Patrycja Hoffmann

Early-onset stroke and vasculopathy associated with mutations in ADA2

BACKGROUND We observed a syndrome of intermittent fevers, early-onset lacunar strokes and other neurovascular manifestations, livedoid rash, hepatosplenomegaly, and systemic vasculopathy in three unrelated patients. We suspected a genetic cause because the disorder presented in early childhood. METHODS We performed whole-exome sequencing in the initial three patients and their unaffected parents and candidate-gene sequencing in three patients with a similar phenotype, as well as two young siblings with polyarteritis nodosa and one patient with small-vessel vasculitis. Enzyme assays, immunoblotting, immunohistochemical testing, flow cytometry, and cytokine profiling were performed on samples from the patients. To study protein function, we used morpholino-mediated knockdowns in zebrafish and short hairpin RNA knockdowns in U937 cells cultured with human dermal endothelial cells. RESULTS All nine patients carried recessively inherited mutations in CECR1 (cat eye syndrome chromosome region, candidate 1), encoding adenosine deaminase 2 (ADA2), that were predicted to be deleterious; these mutations were rare or absent in healthy controls. Six patients were compound heterozygous for eight CECR1 mutations, whereas the three patients with polyarteritis nodosa or small-vessel vasculitis were homozygous for the p.Gly47Arg mutation. Patients had a marked reduction in the levels of ADA2 and ADA2-specific enzyme activity in the blood. Skin, liver, and brain biopsies revealed vasculopathic changes characterized by compromised endothelial integrity, endothelial cellular activation, and inflammation. Knockdown of a zebrafish ADA2 homologue caused intracranial hemorrhages and neutropenia - phenotypes that were prevented by coinjection with nonmutated (but not with mutated) human CECR1. Monocytes from patients induced damage in cocultured endothelial-cell layers. CONCLUSIONS Loss-of-function mutations in CECR1 were associated with a spectrum of vascular and inflammatory phenotypes, ranging from early-onset recurrent stroke to systemic vasculopathy or vasculitis. (Funded by the National Institutes of Health Intramural Research Programs and others.).

Loss-of-function mutations in TNFAIP3 leading to A20 haploinsufficiency cause an early-onset autoinflammatory disease

Systemic autoinflammatory diseases are driven by abnormal activation of innate immunity. Herein we describe a new disease caused by high-penetrance heterozygous germline mutations in TNFAIP3, which encodes the NF-κB regulatory protein A20, in six unrelated families with early-onset systemic inflammation. The disorder resembles Behçets disease, which is typically considered a polygenic disorder with onset in early adulthood. A20 is a potent inhibitor of the NF-κB signaling pathway. Mutant, truncated A20 proteins are likely to act through haploinsufficiency because they do not exert a dominant-negative effect in overexpression experiments. Patient-derived cells show increased degradation of IκBα and nuclear translocation of the NF-κB p65 subunit together with increased expression of NF-κB–mediated proinflammatory cytokines. A20 restricts NF-κB signals via its deubiquitinase activity. In cells expressing mutant A20 protein, there is defective removal of Lys63-linked ubiquitin from TRAF6, NEMO and RIP1 after stimulation with tumor necrosis factor (TNF). NF-κB–dependent proinflammatory cytokines are potential therapeutic targets for the patients with this disease.

Brief Report: Cryopyrin-Associated Periodic Syndrome Caused by a Myeloid-Restricted Somatic NLRP3 Mutation.

To identify the cause of disease in an adult patient presenting with recent‐onset fevers, chills, urticaria, fatigue, and profound myalgia, who was found to be negative for cryopyrin‐associated periodic syndrome (CAPS) NLRP3 mutations by conventional Sanger DNA sequencing.

Anakinra use during pregnancy in patients with cryopyrin-associated periodic syndromes (CAPS).

To describe the pregnancy course and outcome and the use of anakinra, a recombinant selective interleukin‐1 receptor blocker, during pregnancy in patients with cryopyrin‐associated periodic syndromes (CAPS), including familial cold autoinflammatory syndrome (FCAS), Muckle‐Wells syndrome (MWS), and neonatal‐onset multisystem inflammatory disease (NOMID).

The deficiency of adenosine deaminase type 2-results of therapeutic intervention

The deficiency of adenosine deaminase type 2 (DADA2) is a recessively inherited condition caused by mutations in CECR1. Patients present with recurrent fevers and evidence of vasculitis/vasculopathy, including livedo racemosa, lacunar strokes, polyarteritis nodosa, endothelialization of the hepatic sinusoids with portal hypertension, and active colitis. There is no recombinant form of ADA2 and thus we attempted a) exogenous replacement of ADA2 via fresh frozen plasma (FFP) and b) suppression of the inflammatory response using anti-tumor necrosis factor (anti-TNF) therapy. This abstract documents 22 months of clinical treatment in the NIH DADA2 cohort.

A20 haploinsufficiency (HA20): clinical phenotypes and disease course of patients with a newly recognised NF-kB-mediated autoinflammatory disease

Objectives The association between mutations in TNFAIP3, encoding the NF-kB regulatory protein A20, and a new autoinflammatory disease has recently been recognised. This study aims at describing the clinical phenotypes and disease course of patients with A20 haploinsufficiency (HA20). Methods Data for all cases from the initial publication, and additional cases identified through collaborations since, were collected using standardised data collection forms. Results A total of 16 patients (13 female) from seven families with a genetic diagnosis of HA20 were included. The disease commonly manifested in early childhood (range: first week of life to 29 years of age). The main clinical symptoms were recurrent oral, genital and/or gastrointestinal ulcers (16/16), musculoskeletal (9/16) and gastrointestinal complaints (9/16), cutaneous lesions (8/16), episodic fever (7/16), and recurrent infections (7/16). Clinical phenotypes varied considerably, even within families. Relapsing-remitting disease course was most common, and one patient died. Laboratory abnormalities included elevated acute-phase reactants and fluctuating presence of various autoantibodies such as antinuclear antibodies (4/10 patients tested) and anti-dsDNA (2/5). Tissue biopsy of different sites revealed non-specific chronic inflammation (6/12 patients tested), findings consistent with class V lupus nephritis in one patient, and pustules and normal results in two patients each. All patients were treated: 4/16 received colchicine and 12/16 various immunosuppressive agents. Cytokine inhibitors effectively suppressed systemic inflammation in 7/9 patients. Conclusions Early-onset recurrent oral, genital and/or gastrointestinal ulcers are the hallmark feature of HA20. Frequency and intensity of other clinical manifestations varied highly. Treatment regimens should be based on disease severity, and cytokine inhibitors are often required to control relapses.

Brief Report: Connecting Two Pathways Through Ca2+ Signaling: NLRP3 Inflammasome Activation Induced by a Hypermorphic PLCG2 Mutation

We previously reported that p.Ser707Tyr, a novel variant in phospholipase Cγ2 (PLCγ2), is the cause of a dominantly inherited autoinflammatory disease, autoinflammation and PLCγ2‐associated antibody deficiency and immune dysregulation (APLAID). The hypermorphic mutation enhances PLCγ2 activity and causes an increase in intracellular Ca2+ release from endoplasmic reticulum stores. Because increased intracellular Ca2+ signaling has been associated with NLRP3 inflammasome activation, we studied the role of the NLRP3 inflammasome in the pathogenesis of APLAID.

Connecting Two Pathways through Ca2+ Signaling: NLRP3 Inflammasome Activation Induced by a Hypermorphic PLCG2 Mutation

We previously reported that p.Ser707Tyr, a novel variant in phospholipase Cγ2 (PLCγ2), is the cause of a dominantly inherited autoinflammatory disease, autoinflammation and PLCγ2‐associated antibody deficiency and immune dysregulation (APLAID). The hypermorphic mutation enhances PLCγ2 activity and causes an increase in intracellular Ca2+ release from endoplasmic reticulum stores. Because increased intracellular Ca2+ signaling has been associated with NLRP3 inflammasome activation, we studied the role of the NLRP3 inflammasome in the pathogenesis of APLAID.

International multi-centre study of pregnancy outcomes with interleukin-1 inhibitors

Objective To provide outcome data concerning pregnancies exposed to the Interleukin-1 (IL-1) inhibitors prior to conception in both men and women, during pregnancy and breast feeding. Methods Retrospective data were collected from members of the International Society for Systemic Autoinflammatory diseases and collated in a single centre. A uniform data collection sheet was used to obtain standardized data including maternal age and diagnosis, type, duration of and response to IL-1 blockade, pregnancy duration, delivery, mode of feeding and neonatal development. Results There were 31 maternal-exposed pregnancies from seven countries and we report the first data on paternal exposure: six to anakinra and five to canakinumab, with no negative outcomes. We also report the first data on canakinumab-exposed pregnancies: eight pregnancies that resulted in the delivery of seven healthy infants of normal gestational age and birthweight. There were 23 anakinra-exposed pregnancies resulting in the birth of 21 healthy infants, and one baby with unilateral renal agenesis and ectopic neurohypophysis. There were two first trimester miscarriages affecting a mother with active disease. There were no serious neonatal infections. Fourteen infants were breast fed with no complications. There were no reports of developmental delay, with follow-up of up to 10 years (median 18 months). Conclusion This series substantially increases the published experience of IL-1 blockade and reproduction including the first data on canakinumab and on paternal exposure to these agents. Data are generally reassuring, although the case of renal agenesis is the second reported in an anakinra-exposed pregnancy.

International experience of pregnancy outcomes in auto-inflammatory syndromes treated with Interleukin-1 inhibitors.

Many patients on anti-IL-1 therapy are unable to stop treatment prior to conception or during pregnancy but little data exist regarding safety. We report the outcomes of 20 IL-1 inhibitor exposed pregnancies in 18 women from 7 countries (including the first data on canakinumab exposed pregnancy) and paternal exposure to anakinra or canakinumab at conception.