Hidradenitis Suppurativa-Related Autoinflammatory Syndromes: An Updated Review on the Clinics, Genetics, and Treatment of Pyoderma gangrenosum, Acne and Suppurative Hidradenitis (PASH), Pyogenic Arthritis, Pyoderma gangrenosum, Acne and Suppurative Hidradenitis (PAPASH), Synovitis, Acne, Pustulosis, Hyperostosis and Osteitis (SAPHO), and Rarer Forms

Hidradenitis suppurativa (HS) is an autoinflammatory skin disorder of the terminal hair follicle, which can present in sporadic, familial, or syndromic form. A classification has been proposed for the latter, distinguishing cases associated with a known genetic condition, with follicular keratinization disorders or with autoinflammatory diseases. This review focuses on the clinical and genetic features of those entities (ie, pyoderma gangrenosum [PG], acne and HS; PG, acne, pyogenic arthritis and HS; psoriatic arthritis, PG, acne and HS; synovitis, acne, pustulosis, hyperostosis, osteitis; and so forth) for which the collective term HS-related autoinflammatory syndromes is proposed.

Clinical and genetic analysis of the first Mexican patient with a diagnosis of pyogenic sterile arthritis, pyoderma gangrenosum and acne (PAPA) syndrome

Our report discusses the first Mexican patient with a clinical and molecular diagnosis of pyogenic sterile arthritis, pyoderma gangrenosum and acne syndrome. In addition, a literature review of the clinical and molecular spectrum of the disease is included.

Genetic mutations in pyoderma gangrenosum, hidradenitis suppurativa, and associated autoinflammatory syndromes: Insights into pathogenic mechanisms and shared pathways

Pyoderma gangrenosum (PG), hidradenitis suppurativa (HS), and the associated autoinflammatory syndromes, including pyogenic arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome, PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PASH) syndrome, and pyogenic arthritis, pyoderma gangrenosum, acne, and suppurative hidradenitis (PAPASH) syndrome are dermatological conditions characterized by chronic inflammation and tissue damage. Recent advances in genetic research have identified specific mutations associated with these disorders, shedding light on their underlying pathogenic mechanisms. This review aims to summarize the current knowledge of identified mutations and presumed pathophysiology in PG, HS, and the associated autoinflammatory syndromes.

What can inherited immunodeficiencies reveal about pyoderma gangrenosum?

Pyoderma gangrenosum (PG) is a rare ulcerative neutrophilic dermatosis that is occasionally associated with primary immunodeficiency. Though contributions from dysregulation of the innate immune system, neutrophil dysfunction and genetic predisposition have been postulated, the precise pathogenesis of PG has not yet been elucidated. This article reviews reported cases of coexisting PG and primary immunodeficiency in order to gain insight into the complex pathophysiology of PG. Our findings suggest that variations in genes such as RAG1, ITGB2, IRF2BP2 and NFκB1 might play a role in genetically predisposing patients to develop PG. These studies support the feasibility of the role of somatic gene variation in the pathogenesis of PG which warrants further exploration to guide targeted therapeutics.

Altered keratinization and vitamin D metabolism may be key pathogenetic pathways in syndromic hidradenitis suppurativa: a novel whole exome sequencing approach

BACKGROUND

Diagnosis of pyoderma gangrenosum, acne and hidradenitis suppurativa (PASH) and pyogenic arthritis, pyoderma gangrenosum, acne, and hidradenitis suppurativa (PAPASH) patients, in spite of recently identified genetic variations, is just clinical, since most patients do not share the same mutations, and the mutations themselves are not informative of the biological pathways commonly disrupted in these patients.

OBJECTIVE

To reveal genetic changes more closely related to PASH and PAPASH etiopathogenesis, identifying novel common pathways involved in these diseases.

METHODS

Cohort study on PASH (n = 4) and PAPASH (n = 1) patients conducted using whole exome sequencing (WES) approach and a novel bioinformatic pipeline aimed at discovering potentially candidate genes selected from density mutations and involved in pathways relevant to the disease.

RESULTS

WES results showed that patients presented 90 genes carrying mutations with deleterious and/or damage impact: 12 genes were in common among the 5 patients and bared 237 ns ExonVar (54 and 183 in homozygosis and heterozygosis, respectively). In the pathway enrichment analysis, only 10 genes were included, allowing us to retrieve 4 pathways shared by all patients: (1) Vitamin D metabolism, (2) keratinization, (3) formation of the cornified envelope and (4) steroid metabolism. Interestingly, all patients had vitamin D levels lower than normal, with a mean value of 10 ng/mL.

CONCLUSION

Our findings, through a novel strategy for analysing the genetic background of syndromic HS patients, suggested that vitamin D metabolism dysfunctions seem to be crucial in PASH and PAPASH pathogenesis. Based on low vitamin D serum levels, its supplementation is envisaged.

Monogenic Auto-inflammatory Syndromes: A Review of the Literature

Auto-inflammatory syndromes are a new group of distinct hereditable disorders characterized by episodes of seemingly unprovoked inflammation (most commonly in skin, joints, gut, and eye), the absence of a high titer of auto-antibodies or auto-reactive T cells, and an inborn error of innate immunity. A narrative literature review was carried out of studies related to auto-inflammatory syndromes to discuss the pathogenesis and clinical manifestation of these syndromes. This review showed that the main monogenic auto-inflammatory syndromes are familial Mediterranean fever (FMF), mevalonate kinase deficiency (MKD), Blau syndrome, TNF receptor-associated periodic syndrome (TRAPS), cryopyrin-associated periodic syndrome (CAPS), and pyogenic arthritis with pyoderma gangrenosum and acne (PAPA). The data suggest that correct diagnosis and treatment of monogenic auto-inflammatory diseases relies on the physicians' awareness. Therefore, understanding of the underlying pathogenic mechanisms of auto-inflammatory syndromes, and especially the fact that these disorders are mediated by IL-1 secretion stimulated by monocytes and macrophages, facilitated significant progress in patient management.

Certain Autoimmune Manifestations Are Associated With Distinctive Karyotypes and Outcomes in Patients With Myelodysplastic Syndrome: A Retrospective Cohort Study

Autoimmune manifestations (AIMs) are common in patients with myelodysplastic syndrome (MDS). This study aimed to investigate whether AIMs are associated with a specific cytogenetic abnormalities and worse survival in patients with MDS. A total of 67 MDS patients with AIMs and 134 age- and sex-matched MDS patients without AIMs, all of whom received medical care at Seoul National University Hospital from January 2000 through July 2014, were enrolled. The clinical features, chromosomal abnormalities, and outcomes were examined. The effect of AIMs on mortality was estimated after adjusting for age, sex, and the International Prognostic Scoring System. The mean age (±SD) at the time of MDS diagnosis was 54.5 ± 17.1 years, and 44.8% of patients were male. Neutrophilic dermatosis (ND; Sweet syndrome and pyoderma gangrenosum) was the most prevalent AIM (n = 24 36%]), followed by Behcet disease (10 [15%]), rheumatoid arthritis (9 [13%]), vasculitis (8 [12%]), myositis (3 [4%]), spondyloarthropathy (3 [4%]), and systemic lupus erythematous (2 [3%]). ND and vasculitis occurred at the time of MDS diagnosis, whereas other AIMs occurred years after MDS diagnosis. Deletion of 5q was associated with ND (P = 0.001), whereas trisomy 8 was associated with Behcet disease (P = 0.015). Strikingly, ND was associated with a 1.8-fold increase in mortality (95% CI 1.033-3.093; P = 0.038). Certain AIMs in MDS patients are associated with distinctive karyotypes and worse survival. A larger study is needed to confirm whether the presence of AIMs influences disease outcome in MDS.

Pathophysiology of pyoderma gangrenosum (PG): an updated review

Pyoderma gangrenosum is a challenging skin condition to identify and treat because of its multifactorial pathogenesis. It is a rare cutaneous manifestation diagnosed clinically by exclusion of infection, neoplasia, thrombophilia, and other inflammatory conditions. Pathogenetic and treatment studies are scarce. Abnormalities in the function of inflammatory cytokines, the immune system, and neutrophils combined with specific genetic mutations predispose patients to develop this complex disease process. Early recognition of patients at risk for pyoderma gangrenosum, the necessity to improve its early diagnosis, and the future outlook of targeted and personalized therapies relies on the improved comprehension of the complex pathogenesis of pyoderma gangrenosum.

Association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) shares genetic and cytokine profiles with other autoinflammatory diseases

The association of pyoderma gangrenosum, acne, and suppurative hidradenitis (PASH) has recently been described and suggested to be a new entity within the spectrum of autoinflammatory syndromes, which are characterized by recurrent episodes of sterile inflammation, without circulating autoantibodies and autoreactive T-cells. We conducted an observational study on 5 patients with PASH syndrome, analyzing their clinical features, genetic profile of 10 genes already known to be involved in autoinflammatory diseases (AIDs), and cytokine expression pattern both in lesional skin and serum. In tissue skin samples, the expressions of interleukin (IL)-1β and its receptors I and II were significantly higher in PASH (P = 0.028, 0.047, and 0.050, respectively) than in controls. In PASH patients, chemokines such as IL-8 (P = 0.004), C-X-C motif ligand (CXCL) 1/2/3 (P = 0.028), CXCL 16 (P = 0.008), and regulated on activation, normal T cell expressed and secreted (RANTES) (P = 0.005) were overexpressed. Fas/Fas ligand and cluster of differentiation (CD)40/CD40 ligand systems were also overexpressed (P = 0.016 for Fas, P = 0.006 for Fas ligand, P = 0.005 for CD40, and P = 0.004 for CD40 ligand), contributing to tissue damage and inflammation. In peripheral blood, serum levels of the main proinflammatory cytokines, that is, IL-1β, tumor necrosis factor-α, and IL-17, were within the normal range, suggesting that in PASH syndrome, the inflammatory process is mainly localized into the skin. Four out of our 5 PASH patients presented genetic alterations typical of well-known AIDs, including inflammatory bowel diseases, and the only patient lacking genetic changes had clinically evident Crohn disease. In conclusion, overexpression of cytokines/chemokines and molecules amplifying the inflammatory network, along with the genetic changes, supports the view that PASH syndrome is autoinflammatory in origin.

A novel de novo PSTPIP1 mutation in a boy with pyogenic arthritis, pyoderma gangrenosum, acne (PAPA) syndrome

Autoinflammatory disorders are a group of Mendelian disorders characterized by seemingly unprovoked inflammatory bouts without high-titer autoantibodies or antigen-specific T-cells and are probably due to defects in the innate immunity. We here report on a 4-year-old Arabic boy with the clinical presentation of an autoinflammatory disorder, namely Pyogenic Arthritis, Pyoderma Gangrenosum and Acne (PAPA) syndrome. The presentation includes abscess formation after immunization and recurrent mono-articular acute arthritis in various joints that responded favourably to systemic glucocorticosteroids, albeit without acne or pyoderma gangrenosum. The mutation analysis of the boy identified a novel de novo mutation in PSTPIP1, the gene responsible for PAPA syndrome. We recommend that the diagnosis of PAPA syndrome should be entertained in the differential diagnosis of patients with recurrent sterile pyogenic arthritis prior to the development of pyoderma gangrenosum or acne in order to initiate a timely management of the disorder.

The inherited autoinflammatory syndrome: a decade of discovery

The hereditary autoinflammatory diseases arise from mutations of genes regulating the innate immune system. These rare disorders are well characterized, both clinically and in terms of their molecular pathogenesis. The recurrent attacks of febrile polyserositis of Familial Mediterranean Fever (FMF) are due to defective pyrin, a protein that down-regulates inflammation. The Hyperimmunoglobulinemia D Syndrome (HIDS), which mimics FMF, results from a genetically conferred deficiency of mevalonate kinase. TRAPS (TNF Receptor Associated Periodic Syndrome), formerly known as Familial Hibernian Fever, is caused by a defective membrane receptor for TNF. Three other hereditary disorders which overlap in their clinical expression - Familial Cold Autoinflammatory Syndrome, the Muckle Wells syndrome, and Neonatal Onset Multisystem Inflamatory Disease (NOMID) - are a consequence of gain-of-function mutations of the gene encoding cryopyrin, the scaffolding protein of the inflammasome. The PAPA syndrome (Pyogenic Arthritis, Pyoderma gangrenosum, Acne) results from mutations of a gene that increases the binding of its product (PSPSTPIP1) to pyrin, thereby blunting the inhibitory effect of pyrin on inflammasome activation.

Clonality in the setting of Sweet's syndrome and pyoderma gangrenosum is not limited to underlying myeloproliferative disease

BACKGROUND

The neutrophilic dermatoses encompass, among others, Sweet's syndrome (SS) and pyoderma gangrenosum (PG), which are associated with underlying systemic diseases including myeloid dyscrasias.

METHODS

On skin biopsies from 16 patients with biopsy-proven SS and/or PG, we performed an X-inactivation assay to detect clonal restriction of neutrophils. There were two patient categories based on known diseases at the time of diagnosis: patients with myeloproliferative disease and patients without myeloproliferative disease.

RESULTS

Among seven patients with acute myelogenous leukemia and two with myelodysplastic syndrome, clonal restriction was found in five; three were homozygous, precluding analysis. Among the seven control patients, infiltrates were clonally restricted in five; one was polyclonal and the other was homozygous for the allele, precluding analysis. Of the five patients with clonally restricted infiltrates, one was subsequently diagnosed with myelodysplasia, one had unexplained neutropenia and an additional patient developed breast cancer. Overall, the incidence of clonality in both groups was the same, averaging 81%.

CONCLUSION

These findings suggest that clonality in neutrophilic dermatoses, while characteristic of underlying myeloid dyscrasia, is not observed exclusively in the setting of myeloproliferative diseases. The significance of clonal neutrophilic infiltrates unassociated with myeloproliferative disease is unclear, but it may have some implications regarding the pathogenesis of sterile neutrophilic infiltrates. Clonality is well described in the setting of lymphomatoid hypersensitivity, reflecting an overzealous response to antigenic stimuli. One could speculate a similar mechanism operational in cases of apparently reactive SS/PG associated with monoclonality; a localized form of cutaneous neutrophilic dyscrasia is also possible.

The systemic autoinflammatory diseases: inborn errors of the innate immune system

The autoinflammatory syndromes are a newly recognized group of immune disorders that lack the high titers of self-reactive antibodies and T cells characteristic of classic autoimmune disease. Nevertheless, patients with these illnesses experience unprovoked inflammatory disease in the absence of underlying infection. Here we discuss recent advances in eight Mendelian autoinflammatory diseases. The causative genes and the proteins they encode play a critical role in the regulation of innate immunity. Both pyrin and cryopyrin, the proteins mutated in familial Mediterranean fever and the cryopyrinopathies, respectively, are involved in regulation of the proinflammatory cytokine, IL-1beta, and may influence the activity of the transcription factor, NFkappaB. NOD2, the Blau syndrome protein, shares certain domains with cryopyrin and appears to be a sensor of intracellular bacteria. PSTPIP1, mutated in the syndrome of pyogenic arthritis with pyoderma gangrenosum and acne, interacts both with pyrin and a protein tyrosine phosphatase to regulate innate and adaptive immune responses. Somewhat unexpectedly, mutations in the p55 TNF receptor lead not to immunodeficiency but to dramatic inflammatory disease, the mechanisms of which are still under investigation. Finally, the discovery of the genetic basis of the hyperimmunoglobulinemia D with periodic fever syndrome has provided a fascinating but incompletely understood link between cholesterol biosynthesis and autoinflammation. In this manuscript, we summarize the current state of the art with regard to the diagnosis, pathogenesis, and treatment of these inborn errors of the innate immune system.

Hereditary auto-inflammatory disorders and biologics

The term auto-inflammatory disorders has been coined to describe a group of conditions characterized by spontaneously relapsing and remitting bouts of systemic inflammation without apparent involvement of antigen-specific T cells or significant production of auto-antibodies. The hereditary periodic fever syndromes are considered as the prototypic auto-inflammatory diseases, and genetic studies have yielded important new insights into innate immunity. DNA analysis has greatly enhanced the clinical characterization of these conditions, and elucidation of their molecular aetiopathogenesis has suggested that therapies may be aimed at specific targets within the immune cascade. The availability of biologic response modifiers such as inhibitors of tumour necrosis factor (TNF) and interleukin-1beta has greatly improved the outlook for some of these disorders, although effective therapies remain elusive in patients with certain conditions, including hyperimmunoglobulinaemia-D with periodic fever syndrome (HIDS) and a proportion of those with TNF-receptor associated periodic syndrome (TRAPS). Indeed, outstanding challenges and the unique potential to further elucidate molecular mechanisms in innate immunity are illustrated by the dashed early hope that TNF blockade would be a panacea for TRAPS: not only is etanercept (Enbrel) ineffective in some cases, but there are anecdotal reports of this condition being greatly exacerbated by infliximab (Remicade).

Peculiarities of PAPA syndrome

OBJECTIVES

To describe a family from New Zealand with the pyogenic arthritis, pyoderma gangrenosum and acne (PAPA) syndrome, an autoinflammatory, variably expressed, erosive destructive form of arthritis.

METHODS

Information was gained through medical records and interviews of the affected patients and wider family. DNA sequencing was performed at Seay Center for Musculoskeletal Research Texas Scottish Rite Hospital for Children.

RESULTS

Five patients were affected over three generations with an E250Q mutation found on the CD2BP1 gene on chromosome 15. Common features included a severe, pauciarticular-onset, destructive peripheral arthritis, beginning at ages 5, 5, 2, 3 and 1(1/2) years. This combination marked cervical ankylosis (in two members), micrognathia and a more severe phenotype is unique. A third-generation family member treated early with DMARDs is following a less severe course. The skin involvement was variable, all with degrees of acne from puberty, though only one patient displayed pyoderma gangrenosum. A clear pattern of the arthritis switching off in adolescence and the triggering of skin disease was observed.

CONCLUSIONS

Differing degrees of joint destruction, and cervical ankylosis in this family with the E250Q mutation demonstrate PAPA syndrome's variable expression. Further understanding of this rare condition and its pathway may allow better targeting of treatments, not just for families with this specific syndrome but also for other, more common, forms of arthritis.

Familial Mediterranean fever and the other autoinflammatory syndromes: evaluation of the patient with recurrent fever

PURPOSE OF REVIEW

The aim of this article is to summarize recent clinical, genetic and pathophysiologic findings of familial Mediterranean fever and several of the other systemic autoinflammatory diseases, a recently recognized group of disorders characterized by seemingly unprovoked inflammation but lacking high-titer autoantibodies. Genetic and clinical tools are improving the ability of the clinician to better approach patients with periodic fever and inflammation.

RECENT FINDINGS

The spectrum of reported genetic mutations and susceptible ethnicities for the hereditary periodic fever subset of the autoinflammatory diseases has continued to expand. At the same time, the pathogeneses of many of these diseases are now understood to involve different aspects of a common pathway, largely affecting inflammatory cascades related to IL-1 or tumor necrosis factor-alpha. Three of these diseases which have been grouped as the cryopyrin-associated periodic syndromes result from defects in the same gene, and all three appear to respond well to anti-IL-1 therapy although controlled trials are still in progress. In addition, cytokine-based therapies are also now under investigation for hyperimmunoglobulinemia D with periodic fever syndrome and pyogenic sterile arthritis, pyoderma gangrenosum, and acne syndrome.

SUMMARY

The identification of the genes and proteins mutated in many of the autoinflammatory diseases has broadened our understanding of the regulation of inflammation and the immune system, and provided the basis for the use of targeted therapies in these syndromes. We propose an algorithm for the evaluation of a patient with periodic fever, taking into account the patient's age, ethnicity, symptoms and signs, and results from laboratory and genetic testing.

Dramatic improvement of pyoderma gangrenosum with infliximab in a patient with PAPA syndrome

Infliximab, a chimeric antitumor necrosis factor alpha monoclonal antibody (anti-TNF alpha), has been recently shown to have a beneficial effect on pyoderma gangrenosum associated with inflammatory bowel disease. Patients with the syndromic triad of pyogenic sterile arthritis, pyoderma gangrenosum, and acne, an autoinflammatory process caused by mutations in the CD2 binding protein-1 (CD2BP1) gene, can have severe pyoderma gangrenosum. We describe a 14-year-old patient with this syndrome who was unresponsive to multiple therapies. A dramatic improvement in his pyoderma gangrenosum was observed after one infusion of infliximab, and a second infusion led to its resolution. Our observation extends the therapeutic use of infliximab to this component of PAPA syndrome.

Infevers: an evolving mutation database for auto-inflammatory syndromes

The Infevers database (http://fmf.igh.cnrs.fr/infevers/) was established in 2002 to provide investigators with access to a central source of information about all sequence variants associated with periodic fevers: Familial Mediterranean fever (FMF), TNF Receptor Associated Periodic Syndrome (TRAPS), Hyper IgD Syndrome (HIDS), Familial Cold Autoinflammatory Syndrome/Muckle-Wells Syndrome/Chronic Infantile Neurological Cutaneous and Articular Syndrome (FCAS/MWS/CINCA). The prototype of this group of disorders is FMF, a recessive disease characterized by recurrent bouts of unexplained inflammation. FMF is the pivotal member of an expanding family of autoinflammatory disorders, a new term coined to describe illnesses resulting from a defect of the innate immune response. Therefore, we decided to extend the Infevers database to genes connected with autoinflammatory diseases. We present here the biological content of the Infevers database, including the introduction of two new entries: Crohn/Blau and Pyogenic sterile arthritis, pyoderma gangrenosum and acne (PAPA syndrome). Infevers has a range of query capabilities, allowing for simple or complex interrogation of the database. Currently, the database contains 291 sequence variants in related genes (MEFV, TNFRSF1A, MVK, CARD15, PSTPIP1, and CIAS1), consisting of published data and personal communications, which has revealed or refined the preferential mutational sites for each gene. This database will continue to evolve in its content and to improve in its presentation.

Association of pyoderma gangrenosum and sterile osteomyelitis in a patient having myelodysplastic syndrome with der(1;7)(q10;q10)

Neutrophilic dermatoses such as Sweet's disease and pyoderma gangrenosum (PG) are occasionally associated with myelodysplastic syndrome (MDS). We present here a 67-yr-old male having PG and sterile osteomyelitis in association with underlying MDS (refractory anemia) and Crohn's disease. To establish the diagnosis of MDS, sternal bone marrow puncture was performed, which showed chromosomal abnormality containing der(1;7)(q10;q10). After the puncture, he suffered from gradually progressive skin ulceration, flare, and bone pain. Magnetic resonance imaging (MRI) of the sternum showed severe inflammation in the sternum and the overlying subcutaneous tissue. All of the cultures obtained from the wound were negative for both bacteria and fungus. Biopsy was performed from the antero-sternal skin lesion, which showed epidermal ulceration with prominent infiltration of neutrophils. He was thus diagnosed as having PG and sterile osteomyelitis, and was treated with prednisolone, which completely resolved the symptoms. We consider that the bone marrow aspiration in the present patient provoked PG and sterile osteomyelitis. As was previously reported by others, certain chromosomal abnormalities in MDS may be related with the development of neutrophilic dermatoses.

[Familial pyoderma gangrenosum following a mammoplasty reduction: a case report]

The authors report a case of familial pyoderma gangrenosum following a mammoplasty reduction. This disease should be known by all surgeons, because its occurrence may follow all surgical procedure. The only efficient treatment is based on steroids and large surgical excisions must be contraindicated.

Familial ulcerative pyoderma gangrenosum: a report of 2 kindred

Pyoderma gangrenosum is a rare, chronic ulcerative skin disease. It is a diagnosis of exclusion, after ruling out other causes of cutaneous ulceration. The etiology of pyoderma gangrenosum is poorly understood but is likely multifactorial. We describe 2 families affected by ulcerative pyoderma gangrenosum. This familial clustering suggests a possible genetic role in the development of pyoderma gangrenosum in some cases.

Mutations in CD2BP1 disrupt binding to PTP PEST and are responsible for PAPA syndrome, an autoinflammatory disorder

PAPA syndrome (pyogenic sterile arthritis, pyoderma gangrenosum, and acne, OMIM #604416) and familial recurrent arthritis (FRA) are rare inherited disorders of early onset, primarily affecting skin and joint tissues. Recurring inflammatory episodes lead to accumulation of sterile, pyogenic, neutrophil-rich material within the affected joints, ultimately resulting in significant destruction. We recently localized the genes for PAPA syndrome and FRA to chromosome 15q and suggested that they are the same disorder. We have now established this by the identification of co-segregating disease-causing mutations in the CD2-binding protein 1 (CD2BP1; GenBank accession no XM 044569) gene in the two reported families with this disorder. E250Q or A230T amino acid substitutions occur within a domain highly homologous to yeast cleavage furrow-associated protein CDC15. CD2BP1 and its murine ortholog, proline-serine-threonine phosphatase interacting protein (PSTPIP1), are adaptor proteins known to interact with PEST-type protein tyrosine phosphatases (PTP). Yeast two-hybrid assays demonstrate severely reduced binding between PTP PEST and both the E250Q and A230T mutant proteins. Previous evidence supports the integral role of CD2BP1 and its interacting proteins in actin reorganization during cytoskeletal-mediated events. We hypothesize that the disease-causing mutations that we have identified compromise physiologic signaling necessary for the maintenance of proper inflammatory response. Accordingly we suggest classification of PAPA syndrome as an autoinflammatory disease. This CD2BP1-mediated biochemical pathway(s) may function in common inflammatory disorders with apparent etiological overlap, such as rheumatoid arthritis and inflammatory bowel disease.

Pyoderma gangrenosum in two siblings: a familial predisposition

We report pyoderma gangrenosum in two siblings with onset during childhood and no associated systemic abnormalities. The patients were born of nonconsanguineous, healthy parents. Treatment with oral corticosteroids produced an excellent clinical response, followed by recurrence after cessation of therapy. Steroids were restarted in combination with dapsone to prevent further recurrence.

Pyogenic arthritis, pyoderma gangrenosum, and acne syndrome maps to chromosome 15q

Pyoderma gangrenosum, cystic acne, and aseptic arthritis are clinically distinct disorders within the broad class of inflammatory diseases. Although this triad of symptoms is rarely observed in a single patient, a three-generation kindred with autosomal-dominant transmission of these three disorders has been reported as "PAPA syndrome" (MIM 604416). We report mapping of a disease locus for familial pyoderma gangrenosum-acne-arthritis to the long arm of chromosome 15 (maximum two-point LOD score, 5.83; recombination fraction [straight theta] 0 at locus D15S206). Under the assumption of complete penetrance, haplotype analysis of recombination events defined a disease interval of 10 cM, between D15S1023 and D15S979. Successful identification of a single disease locus for this syndrome suggests that these clinically distinct disorders may share a genetic etiology. These data further indicate the role of genes outside the major histocompatibility locus in inflammatory disease.

A new autosomal dominant disorder of pyogenic sterile arthritis, pyoderma gangrenosum, and acne: PAPA syndrome

OBJECTIVE

To describe a multigenerational family with transmission of an autosomal dominant disorder characterized by pyogenic arthritis, pyoderma gangrenosum, and severe cystic acne.

MATERIAL AND METHODS

We present a detailed case report of a 39-year-old man with arthritic changes in several joints, pyoderma gangrenosum, and cystic acne. Several relatives from three generations of his family underwent clinical and genetic investigations. The findings in this kindred are reported.

RESULTS

Ten affected family members in three generations manifested variable expression of a pauciarticular, nonaxial, destructive, corticosteroid-responsive arthritis that began in childhood; pyoderma gangrenosum; and severe cystic acne in adolescence and beyond. Other less commonly associated features included adult-onset insulin-dependent diabetes mellitus, proteinuria, abscess formation at the site of parenteral injections, and cytopenias attributable to sulfonamide medications. Laboratory evaluation was nondiagnostic. Genetic studies excluded linkage to the major histocompatibility locus.

CONCLUSION

The acronym of PAPA syndrome (pyogenic sterile arthritis, pyoderma gangrenosum, and acne) is suggested for this newly recognized pleiotropic autosomal dominant disorder. The nature of the genetic alteration in PAPA syndrome is unknown.

Familial pyoderma gangrenosum presenting in infancy

Pyoderma gangrenosum (PG) is a rare, poorly understood skin disease that occurs in all age groups. Less than 0.4% of patients are infants and represent a diagnostic challenge as early lesions may resemble other skin disorders. Here we report for the first time three siblings affected with PG all presenting during infancy. Unlike the older age group, the ulcers spared the legs but involved the buttocks, thighs and perianal area in all the infants.

CONCLUSION

This is the first reported family with PG affecting three siblings suggesting autosomal recessive inheritance. The diagnosis may be more difficult in infants due to absence of underlying associated disorders and the tendency of the lesions to appear in areas where infants frequently have other dermatoses. PG characteristically involves the buttocks, thighs and perianal area and spares the legs.