Thierry Lazure

Adipose Tissue Is a Neglected Viral Reservoir and an Inflammatory Site during Chronic HIV and SIV Infection

Two of the crucial aspects of human immunodeficiency virus (HIV) infection are (i) viral persistence in reservoirs (precluding viral eradication) and (ii) chronic inflammation (directly associated with all-cause morbidities in antiretroviral therapy (ART)-controlled HIV-infected patients). The objective of the present study was to assess the potential involvement of adipose tissue in these two aspects. Adipose tissue is composed of adipocytes and the stromal vascular fraction (SVF); the latter comprises immune cells such as CD4+ T cells and macrophages (both of which are important target cells for HIV). The inflammatory potential of adipose tissue has been extensively described in the context of obesity. During HIV infection, the inflammatory profile of adipose tissue has been revealed by the occurrence of lipodystrophies (primarily related to ART). Data on the impact of HIV on the SVF (especially in individuals not receiving ART) are scarce. We first analyzed the impact of simian immunodeficiency virus (SIV) infection on abdominal subcutaneous and visceral adipose tissues in SIVmac251 infected macaques and found that both adipocytes and adipose tissue immune cells were affected. The adipocyte density was elevated, and adipose tissue immune cells presented enhanced immune activation and/or inflammatory profiles. We detected cell-associated SIV DNA and RNA in the SVF and in sorted CD4+ T cells and macrophages from adipose tissue. We demonstrated that SVF cells (including CD4+ T cells) are infected in ART-controlled HIV-infected patients. Importantly, the production of HIV RNA was detected by in situ hybridization, and after the in vitro reactivation of sorted CD4+ T cells from adipose tissue. We thus identified adipose tissue as a crucial cofactor in both viral persistence and chronic immune activation/inflammation during HIV infection. These observations open up new therapeutic strategies for limiting the size of the viral reservoir and decreasing low-grade chronic inflammation via the modulation of adipose tissue-related pathways.

NCR3/NKp30 Contributes to Pathogenesis in Primary Sjögren’s Syndrome

Genetic and functional analyses implicate NCR3/NKp30 in the pathogenesis of primary Sjögren’s syndrome. Sjögren’s Research to Make Your Mouth Water Sjögren’s syndrome is an autoimmune disorder where the body’s own immune cells attack and destroy the exocrine glands that produce such things as tears and saliva. Some patients may have only minor irritation, whereas others may have more serious systemic effects. Sjögren’s syndrome is most common in women over 40, and treatment only attempts to alleviate the symptoms—there is no cure. Now, Rusakiewicz et al. implicate natural killer (NK) cells in the pathogenesis of Sjögren’s syndrome. The authors found that a genetic polymorphism is NKp30, an NK cell–activating receptor, associated with susceptibility to Sjögren’s syndrome in human patients compared with healthy controls. NK cells in these patients expressed high levels of NKp30 and secreted more proinflammatory cytokines. What’s more, these NK cells accumulated in inflammatory foci in minor salivary glands, and salivary epithelial cells expressed B7H6, a ligand that activates NKp30. These data strongly suggest that NK cells may contribute to Sjögren’s syndrome pathogenesis, and put forth NKp30 as a therapeutic target, providing a potential oasis for Sjögren’s patients. Primary Sjögren’s syndrome (pSS) is a chronic autoimmune disease characterized by a lymphocytic exocrinopathy. However, patients often have evidence of systemic autoimmunity, and they are at markedly increased risk for the development of non- Hodgkin’s lymphoma. Similar to other autoimmune disorders, a strong interferon (IFN) signature is present among subsets of pSS patients, although the precise etiology remains uncertain. NCR3/NKp30 is a natural killer (NK)–specific activating receptor regulating the cross talk between NK and dendritic cells and type II IFN secretion. We performed a case-control study of genetic polymorphisms of the NCR3/NKp30 gene and found that rs11575837 (G>A) residing in the promoter was associated with reduced gene transcription and function as well as protection to pSS. We also demonstrated that circulating levels of NCR3/NKp30 were significantly increased among pSS patients compared with controls and correlated with higher NCR3/NKp30 but not CD16-dependent IFN-γ secretion by NK cells. Excess accumulation of NK cells in minor salivary glands correlated with the severity of the exocrinopathy. B7H6, the ligand of NKp30, was expressed by salivary epithelial cells. These findings suggest that NK cells may promote an NKp30-dependent inflammatory state in salivary glands and that blockade of the B7H6/NKp30 axis could be clinically relevant in pSS.

Germline and somatic genetic variations of TNFAIP3 in lymphoma complicating primary Sjögren’s syndrome

Several autoimmune diseases, including primary Sjögrens syndrome (pSS), are associated with an increased risk for lymphoma. Polymorphisms of TNFAIP3, which encodes the A20 protein that plays a key role in controlling nuclear factor κB activation, have been associated with several autoimmune diseases. Somatic mutations of TNFAIP3 have been observed in the mucosa-associated lymphoid tissue lymphoma subtype frequently associated with pSS. We studied germline and somatic abnormalities of TNFAIP3 in 574 patients with pSS, including 25 with lymphoma. Nineteen additional patients with pSS and lymphoma were available for exome sequence analysis. Functional abnormalities of A20 were assessed by gene reporter assays. The rs2230926 exonic variant was associated with an increased risk for pSS complicated by lymphoma (odds ratio, 3.36 [95% confidence interval, 1.34-8.42], and odds ratio, 3.26 [95% confidence interval, 1.31-8.12], vs controls and pSS patients without lymphoma, respectively; P = .011). Twelve (60%) of the 20 patients with paired germline and lymphoma TNFAIP3 sequence data had functional abnormalities of A20: 6 in germline DNA, 5 in lymphoma DNA, and 1 in both. The frequency was even higher (77%) among pSS patients with mucosa-associated lymphoid tissue lymphoma. Some of these variants showed impaired control of nuclear factor κB activation. These results support a key role for germline and somatic variations of A20 in the transformation between autoimmunity and lymphoma.

Diffuse large B-cell lymphoma with concordant bone marrow involvement has peculiar genomic profile and poor clinical outcome

Bone marrow (BM) involvement in diffuse large B‐cell lymphoma (DLBCL) can be morphologically discordant from the primary tumor. Concordant BM infiltration has been shown associated with a poorer outcome in patients treated with CHOP. In order to evaluate tumor‐related factors leading to BM involvement in DLBCL, we performed an integrated analysis of i) genomic profiles obtained with a high‐density genome wide SNP‐based arrays ii) immunomorphological and iii) clinical data from 133 patients uniformly treated with R‐CHOP. BM infiltration was found in 27 of 133 (20%) cases; and it was concordant in 18/27 (67%) cases. Concordant infiltration, but not discordant, influenced negatively OS, PFS and DFS and was associated with higher serum LDH, lower CR and higher PD rates. No association with cell of origin was found between BM+ and BM‐ DLBCL. As compared with BM‐ cases, BM+ DLBCL showed absence of 7q gain. Copyright

Gastric inflammatory myofibroblastic tumors in children: an unpredictable course.

Inflammatory myofibroblastic tumors (IMT) are lesions that most often affect young adults and children (1). These tumors have been found in numerous extrapulmonary sites, but rarely in the stomach (1). It is unknown whether this process is reactive or neoplastic. Despite similar pathologic features (1,2), some patients have a favorable course after surgical resection, whereas in others the tumors recur and occasionally lead to death. Inflammatory myofibroblastic tumors probably constitute a heterogeneous spectrum of entities that include reactive lesions and neoplastic, benign, and malignant mesenchymal tumors (1,3,4). We report two pediatric cases of gastric IMT with opposite courses, illustrating the polymorphism of these lesions and raising questions about prognosis and treatment.

Low numbers of blood and salivary natural killer cells are associated with a better response to belimumab in primary Sjogren's syndrome: results of the BELISS study.

IntroductionIn this study, we sought to address changes in blood lymphocyte subpopulations and labial salivary gland (LSG) inflammation after belimumab treatment in patients with primary Sjögren’s syndrome (pSS) and to identify predictors of response to treatment.MethodsSequential blood lymphocyte subsets and LSG biopsies were analysed between week 0 (W0) and W28 in 15 patients with pSS treated with belimumab. Systemic response to treatment was defined as a decrease in the European League Against Rheumatism Sjögren’s Syndrome Disease Activity Index score of ≥3 points at W28.ResultsAfter belimumab, we observed a decrease in blood B lymphocytes primarily involving CD27-negative/immunoglobulin D–positive naïve B cells (p=0.008). Lymphocytic sialadenitis (focus score >1) that was present in 12 patients (80.0 %) before belimumab treatment became negative in 5 of them after treatment (p=0.03). The median (interquartile range) LSG B-cell/T-cell ratio decreased from 0.58 (0.5–0.67) to 0.50 (0.5–0.5) (p=0.06). B-cell activating factor (BAFF) staining was detected in 11 (78.6 %) of 14 patients before belimumab treatment compared with 7 (50.0 %) of 14 after belimumab therapy (p=0.10). The median percentage of BAFF-positive cells in foci significantly decreased from 27.5 % (10–40) to 5 % (0–20) (p=0.03). A systemic response was achieved in six patients (40 %). The only predictor of response was the presence of a low number of natural killer (NK) cells, both in blood (8.5 % [7–10] vs 11 % [9–21]; p=0.04) and in LSG (20.6/mm3 [20.0–21.4] vs 30.0/mm3 [25.0–100.0], p=0.003). Serum BAFF levels did not influence response to treatment.ConclusionsLow blood and salivary NK cell numbers are associated with a better response to belimumab. This suggests that two distinct subsets of pSS may exist: one with a predominant type I interferon (IFN)–BAFF–B-cell axis, representing good responders to belimumab; and one with a predominant type II IFN–NK cell axis, representing non-responders.Trial registrationClinicalTrials.gov identifier: NCT01160666. Registered 9 July 2010.

The mechanisms underlying MMR deficiency in immunodeficiency-related non-Hodgkin lymphomas are different from those in other sporadic microsatellite instable neoplasms

The spectrum of tumors showing microsatellite instability (MSI) has recently been enlarged to sporadic neoplasms whose incidence is favored in the context of chronic immunosuppression. We investigated the biological, therapeutic and clinical features associated with MSI in immunodeficiency‐related non‐Hodgkin lymphomas (ID‐RL). MSI screening was performed in 275 ID‐RL. MSI ID‐RL were further analyzed for MMR gene expression and for BRAF/KRAS mutations since these genes are frequently altered in MSI cancers. We also assessed the expression of O6‐methylguanine‐DNA methyltransferase (MGMT), an enzyme whose inactivation has been reported in lymphomas and may help in the selection of MMR deficient clones. Unlike other sporadic MSI neoplasms, MSI ID‐RL (N = 17) presented with heterogeneous MMR defects and no MLH1 promoter methylation. About one third of these tumors presented with normal expression of MLH1, MSH2, MSH6 and PMS2. They accumulated BRAF activating mutations (33%). Unlike other ID‐RL, MSI ID‐RL were primarily EBV‐negative NHL of T‐cell origin, and arose after long‐term immunosuppression in patients who received azathioprine as part of their immunosuppressive regimen (p = 0.05) and/or who exhibited methylation‐induced loss of expression of MGMT in tumor cells (p= 0.02). Overall, these results highlight that, in the context of deficient immune status, some MSI neoplasms arise through alternative mechanism when compared to other sporadic MSI neoplasms. They give the exact way how to make the diagnosis of MSI in these tumors and may help to define biological and clinicalrisk factors associated with their emergence in such a clinicalcontext.

Clinical and molecular characterization of diffuse large B-cell lymphomas with 13q14.3 deletion

BACKGROUND Deletions at 13q14.3 are common in chronic lymphocytic leukemia and are also present in diffuse large B-cell lymphomas (DLBCL) but never in immunodeficiency-related DLBCL. To characterize DLBCL with 13q14.3 deletions, we combined genome-wide DNA profiling, gene expression and clinical data in a large DLBCL series treated with rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 days (R-CHOP21). PATIENTS AND METHODS Affymetrix GeneChip Human Mapping 250K NspI and U133 plus 2.0 gene were used. MicroRNA (miRNA) expression was studied were by real-time PCR. Median follow-up of patients was 4.9 years. RESULTS Deletions at 13q14.3, comprising DLEU2/MIR15A/MIR16, occurred in 22/166 (13%) cases. The deletion was wider, including also RB1, in 19/22 cases. Samples with del(13q14.3) had concomitant specific aberrations. No reduced MIR15A/MIR16 expression was observed, but 172 transcripts were significantly differential expressed. Among the deregulated genes, there were RB1 and FAS, both commonly deleted at genomic level. No differences in outcome were observed in patients treated with R-CHOP21. CONCLUSIONS Cases with 13q14.3 deletions appear as group of DLBCL characterized by common genetic and biologic features. Deletions at 13q14.3 might contribute to DLBCL pathogenesis by two mechanisms: deregulating the cell cycle control mainly due RB1 loss and contributing to immune escape, due to FAS down-regulation.BACKGROUND Deletions at 13q14.3 are common in chronic lymphocytic leukemia and are also present in diffuse large B-cell lymphomas (DLBCL) but never in immunodeficiency-related DLBCL. To characterize DLBCL with 13q14.3 deletions, we combined genome-wide DNA profiling, gene expression and clinical data in a large DLBCL series treated with rituximab, cyclophosphamide, doxorubicine, vincristine and prednisone repeated every 21 days (R-CHOP21). PATIENTS AND METHODS Affymetrix GeneChip Human Mapping 250K NspI and U133 plus 2.0 gene were used. MicroRNA (miRNA) expression was studied were by real-time PCR. Median follow-up of patients was 4.9 years. RESULTS Deletions at 13q14.3, comprising DLEU2/MIR15A/MIR16, occurred in 22/166 (13%) cases. The deletion was wider, including also RB1, in 19/22 cases. Samples with del(13q14.3) had concomitant specific aberrations. No reduced MIR15A/MIR16 expression was observed, but 172 transcripts were significantly differential expressed. Among the deregulated genes, there were RB1 and FAS, both commonly deleted at genomic level. No differences in outcome were observed in patients treated with R-CHOP21. CONCLUSIONS Cases with 13q14.3 deletions appear as group of DLBCL characterized by common genetic and biologic features. Deletions at 13q14.3 might contribute to DLBCL pathogenesis by two mechanisms: deregulating the cell cycle control mainly due RB1 loss and contributing to immune escape, due to FAS down-regulation.

Successful outcome of a corticodependent henoch-schönlein purpura adult with rituximab.

Henoch-Schönlein purpura (HSP) is a systemic vasculitis involving small vessels with deposition of immunoglobulin A (IgA) complexes, usually affecting children. Compared with children, HSP in adults is more severe and frequently associated with cancer. We report the case of a 49-year-old woman with medical history of kidney transplantation for segmental glomerular hyalinosis. Eight years after the transplantation, while taking combined immunosuppressive therapy with tacrolimus and azathioprine indicated for the prevention against transplant rejection, she developed a Henoch-Schönlein purpura. Vasculitis involves skin and sciatic peroneal nerve and she received systemic corticosteroid treatment. Because of four relapses and corticosteroid dependence, the patient was treated with rituximab (two intravenous infusions of 1000 mg given two weeks apart). Successful outcome was observed along two years of follow-up. This new case of successful use of rituximab in HSP promotes more investigations of this treatment in clinical trials.

Congenital anerythremic erythroleukemia presenting as hepatic failure

We report an atypical case of congenital erythroleukemia in a child born with hepatosplenomegaly and abnormal liver tests. The initial peripheral blood cell count showed anemia and hyperleukocytosis with erythroblastosis that disappeared 1 week later. During the next 5 weeks, no blasts were found in the blood, and less than 5% were found on 2 successive bone marrow aspirates. The infant died of hepatic failure. The suspected diagnosis on a premortem liver biopsy was confirmed by an autopsy that showed a blastic infiltration in many organs. These cells expressed only erythroid markers glycophorin A and C. Rearrangement of the myeloid lymphoid leukemia gene was not found by fluorescence in situ hybridization. The main differential diagnoses include metabolic diseases, Langerhans histiocytosis, Pepper syndrome, transient myeloproliferative disorder, and leukemoid reactions. Although some of these can be excluded by the pathologist, others require a multidisciplinary confrontation: clinical, biologic, genetic, and pathologic examinations.