Evidence for Distinct Mechanisms in the Shaping of the CD4 T Cell Repertoire in Histologically Distinct Myasthenia Gravis – Associated Thymomas

The major histocompatibility complex (MHC) class II is involved both in thymocyte maturation and peptide presentation and might thus play a key role in the pathogenesis of paraneoplastic myasthenia gravis (MG) in thymomas. To further investigate this issue, we analyzed and scored the expression of epithelial class II expression in 35 thymomas (medullary, MDT; mixed, MXT; cortical and well differentiated thymic carcinoma, CT / WDTC) and correlated it with the histological tumor subtype, prevalence of MG and thymocyte maturation, which was analyzed by flow cytometry and RT-PCR. Our results show that both MHC class II expression and thymocyte maturation are highly dependent on the histological tumor subtype. CT / WDTC retain features of the normal outer thymic cortex, namely substantial MHC class II expression together with normal early thymocyte maturation until late phases of positive selection, but disturbed terminal thymopoiesis. By contrast, MDT and MXT retain features of the normal inner cortex and the medulla with low to absent class II expression and highly abnormal early thymocyte maturation including impaired positive selection, while terminal T cell maturation in MXT appeared undisturbed. There was no correlation between MHC class II expression and MG status for a given tumor subtype. In conclusion, our results provide evidence for a different histogenesis of cortical thymomas and well differentiated carcinomas on the one hand and mixed and medullary thymomas on the other

Predictors of persistence of anxiety disorders across the lifespan:a systematic review

Despite the substantial disease burden of anxiety disorders, physicians have a poor understanding of factors that predict their typical persistent course. This systematic review of predictors of persistent anxiety disorders covered 48 studies with 29 690 patients diagnosed with an anxiety disorder that were published in PubMed, PsycINFO, and Web of Science between Jan 1, 1980 (introduction of DSM-III), and Dec 1, 2019. We also compared predictors between children, adolescents, adults, and older adults (ie, ≥55 years). A persistent course was primarily predicted by clinical and psychological characteristics, including having panic attacks, co-occurring personality disorders, treatment seeking, poor clinical status after treatment, higher severity and longer duration of avoidance behaviour, low extraversion, higher anxiety sensitivity, and higher behavioural inhibition. Unlike disorder onset, sociodemographic characteristics did not predict persistence. Our results outline a profile of patients with specific clinical and psychological characteristics who are particularly vulnerable to anxiety disorder persistence. Clinically, these patients probably deserve additional or more intensive treatment to prevent development of chronicity

Concordance of KRAS/BRAF Mutation Status in Metastatic Colorectal Cancer before and after Anti-EGFR Therapy

Anti-EGFR targeted therapy is a potent strategy in the treatment of metastatic colorectal cancer (mCRC) but activating mutations in the KRAS gene are associated with poor response to this treatment. Therefore, KRAS mutation analysis is employed in the selection of patients for EGFR-targeted therapy and various studies have shown a high concordance between the mutation status in primary CRC and corresponding metastases. However, although development of therapy related resistance occurs also in the context of novel drugs such as tyrosine kinase-inhibitors the effect of the anti-EGFR treatment on the KRAS/BRAF mutation status itself in recurrent mCRC has not yet been clarified. Therefore, we analyzed 21 mCRCs before/after anti-EGFR therapy and found a pre-/posttherapeutic concordance of the KRAS/BRAF mutation status in 20 of the 21 cases examined. In the one discordant case, further analyses revealed that a tumor mosaicism or multiple primary tumors were present, indicating that anti-EGFR therapy has no influence on KRAS/BRAF mutation status in mCRC. Moreover, as the preselection of patients with a KRASwt genotype for anti-EGFR therapy has become a standard procedure, sample sets such ours might be the basis for future studies addressing the identification of potential anti-EGFR therapy induced genetic alterations apart from KRAS/BRAF mutations

CD40 Ligand and Autoantigen Are Involved in the Pathogenesis of Low-Grade B-Cell Lymphomas of Mucosa-Associated Lymphoid Tissue

Low-grade MALT-type lymphomas are malignancies of mucosal marginal-zone B cells and preceded by reactive inflammatory lymphoid tissue. Experimental observations suggest that antigen and CD40 Ligand act during cognate T/B cell interaction and are crucial for germinal center B-cell maturation generating marginal-zone B cells. To investigate the mechanisms underlying the development of extranodal MALT-type lymphomas, the immunoglobulin receptor was sequenced and analyzed for antigen specificity using heterohybridoma technology. Furthermore, CD40 ligand expression was evaluated by immunohistochemistry and by semiquantitative RT-PCR, and ligand binding to the CD40 of tumor B cells was studied using the CD40 system. Hypermutations were found in low-grade lymphomas throughout CDR1- CDR3 suggestive of positive selection through their antigen receptor. Different VH families were used and more than 69% of tumor immunoglobulins bound different mucosal antigens. CD40L expression was found in the tumor marginal zone in substantial amounts. The in vitro proliferation response of all low-grade MALT-type lymphomas was dependent on anti-CD40- mediated signals and cytokines. Our data provide evidence that autoantigen as well as the CD40L expressed by activated nonneoplastic T cells may drive the evolution of low-grade MALT-type lymphomas either directly or by paracrine mechanisms and that antigen may contribute to lymphoma pathogenesis

A Human Recombinant Autoantibody-Based Immunotoxin Specific for the Fetal Acetylcholine Receptor Inhibits Rhabdomyosarcoma Growth In Vitro and in a Murine Transplantation Model

Rhabdomyosarcoma (RMS) is the most common malignant soft tissue tumor in children and is highly resistant to all forms of treatment currently available once metastasis or relapse has commenced. As it has recently been determined that the acetylcholine receptor (AChR) γ-subunit, which defines the fetal AChR (fAChR) isoform, is almost exclusively expressed in RMS post partum, we recombinantly fused a single chain variable fragment (scFv) derived from a fully human anti-fAChR Fab-fragment to Pseudomonas exotoxin A to generate an anti-fAChR immunotoxin (scFv35-ETA). While scFv35-ETA had no damaging effect on fAChR-negative control cell lines, it killed human embryonic and alveolar RMS cell lines in vitro and delayed RMS development in a murine transplantation model. These results indicate that scFv35-ETA may be a valuable new therapeutic tool as well as a relevant step towards the development of a fully human immunotoxin directed against RMS. Moreover, as approximately 20% of metastatic malignant melanomas (MMs) display rhabdoid features including the expression of fAChR, the immunotoxin we developed may also prove to be of significant use in the treatment of these more common and most often fatal neoplasms

Standard and increased-dose BEACOPP chemotherapy compared with COPP-ABVD for advanced Hodgkins disease

BACKGROUND: Faced with unsatisfactory results of treatment for advanced Hodgkin's disease, we investigated three combinations of chemotherapy. METHODS: From 1993 to 1998, 1201 eligible patients 15 to 65 years of age who had newly diagnosed Hodgkin's disease in unfavorable stage IIB or IIIA or stage IIIB or IV were randomly assigned to receive eight cycles of cyclophosphamide, vincristine, procarbazine, and prednisone alternating with doxorubicin, bleomycin, vinblastine, and dacarbazine (COPP-ABVD); bleomycin, etoposide, doxorubicin, cyclophosphamide, vincristine, procarbazine, and prednisone (BEACOPP); or increased-dose BEACOPP, each followed by local radiotherapy when indicated. Enrollment in the COPP-ABVD group was stopped in 1996 owing to inferior results. RESULTS: For the final analysis, 1195 of 1201 patients could be evaluated: 260 in the COPP-ABVD group, 469 in the BEACOPP group, and 466 in the increased-dose BEACOPP group; the median follow-up was 72, 54, and 51 months, respectively. The rate of freedom from treatment failure at five years was 69 percent in the COPP-ABVD group, 76 percent in the BEACOPP group, and 87 percent in the increased-dose BEACOPP group (P=0.04 for the comparison of the COPP-ABVD group with the BEACOPP group and P<0.001 for the comparison of the increased-dose BEACOPP group with the COPP-ABVD group and with the BEACOPP group), and the five-year rates of overall survival were 83 percent, 88 percent, and 91 percent, respectively (P=0.16 for the comparison of the COPP-ABVD group with the BEACOPP group, P=0.06 for the comparison of the BEACOPP group with the increased-dose BEACOPP group, and P=0.002 for the comparison of the COPP-ABVD group with the increased-dose BEACOPP group). Rates of early progression were significantly lower with increased-dose BEACOPP than with COPP-ABVD or standard BEACOPP. CONCLUSIONS: Increased-dose BEACOPP resulted in better tumor control and overall survival than did COPP-ABVD

Stability of chronotype over a 7-year follow-up period and its association with severity of depressive and anxiety symptoms

Background: Chronotype is an individual's preferred timing of sleep and activity, and is often referred to as a later chronotype (or evening-type) or an earlier chronotype (or morning-type). Having an evening chronotype is associated with more severe depressive and anxiety symptoms. Based on these findings it is has been suggested that chronotype is a stable construct associated with vulnerability to develop depressive or anxiety disorders. To examine this, we test the stability of chronotype over 7 years, and its longitudinal association with the change in severity of depressive and anxiety symptoms. Methods: Data of 1,417 participants with a depressive and/or anxiety disorder diagnosis and healthy controls assessed at the 2 and 9-year follow-up waves of the Netherlands Study of depression and anxiety were used. Chronotype was assessed with the Munich chronotype questionnaire. Severity of depressive and anxiety symptoms were assessed with the inventory of depressive symptomatology and Beck anxiety inventory. Results: Chronotype was found to be moderately stable (r = 0.53) and on average advanced (i.e., became earlier) with 10.8 min over 7 years (p <.001). Controlling for possible confounders, a decrease in severity of depressive symptoms was associated with an advance in chronotype (B = 0.008, p =.003). A change in severity of anxiety symptoms was not associated with a change in chronotype. Conclusion: Chronotype was found to be a stable, trait-like construct with only a minor level advance over a period of 7 years. The change in chronotype was associated with a change in severity of depressive, but not anxiety, symptoms