Interrupting an IFN-γ-dependent feedback loop in the syndrome of pyogenic arthritis with pyoderma gangrenosum and acne

OBJECTIVES

To study the molecular pathogenesis of PAPA (pyogenic arthritis, pyoderma gangrenosum and acne) syndrome, a debilitating hereditary autoinflammatory disease caused by dominant mutation in PSTPIP1.

METHODS

Gene knock-out and knock-in mice were generated to develop an animal model. THP1 and retrovirally transduced U937 human myeloid leukaemia cell lines, peripheral blood mononuclear cells, small interfering RNA (siRNA) knock-down, site-directed mutagenesis, cytokine immunoassays, coimmunoprecipitation and immunoblotting were used to study inflammasome activation. Cytokine levels in the skin were evaluated by immunohistochemistry. Responsiveness to Janus kinase (JAK) inhibitors was evaluated ex vivo with peripheral blood mononuclear cells and in vivo in five treatment-refractory PAPA patients.

RESULTS

The knock-in mouse model of PAPA did not recapitulate the human disease. In a human myeloid cell line model, PAPA-associated PSTPIP1 mutations activated the pyrin inflammasome, but not the NLRP3, NLRC4 or AIM2 inflammasomes. Pyrin inflammasome activation was independent of the canonical pathway of pyrin serine dephosphorylation and was blocked by the p.W232A PSTPIP1 mutation, which disrupts pyrin-PSTPIP1 interaction. IFN-γ priming of monocytes from PAPA patients led to IL-18 release in a pyrin-dependent manner. IFN-γ was abundant in the inflamed dermis of PAPA patients, but not patients with idiopathic pyoderma gangrenosum. Ex vivo JAK inhibitor treatment attenuated IFN-γ-mediated pyrin induction and IL-18 release. In 5/5 PAPA patients, the addition of JAK inhibitor therapy to IL-1 inhibition was associated with clinical improvement.

CONCLUSION

PAPA-associated PSTPIP1 mutations trigger a pyrin-IL-18-IFN-γ positive feedback loop that drives PAPA disease activity and is a target for JAK inhibition.

Multiomics integration of 22 immune-mediated monogenic diseases reveals an emergent axis of human immune health

Monogenic diseases are often studied in isolation due to their rarity. Here we utilize multiomics to assess 22 monogenic immune-mediated conditions with age- and sex-matched healthy controls. Despite clearly detectable disease-specific and "pan-disease" signatures, individuals possess stable personal immune states over time. Temporally stable differences among subjects tend to dominate over differences attributable to disease conditions or medication use. Unsupervised principal variation analysis of personal immune states and machine learning classification distinguishing between healthy controls and patients converge to a metric of immune health (IHM). The IHM discriminates healthy from multiple polygenic autoimmune and inflammatory disease states in independent cohorts, marks healthy aging, and is a pre-vaccination predictor of antibody responses to influenza vaccination in the elderly. We identified easy-to-measure circulating protein biomarker surrogates of the IHM that capture immune health variations beyond age. Our work provides a conceptual framework and biomarkers for defining and measuring human immune health.

Case report: Novel variants in RELA associated with familial Behcet's-like disease

RELA haploinsufficiency is a recently described autoinflammatory condition presenting with intermittent fevers and mucocutaneous ulcerations. The RELA gene encodes the p65 protein, one of five NF-κB family transcription factors. As RELA is an essential regulator of mucosal homeostasis, haploinsufficiency leads to decreased NF-κB signaling which promotes TNF-driven mucosal apoptosis with impaired epithelial recovery. Thus far, only eight cases have been reported in the literature. Here, we report four families with three novel and one previously described pathogenic variant in RELA. These four families included 23 affected individuals for which genetic testing was available in 16. Almost half of these patients had been previously diagnosed with more common rheumatologic entities (such as Behcet's Disease; BD) prior to the discovery of their pathogenic RELA variants. The most common clinical features were orogenital ulcers, rash, joint inflammation, and fever. The least common were conjunctivitis and recurrent infections. Clinical variability was remarkable even among familial cases, and incomplete penetrance was observed. Patients in our series were treated with a variety of medications, and benefit was observed with glucocorticoids, colchicine, and TNF inhibitors. Altogether, our work adds to the current literature and doubles the number of reported cases with RELA-Associated Inflammatory Disease (RAID). It reaffirms the central importance of the NF-κB pathway in immunity and inflammation, as well as the important regulatory role of RELA in mucosal homeostasis. RELA associated inflammatory disease should be considered in all patients with BD, particularly those with early onset and/or with a strong family history.

The Spectrum of the Deficiency of Adenosine Deaminase 2: An Observational Analysis of a 60 Patient Cohort

The deficiency of adenosine deaminase 2 (DADA2) is an autosomal recessively inherited disease that has undergone extensive phenotypic expansion since being first described in patients with fevers, recurrent strokes, livedo racemosa, and polyarteritis nodosa in 2014. It is now recognized that patients may develop multisystem disease that spans multiple medical subspecialties. Here, we describe the findings from a large single center longitudinal cohort of 60 patients, the broad phenotypic presentation, as well as highlight the cohort’s experience with hematopoietic cell transplantation and COVID-19. Disease manifestations could be separated into three major phenotypes: inflammatory/vascular, immune dysregulatory, and hematologic, however, most patients presented with significant overlap between these three phenotype groups. The cardinal features of the inflammatory/vascular group included cutaneous manifestations and stroke. Evidence of immune dysregulation was commonly observed, including hypogammaglobulinemia, absent to low class-switched memory B cells, and inadequate response to vaccination. Despite these findings, infectious complications were exceedingly rare in this cohort. Hematologic findings including pure red cell aplasia (PRCA), immune-mediated neutropenia, and pancytopenia were observed in half of patients. We significantly extended our experience using anti-TNF agents, with no strokes observed in 2026 patient months on TNF inhibitors. Meanwhile, hematologic and immune features had a more varied response to anti-TNF therapy. Six patients received a total of 10 allogeneic hematopoietic cell transplant (HCT) procedures, with secondary graft failure necessitating repeat HCTs in three patients, as well as unplanned donor cell infusions to avoid graft rejection. All transplanted patients had been on anti-TNF agents prior to HCT and received varying degrees of reduced-intensity or non-myeloablative conditioning. All transplanted patients are still alive and have discontinued anti-TNF therapy. The long-term follow up afforded by this large single-center study underscores the clinical heterogeneity of DADA2 and the potential for phenotypes to evolve in any individual patient.

Excess Serum Interleukin-18 Distinguishes Patients With Pathogenic Mutations in PSTPIP1

OBJECTIVE

Dominantly inherited PSTPIP1 mutations cause a spectrum of autoinflammatory manifestations epitomized by PAPA syndrome (pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome.). The connections between PSTPIP1 and PAPA syndrome are poorly understood, although evidence suggests involvement of pyrin inflammasome activation. Interleukin-18 (IL-18) is an inflammasome-activated cytokine associated with susceptibility to macrophage activation syndrome (MAS). This study was undertaken to investigate an association of IL-18 with PAPA syndrome.

METHODS

Clinical and genetic data and serum samples were obtained from patients referred to institutions due to symptoms indicative of PAPA syndrome. Serum IL-18, IL-18 binding protein (IL-18BP), and CXCL9 levels were assessed by bead-based assay, and free IL-18 levels were assessed by enzyme-linked immunosorbent assay.

RESULTS

The symptoms of PSTPIP1-positive patients with PAPA syndrome overlapped with those of mutation-negative patients with PAPA-like conditions, but mutation-positive patients had earlier onset and a greater proportion had a history of arthritis. We found uniform elevation of total serum IL-18 in treated PAPA syndrome patients at levels nearly as high as those seen in NLRC4-associated autoinflammation with infantile enterocolitis patients, and well above levels found in most familial Mediterranean fever patients. Serum IL-18 elevation in PAPA syndrome patients persisted despite fluctuations in disease activity. Levels of the soluble IL-18 antagonist IL-18BP were modestly elevated, and PAPA syndrome patients had detectable free IL-18. PAPA syndrome was rarely associated with elevation of CXCL9, an indicator of interferon-γ activity, but no PAPA syndrome patients had a history of MAS.

CONCLUSION

PAPA syndrome is a refractory and often disabling monogenic autoinflammatory disease associated with chronic and unopposed elevation of serum IL-18 levels but not with risk of MAS. These findings affect our understanding of the diseases in which IL-18 is overproduced and suggest a link between pyrin inflammasome activation, IL-18, and autoinflammation, without susceptibility to MAS.

Systematic evaluation of nine monogenic autoinflammatory diseases reveals common and disease-specific correlations with allergy-associated features

BACKGROUND

Monogenic autoinflammatory diseases (AID) are caused by mutations in innate immune genes. The effects of these mutations on allergic inflammation are unknown.

OBJECTIVES

We investigated allergic, immunological and clinical phenotypes in FMF (familial Mediterranean fever), CAPS (cryopyrin-associated periodic syndrome), TRAPS (tumour necrosis factor receptor-associated periodic syndrome), HIDS (hyper-IgD syndrome), PAPA (pyogenic arthritis, pyoderma gangrenosum and acne), DADA2 (deficiency of adenosine deaminase 2), HA20 (haploinsufficiency of A20), CANDLE (chronic atypical neutrophilic dermatosis, lipodystrophy, elevated temperature) and SAVI (STING-associated vasculopathy of infancy).

METHODS

In this cross-sectional study, clinical data were assessed in 425 patients with AID using questionnaires and chart reviews. Comparator data were obtained from public databases. Peripheral blood mononuclear cells obtained from 55 patients were stimulated and CD4⁺ cytokine production assessed.

RESULTS

Clinical laboratory features of Type 2 immunity were elevated in CAPS but reduced in most AID, particularly DADA2. Physician-diagnosed allergic diseases were prevalent in multiple AID, including CAPS and DADA2. T helper 2 (Th2) cells were expanded in CAPS, TRAPS and HIDS; Th9 cells were expanded in HA20.

CONCLUSIONS

CAPS is characterised by an enhanced Type 2 signature, whereas FMF and CANDLE are associated with reduced Type 2 responses. DADA2 is associated with reduced Type 2 responses but a high rate of physician-diagnosed allergy. Therefore, NLRP3-driven autoinflammation may promote Type 2 immunity, whereas AID like DADA2 may manifest clinical phenotypes that masquerade as allergic disorders. Further investigations are needed to determine the contribution of autoinflammation to allergic clinical and immunological phenotypes, to improve the treatment of patients with AID.

Deficiency of Adenosine Deaminase 2 (DADA2): Hidden Variants, Reduced Penetrance, and Unusual Inheritance

PURPOSE

Deficiency of adenosine deaminase 2 (DADA2) is an autosomal recessive disorder that manifests with fever, early-onset vasculitis, strokes, and hematologic dysfunction. This study aimed to identify disease-causing variants by conventional Sanger and whole exome sequencing in two families suspected to have DADA2 and non-confirmatory genotypes. ADA2 enzymatic assay confirmed the clinical diagnosis of DADA2. Molecular diagnosis was important to accurately identify other family members at risk.

METHODS

We used a variety of sequencing technologies, ADA2 enzymatic testing, and molecular methods including qRT-PCR and MLPA.

RESULTS

Exome sequencing identified heterozygosity for the known pathogenic variant ADA2: c.1358A>G, p.Tyr453Cys in a 14-year-old female with a history of ischemic strokes, livedo, and vasculitis. No second pathogenic variant could be identified. ADA2 enzymatic testing in combination with quantitative RT-PCR suggested a loss-of-function allele. Subsequent genome sequencing identified a canonical splice site variant, c.-47+2T>C, within the 5'UTR of ADA2. Two of her unaffected siblings were found to carry the same two pathogenic variants. A homozygous 800-bp duplication comprising exon 7 of ADA2 was identified in a 5-year-old female with features consistent with Diamond-Blackfan anemia (DBA). The duplication was missed by Sanger sequencing of ADA2, chromosomal microarray, and exome sequencing but was detected by MLPA in combination with long-read PCR sequencing. The exon 7 duplication was also identified in her non-symptomatic father and younger sister.

CONCLUSIONS

ADA2 pathogenic variants may not be detected by conventional sequencing and genetic testing and may require the incorporation of additional diagnostic methods. A definitive molecular diagnosis is crucial for all family members to make informed treatment decisions.

Mutations that prevent caspase cleavage of RIPK1 cause autoinflammatory disease

Receptor Interacting Protein Kinase 1 (RIPK1) is a key regulator of innate immune signalling pathways. To ensure an optimal inflammatory response, RIPK1 is post-translationally regulated by well characterised ubiquitylation and phosphorylation events, as well as caspase-8 mediated cleavage^1–7. The physiological relevance of this cleavage remains unclear, though it is believed to inhibit activation of RIPK3 and necroptosis⁸. Here we show that heterozygous missense mutations p.D324N, p.D324H and p.D324Y prevent caspase cleavage of RIPK1 in humans and result in early-onset periodic fever episodes and severe intermittent lymphadenopathy, a condition we designate ‘Cleavage-resistant RIPK1-Induced Autoinflammatory’ (CRIA) syndrome. To define the mechanism for this disease we generated a cleavage-resistant Ripk1^D325A mutant mouse strain. While Ripk1^-/- mice die postnatally from systemic inflammation, Ripk1^D325A/D325A mice died during embryogenesis. Embryonic lethality was completely prevented by combined loss of Casp8 and Ripk3 but not by loss of Ripk3 or Mlkl alone. Loss of RIPK1 kinase activity also prevented Ripk1^D325A/D325A embryonic lethality, however the mice died before weaning from multi organ inflammation in a RIPK3 dependent manner. Consistently, Ripk1^D325A/D325A and Ripk1^D325A/+ cells were hypersensitive to RIPK3 dependent TNF-induced apoptosis and necroptosis. Heterozygous Ripk1^D325A/+ mice were viable and grossly normal, but were hyper-responsive to inflammatory stimuli in vivo. Our results demonstrate the importance of caspase-mediated RIPK1 cleavage during embryonic development and show that caspase cleavage of RIPK1 not only inhibits necroptosis but maintains inflammatory homeostasis throughout life.

Deficiency of adenosine deaminase 2 triggers adenosine-mediated NETosis and TNF production in patients with DADA2

Reduction of adenosine deaminase 2 (ADA2) activity due to autosomal-recessive loss-of-function mutations in the ADA2 gene (previously known as CECR1) results in a systemic vasculitis known as deficiency of ADA2 (DADA2). Neutrophils and a subset of neutrophils known as low-density granulocytes (LDGs) have been implicated in the pathogenesis of vasculitis, at least in part, through the formation of neutrophil extracellular traps (NETs). The study objective was to determine whether neutrophils and NETs play a pathogenic role in DADA2. In vivo evidence demonstrated NETs and macrophages in affected gastrointestinal tissue from patients with DADA2. An abundance of circulating LDGs prone to spontaneous NET formation was observed during active disease in DADA2 and were significantly reduced after remission induction by anti-tumor necrosis factor (TNF) therapy. Increased circulating LDGs were identified in unaffected family members with monoallelic ADA2 mutations. Adenosine triggered NET formation, particularly in neutrophils from female patients, by engaging A1 and A3 adenosine receptors (ARs) and through reactive oxygen species- and peptidylarginine deiminase-dependent pathways. Adenosine-induced NET formation was inhibited by recombinant ADA2, A1/A3 AR antagonists, or by an A2A agonist. M1 macrophages incubated with NETs derived from patients with DADA2 released significantly greater amounts of TNF-α. Treatment with an A2AAR agonist decreased nuclear translocation of NF-κB and subsequent production of inflammatory cytokines in DADA2 monocyte-derived macrophages. These results suggest that neutrophils may play a pathogenic role in DADA2. Modulation of adenosine-mediated NET formation may contribute a novel and directed therapeutic approach in the treatment of DADA2 and potentially other inflammatory diseases.

Dysregulated neutrophil responses and neutrophil extracellular trap formation and degradation in PAPA syndrome

OBJECTIVES

Pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome is characterised by flares of sterile arthritis with neutrophil infiltrate and the overproduction of interleukin (IL)-1β. The purpose of this study was to elucidate the potential role of neutrophil subsets and neutrophil extracellular traps (NET) in the pathogenesis of PAPA.

METHODS

Neutrophils and low-density granulocytes (LDG) were quantified by flow cytometry. Circulating NETs were measured by ELISA and PAPA serum was tested for the ability to degrade NETs. The capacity of NETs from PAPA neutrophils to activate macrophages was assessed. Skin biopsies were analysed for NETs and neutrophil gene signatures.

RESULTS

Circulating LDGs are elevated in PAPA subjects. PAPA neutrophils and LDGs display enhanced NET formation compared with control neutrophils. PAPA sera exhibit impaired NET degradation and this is corrected with exogenous DNase1. Recombinant human IL-1β induces NET formation in PAPA neutrophils but not healthy control neutrophils. NET formation in healthy control neutrophils is induced by PAPA serum and this effect is inhibited by the IL-1 receptor antagonist, anakinra. NETs from PAPA neutrophils and LDGs stimulate IL-6 release in healthy control macrophages. NETs are detected in skin biopsies of patients with PAPA syndrome in association with increased tissue IL-1β, IL-8 and IL-17. Furthermore, LDG gene signatures are detected in PAPA skin.

CONCLUSIONS

PAPA syndrome is characterised by an imbalance of NET formation and degradation that may enhance the half-life of these structures in vivo, promoting inflammation. Anakinra ameliorates NET formation in PAPA and this finding supports a role for IL-1 signalling in exacerbated neutrophil responses in this disease. The study also highlights other inflammatory pathways potentially pathogenic in PAPA, including IL-17 and IL-6, and these results may help guide new therapeutic approaches in this severe and often treatment-refractory condition.

JAK1/2 inhibition with baricitinib in the treatment of autoinflammatory interferonopathies

BACKGROUND

Monogenic IFN-mediated autoinflammatory diseases present in infancy with systemic inflammation, an IFN response gene signature, inflammatory organ damage, and high mortality. We used the JAK inhibitor baricitinib, with IFN-blocking activity in vitro, to ameliorate disease.

METHODS

Between October 2011 and February 2017, 10 patients with CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures), 4 patients with SAVI (stimulator of IFN genes-associated [STING-associated] vasculopathy with onset in infancy), and 4 patients with other interferonopathies were enrolled in an expanded access program. The patients underwent dose escalation, and the benefit was assessed by reductions in daily disease symptoms and corticosteroid requirement. Quality of life, organ inflammation, changes in IFN-induced biomarkers, and safety were longitudinally assessed.

RESULTS

Eighteen patients were treated for a mean duration of 3.0 years (1.5-4.9 years). The median daily symptom score decreased from 1.3 (interquartile range [IQR], 0.93-1.78) to 0.25 (IQR, 0.1-0.63) (P < 0.0001). In 14 patients receiving corticosteroids at baseline, daily prednisone doses decreased from 0.44 mg/kg/day (IQR, 0.31-1.09) to 0.11 mg/kg/day (IQR, 0.02-0.24) (P < 0.01), and 5 of 10 patients with CANDLE achieved lasting clinical remission. The patients' quality of life and height and bone mineral density Z-scores significantly improved, and their IFN biomarkers decreased. Three patients, two of whom had genetically undefined conditions, discontinued treatment because of lack of efficacy, and one CANDLE patient discontinued treatment because of BK viremia and azotemia. The most common adverse events were upper respiratory infections, gastroenteritis, and BK viruria and viremia.

CONCLUSION

Upon baricitinib treatment, clinical manifestations and inflammatory and IFN biomarkers improved in patients with the monogenic interferonopathies CANDLE, SAVI, and other interferonopathies. Monitoring safety and efficacy is important in benefit-risk assessment.

TRIAL REGISTRATION

ClinicalTrials.gov NCT01724580 and NCT02974595.

FUNDING

This research was supported by the Intramural Research Program of the NIH, NIAID, and NIAMS. Baricitinib was provided by Eli Lilly and Company, which is the sponsor of the expanded access program for this drug.

JAK1/2 inhibition with baricitinib in the treatment of autoinflammatory interferonopathies

BACKGROUND. Monogenic IFN–mediated autoinflammatory diseases present in infancy with systemic inflammation, an IFN response gene signature, inflammatory organ damage, and high mortality. We used the JAK inhibitor baricitinib, with IFN-blocking activity in vitro, to ameliorate disease.

METHODS. Between October 2011 and February 2017, 10 patients with CANDLE (chronic atypical neutrophilic dermatosis with lipodystrophy and elevated temperatures), 4 patients with SAVI (stimulator of IFN genes–associated [STING-associated] vasculopathy with onset in infancy), and 4 patients with other interferonopathies were enrolled in an expanded access program. The patients underwent dose escalation, and the benefit was assessed by reductions in daily disease symptoms and corticosteroid requirement. Quality of life, organ inflammation, changes in IFN-induced biomarkers, and safety were longitudinally assessed.

RESULTS. Eighteen patients were treated for a mean duration of 3.0 years (1.5–4.9 years). The median daily symptom score decreased from 1.3 (interquartile range [IQR], 0.93–1.78) to 0.25 (IQR, 0.1–0.63) (P < 0.0001). In 14 patients receiving corticosteroids at baseline, daily prednisone doses decreased from 0.44 mg/kg/day (IQR, 0.31–1.09) to 0.11 mg/kg/day (IQR, 0.02–0.24) (P < 0.01), and 5 of 10 patients with CANDLE achieved lasting clinical remission. The patients’ quality of life and height and bone mineral density Z-scores significantly improved, and their IFN biomarkers decreased. Three patients, two of whom had genetically undefined conditions, discontinued treatment because of lack of efficacy, and one CANDLE patient discontinued treatment because of BK viremia and azotemia. The most common adverse events were upper respiratory infections, gastroenteritis, and BK viruria and viremia.

CONCLUSION. Upon baricitinib treatment, clinical manifestations and inflammatory and IFN biomarkers improved in patients with the monogenic interferonopathies CANDLE, SAVI, and other interferonopathies. Monitoring safety and efficacy is important in benefit-risk assessment.

TRIAL REGISTRATION. ClinicalTrials.gov NCT01724580 and NCT02974595.

FUNDING. This research was supported by the Intramural Research Program of the NIH, NIAID, and NIAMS. Baricitinib was provided by Eli Lilly and Company, which is the sponsor of the expanded access program for this drug.

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.

Aberrant tRNA processing causes an autoinflammatory syndrome responsive to TNF inhibitors

OBJECTIVES

To characterise the clinical features, immune manifestations and molecular mechanisms in a recently described autoinflammatory disease caused by mutations in TRNT1, a tRNA processing enzyme, and to explore the use of cytokine inhibitors in suppressing the inflammatory phenotype.

METHODS

We studied nine patients with biallelic mutations in TRNT1 and the syndrome of congenital sideroblastic anaemia with immunodeficiency, fevers and developmental delay (SIFD). Genetic studies included whole exome sequencing (WES) and candidate gene screening. Patients' primary cells were used for deep RNA and tRNA sequencing, cytokine profiling, immunophenotyping, immunoblotting and electron microscopy (EM).

RESULTS

We identified eight mutations in these nine patients, three of which have not been previously associated with SIFD. Three patients died in early childhood. Inflammatory cytokines, mainly interleukin (IL)-6, interferon gamma (IFN-γ) and IFN-induced cytokines were elevated in the serum, whereas tumour necrosis factor (TNF) and IL-1β were present in tissue biopsies of patients with active inflammatory disease. Deep tRNA sequencing of patients' fibroblasts showed significant deficiency of mature cytosolic tRNAs. EM of bone marrow and skin biopsy samples revealed striking abnormalities across all cell types and a mix of necrotic and normal-appearing cells. By immunoprecipitation, we found evidence for dysregulation in protein clearance pathways. In 4/4 patients, treatment with a TNF inhibitor suppressed inflammation, reduced the need for blood transfusions and improved growth.

CONCLUSIONS

Mutations of TRNT1 lead to a severe and often fatal syndrome, linking protein homeostasis and autoinflammation. Molecular diagnosis in early life will be crucial for initiating anti-TNF therapy, which might prevent some of the severe disease consequences.

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.

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 Behçet's 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.

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 Behçet's 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.

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

Objective: To describe the pregnancy course and outcome, and use of anakinra, a recombinant selective IL-1 receptor blocker, during pregnancy in patients with cryopyrin-associated periodic syndromes (CAPS), including familial cold auto-inflammatory syndrome (FCAS), Muckle-Wells syndrome (MWS) and neonatal onset multi-system inflammatory disease (NOMID). Methods: Women currently enrolled in natural history protocols (NCT00059748, and/or NCT00069329 under IND) who have been pregnant were included. Subjects underwent a structured, standardized interview with regards to maternal health, pregnancy and fetal outcomes. Medical records were reviewed. Results: Nine women (four with FCAS, one with MWS and four with NOMID) reported one to four pregnancies, each resulting in a total of fifteen FCAS, three MWS, and six NOMID pregnancies. Six births from FCAS mothers and three births from NOMID mothers occurred while patients were receiving anakinra. If a woman became pregnant while taking anakinra, the pre-pregnancy anakinra dose was continued. Anakinra dose was increased during one twin pregnancy. No preterm births or serious complications of pregnancy were observed. One fetus of the twin pregnancy had renal agenesis and suffered fetal demise. Genetic testing showed the deceased twin carried the same NLRP3 c.785T>C, p.V262A mutation as the mother. The other twin is healthy and mutation negative. Conclusions: Anakinra was continued during pregnancy in women with CAPS and provided significant, persistent CAPS symptom relief while continuing to prevent the long-term sequelae of CAPS. Anakinra was well tolerated. Although a causal relation between anakinra and renal agenesis seems unlikely, further safety data are needed.

Activated STING in a vascular and pulmonary syndrome

BACKGROUND

The study of autoinflammatory diseases has uncovered mechanisms underlying cytokine dysregulation and inflammation.

METHODS

We analyzed the DNA of an index patient with early-onset systemic inflammation, cutaneous vasculopathy, and pulmonary inflammation. We sequenced a candidate gene, TMEM173, encoding the stimulator of interferon genes (STING), in this patient and in five unrelated children with similar clinical phenotypes. Four children were evaluated clinically and immunologically. With the STING ligand cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), we stimulated peripheral-blood mononuclear cells and fibroblasts from patients and controls, as well as commercially obtained endothelial cells, and then assayed transcription of IFNB1, the gene encoding interferon-β, in the stimulated cells. We analyzed IFNB1 reporter levels in HEK293T cells cotransfected with mutant or nonmutant STING constructs. Mutant STING leads to increased phosphorylation of signal transducer and activator of transcription 1 (STAT1), so we tested the effect of Janus kinase (JAK) inhibitors on STAT1 phosphorylation in lymphocytes from the affected children and controls.

RESULTS

We identified three mutations in exon 5 of TMEM173 in the six patients. Elevated transcription of IFNB1 and other gene targets of STING in peripheral-blood mononuclear cells from the patients indicated constitutive activation of the pathway that cannot be further up-regulated with stimulation. On stimulation with cGAMP, fibroblasts from the patients showed increased transcription of IFNB1 but not of the genes encoding interleukin-1 (IL1), interleukin-6 (IL6), or tumor necrosis factor (TNF). HEK293T cells transfected with mutant constructs show elevated IFNB1 reporter levels. STING is expressed in endothelial cells, and exposure of these cells to cGAMP resulted in endothelial activation and apoptosis. Constitutive up-regulation of phosphorylated STAT1 in patients' lymphocytes was reduced by JAK inhibitors.

CONCLUSIONS

STING-associated vasculopathy with onset in infancy (SAVI) is an autoinflammatory disease caused by gain-of-function mutations in TMEM173. (Funded by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases; ClinicalTrials.gov number, NCT00059748.).

Activated STING in a vascular and pulmonary syndrome

BACKGROUND

The study of autoinflammatory diseases has uncovered mechanisms underlying cytokine dysregulation and inflammation.

METHODS

We analyzed the DNA of an index patient with early-onset systemic inflammation, cutaneous vasculopathy, and pulmonary inflammation. We sequenced a candidate gene, TMEM173, encoding the stimulator of interferon genes (STING), in this patient and in five unrelated children with similar clinical phenotypes. Four children were evaluated clinically and immunologically. With the STING ligand cyclic guanosine monophosphate-adenosine monophosphate (cGAMP), we stimulated peripheral-blood mononuclear cells and fibroblasts from patients and controls, as well as commercially obtained endothelial cells, and then assayed transcription of IFNB1, the gene encoding interferon-β, in the stimulated cells. We analyzed IFNB1 reporter levels in HEK293T cells cotransfected with mutant or nonmutant STING constructs. Mutant STING leads to increased phosphorylation of signal transducer and activator of transcription 1 (STAT1), so we tested the effect of Janus kinase (JAK) inhibitors on STAT1 phosphorylation in lymphocytes from the affected children and controls.

RESULTS

We identified three mutations in exon 5 of TMEM173 in the six patients. Elevated transcription of IFNB1 and other gene targets of STING in peripheral-blood mononuclear cells from the patients indicated constitutive activation of the pathway that cannot be further up-regulated with stimulation. On stimulation with cGAMP, fibroblasts from the patients showed increased transcription of IFNB1 but not of the genes encoding interleukin-1 (IL1), interleukin-6 (IL6), or tumor necrosis factor (TNF). HEK293T cells transfected with mutant constructs show elevated IFNB1 reporter levels. STING is expressed in endothelial cells, and exposure of these cells to cGAMP resulted in endothelial activation and apoptosis. Constitutive up-regulation of phosphorylated STAT1 in patients' lymphocytes was reduced by JAK inhibitors.

CONCLUSIONS

STING-associated vasculopathy with onset in infancy (SAVI) is an autoinflammatory disease caused by gain-of-function mutations in TMEM173. (Funded by the Intramural Research Program of the National Institute of Arthritis and Musculoskeletal and Skin Diseases; ClinicalTrials.gov number, NCT00059748.).

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.).

Sustained response and prevention of damage progression in patients with neonatal-onset multisystem inflammatory disease treated with anakinra: a cohort study to determine three- and five-year outcomes

OBJECTIVE

Blocking interleukin-1 with anakinra in patients with the autoinflammatory syndrome neonatal-onset multisystem inflammatory disease (NOMID) reduces systemic and organ-specific inflammation. However, the impact of long-term treatment has not been established. This study was undertaken to evaluate the long-term effect of anakinra on clinical and laboratory outcomes and safety in patients with NOMID.

METHODS

We conducted a cohort study of 26 NOMID patients ages 0.80-42.17 years who were followed up at the NIH and treated with anakinra 1-5 mg/kg/day for at least 36 months. Disease activity was assessed using daily diaries, questionnaires, and C-reactive protein level. Central nervous system (CNS) inflammation, hearing, vision, and safety were evaluated.

RESULTS

Sustained improvements in diary scores, parent's/patient's and physician's global scores of disease activity, parent's/patient's pain scores, and inflammatory markers were observed (all P<0.001 at 36 and 60 months). At 36 and 60 months, CNS inflammation was suppressed, with decreased cerebrospinal fluid white blood cell counts (P=0.0026 and P=0.0076, respectively), albumin levels, and opening pressures (P=0.0012 and P<0.001, respectively). Most patients showed stable or improved hearing. Cochlear enhancement on magnetic resonance imaging correlated with continued hearing loss. Visual acuity and peripheral vision were stable. Low optic nerve size correlated with poor visual field. Bony lesions progressed. Adverse events other than viral infections were rare, and all patients continued to receive the medication.

CONCLUSION

These findings indicate that anakinra provides sustained efficacy in the treatment of NOMID for up to 5 years, with the requirement of dose escalation. Damage progression in the CNS, ear, and eye, but not bone, is preventable. Anakinra is well tolerated overall.

An autoinflammatory disease with deficiency of the interleukin-1-receptor antagonist

BACKGROUND

Autoinflammatory diseases manifest inflammation without evidence of infection, high-titer autoantibodies, or autoreactive T cells. We report a disorder caused by mutations of IL1RN, which encodes the interleukin-1-receptor antagonist, with prominent involvement of skin and bone.

METHODS

We studied nine children from six families who had neonatal onset of sterile multifocal osteomyelitis, periostitis, and pustulosis. Response to empirical treatment with the recombinant interleukin-1-receptor antagonist anakinra in the first patient prompted us to test for the presence of mutations and changes in proteins and their function in interleukin-1-pathway genes including IL1RN.

RESULTS

We identified homozygous mutations of IL1RN in nine affected children, from one family from Newfoundland, Canada, three families from The Netherlands, and one consanguineous family from Lebanon. A nonconsanguineous patient from Puerto Rico was homozygous for a genomic deletion that includes IL1RN and five other interleukin-1-family members. At least three of the mutations are founder mutations; heterozygous carriers were asymptomatic, with no cytokine abnormalities in vitro. The IL1RN mutations resulted in a truncated protein that is not secreted, thereby rendering cells hyperresponsive to interleukin-1beta stimulation. Patients treated with anakinra responded rapidly.

CONCLUSIONS

We propose the term deficiency of the interleukin-1-receptor antagonist, or DIRA, to denote this autosomal recessive autoinflammatory disease caused by mutations affecting IL1RN. The absence of interleukin-1-receptor antagonist allows unopposed action of interleukin-1, resulting in life-threatening systemic inflammation with skin and bone involvement. (ClinicalTrials.gov number, NCT00059748.)

A computer generated index for the assessment of coronary angiography

Mortality in patients with coronary artery disease is related to its severity. The commonly used classification of 1, 2 or 3 vessel disease is relatively insensitive. We have designed a new classification which takes into account site, severity and effect of multiple lesions in the coronary circulation. Data is recorded on Mark Sense computer cards and a coronary index (CI) obtained. We have collected data from 1100 patients and shown correlations of the index with clinical variables, ventricular function and in particular, mortality.

The E326K mutation and Gaucher disease: mutation or polymorphism?

Gaucher disease is caused by mutations in the gene for human glucocerebrosidase, a lysosomal enzyme involved in the intracellular hydrolysis of glucosylceramide. While over 150 different glucocerebrosidase mutations have been identified in patients with Gaucher disease, not all reported mutations have been fully characterized as being causative. One such mutation is the E326K mutation, which results from a G to A nucleotide substitution at genomic position 6195 and has been identified in patients with type 1, type 2 and type 3 Gaucher disease. However, in each instance, the E326K mutation was found on the same allele with another glucocerebrosidase mutation. Utilizing polymerase chain reaction (PCR) screening and restriction digestions of both patients with Gaucher disease and normal controls, we identified the E326K allele in both groups. Of the 310 alleles screened from patients with Gaucher disease, the E326K mutation was detected in four alleles (1.3%). In addition, screening for the E326K mutation among normal controls from a random population revealed that three alleles among 316 screened (0.9%) also carried the E326K mutation. In the normal controls with the E326K allele, the glucocerebrosidase gene was completely sequenced, but no additional mutations were found. Because the E326K mutation may be a polymorphism, we caution that a careful examination of any allele with this mutation should be performed to check for the presence of other glucocerebrosidase mutations.

Scanning for telomeric deletions and duplications and uniparental disomy using genetic markers in 120 children with malformations

We screened 120 children with sporadic multiple congenital anomalies and either growth or mental retardation for uniparental disomy (UPD) or subtelomeric deletions. The screening used short tandem repeat polymorphisms (STRP) from the subtelomeric regions of 41 chromosome arms. Uninformative marker results were reanalyzed by using the next available marker on that chromosome arm. In total, approximately 25,000 genotypes were generated and analyzed for this study. Subtelomeric deletions of 1 Mb in size were excluded for 27 of 40 chromosome arms. Among the 120 subjects none was found to have UPD, but five subjects (4%, 95% confidence interval 1-9%) were found to have a deletion or duplication of one or more chromosome arms. We conclude that UPD is not a frequent cause of undiagnosed multiple congenital anomaly syndrome. In addition, we determined that 9p and 7q harbor chromosome length variations in the normal population. We conclude that subtelomeric marker analysis is effective for the detection of subtelomeric duplications and deletions, although it is labor intensive. Given a detection rate that is similar to prior studies and the large workload imposed by STRPs, we conclude that STRPs are an effective, but impractical, approach to the determination of segmental aneusomy given current technology.

Glucocerebrosidase mutations among African-American patients with type 1 Gaucher disease

While the inherited deficiency of the enzyme glucocerebrosidase (Gaucher disease) is panethnic in its distribution, there have not been studies of the mutations encountered in specific ethnic groups in the United States, other than those on Ashkenazi Jews. We present the clinical descriptions and genotypes of seven patients of African-American ancestry with type 1 Gaucher disease, and summarize the published literature regarding the genotypes encountered in this population. All seven of the patients had moderate-to-severe manifestations of the disease, and all developed symptoms by adolescence. Genotypic analyses revealed that no two probands shared the same genotype. The common mutations N370S, c.84-85insG, IVS2+1 G-->A, and R463C were not seen. Mutation L444P was present on one allele in each of the patients; but the same mutation was encountered as a single point mutation in three of the patients, and as part of a recombinant allele in four of the patients. Southern blot analyses revealed a glucocerebrosidase fusion allele in one patient, and a duplication resulting from recombination in the region downstream from the glucocerebrosidase gene in three of the patients. Five different point mutations (A90T, R48W, N117D, R170C, and V352L), one deletion mutation (c.222-224 delTAC), and one insertion mutation (c.153-154 insTACAGC) were encountered. Our results demonstrate that there is significant genotypic heterogeneity among African-American patients with type 1 Gaucher disease, and that recombinations in the glucocerebrosidase gene locus are particularly common in this patient group. Published 2001 Wiley-Liss, Inc.

Leucocyte copper, a marker of copper body status is low in coronary artery disease

To elucidate the relationship between leucocyte copper as a reliable, sensitive index of copper body status and extent of atherosclerosis in patients with Coronary Artery Disease (CAD) the present case-control study was carried out. 80 subjects were studied (23 females and 57 males), aged between 30-70, due to have a angiography. Individual angiograms were scored by combining the individual scores in all the major coronary arteries into one score of a scale 1.00 for patency to 0.00 for severe CAD. Serum and leucocyte copper and zinc were determined by GFAAS. No significant difference between patients with advanced CAD and relatively normal arteries were observed in the lipid profile and levels of plasma copper. Leucocyte copper had a significant link with the severity of atherosclerosis which was independent of sex. There was a linear relationship between the degree of decreasing leucocyte copper concentration and angiogram score. These findings give support to the hypothesis that marginal copper status, assessed by decreased leucocyte copper level, is associated with developing CAD.

Lesson of the week. Unrecognised accidental overdose with diltiazem

Invasive haemodynamic monitoring should be considered when hypotension fails to respond to empirical treatments

Pretreatment plasma HVA and haloperidol response in acute mania

INTRODUCTION

Pretreatment plasma homovanillic acid (HVA) levels have been reported to be a correlate of clinical response to typical antipsychotics for schizophrenic, bipolar manic, and mixed groups of psychotic patients. Biological markers of clinical response to antipsychotics could be useful for optimizing drug treatment.

METHOD

Thirty-one consenting acute inpatient subjects between ages 19 and 66 years with a DSM-III-R clinical diagnosis of bipolar disorder, manic with psychotic features were entered into this double-blind study and were randomly assigned to receive either haloperidol 25 mg/day or haloperidol 5 mg for the 3-week study. Subjects also received one of the following concomitant medications: standard lithium, lorazepam 4 mg/day, or placebo.

RESULTS

The primary multiple regression analysis, including all subjects on both haloperidol doses, yielded a significant main effect for pretreatment plasma HVA (n=31, F=5.7, P=0.025), indicating that higher pretreatment plasma HVA was predictive of better clinical response. In addition, the interaction between haloperidol dose and pretreatment plasma HVA was also significantly associated with clinical response (F=12.59, P=0.0015). When the two haloperidol doses were analyzed separately, we found that pretreatment plasma HVA was only correlated with clinical response in the low haloperidol 5 mg/day group (n=18, F=11.73, P=0.0038) and was unrelated to clinical response to the high haloperidol 25 mg/day group.

LIMITATIONS

The sample size was small. Results may have been confounded by prior antipsychotic treatment and concomitant use of lithium or lorazepam.

DISCUSSION

These results suggest that pretreatment plasma HVA could be useful for dosing antipsychotics. Patients with high plasma HVA levels would be good candidates for low-dose treatment because they are more likely to improve on such a dose, while patients with low plasma HVA levels might warrant more rapid dosage escalation.

Analysis and classification of 304 mutant alleles in patients with type 1 and type 3 Gaucher disease

Gaucher disease results from the inherited deficiency of the enzyme glucocerebrosidase (EC 3.2.1.45). Although >100 mutations in the gene for human glucocerebrosidase have been described, most genotype-phenotype studies have focused upon screening for a few common mutations. In this study, we used several approaches-including direct sequencing, Southern blotting, long-template PCR, restriction digestions, and the amplification refraction mutation system (ARMS)-to genotype 128 patients with type 1 Gaucher disease (64 of Ashkenazi Jewish ancestry and 64 of non-Jewish extraction) and 24 patients with type 3 Gaucher disease. More than 97% of the mutant alleles were identified. Fourteen novel mutations (A90T, N117D, T134I, Y135X, R170C, W184R, A190T, Y304X, A341T, D399Y, c.153-154insTACAGC, c.203-204insC, c.222-224delTAC, and c.1122-1123insTG) and many rare mutations were detected. Recombinant alleles were found in 19% of the patients. Although 93% of the mutant alleles in our Ashkenazi Jewish type 1 patients were N370S, c.84-85insG, IVS2+1G-->A or L444P, these four mutations accounted for only 49% of mutant alleles in the non-Jewish type 1 patients. Genotype-phenotype correlations were attempted. Homozygosity or heterozygosity for N370S resulted in type 1 Gaucher disease, whereas homozygosity for L444P was associated with type 3. Genotype L444P/recombinant allele resulted in type 2 Gaucher disease, and homozygosity for a recombinant allele was associated with perinatal lethal disease. The phenotypic consequences of other mutations, particularly R463C, were more inconsistent. Our results demonstrate a high rate of mutation detection, a large number of novel and rare mutations, and an accurate assessment of the prevalence of recombinant alleles. Although some genotype-phenotype correlations do exist, other genetic and environmental factors must also contribute to the phenotypes encountered, and we caution against relying solely upon genotype for prognostic or therapeutic judgements.

Current gender stereotypes and their evaluative content

A sample of 173 undergraduate students rated 300 attributes to assess current gender stereotypes, and a second independent sample (n = 57) evaluated the favorability of these attributes. Statistical results indicated that the college students ascribed different attributes to men and women. Although the content of gender stereotypes seems to have remained unchanged over the years, the value attached to stereotypic gender traits seems to be changing. More specifically, a greater number of unfavorable attributes were used to describe men than women, thereby creating a more negative masculine stereotype.

Life-threatening splenic hemorrhage in two patients with Gaucher disease

Massive splenomegaly is a frequent finding in patients with Gaucher disease, the most common of the sphingolipidoses. Even so, the risk for splenic rupture and intracapsular hemorrhage has not been emphasized due to the rarity of this occurrence and the fibrotic, rubbery consistency of splenic tissue in these patients. We report two adult patients with type 1 Gaucher disease who suffered life-threatening splenic bleeds that were not acutely diagnosed. Both patients ultimately required emergent splenectomies. Factors complicating the diagnosis of splenic hemorrhage in patients with Gaucher disease are discussed. Published 2000 Wiley-Liss, Inc.

Mutation of a gene encoding a putative chaperonin causes McKusick-Kaufman syndrome

McKusick-Kaufman syndrome (MKKS, MIM 236700) is a human developmental anomaly syndrome comprising hydrometrocolpos (HMC), postaxial polydactyly (PAP) and congenital heart disease (CHD). MKKS has been mapped in the Old Order Amish population to 20p12, between D20S162 and D20S894 (ref. 3). Here we describe the identification of a gene mutated in MKKS. We analysed the approximately 450-kb candidate region by sample sequencing, which revealed the presence of several known genes and EST clusters. We evaluated candidate transcripts by northern-blot analysis of adult and fetal tissues. We selected one transcript with widespread expression, MKKS, for analysis in a patient from the Amish pedigree and a sporadic, non-Amish case. The Old Order Amish patient was found to be homozygous for an allele that had two missense substitutions and the non-Amish patient was a compound heterozygote for a frameshift mutation predicting premature protein truncation and a distinct missense mutation. The MKKS predicted protein shows amino acid similarity to the chaperonin family of proteins, suggesting a role for protein processing in limb, cardiac and reproductive system development. We believe that this is the first description of a human disorder caused by mutations affecting a putative chaperonin molecule.

Type 2 Gaucher disease: the collodion baby phenotype revisited

The association of Gaucher disease, the inherited deficiency of lysosomal glucocerebrosidase (EC 3.2.1.45), and congenital ichthyosis was first noted a decade ago. Subsequently, a null allele type 2 Gaucher mouse was generated that also exhibited ichthyotic skin, confirming that the skin disorder and enzyme deficiency were directly related. This paper details the clinical and molecular characterisation of 6 cases of type 2 Gaucher disease presenting with the collodion baby phenotype. The identified mutant glucocerebrosidase alleles include two novel mutations (S196P and R131L) and two rare point mutations (R120W and R257Q), as well as alleles resulting from recombination with the nearby glucocerebrosidase pseudogene. There is significant genotypic heterogeneity in this rare subset of patients with type 2 Gaucher disease. Gaucher disease should be considered in the differential diagnosis of congenital ichthyosis in the newborn period.

Glucocerebrosidase gene mutations in patients with type 2 Gaucher disease

Gaucher disease, the most common lysosomal storage disorder, results from the inherited deficiency of the enzyme glucocerebrosidase. Three clinical types are recognized: type 1, non-neuronopathic; type 2, acute neuronopathic; and type 3, subacute neuronopathic. Type 2 Gaucher disease, the rarest type, is progressive and fatal. We have performed molecular analyses of a cohort of 31 patients with type 2 Gaucher disease. The cases studied included fetuses presenting prenatally with hydrops fetalis, infants with the collodion baby phenotype, and infants diagnosed after several months of life. All 62 mutant glucocerebrosidase (GBA) alleles were identified. Thirty-three different mutant alleles were found, including point mutations, splice junction mutations, deletions, fusion alleles and recombinant alleles. Eleven novel mutations were identified in these patients: R131L, H255Q, R285H, S196P, H311R, c.330delA, V398F, F259L, c.533delC, Y304C and A190E. Mutation L444P was found on 25 patient alleles. Southern blots and direct sequencing demonstrated that mutation L444P occurred alone on 9 alleles, with E326K on one allele and as part of a recombinant allele on 15 alleles. There were no homozygotes for point mutation L444P. The recombinant alleles that included L444P resulted from either reciprocal recombination or gene conversion with the nearby glucocerebrosidase pseudogene, and seven different sites of recombination were identified. Homozygosity for a recombinant allele was associated with early lethality. We have also summarized the literature describing mutations associated with type 2 disease, and list 50 different mutations. This report constitutes the most comprehensive molecular study to date of type 2 Gaucher disease, and it demonstrates that there is significant phenotypic and genotypic heterogeneity among patients with type 2 Gaucher disease. Hum Mutat 15:181-188, 2000. Published 2000 Wiley-Liss, Inc.

Coronary angiography in the presence of peripheral vascular disease: femoral or brachial/radial approach?

Peripheral vascular disease is considered a relative contraindication to the femoral approach for coronary angiography, but no data exist comparing the femoral and brachial/radial routes under these circumstances. We examined the influence of vascular approach on outcome. Two hundred and ninety-seven patients, mean age 67.1 +/- 8.4 years, with clinical or radiographic evidence of aortofemoral peripheral arterial disease underwent diagnostic coronary angiography during a 3-year period at this cardiothoracic center. The approach was successful in 121 of 154 femoral cases (79%) compared with 130 of 143 brachial/radial cases (91%; P < 0.01). Of the 33 failed femoral cases, 15 were then approached from the other femoral artery, with success in 6 (40%), while 18 were approached from the arm, with success in all (100%; P < 0.01). Brachial/radial cases took significantly longer than femoral cases (51 +/- 19 vs. 42 +/- 22 mins; P < 0.01). In cases where the femoral pulse was considered normal, the femoral approach nonetheless failed in 19 of 95 (20%). Major vascular complications (e.g., pulseless limb, arterial dissection, hemorrhage, or false aneurysm) occurred in nine femoral cases vs. zero brachial/radial cases (P < 0.01). Patients with peripheral vascular disease who undergo coronary angiography from the femoral artery have a 1-in-5 risk of procedural failure, necessitating use of an alternative vascular approach, and a 1-in-20 risk of a major vascular complication. Normality of femoral arterial pulsation is not a good predictor of femoral success. Brachial/radial approaches take longer, but succeed more frequently and have a negligible major vascular complication rate. We believe that patients with peripheral vascular disease should undergo coronary angiography via brachial or radial approach. Cathet. Cardiovasc. Intervent. 49:32-37, 2000.

Is the perinatal lethal form of Gaucher disease more common than classic type 2 Gaucher disease?

In recent years there has been increased recognition of a severe perinatal lethal form of Gaucher disease, the inherited deficiency of lysosomal glucocerebrosidase. We previously reported a case of severe type 2 Gaucher disease which was seen in a medical center in Rotterdam and now present three new cases from two other families seen at the same center. Mutational analyses of these cases revealed two novel mutations, H311R and V398F, located in exons 8 and 9, respectively. The identification of four cases of lethal type 2 Gaucher disease in a single center seems to be a function of increased awareness of this phenotype, rather than of geographic clustering. The actual incidence of lethal type 2 Gaucher disease may be underestimated, as many cases may have been misclassified as collodion babies or hydrops of unknown cause.

Two novel polymorphic sequences in the glucocerebrosidase gene region enhance mutational screening and founder effect studies of patients with Gaucher disease

Gaucher disease, an inherited glycolipid storage disorder, is caused by a deficiency of the catabolic enzyme glucocerebrosidase (EC 3.2.1.45). The gene for human glucocerebrosidase is located on chromosome 1q21 and has a highly homologous pseudogene situated 16 kb downstream. We report two novel polymorphic sequences in the glucocerebrosidase gene region: the first consists of a variable number of dinucleotide (CT) repeats located 3.2 kb upstream from the glucocerebrosidase gene, and the second is a tetranucleotide (AAAT) repeat found between the glucocerebrosidase gene and its pseudogene, 9.8 kb downstream from the functional gene. These polymorphic sequences, along with a previously reported PvuII polymorphism in intron 6 of the glucocerebrosidase gene, were analyzed in patients with Gaucher disease (n=106) and in two normal control populations, one of Ashkenazi Jewish ancestry (n=72) and the second comprising non-Jewish individuals (n=46). In these samples, strong linkage disequilibrium was found between mutations N370S, c.84-85insG, and R463C and specific haplotypes; no significant linkage disequilibrium was found when examining haplotypes of patients with the L444P mutation. Studies of these polymorphic sites in several instances also led to the recognition of genotyping errors and the identification of unusual recombinant alleles. These new polymorphic sites provide additional tools for mutational screening and founder effect studies of Gaucher disease.

Hydrops fetalis: lysosomal storage disorders in extremis

In recent years there has been an increased recognition that hydrops fetalis may be an extreme presentation of many of the lysosomal storage disorders. Hydrops fetalis, the excessive accumulation of serous fluid in the subcutaneous tissues and serous cavities of the fetus, has many possible etiologies, providing a diagnostic challenge for the physician. Ten different lysosomal storage disorders have now been diagnosed in infants with hydrops fetalis, including mucopolysaccharidosis (MPS) VII and IVA, type 2 Gaucher disease, sialidosis, GMI gangliosidosis, galactosialidosis, Niemann-Pick disease type C, disseminated lipogranulomatosis (Farber disease), infantile free sialic acid storage disease (ISSD), and mucolipidosis II (I-cell disease). Frequently, these inborn errors of metabolism are recognized only after the unfortunate recurrence of hydrops fetalis in several pregnancies of a family. Making the diagnosis relies on the physician having a high index of suspicion and ordering appropriate testing, which can often be performed prenatally. In several of these disorders, including MPS VII, infantile galactosialidosis, type 2 Gaucher disease, and ISSD, hydrops fetalis is a relatively common presentation. A greater physician awareness of hydrops fetalis as a presentation of lysosomal disease will facilitate establishing a diagnosis in cases that would have previously been considered idiopathic and will enable a better estimation of the incidence of this association. Lysosomal disorders are among the few causes of nonimmune hydrops fetalis in which an accurate recurrence risk can be ascertained. With an early and accurate diagnosis, genetic counseling and family planning can be offered in these difficult cases.

Late complications following permanent pacemaker implantation or elective unit replacement

OBJECTIVE

To determine the rate of late complications following first implantation or elective unit replacement of a permanent pacemaker system.

DESIGN

Analysis of pacemaker data and complications prospectively acquired on a computerised database. Complications were studied over an 11 year period from January 1984 to December 1994.

SETTING

Tertiary referral cardiothoracic centre.

PATIENTS

Records of 2621 patients were analysed retrospectively.

MAIN OUTCOME MEASURES

Complications requiring repeat procedures occurring more than six weeks after pacemaker implantation or elective unit replacement.

RESULTS

The overall rate of late complications was significantly lower after first implantation of a permanent pacemaker (34 cases, complication rate 1.4%, 95% confidence interval 0.9% to 1.9%) than after elective unit replacement (16 cases, complication rate 6.5% (3.3% to 9.7%). There were 20 cases of erosion, 18 infections, five electrode problems, and seven miscellaneous problems. Complications were more common with inexperienced operators (18.9% (6.0% to 31.8%)) than with experienced operators (0.9% (0.3% to 1.5%).

CONCLUSIONS

The incidence of late complications following pacemaker implantation is low and compares favourably with early complication rates. The majority are caused by erosion and infection. Patients who have undergone elective unit replacement are at particular risk.

Coronary angiography from the radial artery--experience, complications and limitations

AIMS

to assess the outcomes, complications and limitations of coronary angiography performed via percutaneous radial artery puncture.

METHODS AND RESULTS

two hundred and fifty patients underwent diagnostic coronary angiography from the radial artery, 182 (72.8%) of whom had contraindications to the femoral approach, for example due to peripheral vascular disease (n=85), therapeutic anticoagulation (29), or failed femoral approach (17). Procedural success in this high-risk population was achieved in 231 patients (92.4%). Principle reasons for failure were unsuccessful radial access (5) and arterial spasm (5). Procedure duration (SD) for an operator's first 20 cases compared with cases thereafter (min) was 47.7 (16.7) vs. 41.5 (14.6), P=0.0004; fluoroscopy time (min) 9.7 (7.1) vs. 6.6 (5.1), P=0.0001 and procedural success 89.6% vs. 94.1%, P=ns. Complications included two deaths associated temporally with catheterisation, three cases of arterial dissection without ischaemic sequelae and one transient ischaemic attack.

CONCLUSIONS

coronary angiography can be performed successfully from the radial artery, but this approach has limitations, which include the need to demonstrate dual palmar vascular supply, the prolonged learning phase, the procedural failure rate, patient discomfort and a demonstrable incidence of vascular and haemodynamic complications. We believe that radial coronary angiography should only be undertaken when there is a contraindication to the femoral approach.

Sotalol associated polymorphic ventricular tachycardia and coronary spasm

Sotalol may induce torsade de pointes through cardiac action potential prolongation, but a proarrhythmic effect secondary to its beta blocking action has not been reported. A 54 year old man presented with symptoms of angina and presyncope, subsequently demonstrated to be associated with coronary spasm. Treatment with sotalol exacerbated his symptoms and resulted in recurrent polymorphic ventricular tachycardia with a pattern indistinguishable from that caused by a class III action. Following sotalol with-drawal polymorphic ventricular tachycardia resolved completely. Polymorphic ventricular tachycardia in patients treated with sotalol may therefore not always be the result of delayed repolarisation, but may be caused by beta adrenoceptor blockade.