to influence T cell activity and to modulate chemotaxis. DPP IV is also implicated in HIV-1 entry, malignant transformation, and tumor invasion.

Immune Restoration Inflammatory Syndromes: The Dark Side of Successful Antiretroviral Treatment

The prevalence of cellular immunodeficiency has increased due to rising use of immunosuppressive therapies and the pandemic spread of HIV infection. More recently, the introduction of highly active antiretroviral therapy (HAART) in HIV has led to significant immune reconstitution, even in patients with previously long-lasting secondary immunodeficiency. HAART reduces morbidity and mortality in HIV infection and also changes the clinical course of prevalent subclinical opportunistic infections or autoimmune diseases. Atypical inflammatory disorders develop after initiation of HAART and have been summarized as "immune reconstitution syndrome," "immune restoration disease," and "immune restoration inflammatory syndrome." However, diagnostic criteria and standards of therapy are yet to be defined. The awareness for these diseases is of increasing importance from a clinical point of view. This review summarizes the variety of immunoreconstitution disorders and describes possible diagnostic pitfalls. We also propose possible therapeutic options.

Therapeutic potential of dipeptidyl peptidase IV inhibitors for the treatment of type 2 diabetes

Incretins are peptide hormones, exemplified by glucose-dependent insulinotropic peptide and glucagon-like peptide 1 that are released from the gut in response to nutrient ingestion and enhance glucose-stimulated insulin secretion. Incretin action is terminated due to N-terminal cleavage of the peptides by the aminopeptidase dipeptidyl peptidase IV (DPP-IV). Hence, inhibition of glucose-dependent insulinotropic peptide and glucagon-like peptide 1 degradation via reduction of DPP-IV activity represents an innovative strategy for enhancing incretin action in vivo. This review summarises the biology of incretin action, the structure, expression and pleiotropic biological activities of DPP-IV and provides an overview of the rationale, potential merits and theoretical pitfalls in the development of DPP-IV inhibitors for the treatment of type 2 diabetes.

Immunological markers predicting outcome in patients with hepatitis C treated with interferon-alpha and ribavirin

Type 1 (T1) cytokine responses are required for the clearance of hepatitis C virus by cytotoxic T lymphocytes, but can promote liver damage. Interferon-alpha (IFN alpha) can be expected to promote T1 cytokine responses, so treatment outcome may depend on the T1/T2 cytokine environment and levels of immune activation at baseline. This model was tested by monitoring immunological markers in a pilot study of treatment naïve patients given IFN alpha 2b and ribavirin, with the aim of finding markers that predict virological outcome. Soluble (s) CD26/dipeptidyl peptidase IV enzyme activity and levels of sCD30, bioavailable IL-6, sTNF-RI, IL-1ra and nitrite/nitrate (NO(2)(-)/NO(3)(-)) were measured. Levels of IL-1ra and bioavailable IL-6 were lower in patients than controls and did not change with therapy. Treatment decreased sCD26/dipeptidyl peptidase IV enzyme activities and sCD30 levels and increased NO(2)(-)/NO(3)(-) levels. High baseline sCD30 levels predicted an early (P = 0.008) and sustained (P = 0.03) virological response to therapy, suggesting treatment may be more effective in patients with a predominant T2 profile.

Immune dysfunction and immune restoration disease in HIV patients given highly active antiretroviral therapy

BACKGROUND

Some immune defects caused by HIV infection resolve following treatment with highly active antiretroviral therapy (HAART), but residual immune dysfunction may cause disease. Problems with the regulation of the restored immune system in the first six months of treatment can lead to atypical presentations of mycobacterial, cytomegalovirus (CMV), hepatitis B virus or hepatitis C virus (HCV) disease. We defined these conditions as immune restoration diseases (IRD) and showed that they occur in 30-40% of individuals who begin HAART from low CD4 T cell counts.

OBJECTIVES

Analysis of immune dysregulation in patients who have responded to HAART.

STUDY DESIGN

Patients with successful immune reconstitution following HAART were selected from a database containing details of all patients managed at Royal Perth Hospital (Western Australia) on the basis a CD4 T cell count <100/microl before HAART and an increase of >4-fold or to >200 CD4 T cells/microl.

RESULTS

Patients who had experienced an IRD demonstrated increased levels of bioavailable IL-6 and increased expression of CCR5 and CCR3 on monocytes and granulocytes, but numbers of gammadeltaT-cells were similar to patients with similar CD4 T cell counts without an IRD. Carriage of HLA-A2, -B44 was associated with a history of CMV retinitis and/or encephalomyelitis as an IRD, but not with IRD initiated by Mycobacterium sp., cutaneous varicella zoster or herpes simplex infections or HCV. We also identified a patient with Graves' thyrotoxicosis and pronounced lymphadenopathy after HAART, and demonstrated that thyroid stimulating hormone receptor antibody production was associated with an increase in serum soluble CD30, suggesting acquired immune dysregulation.

CONCLUSIONS

IRD are associated with persistent immune activation, where differences in genetic profiles suggest that distinct pathological mechanisms are responsible for retinitis/encephalomyelitis IRD. Further studies are important as dysregulated T-cell responses may cause disease later in the course of immune reconstitution.