1. High burden of clonal mast cell disorders and hereditary ▫$α-tryptasemia$▫ in patients who need Hymenoptera venom immunotherapyPeter Korošec, Gunter Sturm, Jonathan J. Lyons, Tinkara Pirc Marolt, Manca Svetina, Mitja Košnik, Mihaela Zidarn, Mark Kačar, Nina Frelih, Nika Lalek, Ajda Demšar Luzar, Samo Zver, Matevž Škerget, Ewa Czarnobilska, Wojciech Dyga, Sanja Popović-Grle, Miroslav Samaržija, Lisa Arzt-Gradwohl, Urban Čerpes, Grzegorz Porebski, Branko Pevec, Eva Schadelbauer, Peter Kopač, Julij Šelb, Matija Rijavec, 2024, original scientific article Abstract: Background
In patients who require venom immunotherapy (VIT), there is a need to identify underlying mast cell (MC) disorders since these may affect the risk and severity of future sting reactions and the long-term effectiveness of VIT.
Methods
1319 individuals with Hymenoptera venom allergy (HVA) who needed VIT from referral centers in Slovenia, Austria, Croatia, and Poland underwent examination for KIT p.D816V in peripheral blood leukocytes (PBL) using a highly sensitive PCR test and tryptase genotyping by digital droplet PCR. We also included 183 control individuals with large local reactions (LLRs) to Hymenoptera stings and with asymptomatic sensitization to Hymenoptera venoms.
Results
285 of 1319 individuals recommended for VIT (21.6%) were positive for KIT p.D816V in PBL, preferably those who present with severe reaction (33.9% [n = 207 of 610] with Ring-Messmer grade 3–4 vs. 11% [n = 78 of 709] with Grade 1–2; p < .0001), whereas only 1.3% (n = 2 of 152) of controls with LLR and none with asymptomatic sensitization (n = 31) had KIT p.D816V. KIT p.D816V allelic burden was higher in those with severe reaction (median 0.018% [n = 207] in Grade 3–4 vs. 0.001% [n = 78] in Grade 1–2; p < .0001), and the majority had normal baseline serum tryptase levels (69% [n = 196 of 285]). All KIT p.D816V-positive individuals (n = 41) who underwent bone marrow (BM) biopsy were found to have underlying clonal diseases, principally BM mastocytosis. HαT was also associated with severe HVA and symptoms (p < .01), and remarkably, 31.0% (n = 31 of 100) were found to have concomitant KIT p.D816V. Concomitant HαT and KIT p.D816V showed an additive effect, and having both was associated with the highest risk for severe HVA, even higher than having either HαT or KIT p.D816V alone (OR = 3.8; p < .01).
Conclusions
By employing prospective universal tryptase genotyping and examination for KIT p.D816V in PBL in large HVA populations, we have demonstrated a high burden of clonal MC disorders and HαT in patients who require VIT.
Keywords: anaphylaxis, hereditary α-tryptasemia, hypersensitivity, immunotherapy, mast cell, mastocytosis, venom
Published in DiRROS: 17.06.2024; Views: 96; Downloads: 57
 Full text (6,80 MB)
This document has many files! More... |
2. BAP1-defficient breast cancer in a patient with BAP1 cancer syndromeAna Blatnik, Domen Ribnikar, Vita Šetrajčič Dragoš, Srdjan Novaković, Vida Stegel, Biljana Grčar-Kuzmanov, Nina Boc, Barbara Perić, Petra Škerl, Gašper Klančar, Mateja Krajc, 2022, original scientific article Abstract: BAP1 cancer syndrome is a rare and highly penetrant hereditary cancer predisposition. Uveal melanoma, mesothelioma, renal cell carcinoma (RCC) and cutaneous melanoma are considered BAP1 cancer syndrome core cancers, whereas association with breast cancer has previously been suggested but not confirmed so far. In view of BAP1 immunomodulatory functions, BAP1 alterations could prove useful as possible biomarkers of response to immunotherapy in patients with BAP1-associated cancers. We present a case of a patient with BAP1 cancer syndrome who developed a metastatic breast cancer with loss of BAP1 demonstrated on immunohistochemistry. She carried a germline BAP1 likely pathogenic variant (c.898_899delAG p.(Arg300Glyfs*6)). In addition, tumor tissue sequencing identified a concurrent somatic variant in BAP1 (partial deletion of exon 12) and a low tumor mutational burden. As her triple negative tumor was shown to be PD-L1 positive, the patient was treated with combination of atezolizumab and nab-paclitaxel. She had a complete and sustained response to immunotherapy even after discontinuation of nab-paclitaxel. This case strengthens the evidence for including breast cancer in the BAP1 cancer syndrome tumor spectrum with implications for future cancer prevention programs. It also indicates immune checkpoint inhibitors might prove to be an effective treatment for BAP1-deficient breast cancer.
Keywords: BAP1, breast cancer, hereditary cancer syndromes, immunotherapy
Published in DiRROS: 19.09.2022; Views: 546; Downloads: 228
Full text (1,12 MB) |
3. Identification of spliceogenic variants beyond canonical GT-AG splice sites in hereditary cancer genesVita Šetrajčič Dragoš, Ksenija Strojnik, Gašper Klančar, Petra Škerl, Vida Stegel, Ana Blatnik, Marta Banjac, Mateja Krajc, Srdjan Novaković, 2022, original scientific article Abstract: Pathogenic/likely pathogenic variants in susceptibility genes that interrupt RNA splicing are a well-documented mechanism of hereditary cancer syndromes development. However, if RNA studies are not performed, most of the variants beyond the canonical GT-AG splice site are characterized as variants of uncertain significance (VUS). To decrease the VUS burden, we have bioinformatically evaluated all novel VUS detected in 732 consecutive patients tested in the routine genetic counseling process. Twelve VUS that were predicted to cause splicing defects were selected for mRNA analysis. Here, we report a functional characterization of 12 variants located beyond the first two intronic nucleotides using RNAseq in APC, ATM, FH, LZTR1, MSH6, PALB2, RAD51C, and TP53 genes. Based on the analysis of mRNA, we have successfully reclassified 50% of investigated variants. 25% of variants were downgraded to likely benign, whereas 25% were upgraded to likely pathogenic leading to improved clinical management of the patient and the family members.
Keywords: hereditary cancer, RNA sequencing, spliceogenic
Published in DiRROS: 07.09.2022; Views: 608; Downloads: 308
Full text (778,18 KB)
This document has many files! More... |
4. SERPING1 variants and C1-INH biological function : a close relationship with C1-INH-HAEChristian Drouet, Alberto López Lera, Arije Ghannam, Margarita López-Trascasa, Sven Cichon, Denise Ponard, Faidra Parsopoulou, Hana Grombirikova, Tomas Freiberger, Matija Rijavec, Camila Lopes Veronez, João Bosco Pesquero, Anastasios E. Germenis, 2022, review article Abstract: Hereditary angioedema with C1 Inhibitor deficiency (C1-INH-HAE) is caused by a constellation of variants of the SERPING1 gene (n = 809; 1,494 pedigrees), accounting for 86.8% of HAE families, showing a pronounced mutagenic liability of SERPING1 and pertaining to 5.6% de novo variants. C1-INH is the major control serpin of the kallikrein–kinin system (KKS). In addition, C1-INH controls complement C1 and plasminogen activation, both systems contributing to inflammation. Recognizing the failed control of C1s protease or KKS provides the diagnosis of C1-INH-HAE. SERPING1 variants usually behave in an autosomal-dominant character with an incomplete penetrance and a low prevalence. A great majority of variants (809/893; 90.5%) that were introduced into online database have been considered as pathogenic/likely pathogenic. Haploinsufficiency is a common feature in C1-INH-HAE where a dominant-negative variant product impacts the wild-type allele and renders it inactive. Small (36.2%) and large (8.3%) deletions/duplications are common, with exon 4 as the most affected one. Point substitutions with missense variants (32.2%) are of interest for the serpin structure–function relationship. Canonical splice sites can be affected by variants within introns and exons also (14.3%). For noncanonical sequences, exon skipping has been confirmed by splicing analyses of patients' blood-derived RNAs (n = 25). Exonic variants (n = 6) can affect exon splicing. Rare deep-intron variants (n = 6), putatively acting as pseudo-exon activating mutations, have been characterized as pathogenic. Some variants have been characterized as benign/likely benign/of uncertain significance (n = 74). This category includes some homozygous (n = 10) or compound heterozygous variants (n = 11). They are presenting with minor allele frequency (MAF) below 0.00002 (i.e., lower than C1-INH-HAE frequency), and may be quantitatively unable to cause haploinsufficiency. Rare benign variants could contribute as disease modifiers. Gonadal mosaicism in C1-INH-HAE is rare and must be distinguished from a de novo variant. Situations with paternal or maternal disomy have been recorded (n = 3). Genotypes must be interpreted with biological investigation fitting with C1-INH expression and typing. Any SERPING1 variant reminiscent of the dysfunctional phenotype of serpin with multimerization or latency should be identified as serpinopathy.
Keywords: Hereditary angioedemas -- genetics -- diagnosis, genetic variation, serpins, SERPING1 gene, C1-INH, C1-INH-HAE, C1 inhibitor, serpinopathy
Published in DiRROS: 06.04.2022; Views: 977; Downloads: 564
Full text (2,51 MB)
This document has many files! More... |
5. Hereditary angioedema due to C1-inhibitor deficiency in pediatric patients in Croatia : first national study, diagnostic and prophylactic challengesLjerka Karadža-Lapić, Marko Barešić, Renata Vrsalović, Irena Ivković-Jureković, Saša Sršen, Ingrid Prkačin, Matija Rijavec, Draško Cikojević, 2019, review article Abstract: Hereditary angioedema (HAE) is a rare autosomal dominant disease with deficiency (type I) or dysfunction (type II) of C1 inhibitor, caused by mutations in the C1-INH gene, characterized by recurrent submucosal or subcutaneous edemas including skin swelling, abdominal pain and life-threatening episodes of upper airway obstruction. The aim of this study was to investigate healthcare experiences in children with HAE due to C1 inhibitor deficiency (C1-INH-HAE) in Croatia in order to estimate the number of affected children and to recommend management protocols for diagnosis, short-term prophylaxis and acute treatment. Patients were recruited during a 4-year period at five hospitals in Croatia. Complement testing was performed in patients with a positive family history. This pilot study revealed nine pediatric patients positive for C1-INH- HAE type I, aged 1-16 years, four of them asymptomatic. Before the age of one year, C1-INH levels may be lower than in adults; it is advisable to confirm C1-INH-HAE after the age of one year. Plasma-derived C1- INH is recommended as acute and short-term prophylactic treatment. Recombinant C1-INH and icatibant are licensed for the acute treatment of pediatric patients. In Croatia, HAE is still underdiagnosed in pediatric population.
Keywords: hereditary angioedemas -- genetics -- Croatia, inborn genetic diseases -- Croatia, pediatrics -- Croatia, C1 inhibitor, SERPING1 gene, children
Published in DiRROS: 16.12.2020; Views: 1346; Downloads: 1014
Full text (477,81 KB)
This document has many files! More... |
6. Hereditary angioedema due to C1-inhibitor deficiency in Macedonia : clinical characteristics, novel SERPING1 mutations, and genetic factors modifying the clinical phenotypeVesna Grivčeva-Panovska, Mitja Košnik, Peter Korošec, Slađana Andrejević, Ljerka Karadža-Lapić, Matija Rijavec, 2018, original scientific article Abstract: Objective: Hereditary angioedema due to C1 inhibitor deficiency (C1-INH-HAE) is a rare disease, characterized by swellings. We aimed to characterize on a clinical and molecular basis C1-INH-HAE patients in the Republic of Macedonia. Results: All 15 patients from six unrelated families were diagnosed with C1-INHHAE type I, with a mean age of symptom onset of 11 years and an average delay of diagnosis of 7 years. Patients reported on average 31 angioedema attacks/year, with a median clinical severity score (CSS) of 7. We identified three known mutations, and two mutations (c.813_818delCAACAA and c.1488T>G) were reported for the first time. To address the genotype-phenotype association, a pooled analysis including 78 C1-INH-HAE south-eastern European patients was performed, with additional analysis of F12-46C/T and KLKB1- 428G/A polymorphisms. We demonstrated that patients with nonsense and frameshift mutations, large deletions/insertions, splicing defects, and mutations at Arg444 exhibited an increased CSS compared with missense mutations, excluding mutations at Arg444. In addition, the CC F12-46C/T polymorphism was suggestive of earlier disease onset. Discussion: Genetic analysis helped identify the molecular basis of C1-INH-HAE given that causative mutations in SERPING1 were detected in all patients, including an infant before the appearance of clinical symptoms. We identified two novel mutations and further corroborated the genotype-phenotype relationship, wherein mutations with a clear effect on C1-INH function predispose patients to a more severe disease phenotype and CC F12-46C/T predisposes patients to earlier disease onset.
Keywords: hereditary angioedemas -- genetics -- Macedonia, C1 inhibitor, SERPING1 gene, C1 inhibitor, SERPING1 gene
Published in DiRROS: 30.11.2020; Views: 1372; Downloads: 313
 Link to file |
7. Heritable risk for severe anaphylaxis associated with increased [alpha]-tryptase-encoding germline copy number at TPSAB1Jonathan J. Lyons, Jack Chovanec, Michael P. O'Connell, Yihui Liu, Julij Šelb, Roberta Zanotti, Yun Bai, Jiwon Kim, Quang T. Le, Tom DiMaggio, Matija Rijavec, Peter Korošec, 2020, original scientific article Abstract: Background: An elevated basal serum tryptase level is associated with severe systemic anaphylaxis, most notably caused by Hymenoptera envenomation. Although clonal mast cell disease is the culprit in some individuals, it does not fully explain this clinical association. Objective: Our aim was to determine the prevalence and associated impact of tryptase genotypes on anaphylaxis in humans. Methods: Cohorts with systemic mastocytosis (SM) and venom as well as idiopathic anaphylaxis from referral centers in Italy, Slovenia, and the United States, underwent tryptase genotyping by droplet digital PCR. Associated anaphylaxis severity (Mueller scale) was subsequently examined. Healthy volunteers and controls with nonatopic disease were recruited and tryptase was genotyped by droplet digital PCR and in silico analysis of genome sequence, respectively. The effects of pooled and recombinant human tryptases, protease activated receptor 2 agonist and antagonist peptides, and a tryptase-neutralizing mAb on human umbilical vein endothelial cell permeability were assayed using a Transwell system. Results: Hereditary [alpha]-tryptasemia (H[alpha]T)--a genetic trait caused by increased [alpha]-tryptase-encoding Tryptase-[alpha]/[beta]1 (TPSAB1) copy number resulting in elevated BST level--was common in healthy individuals (5.6% [n = 7 of 125]) and controls with nonatopic disease (5.3% [n = 21 of 398]). H[alpha]T was associated with grade IV venom anaphylaxis (relative risk = 2.0; P < .05) and more prevalent in both idiopathic anaphylaxis (n = 8 of 47; [17%; P = .006]) and SM (n = 10 of 82 [12.2%; P = .03]) relative to the controls. Among patients with SM, concomitant H[alpha]T was associated with increased risk for systemic anaphylaxis (relative risk = 9.5; P = .007). In vitro, protease-activated receptor-2-dependent vascular permeability was induced by pooled mature tryptases but not [alpha]- or [beta]-tryptase homotetramers. Conclusions: Risk for severe anaphylaxis in humans is associated with inherited differences in [alpha]-tryptase-encoding copies at TPSAB1.
Keywords: mastocytosis, venoms, hypersensitivity, anaphylaxis - diagnosis, mast cells, idiopathic anaphylaxis, mast cell activation, hereditary alpha-tryptasemia
Published in DiRROS: 11.09.2020; Views: 2131; Downloads: 410
Link to file |
