Mark Jabbour

Extended use of serum free light chain as a biomarker in lymphoproliferative disorders: a comprehensive review.

Serum free light chain (sFLC) assays were shown to improve detection, management, and prognostication in plasma cell disorders. Recently, sFLC assays improved detection of M proteins when combined with standard methods of protein electrophoresis/immunofixation in patients with non-Hodgkin lymphoma/chronic lymphocytic leukemia (NHL/CLL). Incidence of abnormal sFLC ratio (sFLCr) varied from 0% to 36% and 29.7% to 59% in NHL and CLL, respectively. Increased sFLC levels or abnormal sFLCr predict shorter overall survival in early-stage CLL. Furthermore, abnormal sFLCr correlated with advanced disease stage and poorer outcome. In diffuse large B-cell lymphomas, increased sFLC was demonstrated as an independent, adverse prognostic factor for overall/event-free survival. Moreover, abnormal sFLCr can be a diagnostic tool in central nervous system lymphomas. Finally, the quantitative FLC assay has the potential to become a new, easily measured biomarker for predicting prognosis and enhanced detection in NHL/CLL. It may be used serially at follow-up evaluations to provide clues to relapse.

Primary effusion lymphoma in an elderly patient effectively treated by lenalidomide: case report and review of literature.

Primary effusion lymphoma (PEL) is a rare aggressive subset of non-Hodgkin B-cell lymphoma. It is caused by Kaposi sarcoma-associated herpesvirus/human herpesvirus type 8 (KSHV/HHV8). It occurs mainly, but not exclusively, in HIV-positive patients. PEL predominantly develops in serous cavities and occasionally in extracavitary regions. PEL carries a very poor prognosis with a median survival time of <6 months. Indeed, currently used treatment modalities such as CHOP chemotherapy are far from achieving complete and sustainable remission. Therefore, there is no clear standard of care established in the treatment of PEL patients, stressing the need for novel-targeted approaches. Here, we have attempted a comprehensive assessment of the treatment of PEL, discussed avant-garde therapies and updated the state of preclinical research with promising clinical applications in the field. These include inhibitors of viral replication, modulators of cell signaling and inflammation, nuclear factor kappa B (NF-κB) and histone deacetylase inhibitors, and recently the combination of arsenic trioxide and interferon-alpha. Some of these targeted therapies have not yet reached clinical studies, although others were used in a few individual case reports with low numbers of patients. We also describe the first case of a 77-year-old, HIV-negative, HHV8-positive patient diagnosed with PEL limited to the pleural and peritoneal cavities. He received lenalidomide 25 mg/day for 21 days every 28 days. Treatment was well tolerated with no side effects. He rapidly improved after 1 month of treatment and progressively achieved complete remission persistent after 18 months of therapy. We believe that this review will bridge an important gap between classical chemotherapy and modern approaches of targeted therapy. Finally, our findings warrant further evaluation of lenalidomide in future prospective clinical studies.

Prediction of celiac disease at endoscopy

BACKGROUND AND STUDY AIMS Celiac disease is increasingly recognized worldwide, but guidelines on how to detect the condition and diagnose patients are unclear. In this study the prevalence and predictors of celiac disease were prospectively determined in a cross-sectional sample of Lebanese patients undergoing esophagogastroduodenoscopy (EGD). PATIENTS AND METHODS Consecutive consenting patients (n = 999) undergoing EGD answered a questionnaire and had blood taken for serologic testing. Endoscopic markers for celiac disease were documented and duodenal biopsies were obtained. The diagnosis of celiac disease was based on abnormal duodenal histology and positive serology. Risk factors were used to classify patients to either high or low risk for celiac disease. Independent predictors of celiac disease were derived via multivariate logistic regression. RESULTS Villous atrophy (Marsh 3) and celiac disease were present in 1.8 % and 1.5 % of patients, respectively. Most were missed on clinical and endoscopic grounds. The sensitivity of tissue transglutaminase (tTG) testing for the diagnosis of villous atrophy and celiac disease was 72.2 % and 86.7 %, respectively. The positive predictive value of the deamidated gliadin peptide (DGP) test was 34.2 % and that of a strongly positive tTG was 80 %. While the strongest predictor of celiac disease was a positive tTG (odds ratio [OR] 131.7, 95 % confidence interval [CI] 29.0 - 598.6), endoscopic features of villous atrophy (OR 64.8, 95 %CI 10.7 - 391.3), history of eczema (OR 4.6, 95 %CI 0.8 - 28.8), anemia (OR 6.7, 95 %CI 1.2 - 38.4), and being Shiite (OR 5.4, 95 %CI 1.1 - 26.6) significantly predicted celiac disease. A strategy of biopsying the duodenum based on independent predictors had a sensitivity of 93 % - 100 % for the diagnosis of celiac disease, with an acceptable (22 % - 26 %) rate of performing unnecessary biopsies. A strategy that excluded pre-EGD serology produced a sensitivity of 93 % - 94 % and an unnecessary biopsy rate of 52 %. CONCLUSION An approach based solely on standard clinical suspicion and endoscopic findings is associated with a significant miss rate for celiac disease. A strategy to biopsy based on the derived celiac disease prediction models using easily obtained information prior to or during endoscopy, maximized the diagnosis while minimizing unnecessary biopsies.

Preclinical efficacy of the synthetic retinoid ST1926 for treating adult T-cell leukemia/lymphoma

Adult T-cell leukemia/lymphoma (ATL) is an aggressive neoplasm caused by human T-cell leukemia virus type 1 (HTLV-1). The HTLV-1 oncoprotein Tax plays an important role in ATL pathogenesis. ATL carries a poor prognosis due to chemotherapy resistance, stressing the need for alternative therapies. Here, we investigate the preclinical efficacy of the synthetic retinoid ST1926 in ATL and peripheral T-cell lymphomas. Clinically achievable concentrations of ST1926 induced a dramatic inhibition of cell proliferation in malignant T-cell lines and primary ATL cells with minimal effect on resting or activated normal lymphocytes. ST1926 induced apoptosis, DNA damage, and upregulation of p53 proteins in malignant T cells, whereas it caused an early downregulation of Tax proteins in HTLV-1-positive cells. In murine ATL, oral treatment with ST1926 prolonged survival and reduced leukemia cell infiltration, white blood cell counts, and spleen mass. In spleens of ST1926-treated animals, p53 and p21 proteins were upregulated, poly (ADP-ribose) polymerase was cleaved, and Tax transcripts were reduced. These results highlight the promising use of ST1926 as a targeted therapy for ATL.

Chromatid recommensuration after segmental duplication

BackgroundMidsegment duplication (dup) of chromatid arms may be symmetric or asymmetric. It can be argued that every dup should yield a discommensured RC with (a) loss of at least one duplicated unit to the template counterpart and; (b) deletion of all sections of the replicating chromatid arm that are distal to both the gap left by the duplicating process and the segment closest to the centromere.HypothesisMechanisms capable of recommensuring the stack of chromatids after topological shifts of duplicated units (dups) are discussed. The mechanics might fail in few cases, which are discussed in terms of statistics and scalability.ConclusionThe dynamics of the highly non-linear processes discussed here may be relevant to duplications of smaller (epsilon) subunits such as telomeric units within malignant genomes.

miRNA as Potential Biomarkers of Breast Cancer in the Lebanese Population and in Young Women: A Pilot Study

Relative to western populations, the percentage of women diagnosed with breast cancer at a young age in Lebanon is high. While the younger age of the Lebanese population compared to the West certainly contributes to this difference, potential genetic, reproductive and/or biological factors likely play an important role. The objective of this study is to investigate the contribution of miRNAs in this setting through the analysis of the expression of five reported dysregulated miRNAs, miR-148b, miR-10b, miR-21, miR-221, and miR-155 in 20 normal and 57 cancerous breast tissues from Lebanese breast cancer patients. After finding their relative expression by quantitative reverse transcription real time PCR, the results were analyzed with respect to the patients’ clinical and histopathology presentations. Compared to normal breast tissues, significant upregulation of miR-155, miR-21 and miR-148b, notable downregulation of miR-10b and non-significant expression of miR-221 were observed in tumor tissues. Moreover, miR-10b was significantly underexpressed in estrogen/progesterone receptor (ER/PR) negative tumors relative to ER/PR positive tumor tissues. miR-155 was also significantly overexpressed in postmenopausal patients and in those of age at diagnosis greater than 40 years old as well as in PR negative or in human epidermal growth factor 2 (Her2) positive tissues. This study is the first one to report miRNA expression patterns in Lebanese breast cancer patients. We found that differential miRNA expression in breast cancer could be variable between Lebanese and Western populations. miR-10b was positively correlated with the ER and PR status and miR-155 could be a noteworthy biomarker for the menopausal state, age at diagnosis, PR and Her2 status. Hence, miRNA can be used as biomarkers for early breast cancer detection.

Effective targeting of chronic myeloid leukemia initiating activity with the combination of arsenic trioxide and interferon alpha

Imatinib is the standard of care in chronic meloid leukemia (CML) therapy. However, imatinib is not curative since most patients who discontinue therapy relapse indicating that leukemia initiating cells (LIC) are resistant. Interferon alpha (IFN) induces hematologic and cytogenetic remissions and interestingly, improved outcome was reported with the combination of interferon and imatinib. Arsenic trioxide was suggested to decrease CML LIC. We investigated the effects of arsenic and IFN on human CML cell lines or primary cells and the bone marrow retroviral transduction/transplantation murine CML model. In vitro, the combination of arsenic and IFN inhibited proliferation and activated apoptosis. Importantly, arsenic and IFN synergistically reduced the clonogenic activity of primary bone marrow cells derived from CML patients. Finally, in vivo, combined interferon and arsenic treatment, but not single agents, prolonged the survival of primary CML mice. Importantly, the combination severely impaired engraftment into untreated secondary recipients, with some recipients never developing the disease, demonstrating a dramatic decrease in CML LIC activity. Arsenic/IFN effect on CML LIC activity was significantly superior to that of imatinib. These results support further exploration of this combination, alone or with imatinib aiming at achieving CML eradication rather than long‐term disease control.

The immune microenvironment in cutaneous leishmaniasis.

Cutaneous leishmaniasis is an infection that has spread to non‐endemic regions, stimulating recent interest for the enhanced understanding of this disease. Downregulation of the CD1a receptor on Langerhans cells has been described in various cutaneous infections.

Programmed Death-Ligand 1 Expression in Muscle-Invasive Bladder Cancer Cystectomy Specimens and Lymph Node Metastasis: A Reliable Treatment Selection Biomarker?

BACKGROUND The programmed death-1 (PD-1) pathway negatively regulates T-cell activation and has an important role in regulating antitumor host immunity. Monoclonal antibodies directed against PD-1 or the PD-1 ligand (PD-L1) have shown activity in several tumor types with preliminary data suggesting a relationship between PD-L1 expression and response. The aim of this study was to establish the frequency of PD-L1 expression in muscle-invasive bladder cancer and associated lymph node metastasis using immunohistochemistry and to investigate the feasibility of using PD-L1 expression as a biomarker to select patients for PD-1-directed therapy. PATIENTS AND METHODS Cases of radical cystectomy for muscle-invasive bladder cancer with no exposure to previous chemotherapy were identified and representative slides from archived paraffin-embedded blocks stained with anti-PD-L1 antibody (5H1 clone) were identified. PD-L1 positivity was defined by a 5% expression threshold. RESULTS Fifty-two radical cystectomy specimens were reviewed. PD-L1 was overexpressed in the tumor cells of 5/52 (9.6%) of cystectomy specimens in this cohort with 17/52 (32.7%) of cases showing PD-L1 overexpression in tumor-infiltrating immune cells. Discordance was observed between PD-L1 expression in lymph node metastasis and the primary tumor. CONCLUSION Standard assays for PD-L1 expression have yet to be established. The observation of discordance between PD-L1 expression in metastatic sites and primary tumors suggests that prospective biomarker studies should aim to acquire material immediately before treatment initiation rather than archived tissue from resected specimens that might not reflect the current immune-active microenvironment.

Expression of HIF-1α and Markers of Angiogenesis Are Not Significantly Different in Triple Negative Breast Cancer Compared to Other Breast Cancer Molecular Subtypes: Implications for Future Therapy

Introduction Triple negative breast cancer lacks estrogen, progesterone and epidermal growth factor receptors rendering it refractory to available targetedtherapies. TNBC is associated with central fibrosis and necrosis, both indicators of tumor hypoxia. Hypoxia inducible factor 1α is up-regulated under hypoxia and its expression is associated with induction of angiogenesis resulting in proliferation, aggressive tumor phenotype and metastasis. In this study we evaluate the potential use of HIF-1α as aTNBC-specific marker. Methods 62 TNBC, 64 HER2+, and 64 hormone-receptors positive breast cancer cases were evaluated for central fibrosis and necrosis, HIF-1α, HIF-1β, VEGFR3, CD31 expression and microvessel density. RNA extraction from paraffin-embedded samples, followed by quantitative real-time polymerase chain reaction (qRT-PCR) evaluation of HIF-1α and VEGF transcripts was performed on 54 cases (18 from each subtype). Results HIF-1α protein was expressed in 35.5% TNBC, 45.3% HER2+and 25.0% ER+/PR+ (p = 0.055; χ2 test). PCRanalysis of subgroup of breast cancers, 84.2% expressed HIF-1α protein and its transcripts, while only 66.7% expressed VEGF transcripts simultaneously with the HIF-1α protein and its transcripts. Central fibrosis and necrosis was highest in TNBC (p = 0.015; χ2 test), while MVD was comparable among all groups (p = 0.928; χ2 test). VEGFR3 was highest in TNBC expressing HIF-1α. HIF-1β protein was expressed in 32.0% of HIF-1α(+), and in (44.3%) of HIF-1α(-) breast cancer cases (p = 0.033; χ2 test). Moreover, HIF-1α expression in cases with central fibrosis and necrosis was highest in the HER2+ followed by the TNBC (p = 0.156; χ2 test). Conclusions A proportion of TNBC express HIF-1α but not in a significantly different manner from other breast cancer subtypes. The potential of anti-HIF-1α targeted therapy is therefore not a candidate for exclusive use in TNBC, but should be considered in all breast cancers, especially in the setting of clinically aggressive or refractory disease.