The development of AIDS-associated Burkitt's/small noncleaved cell lymphoma is preceded by elevated serum levels of interleukin 6

Salivary and serum neopterin and interleukin 6 as biomarkers in patients with oral and oropharyngeal squamous cell carcinoma

Because of an increasing incidence of malignant tumours of the head and neck there is an unmet medical need for early diagnosis of the primary disease or precancerous lesions, and timely detection of recurrence by simple non-invasive tests. The analysis of biomarkers in body fluids may be appropriate for this goal. In this review, we compare the data on utilization of neopterin and interleukin-6 (IL-6) measurements in saliva and plasma/serum of patients with oral and oropharyngeal squamous cell carcinoma, indicating the suitability of using saliva as a diagnostic matrix in head and neck cancers on behalf of close anatomical proximity and a potential to study the tumour microenvironment. Salivary neopterin and IL-6 are potential biomarkers of head and neck cancer suitable not only for early diagnosis, but also for monitoring of treatment results and detection of the disease recurrence.

Serum Interleukin-6 and Weight Loss in Antiretroviral-naïve and Antiretroviral-treated Patients with HIV/AIDS: Relationships and Predictors

BACKGROUND

Cachexia is usually associated with elevated serum interleukin-6 (IL.6) as it stimulates the breakdown of muscle proteins and promotes wasting.

OBJECTIVE

A case-control study to evaluate the relationship between weight loss, facial fat loss, and IL-6 in antiretroviral-naïve and treated participants living with HIV/AIDS.

METHODS

IL-6 was assayed by High performance liquid chromatography (HPLC) in 97 in consecutive newly diagnosed antiretroviral-naive (ART-naïve) people living with HIV/AIDS (age ≥18 years); and 118 consecutive, age-matched participants currently on Highly Active Antiretroviral Therapy (HAART), using age as a criterion. In the treated group, 78 (66.7%) subjects were on zidovudine, lamivudine with nevirapine (Z+L+N); 27(23.1%) on tenofovir, lamivudine with emtricitabine (T+L+E); 5(4.3%) on zidovudine, lamivudine with emtricitabine (Z+L+E); 4(3.4%) on zidovudine, lamivudine with tenofovir (Z+L+T); 2(1.7%) on lamivudine, tenofovir with nevirapine (L+T+N); 1(0.9%) on tenofovir, zidovudine, emtricitabine (Z+T+E).

RESULTS

A total of 215 participants: 97 ART-naive and 118 HAART-treated, age-matched subjects (40.3±9.6 versus 42.7±10.20years, p=0.08). The mean IL-6 was significantly higher in naïve than treated (0.69±0.04 versus 0.66±0.04 pg/ml, p =0.002). In all, 73 subjects experienced weight loss, 56(76.7%) naive, 17(23.3%) treated, p <0.0001, with significantly higher IL-6 in those with weight loss (0.69±0.05 versus 0.67±0.05pg/ml, p= 0.047). Fifty-eight (27.0%) subjects experienced facial fat loss, 49 (84.5%) naïve, and 9 (15.5%) treated, p <0.0001, with significantly higher IL-6 in those with facial fat loss (0.7 ± 0.05 versus 0.67±0.05pg/ml, p= 0.0001). Negative correlation exists between IL-6 and CD4+ count (r=-0.141, p=0.041). In logistic regression, independent predictors of weight loss include: IL-6 (Adjusted Odds Ratio, aOR 1.3, 95%CI 0·1-2·6, p=0.047); HIV duration (aOR 11.6, p <0.0001); AIDS-defining illness (aOR 3.5, p <0.0001); CD4+ count (aOR 3.2, p=0.004); HAART status (aOR 2.7, p<0.0001).

CONCLUSION

HIV infection is associated with elevation of serum interleukin-6, which likely contributes to weight and facial fat loss among the treatment-naïve participants; while HAART is associated with suppressed IL-6 levels, thereby ameliorating weight and facial fat loss. Inverse relationship exists between serum IL-6 and CD4+ count; serum IL-6 could differentiate between mild- to moderate and severe immunosuppressive states.

Targeting TfR1 with the ch128.1/IgG1 Antibody Inhibits EBV-driven Lymphomagenesis in Immunosuppressed Mice Bearing EBV+ Human Primary B-cells

Epstein-Barr virus (EBV) is a human gammaherpesvirus associated with the development of hematopoietic cancers of B-lymphocyte origin, including AIDS-related non-Hodgkin lymphoma (AIDS-NHL). Primary infection of B-cells with EBV results in their polyclonal activation and immortalization. The transferrin receptor 1 (TfR1), also known as CD71, is important for iron uptake and regulation of cellular proliferation. TfR1 is highly expressed in proliferating cells, including activated lymphocytes and malignant cells. We developed a mouse/human chimeric antibody targeting TfR1 (ch128.1/IgG1) that has previously shown significant antitumor activity in immunosuppressed mouse models bearing human malignant B-cells, including multiple myeloma and AIDS-NHL cells. In this article, we examined the effect of targeting TfR1 to inhibit EBV-driven activation and growth of human B-cells in vivo using an immunodeficient NOD.Cg-Prkdcscid Il2rgtm1Wjl /SzJ [NOD/SCID gamma (NSG)] mouse model. Mice were implanted with T-cell-depleted, human peripheral blood mononuclear cells (PBMCs), either without EBV (EBV-), or exposed to EBV in vitro (EBV+), intravenously via the tail vein. Mice implanted with EBV+ cells and treated with an IgG1 control antibody (400 μg/mouse) developed lymphoma-like growths of human B-cell origin that were EBV+, whereas mice implanted with EBV+ cells and treated with ch128.1/IgG1 (400 μg/mouse) showed increased survival and significantly reduced inflammation and B-cell activation. These results indicate that ch128.1/IgG1 is effective at preventing the growth of EBV+ human B-cell tumors in vivo, thus, indicating that there is significant potential for agents targeting TfR1 as therapeutic strategies to prevent the development of EBV-associated B-cell malignancies. SIGNIFICANCE: An anti-TfR1 antibody, ch128.1/IgG1, effectively inhibits the activation, growth, and immortalization of EBV+ human B-cells in vivo, as well as the development of these cells into lymphoma-like tumors in immunodeficient mice.

Elevated numbers of PD-L1 expressing B cells are associated with the development of AIDS-NHL

The risk for non-Hodgkin lymphoma (NHL) is markedly increased in persons living with human immunodeficiency virus (HIV) infection, and remains elevated in those on anti-retroviral therapy (cART). Both the loss of immunoregulation of Epstein-Barr virus (EBV) infected cells, as well as chronic B-cell activation, are believed to contribute to the genesis of AIDS-related NHL (AIDS-NHL). However, the mechanisms that lead to AIDS-NHL have not been completely defined. A subset of B cells that is characterized by the secretion of IL10, as well as the expression of the programmed cell death ligand-1 (PD-L1/CD274), was recently described. These PD-L1+ B cells can exert regulatory function, including the dampening of T-cell activation, by interacting with the program cell death protein (PD1) on target cells. The role of PD-L1+ B cells in the development of AIDS-NHL has not been explored. We assessed B cell PD-L1 expression on B cells preceding AIDS-NHL diagnosis in a nested case-control study of HIV+ subjects who went on to develop AIDS-NHL, as well as HIV+ subjects who did not, using multi-color flow cytometry. Archival frozen viable PBMC were obtained from the UCLA Multicenter AIDS Cohort Study (MACS). It was seen that the number of CD19+CD24++CD38++and CD19+PD-L1+cells was significantly elevated in cases 1-4 years prior to AIDS-NHL diagnosis, compared to controls, raising the possibility that these cells may play a role in the etiology of AIDS-NHL. Interestingly, most PD-L1+ expression on CD19+ cells was seen on CD19+CD24++CD38++ cells. In addition, we showed that HIV can directly induce PD-L1 expression on B cells through interaction of virion-associated CD40L with CD40 on B cells.

Pre-diagnosis plasma immune markers and risk of non-Hodgkin lymphoma in two prospective cohort studies

Inflammation and B-cell hyperactivation have been associated with non-Hodgkin lymphoma development. This prospective analysis aimed to further elucidate pre-diagnosis plasma immune marker profiles associated with non-Hodgkin lymphoma risk. We identified 598 incident lymphoma cases and 601 matched controls in Nurses' Health Study and Health Professionals Follow-up Study participants with archived pre-diagnosis plasma samples and measured 13 immune marker levels with multiplexed immunoassays. Using multivariable logistic regression we calculated Odds Ratios (OR) and 95% Confidence Intervals (CI) per standard deviation unit increase in biomarker concentration for risk of non-Hodgkin lymphoma and major histological subtype, stratifying additional models by years (<5, 5 to <10, ≥10) after blood draw. Soluble interleukin-2 receptor-α, CXC chemokine ligand 13, soluble CD30, and soluble tumor necrosis factor receptor-2 were individually positively associated, and B-cell activating factor of the tumor necrosis factor family inversely associated, with all non-Hodgkin lymphoma and one or more subtypes. The biomarker combinations associated independently with lymphoma varied somewhat by subtype and years after blood draw. Of note, the unexpected inverse association between B-cell activating factor and chronic lymphocytic leukemia/small lymphocytic lymphoma risk (OR: 95%CI: 0.51, 0.43-0.62) persisted more than ten years after blood draw (OR: 0.70; 95%CI: 0.52-0.93). In conclusion, immune activation precedes non-Hodgkin lymphoma diagnosis by several years. Decreased B-cell activating factor levels may denote nascent chronic lymphocytic leukemia many years pre-diagnosis.

Combination antiretroviral therapy and cancer risk

PURPOSE OF REVIEW

To review the newest research about the effects of combination antiretroviral therapy (cART) on cancer risk.

RECENT FINDINGS

HIV+ persons are at increased risk of cancer. As this risk is higher for malignancies driven by viral and bacterial coinfections, classifying malignancies into infection-related and infection-unrelated has been an emerging trend. Cohorts have detected major reductions in the incidence of Kaposi sarcoma and non-Hodgkin lymphoma (NHL) following cART initiation among immunosuppressed HIV+ persons. However, recent randomized data indicate that cART reduces risk of Kaposi sarcoma and NHL also during early HIV infection before overt immunosuppression occurs. Long-term effects of cART exposure on cancer risk are not well defined; according to basic and epidemiological research, there might be specific associations of each cART class with distinct patterns of cancer risk.

SUMMARY

The relationship between cART exposure and cancer risk is complex and nuanced. It is an intriguing fact that, whether initiated during severe immunosuppression or not, cART reduces risk of Kaposi sarcoma and NHL. Further research should identify mediators of the benefit of immediate cART initiation in reducing cancer risk, understand the relationship between long-term cART exposure and cancer incidence and assess whether adjuvant anti-inflammatory therapies can reduce cancer risk during treated HIV infection.

Predictive Value of Cytokines and Immune Activation Biomarkers in AIDS-Related Non-Hodgkin Lymphoma Treated with Rituximab plus Infusional EPOCH (AMC-034 trial)

PURPOSE

The aims of this study were to determine whether pretreatment plasma levels of cytokines and immune activation-associated molecules changed following treatment for AIDS-NHL with rituximab plus infusional EPOCH, and to determine whether pretreatment levels of these molecules were associated with response to treatment and/or survival.

EXPERIMENTAL DESIGN

We quantified plasma levels of B-cell activation-associated molecules (sCD27, sCD30, and sCD23) and cytokines (IL6, IL10, and CXCL13) before and after the initiation of treatment in persons with AIDS-NHL (n = 69) in the AIDS Malignancies Consortium (AMC) 034 study, which evaluated treatment of AIDS-NHL with EPOCH chemotherapy and rituximab.

RESULTS

Treatment resulted in decreased plasma levels of some of these molecules (CXCL13, sCD27, and sCD30), with decreased levels persisting for one year following the completion of treatment. Lower levels of CXCL13 before treatment were associated with complete responses following lymphoma therapy. Elevated levels of IL6 pretreatment were associated with decreased overall survival, whereas higher IL10 levels were associated with shorter progression-free survival (PFS), in multivariate analyses. Furthermore, patients with CXCL13 or IL6 levels higher than the median levels for the NHL group, as well as those who had detectable IL10, had lower overall survival and PFS, in Kaplan-Meier analyses.

CONCLUSIONS

These results indicate that CXCL13, IL6, and IL10 have significant potential as prognostic biomarkers for AIDS-NHL.

HIV-1 Tat induces DNMT over-expression through microRNA dysregulation in HIV-related non Hodgkin lymphomas

BACKGROUND

A close association between HIV infection and the development of cancer exists. Although the advent of highly active antiretroviral therapy has changed the epidemiology of AIDS-associated malignancies, a better understanding on how HIV can induce malignant transformation will help the development of novel therapeutic agents.

METHODS

HIV has been reported to induce the expression of DNMT1 in vitro, but still no information is available about the mechanisms regulating DNMT expression in HIV-related B-cell lymphomas. In this paper, we investigated the expression of DNMT family members (DNMT1, DNMT3a/b) in primary cases of aggressive B-cell lymphomas of HIV-positive subjects.

RESULTS

Our results confirmed the activation of DNMT1 by HIV in vivo, and reported for the first time a marked up-regulation of DNMT3a and DNMT3b in HIV-positive aggressive B-cell lymphomas. DNMT up-regulation in HIV-positive tumors correlated with down-regulation of specific microRNAs, as the miR29 family, the miR148-152 cluster, known to regulate their expression. Literature reports the activation of DNMTs by the human polyomavirus BKV large T-antigen and adenovirus E1a, through the pRb/E2F pathway. We have previously demonstrated that the HIV Tat protein is able to bind to the pocket proteins and to inactivate their oncosuppressive properties, resulting in uncontrolled cell proliferation. Therefore, we focused on the role of Tat, due to its capability to be released from infected cells and to dysregulate uninfected ones, using an in vitro model in which Tat was ectopically expressed in B-cells.

CONCLUSIONS

Our findings demonstrated that the ectopic expression of Tat was per se sufficient to determine DNMT up-regulation, based on microRNA down-regulation, and that this results in aberrant hypermethylation of target genes and microRNAs. These results point at a direct role for Tat in participating in uninfected B-cell lymphomagenesis, through dysregulation of the epigenetical control of gene expression.

Factors contributing to risk for cancer among HIV-infected individuals, and evidence that earlier combination antiretroviral therapy will alter this risk

PURPOSE OF REVIEW

To critically appraise recent published literature about factors associated with cancer risk likely to be influenced by combination antiretroviral therapy (cART) in HIV-infected individuals, and the potential of earlier cART initiation to reduce this risk.

RECENT FINDINGS

Factors leading to increased risk of non-AIDS-defining malignancies (NADMs) in particular remain poorly understood. Immunodeficiency appears to be key, whereas evidence is emerging that a direct pro-oncogenic effect of HIV, activated inflammatory and coagulation pathways, and cART toxicity may also contribute. By reducing HIV replication, improving immune function, and limiting chronic inflammation, cART initiation at higher CD4 cell counts may, therefore, reduce NADM risk. However, cART only partly normalizes enhanced inflammation and coagulation seen during HIV infection and conflicting laboratory and epidemiological data have been reported as to whether (and how) cART affects NADM risk. Furthermore, secondary analyses of randomized controlled trials comparing early versus delayed cART initiation were inconclusive.

SUMMARY

Continuous epidemiological surveillance is warranted to monitor trends in cancer incidence among HIV-infected individuals and to better understand the impact of earlier cART on NADM risk. The role of adjuvant anti-inflammatory or antithrombotic therapies to reduce cancer risk deserves further investigation.

Serum levels of cytokines and biomarkers for inflammation and immune activation, and HIV-associated non-Hodgkin B-cell lymphoma risk

BACKGROUND

HIV infection is associated with a marked increase in risk for non-Hodgkin lymphoma (AIDS-NHL). However, the mechanisms that promote the development of AIDS-NHL are not fully understood.

METHODS

In this study, serum levels of several cytokines and other molecules associated with immune activation were measured in specimens collected longitudinally during 1 to 5 years preceding AIDS-NHL diagnosis, in 176 AIDS-NHL cases and 176 HIV(+) controls from the Multicenter AIDS Cohort Study (MACS).

RESULTS

Multivariate analyses revealed that serum levels of immunoglobulin free light chains (FLC), interleukin (IL)-6, IL-10, IP-10/CXCL10, neopterin, and TNF-α were elevated in those HIV(+) individuals who went on to develop AIDS-NHL. In addition, the fraction of specimens with detectable IL-2 was increased and the fraction with detectable IL-4 was decreased in these subjects.

CONCLUSIONS

These results suggest that long-term, chronic immune activation, possibly driven by macrophage-produced cytokines, precedes development of NHL in HIV(+) individuals.

IMPACT

FLC, IL-6, IL-10, IP-10/CXCL10, neopterin, and TNF-α may serve as biomarkers for AIDS-NHL. .

Serum biomarkers of immune activation and subsequent risk of non-hodgkin B-cell lymphoma among HIV-infected women

BACKGROUND

There is increasing evidence that chronic immune activation predisposes to non-Hodgkin lymphoma (NHL). Whether this association exists among women representative of the current HIV epidemic in the United States who are at high risk of HIV-associated NHL (AIDS-NHL), remains to be determined.

METHODS

We conducted a nested case-control study within the Women's Interagency HIV Study with longitudinally collected risk factor data and sera. Cases were HIV-infected women with stored sera collected at three time-windows 3 to 5 years, 1 to 3 years, and 0 to 1 year before AIDS-NHL diagnosis (n = 22). Three to six HIV-infected controls, without AIDS-NHL, were matched to each case on age, race, CD4(+) T-cell count, and study follow-up time (n = 78). ORs and 95% confidence intervals (CI) for the association between one unit increase in log-transformed biomarker levels and AIDS-NHL were computed using random effect multivariate logistic regression models.

RESULTS

Elevated levels of sCD27 (OR = 7.21; 95% CI, 2.62-19.88), sCD30 (OR = 2.64; 95% CI, 1.24-5.64), and CXCL13 (OR = 2.56; 95% CI, 1.32-4.96) were associated with subsequent diagnosis of AIDS-NHL overall. Elevated sCD23 was associated with a two to three-fold increased risk of AIDS-NHL in certain subgroups, whereas elevated interleukin 6 was associated with a two-fold increased risk in the 0 to 1 year time-window, only.

CONCLUSIONS

These findings support the hypothesis that chronic B-cell activation contributes to the development of AIDS-NHL in women.

IMPACT

Soluble CD23 (sCD23), sCD27, sCD30, and CXCL13 may serve as biomarkers for AIDS-NHL.

Levels of murine, but not human, CXCL13 are greatly elevated in NOD-SCID mice bearing the AIDS-associated Burkitt lymphoma cell line, 2F7

Currently, few rodent models of AIDS-associated non-Hodgkin’s lymphoma (AIDS-NHL) exist. In these studies, a novel mouse/human xenograft model of AIDS-associated Burkitt lymphoma (AIDS-BL) was created by injecting cells of the human AIDS-BL cell line, 2F7, intraperitoneally into NOD-SCID mice. Mice developed tumors in the peritoneal cavity, with metastases to the spleen, thymus, and mesenteric lymph nodes. Expression of the chemokine receptor, CXCR5, was greatly elevated in vivo on BL tumor cells in this model, as shown by flow cytometry. CXCL13 is the ligand for CXCR5, and serum and ascites levels of murine, but not human, CXCL13 showed a striking elevation in tumor-bearing mice, with levels as high as 200,000 pg/ml in ascites, as measured by ELISA. As shown by immunohistochemistry, murine CXCL13 was associated with macrophage-like tumor-infiltrating cells that appeared to be histiocytes. Blocking CXCR5 on 2F7 cells with neutralizing antibodies prior to injection into the mice substantially delayed tumor formation. The marked elevations in tumor cell CXCR5 expression and in murine CXCL13 levels seen in the model may potentially identify an important link between tumor-interacting histiocytes and tumor cells in AIDS-BL. These results also identify CXCL13 as a potential biomarker for this disease, which is consistent with previous studies showing that serum levels of CXCL13 were elevated in human subjects who developed AIDS-lymphoma. This mouse model may be useful for future studies on the interactions of the innate immune system and AIDS-BL tumor cells, as well as for the assessment of potential tumor biomarkers for this disease.

Predicting risk of cancer during HIV infection: the role of inflammatory and coagulation biomarkers

OBJECTIVE

To investigate the relationship between inflammatory [interleukin-6 (IL-6) and C-reactive protein (CRP)] and coagulation (D-dimer) biomarkers and cancer risk during HIV infection.

DESIGN

A prospective cohort.

METHODS

HIV-infected patients on continuous antiretroviral therapy (ART) in the control arms of three randomized trials (N=5023) were included in an analysis of predictors of cancer (any type, infection-related or infection-unrelated). Hazard ratios for IL-6, CRP and D-dimer levels (log2-transformed) were calculated using Cox models stratified by trial and adjusted for demographics and CD4+ cell counts and adjusted also for all biomarkers simultaneously. To assess the possibility that biomarker levels were elevated at entry due to undiagnosed cancer, analyses were repeated excluding early cancer events (i.e. diagnosed during first 2 years of follow-up).

RESULTS

During approximately 24,000 person-years of follow-up (PYFU), 172 patients developed cancer (70 infection-related; 102 infection-unrelated). The risk of developing cancer was associated with higher levels (per doubling) of IL-6 (hazard ratio 1.38, P<0.001), CRP (hazard ratio 1.16, P=0.001) and D-dimer (hazard ratio 1.17, P=0.03). However, only IL-6 (hazard ratio 1.29, P=0.003) remained associated with cancer risk when all biomarkers were considered simultaneously. Results for infection-related and infection-unrelated cancers were similar to results for any cancer. Hazard ratios excluding 69 early cancer events were 1.31 (P=0.007), 1.14 (P=0.02) and 1.07 (P=0.49) for IL-6, CRP and D-dimer, respectively.

CONCLUSION

Activated inflammation and coagulation pathways are associated with increased cancer risk during HIV infection. This association was stronger for IL-6 and persisted after excluding early cancer. Trials of interventions may be warranted to assess whether cancer risk can be reduced by lowering IL-6 levels in HIV-positive individuals.

Pretreatment circulating serum cytokines associated with follicular and diffuse large B-cell lymphoma: a clinic-based case-control study

BACKGROUND

Abnormal immune function is a key factor in predisposition to non-Hodgkin lymphoma (NHL). We evaluated the association of 30 cytokines individually and as a profile with diffuse large B-cell (DLBCL) and follicular (FL) lymphomas.

METHODS

We used a multiplexed assay to measure 30 cytokine concentrations in pre-treatment serum in a case-control study of 234 FL, 188 DLBCL, and 400 control participants. Unconditional logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs) adjusted for age and sex, and polytomous regression was used to evaluate heterogeneity between FL and DLBCL. Principal components analysis (PCA) was used to assess cytokine profiles associated with FL and DLBCL.

RESULTS

In single cytokine modeling, we found that 12 of the 30 circulating serum cytokines were significantly (P<0.05) associated with FL and/or DLBCL after accounting for multiple testing (q<0.05). Soluble IL-2R (sIL-2R) had the strongest association with both FL (OR=6.0 for highest versus lowest tertile, 95% CI 3.8-9.5; p-trend=1.8 × 10(-21)) and DLBCL (OR=7.6, 95% CI 4.5-13.1; p-trend=7.2 × 10(-20)). IL1RA and IL-12p40 also showed similar associations for DLBCL and FL. In contrast, HGF, MIG, and MIP-1α had a stronger association with DLBCL compared to FL, and IL-6, IL-8, IL-10, IFN-γ, IP-10, and VEGF were only statistically significantly associated with DLBCL after accounting for multiple testing. However, in PCA modeling, a cytokine profile based on sIL-2R, IL-1RA, MIG, IP-10, IL-8, and IL-12p40 explained most of the variability between controls and both FL and DLBCL.

CONCLUSIONS

We identified some cytokines unique to DLBCL, but overall cytokine associations were more similar than distinct for DLBCL and FL. While these data are limited by concerns of reverse causality, they do suggest cytokines and cytokine profiles that can be prioritized in future studies.

Markers of B-cell activation in relation to risk of non-Hodgkin lymphoma

B-cell activation biomarkers have been associated with increased risk of non-Hodgkin lymphoma (NHL) in HIV-infected populations. However, whether a similar association may exist in general populations has not been established. We conducted a case-control study within the Women's Health Initiative Observational Study cohort to measure the B-cell activation biomarkers sCD23, sCD27, sCD30, sCD44, and CXCL13 in serum samples collected an average of 6 years before NHL diagnosis in 491 cases and 491 controls. Using logistic regression to estimate odds ratios, we observed strong associations between NHL and markers for all B-cell NHL and for major subtypes. Women with marker levels in the highest-versus-lowest quartile categories of CD23, CD27, CD30, or CXCL13 were at 2.8- to 5.5-fold increased risk of B-NHL. In addition, there were significant trends of risk with increasing levels of these markers present. Associations were strongest for cases with shortest lag times between blood draw and diagnosis (<3 years). However, there were also significant associations for cases with the longest prediagnostic lag (9 to 13 years). Taken together, our findings indicate a prominent role for B-cell activation among postmenopausal women in the etiology of B-cell NHL and/or in processes reflective of early disease development as early as 9 years before diagnosis.

A review of the role of lymphoma markers and occupational and environmental exposures

Immune deficiency and altered immunity are among the best characterized and strongest known risk factors of non-Hodgkin lymphomas (NHL). For instance, chronic inflammation or certain disturbances in the immune system are associated with an increased lymphoma risk. Occupational and environmental factors (i.e., dioxin) as well as lifestyle factors (i.e., obesity) may contribute to these risk factors. The precise role of these factors in the etiology of NHL, however, is still not entirely clear. Although the existing epidemiologic studies have not revealed consistent patterns of perturbations of the immune system by these factors, the findings might suggest an adverse impact on both the humoral and cell-mediated immune system.

B-cell activation induced microRNA-21 is elevated in circulating B cells preceding the diagnosis of AIDS-related non-Hodgkin lymphomas

We show that microRNA-21 is significantly elevated in peripheral B cells of HIV-infected individuals who go on to develop AIDS-related non-Hodgkin lymphoma (n=13, <3 years prior to diagnosis) when compared with HIV-negative (n=18) or HIV-positive controls (n=21) (P<0.01). Moreover, miR-21 is overexpressed in activated B cells and can be induced by interleukin 4 alone, or with CD40 or immunoglobulin M co-stimulation, and lipopolysaccharides, suggesting that miR-21 may help maintain B-cell hyperactivation, contributing to lymphomagenesis.

HMG-CoA reductase inhibitors (statins) use and risk of non-Hodgkin lymphoma in HIV-positive persons

OBJECTIVE

Experimental studies suggested that HMG-CoA reductase inhibitors ('statins') may have antilymphoma properties. We investigated whether statin use is associated with reduced risk of non-Hodgkin lymphoma (NHL) in HIV-positive persons.

DESIGN

A nested case-control study was conducted among HIV-positive members of Kaiser Permanente California, a large managed care organization.

METHODS

Cases were incident HIV+ NHL diagnosed from 1996 to 2008. Controls were HIV-positive members without NHL matched 5 : 1 to cases by age, sex, race, index year and known duration of HIV infection. Data were collected from Kaiser Permanente's electronic medical records. Conditional logistic regression was used to examine the effect of statin use on HIV + NHL risk, adjusting for potential confounders (matching factors, prior clinical AIDS diagnosis, antiretroviral use, baseline CD4 cell count, and history of selected co-morbidity) and use of nonstatin lipid-lowering therapy (LLT).

RESULTS

A total of 259 cases and 1295 controls were included. Eight percent of the cases and 14% of the controls had a history of statin use. Statin use was associated with lower risk of HIV + NHL; hazard ratio and 95% confidence intervals for ever use, less than 12, and at least 12 months cumulative use was 0.55 (0.31-0.95), 0.64 (0.31-1.28), and 0.50 (0.23-1.10), respectively. P value for trend for duration of statin use was 0.08. No association between nonstatin LLT use and risk of NHL was observed.

CONCLUSION

Our results suggested an inverse association between statin use and risk of NHL in HIV-positive persons. Potential limitations include the likelihood of residual confounding by indication and limited study power for some statin use subgroups.

Prediagnostic serum levels of cytokines and other immune markers and risk of non-hodgkin lymphoma

Although severe immune dysregulation is an established risk factor for non-Hodgkin lymphoma (NHL), it is unclear whether subclinical immune system function influences lymphomagenesis. To address this question, we conducted a nested case-control study within the Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial to investigate whether circulating levels of cytokines and other immune markers are associated with future risk of NHL. Selected cytokines [interleukin (IL)-4, IL-6, IL-10, and TNF-α] and other immune markers [soluble TNF receptor 1 (sTNF-R1), sTNF-R2, C-reactive protein, and sCD27] were measured in prediagnostic serum specimens from 297 incident NHL cases and 297 individually matched controls. ORs and 95% confidence intervals (CI) relating quartiles of analyte concentration to NHL risk were calculated by using conditional logistic regression. Statistically significant associations with increased NHL risk were observed for elevated serum levels of sTNF-R1 (quartile 4 vs. quartile 1: OR = 1.7, 95% CI: 1.1-2.8; P(trend) = 0.02) and sCD27 (OR = 5.3, 95% CI: 2.9-9.4; P(trend) < 0.0001). These associations remained in analyses of cases diagnosed longer than 6 years following blood collection (sTNF-R1: OR = 2.1, 95% CI: 1.0-4.0, P(trend) = 0.01; sCD27: OR = 4.1, 95% CI: 1.9-8.5, P(trend) = 0.0001). Elevated levels of IL-10, TNF-α and sTNF-R2 were also significantly associated with increased risk of NHL overall; however, these associations weakened with increasing time from blood collection to case diagnosis and were null for cases diagnosed longer than 6 years postcollection. Our findings for sTNF-R1 and sCD27, possible markers for inflammatory and B-cell stimulatory states, respectively, support a role for subclinical inflammation and chronic B-cell stimulation in lymphomagenesis.

HIV-associated immune dysfunction and viral infection: role in the pathogenesis of AIDS-related lymphoma

HIV infection is associated with a much higher risk for the development of non-Hodgkin lymphoma (AIDS-NHL). The principal causes of lymphomagenesis in HIV-infected individuals are thought to be the loss of immune function seen in HIV infection, which results in the loss of immunoregulation of Epstein-Barr virus-infected B cells, as well as HIV infection-associated immune dysregulation, including chronic B-cell activation. In this review, we discuss recent reports that further support the importance of these factors, and we highlight emerging evidence of different mechanisms that potentially drive lymphomagenesis in HIV-infected individuals.

B-cell stimulatory cytokines and markers of immune activation are elevated several years prior to the diagnosis of systemic AIDS-associated non-Hodgkin B-cell lymphoma

BACKGROUND

The risk of developing non-Hodgkin lymphoma (NHL) is greatly increased in HIV infection. The aim of this study was to determine whether elevated serum levels of molecules associated with B-cell activation precede the diagnosis of AIDS-associated NHL (AIDS-NHL).

METHODS

Serum levels of B-cell activation-associated molecules, interleukin (IL)6, IL10, soluble CD23 (sCD23), sCD27, sCD30, C-reactive protein (CRP), and immunoglobulin E were determined in 179 NHL cases and HIV+ controls in the Multicenter AIDS Cohort Study, collected at up to 3 time points per subject, 0 to 5 years prior to AIDS-NHL diagnosis.

RESULTS

Serum IL6, IL10, CRP, sCD23, sCD27, and sCD30 levels were all significantly elevated in the AIDS-NHL group, when compared with HIV+ controls or with AIDS controls, after adjusting for CD4 T-cell number. Elevated serum levels of B-cell activation-associated molecules were seen to be associated with the development of systemic [non-CNS (central nervous system)] NHL, but not with the development of primary CNS lymphoma.

CONCLUSIONS

Levels of certain B-cell stimulatory cytokines and molecules associated with immune activation are elevated for several years preceding the diagnosis of systemic AIDS-NHL. This observation is consistent with the hypothesis that chronic B-cell activation contributes to the development of these hematologic malignancies.

IMPACT

Marked differences in serum levels of several molecules are seen for several years prediagnosis in those who eventually develop AIDS-NHL. Some of these molecules may serve as candidate biomarkers and provide valuable information to better define the etiology of NHL.

Cytokine signatures of transformed B cells with distinct Epstein-Barr virus latencies as a potential diagnostic tool for B cell lymphoma

Immunocompromised individuals, including those infected with human immunodeficiency virus (HIV), are at increased risk of Epstein-Barr virus (EBV)-associated aggressive B cell malignancies such as Burkitt's lymphoma (BL) or diffuse large B cell lymphoma (DLBCL). Differential diagnosis of these lymphomas requires histopathological, immunohistochemical and cytogenetic assessments. Rapid, less invasive approaches to the diagnosis of EBV-associated B cell lymphomas are needed. Here, high-throughput cytokine profiling of BL cell lines and EBV-transformed B lymphoblastoid cell lines (B-LCL), representing DLBCL, was carried out. By monitoring the production of 42 different cytokines, unique cytokine signatures were identified for BL and B-LCL/DLBCL. The BL cells produced interleukin (IL)-10, 10 kDa interferon gamma-induced protein (IP-10)/CXCL10, macrophage-derived chemokine (MDC)/CCL22, macrophage inflammatory protein (MIP)-1α/CCL3 and MIP-1β/CCL4. In addition to these five cytokines, the cytokine signature of B-LCL/DLBCL cells included IL-8/CXCL8, IL-13, platelet-derived growth factor (PDGF)-AA, and regulated upon activation, normal T cell expressed and secreted (RANTES)/CCL5. Epstein-Barr virus latency was responsible for the increased production of IL-10, MDC/CCL22 and MIP-1α/CCL3 in BL cells, suggesting that EBV-mediated BL-genesis involves these three cytokines. These results suggest that high-throughput cytokine profiling might be a valuable tool for the differential diagnosis and might deepen our understanding of the pathogenesis of EBV-associated B cell malignancies.

Cancer biomarkers in HIV patients

PURPOSE OF REVIEW

In this review, we update investigations related to cancer biomarkers in HIV-infected populations.

RECENT FINDINGS

CD4 lymphocyte count is associated with primary central nervous system lymphoma (PCNSL), systemic non-Hodgkin's lymphoma (NHL) (except perhaps for Burkitt lymphoma), Kaposi's sarcoma, cervical cancer, and anal cancer. HIV load is associated with Burkitt lymphoma and systemic NHL (but not PCNSL), with Kaposi's sarcoma and with anal cancer. CD40 ligand incorporated into the HIV envelope and expression of activation-induced cytidine deaminase may help explain the relationship between HIV load and Burkitt lymphoma. Genetic polymorphisms have been identified that are linked to lymphoma in HIV patients. B-cell activation as manifest in immunoglobulin light chain production may be an important marker for NHL risk. Cytokines and related molecules (IL10, sCD30) may identify patients at high risk for NHL. Epstein-Barr virus (EBV) in cerebrospinal fluid (CSF) is useful as a marker for PCNSL, although with the falling incidence of PCNSL, the specificity of the test has been called into question. EBV and Kaposi's sarcoma-associated herpesvirus (KSHV) have not yet emerged as especially promising markers of risk for either lymphoma or Kaposi's sarcoma.

SUMMARY

CD4 lymphocyte count, HIV load, germline genetic polymorphisms, cytokine and related molecules, and immunoglobulin light chains all show increasing promise as biomarkers of malignancy in HIV patients.

Effect of highly active antiretroviral therapy on biomarkers of B-lymphocyte activation and inflammation

OBJECTIVE

Chronic inflammation and B-cell hyperactivation are seen in HIV infection, contributing to an increased risk for the accrual of genetic errors that may result in B-cell lymphoma. The primary objective of this study was to determine the effect of highly active antiretroviral therapy (HAART) on serum levels of molecules that are associated with immune activation and/or inflammation, including several that are associated with B-cell activation, specifically IL-6, sCD30, sCD27, IgG, IgA, CXCL13 (B lymphocyte chemoattractant, BLC), a B-lymphocyte chemokine involved in B-cell trafficking, as well as C-reactive protein, an acute-phase protein.

DESIGN

We used a retrospective cohort study design, measuring serum levels of these markers at each of four 1-year intervals, 2 years before and 2 years after HAART initiation, in a subgroup of 290 HIV-infected men enrolled in the Multicenter AIDS Cohort Study (MACS).

METHODS

Serum levels of immune activation-associated molecules were measured by ELISA and multiplexed immunometric assays. Reference values were determined by the 5th to 95th percentiles from a sample of 109 HIV-uninfected MACS men.

RESULTS

HAART use was associated with a reduction, but not normalization, of most biomarkers tested. Serum levels of IL-6 and C-reactive protein appeared to be unaffected by HAART.

CONCLUSIONS

These results suggest a partial normalization of serum cytokine levels post HAART. However, a chronic state of B-cell hyperactivation continues 2-3 years after HAART initiation. These findings may explain, in part, the excess incidence of lymphoma still occurring in HIV-infected persons in the post-HAART era.

B cells from HIV-infected patients with primary central nervous system lymphoma display an activated phenotype and have a blunted TNF-α response to TLR9 triggering

Each cell in HIV-associated primary central nervous system lymphoma (PCNSL) harbors latent EBV. Notably, the triggering of TLR9, a key event in HIV pathogenesis, also promotes EBV latency and transformation. We hypothesized that because only a minority of HIV-infected patients develops PCNSL, their B cells exhibit aberrant signaling responses to TLR9 triggering. We found higher levels of IL-6, CD80, and CD86 expression at baseline in B cells of those patients than in B cells of matched controls, whereas TNF-a expression was lower. Notably, on TLR9 triggering with CpG 2006, CD80 and TNF-α were up-regulated to a lesser extent in B cells of the former than in those of matched controls. The reduced up-regulation of CD80 might be explained by its higher baseline expression resulting in a more blunted response rather than a specific deficit of the signaling response to TLR9 triggering. However, this cannot explain the blunted TNF-α response, which warrants further investigation. Finally, since increased IL-6 expression is linked to EBV-associated Hodgkin’s lymphoma, the enhanced baseline expression of IL-6 might be important in the pathogenesis of PCNSL in HIV-infected patients.

Assessment of pre-diagnosis biomarkers of immune activation and inflammation: insights on the etiology of lymphoma

The DNA-modifying processes that are involved in B lymphocyte activation, somatic hypermutation (SHM), and IgH class switch recombination (CSR) have the potential to lead to genetic errors that lead to the genesis of B cell cancers, such as lymphoma. Given the potential contribution of these immune mechanisms to the development of cancer, assessment of the expression of cytokines, and other immune stimulatory molecules that drive B cell activation, prior to lymphoma diagnosis, may provide insights into the etiology of these cancers. Here, we review studies that have examined prediagnosis protein biomarkers for non-Hodgkin lymphoma (NHL), both AIDS-related NHL, as well as NHL seen in immunocompetent populations. Overall, these studies provide support for the notion that B cell hyper-activation is elevated preceding the appearance of AIDS-NHL, particularly those forms of AIDS-NHL that are not driven by EBV infection and that presumably arise from errors in IgH CSR and SHM. In more limited studies, it appears that dysregulation of cytokine production also precedes the diagnosis of NHL in HIV-negative persons. The availability of prediagnosis serum/plasma from cohort studies provides unique opportunities for proteomic approaches to identify novel prediagnosis etiologic biomarkers for NHL.

Pretreatment levels of soluble cellular receptors and interleukin-6 are associated with HIV disease progression in subjects treated with highly active antiretroviral therapy

BACKGROUND

To identify inflammatory pathways that may contribute to the pathogenesis of human immunodeficiency virus (HIV) disease, we explored associations between AIDS or death and different inflammatory markers, including selected soluble tumor necrosis factor superfamily receptors (sTNFRs) and ligands, interleukin (IL)-6, and CD8 T cell activation, in individuals treated with highly active antiretroviral therapy (HAART).

METHODS

A case-control study of subjects in AIDS Clinical Trials Group (ACTG) protocols 384 and 5015, who were matched according to the CD4 cell count and plasma viral load at baseline, was performed using conditional logistic regression.

RESULTS

Higher pretreatment concentrations of sTNFR-1, sCD27, sCD40L, and plasma IL-6 were associated with a new AIDS-defining illness or death in separate models adjusted for age, sex, hemoglobin, and the latest CD4 cell counts. In additional models that excluded case patients with opportunistic infections, sTNFR-1, sCD27, and sCD40L were each associated with a new AIDS-defining malignancy or death that developed at a median of 51 weeks after initiation of HAART, by which time the majority of subjects had a CD4 cell count of >200 cells/cm(3) and had achieved a plasma viral load of <50 copies/mL.

CONCLUSION

These data are compatible with a model in which these soluble inflammatory markers identify pathways that may contribute to the pathogenesis of HIV disease progression, pathways that might not be a direct consequence of ongoing HIV type 1 replication.

Plasma cytokines and future risk of non-Hodgkin lymphoma (NHL): a case-control study nested in the Italian European Prospective Investigation into Cancer and Nutrition

BACKGROUND

Recently, biological markers related to the immune system such as cytokines have been studied to further understand the etiology of non-Hodgkin Lymphoma (NHL). However, to date, there are no studies that have studied cytokine levels prospectively in relation to NHL risk in the general population.

METHODS

Using bead-based immunoassays, plasma levels of 11 cytokines, 4 chemokines, and 1 adhesion molecules were measured in prediagnostic blood samples of 86 NHL cases and 86 matched controls (average time between blood collection and diagnosis, 4.5 y). Conditional logistic regression adjusted for body mass index and alcohol consumption was used to analyze the association between individual plasma cytokine levels and the risk of developing NHL.

RESULTS

In multivariate models, excluding cases diagnosed within 2 years after inclusion, we observed a significant association for interleukin 2 (IL2; P trend = 0.004), interferon (IFN)-gamma (P trend = 0.05), and intercellular adhesion molecule (ICAM) (P trend = 0.04). Subanalyses of B-cell NHL patients showed a significant association with IL2 (P trend = 0.003), tumor necrosis factor-alpha (TNF-alpha; P trend = 0.03), and ICAM (P trend = 0.04) and a borderline association with IL5 (P trend = 0.07) and IFN-gamma (P trend = 0.08).

CONCLUSIONS

The results of this study suggest, in a prospective setting, a possible association between plasma levels of IL2, ICAM, IFN-gamma, and TNF-alpha with NHL risk and provide some evidence that risk of NHL might be related to a downregulation of T helper 1 cytokines.

IMPACT

Identification of subtle changes in immune response regulation quantified by plasma cytokine levels possibly provides new insights in the etiology of NHL.

Circulating cytokines and risk of B-cell non-Hodgkin lymphoma: a prospective study

Cytokines play important roles in B-cell activation, proliferation, and apoptosis, thus may be etiologically related to risk of B-cell non-Hodgkin lymphoma (B-NHL). However, the association between circulating levels of cytokines and B-NHL risk has not been prospectively studied in non-HIV populations. The objective of this study was to assess this association by conducting a case-control study nested within a prospective cohort of non-HIV-infected, healthy women. Fifteen cytokines were measured in samples collected a median of 8.2 years prior to diagnosis in 92 cases and two matched controls per case. Only cytokines that showed adequate temporal reproducibility over a two-year period were included. The odds ratio (OR) for the highest tertile relative to the lowest was elevated for soluble IL-2 receptor (sIL-2R) (OR = 2.5, 95% CI = 1.4-4.7, p (trend) < 0.01) and decreased for IL-13 (OR = 0.5, 95% CI = 0.2-1.0, p (trend) = 0.05). Three other cytokines were marginally associated with risk of B-NHL: TNF-alpha (OR = 1.7, 95% CI = 0.9-3.3, p (trend) = 0.11), sTNF-R2 (OR = 1.9, 95% CI = 0.9-3.5, p (trend) = 0.06), and IL-5 (OR = 0.5, 95% CI = 0.3-1.0, p (trend) = 0.06). No association was observed between B-NHL risk and levels of the other cytokines measured (IL-1beta, IL-1RA, IL-2, IL-4, IL-6, IL-10, IL-12, IL-12p70, CRP and sTNF-R1). This study suggests that dysregulated cytokines may be involved in B-NHL development.

Burkitt lymphoma--a stalking horse for cancer research?

Joe Burchenal has predicted in 1966 that Burkitt lymphoma may serve as a stalking horse for cancer research, in revealing new principles. This has been the case with regard to the definition of the Epstein-Barr virus (EBV) in the genesis of virally driven immunoblastomas in immunodefectives, the discovery of the Ig/myc translocation, the main rate limiting event in the genesis of Burkitt lymphoma, the role of secondary events, particularly the inactivation of the Rb and p53 pathways in cells driven by constitutively active myc and other oncogenes and the discovery of the EBV encoded nuclear antigen complex (EBNA) and its role in viral transformation and latency.

Associations of circulating C-reactive protein and interleukin-6 with cancer risk: findings from two prospective cohorts and a meta-analysis

OBJECTIVE

We investigated the associations of circulating C-reactive protein (CRP) and interleukin-6 (IL-6) with cancer risk.

METHODS

We examined the associations of CRP and IL-6 with incident cancer in two prospective cohorts, the British Women's Heart and Health Study (4,286 women aged 60-80) and the Caerphilly Cohort (2,398 men aged 45-59) using Cox regression and pooled our findings with previous prospective studies' in fixed and random effects meta-analyses.

RESULTS

CRP and IL-6 were associated with some incident cancers in our cohorts, but the numbers of cancer cases were small. In our meta-analyses elevated CRP was associated with an increased overall risk of cancer (random effects estimate (RE): 1.10, 95% CI: 1.02, 1.18) and lung cancer (RE: 1.32, 95% CI: 1.08, 1.61). Its associations with colorectal (RE: 1.09, 95% CI: 0.98, 1.21) and breast cancer risks (RE: 1.10, 95% CI: 0.97, 1.26) were weaker. CRP appeared unrelated to prostate cancer risk (RE: 1.00 0.88, 1.13). IL-6 was associated with increased lung and breast cancer risks and decreased prostate cancer risk, and was unrelated to colorectal cancer risk.

CONCLUSIONS

Our findings suggest an etiological role for CRP and IL-6 in some cancers. Further large prospective and genetic studies would help to better understand this role.

Systematic review of the association between circulating interleukin-6 (IL-6) and cancer

Our aim was to systematically review the epidemiologic evidence for an association of circulating interleukin-6 (IL-6), an inflammatory cytokine and cancer. We systematically searched electronic databases Embase, Medline and Web of Science for the studies of circulating IL-6 and any form of cancer. We identified and reviewed 189 discrete studies, consisting of 177 prevalent studies and three prospective studies. Cancer patients' IL-6 concentrations were higher than healthy controls' in most studies, but the results of investigations comparing IL-6 in cancer patients and individuals with benign diseases were less consistent. Due to the small number of prospective studies it is impossible to determine whether IL-6 is causally related to cancer. Large prospective studies of circulating IL-6 or studies using the functional variants of the IL-6 gene as instruments for circulating IL-6 concentrations would provide information on possible aetiological links between IL-6 and malignancy.

Elevated expression of activation induced cytidine deaminase in peripheral blood mononuclear cells precedes AIDS-NHL diagnosis

Non-Hodgkin's B cell lymphoma (NHL) is a common cancer in HIV infection. Many NHL are thought to result from errors in class switch recombination and/or somatic hypermutation, processes that occur in germinal center B cells, and require the activity of activation induced cytidine deaminase (AID). Since NHL is a common cancer in HIV infection, and expression of AID could contribute to the development of NHL, we hypothesized that AID expression would be elevated in those who went on to develop AIDS-associated NHL (AIDS-NHL). AID mRNA levels were measured by TaqMan RT-PCR in peripheral blood mononuclear cells, obtained prior to AIDS-NHL diagnosis, from 16 HIV-infected subjects who developed AIDS-NHL, and from control subjects (AIDS but no NHL, and HIV-negative subjects). PBMC AID expression was markedly elevated in those who developed AIDS-NHL, when compared to AIDS and HIV-negative controls. Additionally, AID expression was seen to differ depending on NHL subtype, with the highest levels of expression seen in those who developed Burkitt's lymphoma.

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.

Serum levels of the homeostatic B cell chemokine, CXCL13, are elevated during HIV infection

HIV infection is associated with B cell dysfunction, which includes B cell hyperactivation, hypergammaglobulinemia, impaired production of antibodies against specific antigens, and a loss of B cell memory. Because lymph node architecture is progressively destroyed during HIV infection, it is possible that normal B cell trafficking is impaired as well, which could be a cause or a result of these abnormalities. Because the homeostatic chemokine, CXCL13 (BLC, BCA-1), is a major regulator of B cell trafficking, we assessed circulating levels of this molecule in HIV infection. Serum levels of CXCL13 were seen to be progressively elevated in HIV disease. Serum levels of CXCL13 correlated strongly with those of the inflammation-associated chemokine, inducible protein-10 (IP-10), in subjects who had advanced HIV disease, and more moderately with levels of soluble CD30 (sCD30), sCD27, and sCD23. CXCL13 levels also correlated moderately with viral load and showed a significant decline after use of highly active antiretroviral treatment (HAART). Elevated levels of CXCL13 could cause impaired or altered trafficking of B cells during HIV infection and could contribute to the previously reported loss of CXCR5, the receptor for CXCL13, from the surface of circulating B cells in HIV infection.

Interleukin-6 (IL-6) expression and natural killer (NK) cell dysfunction and anergy in heart failure

Immune dysfunction has been postulated to play a role in the pathophysiology of chronic heart failure. We examined the relation between interleukin-6 (IL-6) production and natural killer (NK) cell dysfunction in patients with chronic heart failure. Sera and peripheral blood mononuclear cells (PBMCs) were collected from 82 patients with advanced heart failure. Levels of circulating NK cells and T cells were determined by flow cytometry. NK cell function was measured by standard cytotoxicity assays. IL-6 in supernatants of PBMC cultured in vitro was quantitated by an enzyme-linked immunosorbent assay. The levels of circulating NK cells were lower in patients with heart failure than in normal controls (p = 0.0037). NK cells from patients with heart failure also exhibited impaired cytolytic functions in the absence of stimuli and in response to IL-2 and IL-12 (p <0.0001 for all conditions). PBMCs from patients with heart failure produced higher levels of IL-6 in response to a T-cell stimulus than did PBMCs from healthy controls (p = 0.0012). The level of IL-6 produced by unstimulated PBMCs in patients with heart failure correlated with NK cell cytolytic impairment (p = 0.0012). These results demonstrated that PBMCs are a source of IL-6 in patients with heart failure. Production of IL-6 by PBMCs correlated with NK cell anergy to other cytokines that use signal transduction pathways that may be regulated by IL-6. These results support a model of cytokine-induced anergy in conditions that result in high systemic levels of IL-6.

Beta blocker and angiotensin-converting enzyme inhibitor therapy is associated with decreased Th1/Th2 cytokine ratios and inflammatory cytokine production in patients with chronic heart failure

OBJECTIVE

To examine the potential impact of beta-blockers and angiotensin-converting enzyme (ACE) inhibitors, medications which modulate beta-adrenergic signaling, on immune function in patients with chronic heart failure (HF).

METHODS

118 patients attending an HF center were tested for circulating levels of norepinephrine (NE), T cells and the inflammation-associated cytokine interleukin 6 (IL-6). Levels of the cytokines interferon-gamma (IFNgamma), IL-10, and tumor necrosis factor-alpha (TNFalpha) produced by cultured peripheral blood mononuclear cells (PBMC) were measured in culture supernatants following T cell stimulation in vitro.

RESULTS

NE levels were significantly lower in patients receiving ACE inhibitors (p = 0.0263), with a trend toward lower NE in patients receiving beta-blockers. All patients exhibited relatively normal levels of T cells, and there was a trend toward higher levels of total (CD3+) and helper (CD4+) T cells (p = 0.0578 and 0.0932, respectively) in patients receiving either type of medication. The ratios of Th1 (IFNgamma) to Th2 (IL-10) cytokines were lower in patients receiving a combination of beta-blocker and ACE inhibitor therapy (p = 0.0373). NYHA class was a significant predictor of serum IL-6 (p < 0.0001). There was a trend toward lower levels of serum IL-6 in patients receiving both types of medications (p = 0.0606). TNFalpha production by CD3/CD28-stimulated PBMC was significantly lower in patients receiving ACE inhibitor medications (p = 0.0223).

CONCLUSIONS

These results suggest that high sympathetic tone associated with chronic HF affects Th1/Th2 and inflammatory cytokine production, and that these effects can be modulated by medications. In addition to improvement in clinical parameters relating to cardiovascular function, beta-blocker and ACE inhibitor medications also appear to have a beneficial effect on the immune system in HF.

Non-Hodgkin's B cell lymphoma in persons with acquired immunodeficiency syndrome is associated with increased serum levels of IL10, or the IL10 promoter -592 C/C genotype

Interleukin-10 (IL10) may contribute to the development of non-Hodgkin's B cell lymphoma, especially in the context of acquired immunodeficiency syndrome (AIDS), where lymphoma incidence is greatly increased. Utilizing specimens from the Multicenter AIDS Cohort Study (MACS) obtained prior to diagnosis of AIDS-associated lymphoma, detectable serum human IL10 was seen much more frequently in lymphoma cases (n = 61, 26%) compared to CD4-matched AIDS controls (5%, P = 0.004), or to HIV-infected (2%, P = 0.002) or HIV uninfected subjects (0%, P = 0.0003). In longitudinal studies, detectable IL10 occurred at times closest to but preceding lymphoma diagnosis (P = 0.01). In an independent genetic analysis of single-nucleotide polymorphisms within the promoter region of the IL10 gene in 1157 MACS subjects, a high IL10-expressing genotype (-592 C/C) was overrepresented among lymphoma subjects (P = 0.009), even when controlling for race (P = 0.006). These results suggest that elevated serum IL10 or the IL10 promoter -592 C/C genotype are associated with development of AIDS lymphoma.

Fibrates and medroxyprogesterone acetate induce apoptosis of primary Burkitt's lymphoma cells and cell lines: potential for applying old drugs to a new disease

Current therapies for Burkitt's lymphoma (BL) utilise combined cytotoxic chemotherapy, but these treatments are not always available in areas where the disease is endemic and are also markedly less successful in AIDS-related BL. Therefore, additional therapies are urgently required. We demonstrate here that combined fibrates and MPA exert powerful, antiproliferative actions against well-characterised Daudi, Raji and L3055 BL cell lines and primary BL cells. Detailed studies in L3055 demonstrated that this activity was mediated by induced apoptosis and confirmed by observations that overexpression of the antiapoptotic genes bcl-2 or bcl-x(L) conferred significant protection against the drugs. Importantly, since fibrates and MPA are inexpensive and stable with minimal-associated toxicities, we suggest that these drugs should be considered as adjuncts to currently available treatments for BL in endemic and AIDS-related disease.

Pro- and anti-inflammatory cytokines in human immunodeficiency virus infection and acquired immunodeficiency syndrome

In persons with human immunodeficiency virus (HIV) infection and/or acquired immunodeficiency syndrome (AIDS), the immune system becomes dysfunctional in many ways. There is both immunodeficiency due to the loss of CD4-positive T helper cells and hyperactivity as a result of B-cell activation. Likewise, both decreases and increases are seen in the production and/or activity of cytokines. Cytokine changes in HIV infection have been assessed by a variety of techniques, ranging from determination of cytokine gene expression at the mRNA level to secretion of cytokine proteins in vivo and in vitro. Changes in cytokine levels in HIV-infected persons can affect the function of the immune system, and have the potential to directly impact the course of HIV disease by enhancing or suppressing HIV replication. In particular, the balance between the pro-inflammatory cytokines interleukin (IL)-1, IL-6, and tumor necrosis factor-alpha, which up-regulate HIV expression, and IL-10, which can act both as an anti-inflammatory cytokine and a B-cell stimulatory factor, may play an important role in the progression to AIDS. In light of its ability to suppress the production of pro-inflammatory cytokines and, under some conditions, suppress HIV replication, increased IL-10 may be viewed as beneficial in slowing HIV disease progression. However, an association between increased IL-10 and the development of AIDS-associated B-cell lymphoma highlights the bifunctional nature of IL-10 as both an anti-inflammatory and B-cell-stimulatory cytokine that could have beneficial and detrimental effects on the course of HIV infection and AIDS.

B-cell activation and lymphoma in patients with HIV

The risk of developing non-Hodgkin lymphoma (AIDS lymphoma) is greatly increased in HIV infection. Disruption of immune function by HIV infection may contribute to lymphomagenesis by inducing (1) loss of immunoregulation of Epstein-Barr virus-infected B cells [immunoblastic and central nervous system (CNS) lymphoma] caused by loss of T-cell function, and (2) chronic B-cell hyperactivation enhancing the generation of genetic lesions (c- :immunoglobulin gene translocation, -6 overexpression) associated with some forms of AIDS lymphoma (Burkitt lymphoma-like small noncleaved cell lymphoma and large noncleaved cell lymphoma). Also, the overproduction of B-cell-stimulatory cytokines (interleukin 10 and 6) has the potential to contribute to tumor development by supporting the growth and viability of nascent lymphoma cell clones. Therefore, HIV infection-associated B-cell hyperactivation, including direct activation of B cells by various mechanisms, and chronic overproduction of B-cell-stimulatory cytokines have the potential to contribute to the development and growth of AIDS lymphoma. Several recent reports are discussed in this review, including recent work relevant to understanding the potential of a virus-encoded cytokine-like molecule, HHV8 vIL6, to induce B-cell hyperactivation in HIV-infected people, work pointing to the potential role of a chemokine (stromal cell-derived factor 1) in lymphomagenesis, and studies on phenotypic changes in circulating B cells in HIV infection.