Taxonomic reclassification of Kaposi Sarcoma identifies disease entities with distinct immunopathogenesis

BACKGROUND

The taxonomy of Kaposi Sarcoma (KS) is based on a classification system focused on the description of clinicopathological features of KS in geographically and clinically diverse populations. The classification includes classic, endemic, epidemic/HIV associated and iatrogenic KS, and KS in men who have sex with men (MSM). We assessed the medical relevance of the current classification of KS and sought clinically useful improvements in KS taxonomy.

METHODS

We reviewed the demographic and clinicopathological features of 676 patients with KS, who were referred to the national centre for HIV oncology at Chelsea Westminster hospital between 2000 and 2021.

RESULTS

Demographic differences between the different subtypes of KS exist as tautological findings of the current classification system. However, no definitive differences in clinicopathological, virological or immunological parameters at presentation could be demonstrated between the classic, endemic or MSM KS patients. Reclassifying patients as either immunosuppressed or non-immunosuppressed, showed that the immunosuppressed group had a significantly higher proportion of adverse disease features at presentation including visceral disease and extensive oral involvement, classified together as advanced disease (chi² P = 0.0012*) and disseminated skin involvement (chi² P < 0.0001*). Immunosuppressed patients had lower CD4 counts, higher CD8 counts and a trend towards higher HHV8 levels compared to non-immunosuppressed patients, however overall survival and disease specific (KS) survival was similar across groups.

CONCLUSION

The current system of KS classification does not reflect meaningful differences in clinicopathological presentation or disease pathogenesis. Reclassification of patients based on the presence or absence of immunosuppression is a more clinically meaningful system that may influence therapeutic approaches to KS.

Local excision and treatment of early node-negative anal squamous cell carcinomas in a highly HIV prevalent population

Background

Anal squamous cell carcinoma (ASCC) is an uncommon cancer associated with human immunodeficiency virus (HIV) infection. There has been increasing interest in providing organ-sparing treatment in small node-negative ASCC’s, however, there is a paucity of evidence about the use of local excision alone in people living with HIV (PLWH). The aim of this study was to evaluate the efficacy of local excision alone in this patient population.

Methods

We present a case series of stage 1 and stage 2 ASCC in PLWH and HIV negative patients. Data were extracted from a 20-year retrospective cohort study analysing the treatment and outcomes of patients with primary ASCC in a cohort with a high prevalence of HIV.

Results

Ninety-four patients were included in the analysis. Fifty-seven (61%) were PLWH. Thirty-five (37%) patients received local excision alone as treatment for ASCC, they were more likely to be younger (p = 0.037, ANOVA) and have either foci of malignancy or well-differentiated tumours on histology (p = 0.002, Fisher’s exact test).

There was no statistically significant difference in 5-year disease-free survival and recurrence between treatment groups, however, patients who had local excision alone and PLWH were both more likely to recur later compared to patients who received other treatments for ASCC. (72.3 months vs 27.3 months, p = 0.06, ANOVA, and 72.3 months vs 31.8 months, p = 0.035, ANOVA, respectively).

Conclusions

We recommend that local excision be considered the sole treatment for stage 1 node-negative tumours that have clear margins and advantageous histology regardless of HIV status. However, PLWH who have local excision alone must have access to an expert long-term surveillance programme after treatment to identify late recurrences.

The prognostic and predictive role of hyponatremia in patients with advanced non-small cell lung cancer (NSCLC) with bone metastases

PURPOSE

Hyponatremia and bone metastasis (BMs) are known as negative prognostic factors in patients affected by metastatic non-small cell lung cancer (NSCLC). Hyponatremia is associated with higher risk of osteoporosis and bone fracture, but no data are available about the relationship between hyponatremia and bone metastasis. This study aims to analyze the prognostic impact of hyponatremia in NSCLC patients with bone metastases.

METHODS

We retrospectively collected data about advanced NSCLC patients. Survival curves were estimated using Kaplan-Meier method, and comparisons were made using chi-square test.

RESULTS

Six hundred forty-seven patients were enrolled into the study. BMs were present in 264 patients (41%) at diagnosis, while hyponatremia appeared in 237 (37%) patients during the first-line treatment. Patients without BMs had a median overall survival (mOS) of 15.9 months (95% CI 14.1-17.9) versus 11.4 months (95% CI 9.4-13.4) for patients with BMs (p = 0.001). Eunatremic patients had a better outcome (mOS 16.3 months, 95% CI 14.6-18.0 vs 10.3 months, 95% I 7.6-12.8, p = 0.003). Considering the two variables, patients with BMs and hyponatremia had a mOS of 10.1 months (95% CI 4.3-15.9), patients with hyponatremia without BMs 11.9 months (95% CI 11.4-12.4), while mOS was 13.1 months (95% CI 12.0-14.2) for eunatremic patients with BMs versus 17.1 months (95% CI 15.2-19.1) in eunatremic patients without BMs (p = 0.0020). Hyponatremic patients developed metachronous BMs significantly earlier (3.73 vs 5.76 months, p = 0.0187).

CONCLUSIONS

Our study showed that hyponatremia is an important prognostic factor and it should be necessarily considered to enhance the management of NSCLC patients with BMs.

The albumin-bilirubin grade uncovers the prognostic relationship between hepatic reserve and immune dysfunction in HIV-associated hepatocellular carcinoma

BACKGROUND

Hepatocellular carcinoma (HCC) is a leading cause of liver-related mortality in people living with HIV, where co-infection with hepatotropic viruses accelerates the course of chronic liver disease.

AIM

To evaluate whether the albumin-bilirubin (ALBI) grade, a more accurate marker of liver dysfunction in HCC, might identify patients with progressive liver dysfunction in the context of HIV/hepatitis co-infection.

METHODS

Using uni- and multi-variable analyses, we studied the albumin-bilirubin grade as a predictor of overall survival (OS) in a large, multi-center cohort of patients with HIV-associated HCC recruited from 44 centres in 9 countries within the Liver Cancer in HIV study group. Patients who underwent liver transplantation were excluded.

RESULTS

A total of 387 patients, predominantly HCV co-infected (78%) with balanced representation of all Barcelona Clinic Liver Cancer (BCLC) stages (A = 33%, B = 18%, C = 37%, D = 12%) were recruited. At HCC diagnosis, 84% had been on anti-retrovirals for a median duration of 8.8 years. The albumin-bilirubin grade identified significant differences in median survival of 97 months for grade 1 (95% CI 13-180 months), 17 months for grade 2 (95% CI 11-22 months) and 6 months for grade 3 (95% CI 4-9 months, P < .001). A more advanced albumin-bilirubin grade correlated with lower CD4 counts (464/373/288 cells/mm³ for grades 1/2/3) and higher HIV viraemia (3.337/8.701/61.845 copies/mL for grades 1/2/3, P < .001).

CONCLUSIONS

In this large, multi-center retrospective study, the albumin-bilirubin grade highlights the interplay between liver reserve and immune dysfunction as prognostic determinants in HIV-associated HCC.

The extent of B-cell activation and dysfunction preceding lymphoma development in HIV-positive people

OBJECTIVES

B-cell dysfunction and activation are thought to contribute to lymphoma development in HIV-positive people; however, the mechanisms are not well understood. We investigated levels of several markers of B-cell dysfunction [free light chain (FLC)-κ, FLC-λ, immunoglobulin G (IgG), IgA, IgM and IgD] prior to lymphoma diagnosis in HIV-positive people.

METHODS

A nested matched case-control study was carried out within the EuroSIDA cohort, including 73 HIV-positive people with lymphoma and 143 HIV-positive lymphoma-free controls. Markers of B-cell dysfunction were measured in prospectively stored serial plasma samples collected before the diagnosis of lymphoma (or selection date in controls). Marker levels ≤ 2 and > 2 years prior to diagnosis were investigated.

RESULTS

Two-fold higher levels of FLC-κ [odds ratio (OR) 1.84; 95% confidence interval (CI) 1.19, 2.84], FLC-λ (OR 2.15; 95% CI 1.34, 3.46), IgG (OR 3.05; 95% CI 1.41, 6.59) and IgM (OR 1.46; 95% CI 1.01, 2.11) were associated with increased risk of lymphoma > 2 years prior to diagnosis, but not ≤ 2 years prior. Despite significant associations > 2 years prior to diagnosis, the predictive accuracy of each marker was poor, with FLC-λ emerging as the strongest candidate with a c-statistic of 0.67 (95% CI 0.58, 0.76).

CONCLUSIONS

FLC-κ, FLC-λ and IgG levels were higher > 2 years before lymphoma diagnosis, suggesting that B-cell dysfunction occurs many years prior to lymphoma development. However, the predictive value of each marker was low and they are unlikely candidates for risk assessment for targeted intervention.

Management of HIV-related lymphoma in HIV treatment centres in North Thames Region

We describe an audit of lymphoma care in HIV-positive patients. In the smaller units (< 500 patients) areas of potentially sub-optimal care were identified.

The clinical application of plasma Kaposi sarcoma herpesvirus viral load as a tumour biomarker: results from 704 patients

OBJECTIVES

The aim of the study was to evaluate the role of plasma Kaposi sarcoma herpesvirus (KSHV) as a diagnostic and prognostic biomarker in people living with HIV (PLWH) and diagnosed with KSHV-associated diseases.

METHODS

Using quantitative nested polymerase chain reaction (PCR) targeting the open reading frame-26 gene of KSHV, plasma levels of KSHV were measured in consecutive PLWH with KSHV-associated diseases or as part of the investigation of lymphadenopathy.

RESULTS

Plasma KSHV assays were performed on samples from 684 PLWH and 20 HIV-seronegative people with KSHV-associated malignancies. In PLWH, plasma KSHV was detected in 39% of those with KS, 99% of those with multicentric Castleman disease (MCD), 9% of those with non-Hodgkin lymphoma (NHL), 2% of those with non-AIDS-defining malignancies and 0% of those with nonmalignant lymphadenopathy. There was no significant difference in plasma KSHV viral load among those with KS, MCD and KSHV-associated NHL. The 5-year overall survival rate from KS diagnosis of 335 PLWH was 95.2% (95% confidence interval 92.6-97.8%). Plasma KSHV viraemia did not predict overall survival in those with KS (P = 0.73), nor when those with T0 stage KS (P = 0.52) or T1 stage KS (P = 0.62) were analysed separately.

CONCLUSIONS

Measuring the plasma levels of KSHV as a biomarker in KSHV-associated disease has a very limited value in either diagnosis or prognostication. The only potential role of clinical value is the suggestion that an undetectable plasma KSHV excludes a diagnosis of MCD in PLWH.

TLR5-mediated sensing of gut microbiota is necessary for antibody responses to seasonal influenza vaccination

Systems biological analysis of immunity to the trivalent inactivated influenza vaccine (TIV) in humans revealed a correlation between early expression of TLR5 and the magnitude of the antibody response. Vaccination of Trl5(-/-) mice resulted in reduced antibody titers and lower frequencies of plasma cells, demonstrating a role for TLR5 in immunity to TIV. This was due to a failure to sense host microbiota. Thus, antibody responses in germ-free or antibiotic-treated mice were impaired, but restored by oral reconstitution with a flagellated, but not aflagellated, strain of E. coli. TLR5-mediated sensing of flagellin promoted plasma cell differentiation directly and by stimulating lymph node macrophages to produce plasma cell growth factors. Finally, TLR5-mediated sensing of the microbiota also impacted antibody responses to the inactivated polio vaccine, but not to adjuvanted vaccines or the live-attenuated yellow fever vaccine. These results reveal an unappreciated role for gut microbiota in promoting immunity to vaccination.

Liposomal anthracycline chemotherapy and the risk of second malignancies in patients with Kaposi's sarcoma (KS)

PURPOSE

People living with HIV (PLWH) are at increased risk of cancer, both non-AIDS- and AIDS-defining malignancies (NADM and ADM). Systemic chemotherapy also predisposes to secondary cancers. The potential contribution of systemic liposomal anthracycline chemotherapy (SLAC) to the development of second cancers in PLWH is unknown.

METHODS

Since 1998, we have treated 495 PLWH and Kaposi's sarcoma (KS) with a stage-stratified approach including 163 who received SLAC as first-line treatment for KS. Subsequent ADM and NADM diagnosed in this population were recorded.

RESULTS

More patients who received SLAC had T1 stage disease (p < 0.0001) and lower CD4 cell counts (p < 0.0001) in line with the stage-stratified treatment, but there were no significant differences in age (p = 0.29), gender (p = 0.18), prior AIDS-defining illness (p = 0.45), plasma HIV viral load (p = 0.15), or HHV8 viral load (p = 0.39) between the two groups. During a median follow-up of 4.6 years (maximum 15 years) from KS diagnosis, 28 patients developed a second cancer (5 ADM and 23 NADM). The 5-year cumulative risk of second cancer is 5.8 % (95 % CI 3.0-8.6 %), and there is no significant difference in the rate between those treated with SLAC and those not (log rank p = 0.19). Most patients (n = 131) were treated with daunoxome (liposomal daunorubicin) chemotherapy, and there was no significant correlation between risk of second cancer and cumulative dose of daunoxome (p = 0.23).

CONCLUSION

Although the risk of second cancer after a diagnosis of KS in PLWH is high, systemic liposomal anthracycline chemotherapy does not appear to increase the risk.

Salvage surgery for residual primary and locally recurrent anal squamous cell carcinoma after chemoradiotherapy in HIV-positive individuals

BACKGROUND

The treatment of anal cancer in human immunodeficiency virus (HIV) patients-as in the general population-is primarily with chemoradiotherapy (CRT), and abdominoperineal resection of residual or recurrent primary disease. The aim of this study was to evaluate the extent of residual primary disease and local recurrence as well as the outcome of salvage surgery after CRT for anal carcinoma in HIV-positive individuals.

METHODS

We retrospectively studied HIV-positive anal carcinoma patients treated between February 1989 and November 2012 in a specialist London unit. Extent of residual primary disease, local recurrence after CRT, postoperative complications, and survival after salvage surgery were evaluated.

RESULTS

Complete response was experienced in 44 of 53 (83%) of HIV patients treated with CRT for anal carcinoma. One patient (2.3%) developed local recurrence. Nine patients (eight residual primary disease after CRT and one local recurrence) underwent salvage surgery after CRT. There were no perioperative deaths, and perioperative CD4 counts were sustained. Complications occurred in five patients (55%). Median interval to complete perineal healing was 4 months (range 2-11 months), and median hospital stay was 29 days. Survival (median 16 months) was 25% at 2 years from salvage surgery.

CONCLUSIONS

Results in HIV-positive patients receiving highly active antiretroviral therapy (HAART) suggest that loss of HIV sensitivity to HAART can be avoided, but that there is increased postoperative morbidity that may be related to HIV disease. Survival was comparable to that for salvage therapy after optimal CRT in non-HIV anal carcinoma patients.

A systematic review of anal squamous cell carcinoma in inflammatory bowel disease

AIM

The aim of this systematic review was to determine the incidence, aetiology and clinical characteristics of anal squamous cell carcinomas (SCC) presenting in patients with inflammatory bowel disease.

METHOD

A systematic review of the literature was undertaken using Medline, Embase, Cochrane and Web of Science.

RESULTS

A total of 33 cases of anal SCC were described, 7 in ulcerative colitis (UC) and 26 in Crohn's disease (CD). The annual incidence of anal SCCs was 0.9/100,000 and 2.0/100,000 in patients with UC and CD respectively. The gender ratio in CD was 3M:17F with a median age of 42 years, the main presenting symptom was anal pain and 85% of CD cases had peri-anal disease. No studies described anal intra-epithelial neoplasia. The human papilloma virus was found to be positive in 2 out of 5 (40%) cases. The majority of patients (73%) with CD received radical surgery as their first line treatment. The cumulative overall and disease free survival in CD was 37 per cent at five years.

CONCLUSION

The findings of this review when contrasted with the data from cancer registries suggests that there is a higher incidence of anal SCC, an earlier age of presentation and poorer outcomes in patients with Crohn's disease compared to the general population implying a more aggressive neoplastic process. This review supports the hypothesis that peri-anal disease plays a contributing role in anal SCCs and as such targeted surveillance in patients with longstanding peri-anal disease should be considered.

Primary cervical lymphoma: a rare presentation to a genitourinary medicine clinic

Summary

Primary non-Hodgkin's lymphoma of uterine cervix is a rare diagnosis. We present the case of a 47-year-old woman who presented to our genitourinary (GU) medicine service complaining of a malodorous discharge. Speculum examination revealed a necrotic mass on the cervix. She was referred urgently to gynaecology and subsequent histology revealed a diffuse large B-cell lymphoma. She received six cycles of RCHOP chemotherapy and is now in clinical remission. This case highlights the need for GU medicine physicians to remain vigilant with regard to possible gynaecological malignancies in all of our patients, the need for medical backup within GU medicine clinics and for clear pathways of referral to other specialists to exist.

The collagen prolyl hydroxylases are novel transcriptionally silenced genes in lymphoma

BACKGROUND

Prolyl hydroxylation is a post-translational modification that affects the structure, stability and function of proteins including collagen by catalysing hydroxylation of proline to hydroxyproline through action of collagen prolyl hydroxylases3 (C-P3H) and 4 (C-P4H). Three C-P3Hs (nomenclature was amended according to approval by the HGNC symbols and names at http://www.genenames.org/ and Entrez database at http://www.ncbi.nlm.nih.gov/gene) leucineproline-enriched proteoglycan (leprecan) 1 (Lepre1), leprecan-like 1 (Leprel1), leprecan-like 2 (Leprel2) and two paralogs Cartilage-Related Protein (CRTAP) and leprecan-like 4 (Leprel4) are found in humans. The C-P4Hs are tetrameric proteins comprising a variable α subunit, encoded by the P4HA1, P4HA2 and P4HA3 genes and a constant β subunit encoded by P4HB.

METHODS

We used RT-PCR, qPCR, pyrosequencing, methylation-specific PCR, western blotting and immunohistochemistry to investigate expression and regulation of the C-P3H and C-P4H genes in B lymphomas and normal bone marrow.

RESULTS

C-P3H and C-P4H are downregulated in lymphoma. Down-regulation is associated with methylation in the CpG islands and is detected in almost all common types of B-cell lymphoma, but the CpG islands are unmethylated or methylated at lower levels in DNA isolated from normal bone marrow and lymphoblastoid cell lines. Methylation of multiple C-P3H and C-P4H genes is present in some lymphomas, particularly Burkitt's lymphoma.

CONCLUSIONS

Methylation of C-P3H and C-P4H is common in B lymphomas and may have utility in differentiating disease subtypes.

HIV-associated gastric natural killer/T-cell lymphoma

Natural killer (NK)/T-cell lymphoma is a rare form of non-Hodgkin's lymphoma that is seen with increased frequency in HIV infection and in transplant recipients. This case report describes an unusual case of extranodal NK/T-cell lymphoma in a patient with advanced HIV disease in which gastric involvement was a significant feature.

Promotion of hepatocellular carcinoma by the intestinal microbiota and TLR4

Increased translocation of intestinal bacteria is a hallmark of chronic liver disease and contributes to hepatic inflammation and fibrosis. Here we tested the hypothesis that the intestinal microbiota and Toll-like receptors (TLRs) promote hepatocellular carcinoma (HCC), a long-term consequence of chronic liver injury, inflammation, and fibrosis. Hepatocarcinogenesis in chronically injured livers depended on the intestinal microbiota and TLR4 activation in non-bone-marrow-derived resident liver cells. TLR4 and the intestinal microbiota were not required for HCC initiation but for HCC promotion, mediating increased proliferation, expression of the hepatomitogen epiregulin, and prevention of apoptosis. Gut sterilization restricted to late stages of hepatocarcinogenesis reduced HCC, suggesting that the intestinal microbiota and TLR4 represent therapeutic targets for HCC prevention in advanced liver disease.

Severe vitamin D deficiency in a patient treated for hepatitis B with tenofovir

With the increasing use of tenofovir disoproxil in the management of HIV and hepatitis B, serious adverse effects, such as renal dysfunction, will inevitably increase in frequency. We describe a case of a patient presenting with hypophosphataemia suggestive of Fanconi's syndrome, but in fact explicable by simple vitamin D deficiency. This emphasizes that while monitoring for adverse effects is recommended, physicians must consider all alternative causes for biochemical abnormalities prior to discontinuing tenofovir and delaying appropriate management.

Chemoradiotherapy for anal cancer in HIV patients causes prolonged CD4 cell count suppression

BACKGROUND

Despite the advent of highly active antiretroviral therapy, anal cancer remains a significant health problem in human immunodeficiency virus (HIV) patients. We present the clinical features and treatment outcomes of anal cancer in 60 HIV-positive patients over a 20-year period.

PATIENTS AND METHODS

A prospective database of all HIV-positive individuals managed in a specialist unit since 1986 includes 11 112 patients (71 687 person-years of follow-up). Sixty patients with anal cancer were identified. Their clinicopathological and treatment details were analysed.

RESULTS

At anal cancer diagnosis, the mean age was 44 years (range: 28-75 years) and the median CD4 cell count was 305 mm(-3) (range: 16-1252 mm(-3)). Fifty (83%) had chemoradiotherapy (CRT). Forty-six (92%) responded, of whom 10 (22%) subsequently relapsed with locoregional (70%), metastatic disease (10%) or both (20%). The overall 5-year survival is 65% (95% confidence interval 51% to 78%). The median CD4 count fell from 289 mm(-3) before CRT to 132 mm(-3) after 3 months and to 189 mm(-3) after 1 year (P<0.05). Six patients in remission of anal cancer died of acquired immunodeficiency syndrome defining illnesses.

CONCLUSIONS

The management of anal cancer with CRT achieves similar outcomes as the general population. CRT is associated with significant prolonged CD4 suppression that may contribute to late deaths of patients in remission.

Altered phenotype of regulatory T cells associated with lack of human immunodeficiency virus (HIV)-1-specific suppressive function

Mechanisms by which CD4+ regulatory T cells (T(regs)) mediate suppression of virus-specific responses remain poorly defined. Adenosine, mediated via CD39 and CD73, has been shown to play a role in the action of murine T(regs) . In this study we investigate the phenotype of T(regs) in the context of human immunodeficiency virus (HIV)-1 infection, and the function of these cells in response to HIV-1-Gag and cytomegalovirus (CMV) peptides. Phenotypic data demonstrate a decrease in forkhead box transcription factor 3 (FoxP3+) T(reg) numbers in the peripheral blood of HIV-1+ individuals compared to healthy controls, which is most pronounced in those with high HIV-1 RNA plasma load. Due to aberrant expression of CD27 and CD127 during HIV-1 disease, these markers are unreliable for T(reg) identification. The CD3+ CD4+ CD25(hi) CD45RO+ phenotype correlated well with FoxP3 expression in both the HIV-1+ and seronegative control cohorts. We observed expression of CD39 but not CD73 on T(regs) from HIV-1+ and healthy control cohorts. We demonstrate, through T(reg) depletion, the suppressive potential of T(regs) over anti-CMV responses in the context of HIV-1 infection; however, no recovery of the HIV-1-specific T cell response was observed indicating a preferential loss of HIV-1-specific T(reg) function. We propose that before immunotherapeutic manipulation of T(regs) is considered, the immunoregulatory profile and distribution kinetics of this population in chronic HIV-1 infection must be elucidated fully.

High microsatellite and mitochondrial diversity in Anatolian native horse breeds shows Anatolia as a genetic conduit between Europe and Asia

The horse has been a food source, but more importantly, it has been a means for transport. Its domestication was one of the crucial steps in the history of human civilization. Despite the archaeological and molecular studies carried out on the history of horse domestication, which would contribute to conservation of the breeds, the details of the domestication of horses still remain to be resolved. We employed 21 microsatellite loci and mitochondrial control region partial sequences to analyse genetic variability within and among four Anatolian native horse breeds, Ayvacık Pony, Malakan Horse, Hınıs Horse and Canik Horse, as well as samples from indigenous horses of unknown breed ancestry. The aims of the study were twofold: first, to produce data from the prehistorically and historically important land bridge, Anatolia, in order to assess its role in horse domestication and second, to analyse the data from a conservation perspective to help the ministry improve conservation and management strategies regarding native horse breeds. Even though the microsatellite data revealed a high allelic diversity, 98% of the genetic variation partitioned within groups. Genetic structure did not correlate with a breed or geographic origin. High diversity was also detected in mtDNA control region sequence analysis. Frequencies of two haplogroups (HC and HF) revealed a cline between Asia and Europe, suggesting Anatolia as a probable connection route between the two continents. This first detailed genetic study on Anatolian horse breeds revealed high diversity among horse mtDNA haplogroups in Anatolia and suggested Anatolia's role as a conduit between the two continents. The study also provides an important basis for conservation practices in Turkey.

DUSP16 is an epigenetically regulated determinant of JNK signalling in Burkitt's lymphoma

Background:

The mitogen-activated protein kinase (MAPK) phosphatases or dual specificity phosphatases (DUSPs) are a family of proteins that catalyse the inactivation of MAPK in eukaryotic cells. Little is known of the expression, regulation or function of the DUSPs in human neoplasia.

Methods:

We used RT–PCR and quantitative PCR (qPCR) to examine the expression of DUSP16 mRNA. The methylation in the DUSP16 CpG island was analysed using bisulphite sequencing and methylation-specific PCR. The activation of MAPK was determined using western blotting with phospho-specific antibodies for extra-cellular signal-related kinase (ERK), p38 and c-Jun N-terminal kinase (JNK). The proliferation of cell lines was assessed using the CellTiter 96 Aqueous One assay.

Results:

The expression of DUSP16, which inactivates MAPK, is subject to methylation-dependent transcriptional silencing in Burkitt's Lymphoma (BL) cell lines and in primary BL. The silencing is associated with aberrant methylation in the CpG island in the 5′ regulatory sequences of the gene blocking its constitutive expression. In contrast to BL, the CpG island of DUSP16 is unmethylated in other non-Hodgkin's lymphomas (NHLs) and epithelial malignancies. In BL cell lines, neither constitutive nor inducible ERK or p38 activity varied significantly with DUSP16 status. However, activation of JNK was increased in lines with DUSP16 methylation. Furthermore, methylation in the DUSP16 CpG island blocked transcriptional induction of DUSP16, thereby abrogating a normal physiological negative feedback loop that limits JNK activity, and conferred increased cellular sensitivity to agents, such as sorbitol and anthracycline chemotherapeutic agents that activate JNK.

Conclusion:

DUSP16 is a new epigenetically regulated determinant of JNK activation in BL.

The frequency and reasons for antiretroviral switching with specific antiretroviral associations: the SWITCH study

BACKGROUND

We investigated the reasons for switching antiretroviral regimens, an issue rarely addressed in cohort studies.

METHODS

An observed toxicity switch rate (OTSR) was calculated by Poisson regression using the number of days individuals received each individual antiretroviral drug.

RESULTS

Of 3333 individuals receiving HAART, a total of 14% of regimens were switched, the majority occurring after 6 months of therapy. Toxicity was the major reason for switching (61%) and there were no major statistically significant differences in OTSR between the protease inhibitor (OTSR 26.4, 95% CI 18.3-37) and non-nucleoside reverse transcriptase inhibitor (OTSR 22.2, 95% CI 13.6-34.4) based regimes. For individual antiretrovirals, stavudine and zidovudine had significantly higher "switch" scores than all other drugs.

CONCLUSIONS

There were no differences between the major HAART classes in OTSR. We suggest that newer antiretrovirals will require differentiation in terms of longer-term toxicity, as this is the major reason for switching.

Programmed death (PD)-1 molecule and its ligand PD-L1 distribution among memory CD4 and CD8 T cell subsets in human immunodeficiency virus-1-infected individuals

Human immunodeficiency virus (HIV)-1 causes T cell anergy and affects T cell maturation. Various mechanisms are responsible for impaired anti-HIV-1-specific responses: programmed death (PD)-1 molecule and its ligand PD-L1 are negative regulators of T cell activity and their expression is increased during HIV-1 infection. This study examines correlations between T cell maturation, expression of PD-1 and PD-L1, and the effects of their blockade. Peripheral blood mononuclear cells (PBMC) from 24 HIV-1(+) and 17 uninfected individuals were phenotyped for PD-1 and PD-L1 expression on CD4(+) and CD8(+) T cell subsets. The effect of PD-1 and PD-L1 blockade on proliferation and interferon (IFN)-gamma production was tested on eight HIV-1(+) patients. Naive (CCR7(+)CD45RA(+)) CD8(+) T cells were reduced in HIV-1 aviraemic (P = 0.0065) and viraemic patients (P = 0.0130); CD8 T effector memory subsets [CCR7(-)CD45RA(-)(T(EM))] were increased in HIV-1(+) aviraemic (P = 0.0122) and viraemic (P = 0.0023) individuals versus controls. PD-1 expression was increased in CD4 naive (P = 0.0496), central memory [CCR7(+)CD45RA(-) (T(CM)); P = 0.0116], T(EM) (P = 0.0037) and CD8 naive T cells (P = 0.0133) of aviraemic HIV-1(+) versus controls. PD-L1 was increased in CD4 T(EMRA) (CCR7(-)CD45RA(+), P = 0.0119), CD8 T(EM) (P = 0.0494) and CD8 T(EMRA) (P = 0.0282) of aviraemic HIV-1(+)versus controls. PD-1 blockade increased HIV-1-specific proliferative responses in one of eight patients, whereas PD-L1 blockade restored responses in four of eight patients, but did not increase IFN-gamma-production. Alteration of T cell subsets, accompanied by increased PD-1 and PD-L1 expression in HIV-1 infection contributes to anergy and impaired anti-HIV-1-specific responses which are not rescued when PD-1 is blocked, in contrast to when PD-L1 is blocked, due possibly to an ability to bind to receptors other than PD-1.

Methylation reversal in high-grade B lymphoma cell lines and novel epigenetic changes conserved between immunocompetent and HIV-positive hosts

8585

Background: Methylation-dependent transcriptional silencing is an important mechanism of tumour suppressor gene inactivation in neoplasia, including lymphoma. Methods: Pharmacological “unmasking” of transcriptionally silenced genes in B lymphoma cell lines was achieved using 5' deazacytidine ± Trichostatin A and subsequent analysis of mRNA levels on micro-array. Candidate genes thus identified, were further analysed by qPCR, methylation-specific PCR (MSP) and bisulphite sequencing in B lymphoma cell lines and by MSP in clinical samples from sporadic (immunocompetent) (18 cases) and HIV-infected patients (14 cases). Samples in both patient groups were diffuse large B cell lymphoma (DLBCL) and Burkitt's lymphoma (BL). Additionally, we analysed 8 cases of marginal zone lymphoma (MZL) from the immunocompetent group. Results: We report the identification of 13 novel genes, not previously described in the literature, which are subject to methylation-dependent transcriptional silencing in high-grade lymphoma and whose expression can be reactivated by demethylating agents. The novel genes encode proteins involved in diverse functional classes and include pro-apoptotic members of the p53 pathway (Scotin), transcriptional regulators (Baz2B) and regulators of telomerase (Smrf2). The frequency of methylation in individual genes varied from approximately 10% to 75% in specific lymphoma subtypes, but was in general similar in high grade lymphomas in immunocompetent and HIV-infected hosts. Conclusions: Using pharmacological reversal of methylation, we have identified a number of genes, not previously implicated in human neoplasia, which are subject to transcriptional silencing in high-grade B lymphomas. The similar frequencies of methylation, observed in immunocompetent and HIV positive patients implies that the genes are fundamental in suppression of lymphomagenesis. Detection of methylated DNA of one or more of these genes may have utility as biomarkers of clinical outcome in each patient group.

No significant financial relationships to disclose.

The successful treatment of haemophagocytic syndrome in patients with human immunodeficiency virus-associated multi-centric Castleman's disease

Both virus-associated haemophagocytic syndrome (HPS) and human immunodeficiency virus-associated multi-centric Castleman's disease (HIV-MCD) induced by human herpesvirus-8 (HHV-8) are extremely rare. We therefore wished to investigate their occurrence together, and establish the degree of cytokine activation present. From a prospective cohort of individuals with HIV-MCD, we investigated the incidence and outcomes of HPS and measured 15 inflammatory cytokines and the plasma HHV-8 viral loads before and during follow-up. Of 44 patients with HIV-MCD with an incidence of 4.3/10,000 patient years, four individuals (9%) were diagnosed with HPS. All are in remission (range 6-28 months) following splenectomy, etoposide and rituximab-based therapy. Plasma HHV-8 levels were raised markedly at presentation (median 3,840,000 copies/ml). Histological samples from spleen, splenic hilar lymph nodes and bone marrow demonstrated increased phagocytosis by histiocytes and presence of HHV-8-infected plasmablasts outside the follicles. Surprisingly, many known inflammatory plasma cytokines were not elevated, although interleukin (IL)-8 and interferon-gamma were increased in all cases and IL-6 levels were raised in three of four patients. HPS in the setting of HIV-MCD is common and treatment can be successful provided the diagnosis is made appropriately. Systemic activation of cytokines was limited, suggesting that immunosuppressive therapy with steroids is not indicated in HHV-8-driven HPS.

The role of immune suppression and HHV-8 in the increasing incidence of HIV-associated multicentric Castleman's disease

BACKGROUND

In HIV cohorts with access to highly active antiretroviral therapy (HAART), the incidence of Kaposi's sarcoma (KS) is falling; however, the incidence of multicentric Castleman's disease (MCD) in HIV has not previously been described.

METHODS

The incidence of HIV-associated MCD was calculated from a prospective HIV database with 56 202 patient-years of follow-up and compared with KS. Univariate and multivariate analyses were carried out to identify factors associated with MCD. Plasma human herpesvirus (HHV)-8 DNA levels were measured in HIV-seropositive individuals with newly diagnosed MCD (n = 24), KS (n = 72), HIV-associated lymphoma (n = 74) and HIV-positive controls (n = 53).

RESULTS

From 24 cases of HIV-associated MCD, the incidence measured 4.3/10,000 patient-years [95% confidence interval (CI) 2.7-6.4]. The incidence in the pre-HAART (1983-1996), early-HAART (1997-2001) and later HAART (2002-2007) eras were 2.3 (95% CI 0.02-4.2), 2.8 (95% CI 0.9-6.5) and 8.3 (95% CI 4.6-12.6), respectively, representing a statistically significant increase over time (P < 0.05). In contrast, from 1180 cases of KS, the incidence in this cohort decreased with time. Multivariate analysis demonstrated that a nadir CD4 count >200/mm(3), increased age, no previous HAART exposure and non-Caucasian ethnicity were all associated with an increased risk of MCD. Plasma HHV-8 DNA levels were higher in patients with newly diagnosed MCD than with KS, lymphomas or HIV-positive controls (Mann-Whitney U-test, P < 0.0001).

CONCLUSIONS

The incidence of HIV-associated MCD is increasing. It appears to occur more frequently in older HIV-positive individuals with well-preserved immune function.