2009 ESC/ERS Pulmonary Hypertension Guidelines and Connective Tissue Disease

ABSTRACTPulmonary hypertension was defined as mean pulmonary artery pressure ≥25 mmHg at the 4th World Symposium on Pulmonary Hypertension. In 2009, the European Society of Cardiology and European Respiratory Society jointly created guidelines for practical pulmonary hypertension classifications and treatments based on the discussions at the 4th World Symposium. This classification is characterized by division into five groups: Pulmonary arterial hypertension (PAH); Pulmonary hypertension due to left heart disease; Pulmonary hypertension due to lung disease and/or hypoxia; Chronic thromboembolic pulmonary hypertension; and Pulmonary hypertension with unclear and/or multifactorial mechanisms.PAH is a common and fatal complication of connective tissue disease (CTD), but pulmonary hypertension in CTD consists of PAH, pulmonary hypertension caused by myocardial involvement, pulmonary veno-occlusive disorder, pulmonary hypertension due to interstitial lung disease. PAH has been studied widely in SSc and the estimated prevalence of 7-12%. Treatment of CTD associated PAH (CTD-PAH) consists of general therapeutic options and specific treatment. Specific treatment of CTD-PAH patients is targeted to produce vasodilatation. Calcium channel blockers (CCBs) are indicated in cases where a sufficient decrease in pulmonary arterial pressure is seen in vasoreactivity testing. If vasoreactivity is absent in CTD-PAH patients, the treatment consists of the endothelin receptor antagonists, the prostacyclin analogues and phosphodiesterase-type 5 inhibitors. Few data are available to support the use of immunosuppression in CTD-PAH. However, some case reports suggested that a minority of CTD-PAH patients could benefit from immunosuppressive therapy. The treatment of CTD-PAH patients may differ from the treatment of idiopathic PAH

Rubinstein-Taybi Syndrome: spectrum of CREBBP mutations in Italian patients

BACKGROUND: Rubinstein-Taybi Syndrome (RSTS, MIM 180849) is a rare congenital disorder characterized by mental and growth retardation, broad and duplicated distal phalanges of thumbs and halluces, facial dysmorphisms and increased risk of tumors. RSTS is caused by chromosomal rearrangements and point mutations in one copy of the CREB-binding protein gene (CREBBP or CBP) in 16p13.3. To date mutations in CREBBP have been reported in 56.6% of RSTS patients and an average figure of 10% has ascribed to deletions. METHODS: Our study is based on the mutation analysis of CREBBP in 31 Italian RSTS patients using segregation analysis of intragenic microsatellites, BAC FISH and direct sequencing of PCR and RT-PCR fragments. RESULTS: We identified a total of five deletions, two of the entire gene and three, all in a mosaic condition, involving either the 5' or the 3' region. By direct sequencing a total of 14 de novo mutations were identified: 10 truncating (5 frameshift and 5 nonsense), one splice site, and three novel missense mutations. Two of the latter affect the HAT domain, while one maps within the conserved nuclear receptor binding of (aa 1–170) and will probably destroy a Nuclear Localization Signal. Identification of the p.Asn1978Ser in the healthy mother of a patient also carrying a de novo frameshift mutation, questions the pathogenetic significance of the missense change reported as recurrent mutation. Thirteen additional polymorphisms, three as of yet unreported, were also detected. CONCLUSION: A high detection rate (61.3%) of mutations is confirmed by this Italian study which also attests one of the highest microdeletion rate (16%) documented so far

Clinical practice: Coeliac disease

Coeliac disease (CD) is an immune-mediated systemic condition elicited by gluten and related prolamines in genetically predisposed individuals and characterised by gluten-induced symptoms and signs, specific antibodies, a specific human leukocyte antigen (HLA) type and enteropathy. The risk of coeliac disease is increased in first-degree relatives, certain syndromes including Down syndrome and autoimmune disorders. It is thought to occur in 1 in 100–200 individuals, but still only one in four cases is diagnosed. Small-bowel biopsy is no longer deemed necessary in a subgroup of patients, i.e. when all of the following are present: typical symptoms or signs, high titres of and transglutaminase antibodies, endomysial antibodies, and HLA-type DQ2 or DQ8. In all other cases, small-bowel biopsy remains mandatory for a correct diagnosis. Therapy consists of a strictly gluten-free diet. This should result in complete disappearance of symptoms and of serological markers. Adequate follow-up is considered essential. Conclusion: Although small-bowel biopsy may be omitted in a minority of patients, small-bowel biopsy is essential for a correct diagnosis of CD in all other cases. Diagnostic work-up should be completed before treatment with gluten-free diet instituted

A sequence conserved between CD5 and CD6 binds an FERM domain and exerts a restraint on T‐cell activation

CD5 and CD6 are related surface receptors that limit and promote T‐cell responses. Co‐stimulatory effects of CD6 depend on binding a cell surface ligand, CD166, and recruitment of the intracellular adaptor proteins GADS and SLP‐76 by C‐terminal phosphotyrosines. We have continued to identify interactions of CD5 and CD6 to understand their roles in T‐cell activation. In a screen to identify binding partners for peptides containing a cytoplasmic sequence, SDSDY conserved between CD5 and CD6, we identified ezrin radixin moesin (ERM) proteins, which link plasma membrane proteins to actin. Purified radixin FERM domain bound directly to CD5 and CD6 SDSDY peptides in a phosphorylation‐dependent manner (KD = 0·5‐2 μm) at 37°. In human T‐cell blasts, mutation of the CD6 SDSDY sequence enhanced CD69 expression in response to CD3 monoclonal antibody. In this proximal readout, interactions of the SDSDY sequence were dominant compared with the C‐terminal tyrosines of CD6. In contrast, in a more downstream readout, interleukin‐2 expression, in response to immobilized CD3 and CD6 monoclonal antibodies, the C‐terminal tyrosines were dominant. The data suggest that varying functional effects of CD6 and potentially CD5 depend on interactions of different cytoplasmic regions with the cytoskeleton and alter depending on the stimuli

A sequence conserved between CD5 and CD6 binds an FERM domain and exerts a restraint on T‐cell activation

CD5 and CD6 are related surface receptors that limit and promote T‐cell responses. Co‐stimulatory effects of CD6 depend on binding a cell surface ligand, CD166, and recruitment of the intracellular adaptor proteins GADS and SLP‐76 by C‐terminal phosphotyrosines. We have continued to identify interactions of CD5 and CD6 to understand their roles in T‐cell activation. In a screen to identify binding partners for peptides containing a cytoplasmic sequence, SDSDY conserved between CD5 and CD6, we identified ezrin radixin moesin (ERM) proteins, which link plasma membrane proteins to actin. Purified radixin FERM domain bound directly to CD5 and CD6 SDSDY peptides in a phosphorylation‐dependent manner (KD = 0·5‐2 μm) at 37°. In human T‐cell blasts, mutation of the CD6 SDSDY sequence enhanced CD69 expression in response to CD3 monoclonal antibody. In this proximal readout, interactions of the SDSDY sequence were dominant compared with the C‐terminal tyrosines of CD6. In contrast, in a more downstream readout, interleukin‐2 expression, in response to immobilized CD3 and CD6 monoclonal antibodies, the C‐terminal tyrosines were dominant. The data suggest that varying functional effects of CD6 and potentially CD5 depend on interactions of different cytoplasmic regions with the cytoskeleton and alter depending on the stimuli

Addition of the C‐terminus of CD6 to a chimeric antigen receptor enhances cytotoxicity and does not compromise expression

T cells expressing chimeric antigen receptors (CARs) are a promising new cancer immunotherapy that has now reached the clinic. CARs are synthetic receptors that redirect T cells towards a tumour‐associated antigen and activate them through various fused signalling regions, for example derived from CD3ζ, 4‐1BB or CD28. Analysis of the optimal combination of CAR components including signalling domains is not yet comprehensive and may vary with the particular application. The C‐terminus of the T‐cell surface receptor CD6 is critical for its co‐stimulatory effects and signals through two phospho‐tyrosine motifs that bind to the intracellular adaptor proteins GADS and SLP‐76. Addition of the C terminus of CD6 did not compromise CAR expression, showing it was a stable moiety that can be used independently of the native receptor. A third‐generation CAR containing 4‐1BB, CD3ζ and the C terminus of CD6 (4‐1BBz‐CD6) enhanced interferon‐γ release and cytotoxicity when compared with the second‐generation 4‐1BB CD3ζ (4‐1BBz) CAR. The CD6 C terminus is a valuable addition to potential components for modular design of CARs to improve effector function, particularly cytotoxicity

Addition of the C‐terminus of CD6 to a chimeric antigen receptor enhances cytotoxicity and does not compromise expression

T cells expressing chimeric antigen receptors (CARs) are a promising new cancer immunotherapy that has now reached the clinic. CARs are synthetic receptors that redirect T cells towards a tumour‐associated antigen and activate them through various fused signalling regions, for example derived from CD3ζ, 4‐1BB or CD28. Analysis of the optimal combination of CAR components including signalling domains is not yet comprehensive and may vary with the particular application. The C‐terminus of the T‐cell surface receptor CD6 is critical for its co‐stimulatory effects and signals through two phospho‐tyrosine motifs that bind to the intracellular adaptor proteins GADS and SLP‐76. Addition of the C terminus of CD6 did not compromise CAR expression, showing it was a stable moiety that can be used independently of the native receptor. A third‐generation CAR containing 4‐1BB, CD3ζ and the C terminus of CD6 (4‐1BBz‐CD6) enhanced interferon‐γ release and cytotoxicity when compared with the second‐generation 4‐1BB CD3ζ (4‐1BBz) CAR. The CD6 C terminus is a valuable addition to potential components for modular design of CARs to improve effector function, particularly cytotoxicity