Specifications and validation of the ACMG/AMP criteria for clinical interpretation of sequence variants in collagen genes associated with joint hypermobility

Deleterious variants in collagen genes are the most common cause of hereditary connective tissue disorders (HCTD). Adaptations of the American College of Medical Genetics and Genomics/Association for Molecular Pathology (ACMG/AMP) criteria are still lacking. A multidisciplinary team was set up for developing specifications of the ACMG/AMP criteria for COL1A1, COL1A2, COL2A1, COL3A1, COL5A1, COL5A2, COL11A1, COL11A2 and COL12A1, associated with various forms of HCTD featuring joint hypermobility, which is becoming one of the most common reasons of referral for molecular testing in this field. Such specifications were validated against 209 variants, and resulted effective for classifying as pathogenic and likely pathogenic null alleles without downgrading of the PVS1 level of strength and recurrent Glycine substitutions. Adaptations of selected criteria reduced uncertainties on private Glycine substitutions, intronic variants predicted to affect the splicing, and null alleles with a downgraded PVS1 level of strength. Segregation and multigene panel sequencing data mitigated uncertainties on non-Glycine substitutions by the attribution of one or more benignity criteria. These specifications may improve the clinical utility of molecular testing in HCTD by reducing the number of variants with neutral/conflicting interpretations. Close interactions between laboratory and clinicians are crucial to estimate the a priori utility of molecular test and to improve medical reports.

Natural history of MRAS-related Noonan syndrome: Evidence of mild adult-onset left ventricular hypertrophy and neuropsychiatric features

Gain of function pathogenic variants in MRAS have been found in a small subset of pediatric subjects presenting with Noonan syndrome (NS) associated with hypertrophic cardiomyopathy (HCM) and moderate to severe intellectual disability. These variants are considered to confer a high-risk for the development of severe HCM with poor prognosis and fatal outcome. We report on the natural history of the first adult subject with NS carrying the recurrent pathogenic p.Thr68Ile amino acid substitution. Different from what had previously been observed, he presented with a mild, late-onset left ventricular hypertrophy, and a constellation of additional symptoms rarely seen in NS. The present case provides evidence that HCM does not represent an obligatory, early-onset and severe complication in subjects with MRAS variants. It also adds new data about late-onset features suggesting that other unexpected complications might be observed in adult subjects providing anticipatory guidance for individuals of all age.

A novel combined glucocorticoid-mineralocorticoid receptor selective modulator markedly prevents weight gain and fat mass expansion in mice fed a high-fat diet

BACKGROUND

We have previously shown that antagonism of the mineralocorticoid receptor (MR) results in a potent antiadipogenic activity, in vitro and in vivo. Excessive glucocorticoid exposure is associated with obesity and related disorders in humans and mice.

METHODS

In this study, responses to a novel combined glucocorticoid receptor (GR)/MR antagonist were investigated in a model of diet-induced obesity. Female 10-week-old C57BL/6J mice were fed with normal chow or a high-fat diet (HFD) for 9 weeks. Mice fed a HFD were concomitantly treated for 9 weeks with the GR antagonist mifepristone (80 mg kg(-1) per day) or the novel combined GR/MR antagonist CORT118335 (80 mg kg(-1) per day). Male, juvenile 6-week-old C57BL/6J mice fed HFD were treated with CORT118335 for 4 weeks.

RESULTS

Mice fed a HFD showed a significant increase in total body weight and white fat mass, with impaired glucose tolerance and increased fat infiltration in livers. Interestingly, only CORT118335 completely prevented the HFD-induced weight gain and white fat deposition, whereas mifepristone showed no effect on body weight and modestly increased subcutaneous fat mass. Importantly, food intake was not affected by either treatment, and CORT118335 dramatically increased PGC-1α protein expression in adipose tissue, without any effect on UCP1. Both CORT118335 and mifepristone produced metabolic benefit, improving glucose tolerance, increasing adiponectin plasma levels, decreasing leptin and reducing mean adipocyte size. When tested in vitro, CORT118335 markedly reduced 3T3-L1 differentiation and reversed MR-mediated pro-adipogenic effects of aldosterone; differently, GR-mediated effects of dexamethasone were not antagonized by CORT118335, suggesting that it mostly acts as an antagonist of MR in cultured preadipocytes.

CONCLUSIONS

Combined GR/MR pharmacological antagonism markedly reduced HFD-driven weight gain and fat mass expansion in mice through the increase in adipose PGC-1α, suggesting that both receptors represent strategic therapeutic targets to fight obesity. The effects of CORT118335 in adipocytes seem predominantly mediated by MR antagonism.

Role of glutathione-S-transferase (GST) polymorphisms in patients with advanced Hodgkin lymphoma: results from the HD2000 GISL trial

Polymorphisms of the Glutathione-S Transferase (GST) family may influence the prognosis in lymphoma patients. We aimed to validate the impact of GSTT1 and GSTM1 deletions and of the GSTP1Ile105Val polymorphism on outcome and toxicity in 140 patients with advanced Hodgkin's lymphoma enrolled in the prospective multicenter HD2000-GISL trial, comparing ABVD, BEACOPP and CEC regimens. Carriers of the GSTP1Ile105Val polymorphism had a higher rate of grade 3-4 anemia following treatment. Overall, our study failed to validate GST genotyping as prognostic factor for progression-free survival (PFS). Only the small cohort of patients with an international prognostic score (IPS) >3 and undeleted GSTT1 and/or GSTM1, treated with ABVD had worse progression-free survival (PFS) (GSTT1 + vs GSTT1-: HR 5.02, 95% C.I., 1.16-21.8, p = 0.031, GSTM1 + /GSTT1 + vs GSTM1-and/or GSTT1-: HR 4.61, 95% C.I. 1.28- 16.6, p = 0.019, respectively). No differences were observed for patients treated with intensified regimens, as BEACOPP and CEC. In conclusion, the prognostic role of GST polymorphism, if at all, is limited to a small subgroup of patients treated with standard ABVD regimen.

Potential role of progestogens in the control of adipose tissue and salt sensitivity via interaction with the mineralocorticoid receptor

Beside their role in the control of water and electrolyte homeostasis, recent data clearly indicate that aldosterone and the mineralocorticoid receptor (MR) are involved in adipocyte biology. It has been recently shown that aldosterone promotes white and brown adipocyte differentiation in vitro through specific activation of the MR. In addition, a non-epithelial pro-inflammatory role for MR activation has been recently inferred from studies on mineralocorticoid/salt administration in experimental animal models and from clinical studies. The mineralocorticoid system could hence represent a potential target for new therapeutic strategies in obesity and the metabolic syndrome. Progesterone has high affinity for the MR and is a natural antagonist of aldosterone. Differently from classic synthetic progestins, which are devoid of antimineralocorticoid properties, progesterone and new progestogens show remarkable antimineralocorticoid effects. Here, we discuss the potential role of the antimineralocorticoid properties of progestogens in the control of body weight, adipose tissue proliferation and salt sensitivity; their therapeutic use in postmenopausal women, as well as in women affected by polycystic ovary syndrome, may open new and unexpected possibilities in the treatment of related metabolic disorders.

Non-pegylated lyposomal doxorubicin, cyclophosphamide, vincristine, prednisone, and rituximab (R-COMP) as initial treatment for patients with splenic marginal zone lymphoma (SMZL): A GISL study

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Background: SMZL is an indolent lymphoma, presenting with massive splenomegaly generally associated with intrasinusoidal bone marrow infiltration. The encapsulation of doxorubicin into non-pegylated liposomes allows targeting of the drug to affected organs including spleen, lymphnodes and bone marrow. Methods: In 2005, the GISL started a phase II study for the treatment of patients with histologically confirmed SMZL, investigating safety and clinical profile of 6 courses of a modified R-CHOP regimen in which standard doxorubicin was substituted with non pegylated lyposomal doxorubicin (NPLD) used at the same doses (50 mg/m2) (R-COMP). Main inclusion criteria were age >18 yrs, normal cardiac function and active disease (at least one of the following; Hb <10 g/dl; plt <100,000/mmc, symptomatic splenomegaly, elevated LDH, B symptoms, extrasplenic disease, LDT <12 months). Splenectomy was allowed prior to treatment start only in case of symptomatic spleen enlargement. The study was planned according to a two-stage Simon design using overall response rate as primary endpoint. We present the results of the analysis performed after the completion of study stage 1. The access to stage 2 is allowed if at least 12 responses are recorded among among the first 19 evaluable cases. Results: As of January 2007, 20 patient were enrolled with the following characteristics; median age 63 years (30–80), Hb <10 g/dl in 20%, Lymphocytes > 5,000/mmc in 65%, elevated LDH in 65%; 2 patients were splenectomized before treatment start. One patient was not available for response assessment. A clinical response was observed in all remaining 19 cases (ORR 100%); 12 (63%) cases obtained a CR. So far only one patient progressed at +1 month from treatment. Treatment was well tolerated with grade III/IV neutropenia in 8 patients (42%), grade 3 pulmonary toxicity in 1 patient and grade 2 peripheral neuropathy in 5 cases. In one case a reversible cardiac failure was reported after 1 month from the end of treatment. Conclusions: In conclusion 6 cycles of R-COMP combination represent a safe and promising treatment option for patients with clinically active SMZL.

No significant financial relationships to disclose.

Role of hyperhomocystinemia in retinal vascular occlusive disease

Elevated plasma homocysteine (Hcy) level is considered a risk factor for vascular diseases. In recent years, many scientific reports have suggested that hyperhomocystinemia may be associated with an increased risk of retinal vascular occlusive disease (RVOD). The prevalence of elevation of homocysteine in patients with a recent retinal vascular occlusion was compared to a health control group in this study. Forty-nine consecutive patients (22 M; 27 F) (age 26-85 years, mean 69) with diagnosis of retinal vascular occlusion were compared with 71 healthy controls. These patients underwent laboratory evaluation for plasma fasting total homocysteine, activated protein C resistance, protein C, protein S, antithrombin III, and antiphospholipid and anticardiolipin antibodies. The G20210 prothrombin gene mutation (FII G20210A) and Factor V Leiden mutation (FVL) were evaluated. None of these enrolled subjects had other prothrombic risk factors. The health control group consisted of healthy subjects from the general population, with no history or clinical evidence of retinal vascular disease, recruited during the same 2-year period. High fasting homocystinemia (higher than 15 mumol/L) was detected in 24/49 subjects (48.9%) (P < .0005). There was a high prevalence of hyperhomocystinemia: these data suggest an association between RVOD and high fasting homocystinemia. Elevated homocysteine may be an independent risk factor, and its assessment may be important in the investigation, management, and follow-up of patients with RVOD. Further controlled studies are necessary to clarify the exact role of hyperhomocystinemia in RVOD and to evaluate the appropriate therapeutic approach.

BACOP/FR combination chemotherapy as front-line treatment of follicular lymphoma. A phase II study of the Gruppo Italiano Studio Linfomi (GISL)

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Background: Doxorubicin, fludarabine and rituximab are all considered active drugs in the treatment of follicular lymphoma (FL). Howevere, the best induction regimen is still matter of debate. In 2003 the GISL started a phase II trial to assess efficacy and tolerability of a combination of bleomycin, adriamycin, ciclophosphamide, vincristine and prednisone (BACOP) followed by fludarabine and rituximab (FR). Methods: To be included in the study pts should have: histologically confirmed diagnosis of FL, stage II-IV disease, age 18–70, active disease. Pts were assessed for t(14:18) by PCR on bone marrow at diagnosis and at time of response assessment. Treatment consisted in three courses of BACOP followed by 4 courses of FR for pts in partial remission (PR) or complete remission with persistent t(14:18) positivity (CRM+). Pts achieving molecular complete remission (CRM-) stopped therapy after BACOP. The main endpoints of the study were overall response rate (CR+PR) (ORR) and failure free survival (FFS). A final accrual of 60 assessable pts was planned, however a faster accrual than expected allowed to enrol 91 pts between May 2003 and Dec 2005. Results: At time of present analysis 61 pts were valuable for final response: Median age was 56 yrs (25–70), male gender 56%, 18% with systemic symptoms, 88% in stage III-IV disease, 13% had elevated LDH and 21% bulky disease. Molecular marker was present in 30 out of 57 pts. 19 pts achieved a CR after three courses of BACOP; four of them, being in CRM- stopped therapy. 28 pts achieved CR with four additional courses of FR. At the end of treatment CR and ORR were 77% and 90% respectively; relatively to pts with molecular marker at diagnosis CRM- was 60%. Toxicity data are available for 57 patients: grade III/IV anemia and neutropenia were observed in two (3%) and 18 (32%) cases respectively; severe infections occurred in two cases, both bacterial pneumonia. After a median follow-up of 17 months (0.5–31) 12 events were observed: Major toxicity, four; non responders, two; relapse, six. Conclusions: BACOP/FR is a feasible and safe regimen for the treatment of patients with FL with promising efficacy. More mature follow-up is required to confirm these preliminary results.

No significant financial relationships to disclose.

The role of dose size in a chemotherapy regimen (ProMECE-CytaBOM) for the first-line treatment of large B-cell lymphomas: a randomized trial by the Gruppo Italiano Studio Linfomi (GISL)

BACKGROUND

It is still unclear the actual contribute of dose intensity (DI), dose size (DS) and dose density (DD) in the conventional chemotherapy of large, B-cell non-Hodgkin lymphomas.

METHODS

A prospective, randomized trial compared the cyclic schedule of ProMECE-CytaBOM chemotherapy (cyc-PC, 6 cycles) with a modified version of it, which administered the same drugs sequentially (seq-PC), with the same planned cumulative DI and an 83% DD, within the same time frame (113 days), but with three times higher DS of all the drugs except vincristine.

RESULTS

Fifty-six patients received cyc-PC and 52 seq-PC. The actual mean cumulative DI was 0.79 +/- 0.15 with cyc-PC, 0.78 +/- 0.17 with seq-PC. Response was complete in 59% and 52%, partial in 20% and 21%, null in 5% and 6%, respectively. There were four toxic deaths (two per arm). Relapses occurred in 36% and 37%, respectively. Toxicity was similar in both arms. Overall, failure-free, progression-free and disease-free survival (median follow-up: 54 months) were statistically indifferent.

CONCLUSIONS

The very similar DI actually delivered in both arm seems to be the main common determinant of the indifferent results recorded. Increasing DS--at least within the limits clinically attainable without stem cell rescue--does not improve results.

The role of high-dose therapy and autologous stem cell transplantation in patients with primary refractory Hodgkin's lymphoma: a report from the Gruppo Italiano per lo Studio dei Linfomi (GISL)

GISL recently conducted an exhaustive survey of 1078 patients with Hodgkin's Lymphoma (HL) enrolled between 1988 and 2002 in different prospective trials. Treatment failure was observed in 82 out of 1078 patients; of these 82 patients with refractory HL, complete information was available for 72, who form the evaluable population of the present study. After the initial therapy failure, 51 patients were treated with conventional salvage chemotherapy (CC) (n = 24) or high-dose chemotherapy (HDC) (n = 27); 4-year overall survival (OS) was 81% in the HDC group versus 38% in the CC group (P = 0.019). The remaining 21 patients had rapidly progressive disease and died. After a median follow-up of 2.8 years, the projected OS for all 72 patients is 58 and 49% at 3 and 5 years, respectively. Age <45 years, the absence of systemic symptoms and a PS <1 predicted a significantly longer OS. Interestingly, the majority of patients with two or three negative prognostic factors did not receive potentially curative therapy. In conclusion, HDC seems to be a reasonable option for selected patients with refractory HL, although the majority of them did not receive a transplant. Finally, patients with a high-risk score had little chance of receiving potentially curative treatment.

MHC-peptide binding: dimers of cysteine-containing nonapeptides bind with high affinity to HLA-A2.1 class I molecules

Small peptides, 8-10 amino acids long, derived from degradation of cytoplasmic proteins by a proteasome-proteinase complex, are usually presented and recognized by CD8+ cytolytic T lymphocytes (CTLs) associated with major histocompatibility complex (MHC) class I molecules. Recently synthetic peptides were used for the in vitro induction of tumor-specific CTLs, offering another strategy in the study of the immune-response repertoire and providing a new tool in cancer vaccination and immunotherapy. Peptides derived from otherwise normal proteins, overexpressed in many tumors as products of the protooncogene, may represent a target for an immune response. This is the case of HER-2/neu gene (also known as ErbB-2), encoding a cysteine-rich glycoprotein transmembrane receptor with tyrosine kinase activity (gp185neu). Recent data, demonstrating that HLA-A2.1-related peptides are able to stimulate in vitro CD8+ lymphocytes, Prompted us to study the binding to HLA-A2.1 molecules of several gp185 synthetic peptides containing a cystein residue and to define the relevance of this amino acid residue in the reduced or oxidated form of the sulfhydryl group. We found that monomers and their homodimers, linked by a disulfide bridge, bind to HLA-A2.1 molecules with overlapping affinity. These results suggest that additional amino acids of the nonapeptide do not prevent the binding and the HLA refolding through chemical or sterical interactions. This might be of particular relevance for the in vivo processing of cysteine-rich proteins. Because ErbB-2 molecules, as tumor-differentiation antigens in melanoma, are cysteine-rich molecules, it may be relevant to evaluate the possible role of the cystine residues interacting with the T-cell receptor. The recognition of these heterodimers by CD8+ lymphocytes will require functional in vivo studies.