Single-Center Overview of Pediatric Monogenic Autoinflammatory Diseases in the Past Decade: A Summary and Beyond

Autoinflammatory Recurrent Pericarditis Associated with a New NLRP12 Mutation in a Male Adolescent

Idiopathic recurrent pericarditis (IRP) can be the hallmark of an autoinflammatory syndrome with recurrent attacks of chest pain and symptom-free intervals following an acute episode. The recurrence rate may be 35% in the pediatric population, frequently with less severe manifestations than at the first episode. Pericarditis can be the sole clinical manifestation or may be part of a systemic autoinflammatory disease (SAID), especially in the case of a recurrence. Familial Mediterranean Fever (FMF), Tumor Necrosis Factor Receptor-Associated Periodic Syndrome (TRAPS), Mevalonate-Kinase Deficiency (MKD), nucleotide-binding oligomerization domain 2 (NOD2)-associated autoinflammatory syndrome, and others are closely related to IRP based on similar clinical manifestations and treatment responses to anti-interleukin 1 (IL-1) agents, such as anakinra, and should therefore be excluded in patients with IRP. A newly described SAID, an autosomal dominant disorder known as NLRP12-AID (nucleotide-binding leucine-rich repeat-containing receptor 12-related autoinflammatory disease) is caused by heterozygous mutations in the NLRP12 gene and most commonly affects children. Fewer than 40 pediatric patients with NLRP12-AID have been described in the medical literature, with none presenting with RP. We report a case of relapsing pericarditis responsive to anti-IL-1 therapy in a male adolescent who carried a missense mutation in the NLRP12 gene potentially causative of the excessive activation of inflammatory pathways. This is a unique case in the medical literature that associates recurrent pericarditis in an adolescent presumed to be related to the missense mutation in the NLRP12 gene. The role of the NLRP12 inflammasome in generating and maintaining recurrent pericardial inflammation should be considered.

PSTPIP1-Associated Myeloid-Related Proteinemia Inflammatory (PAMI) Syndrome: A Systematic Review

PSTPIP1 (proline-serine-threonine phosphatase-interactive protein 1)-associated myeloid-related proteinemia inflammatory (PAMI) syndrome, previously known as Hyperzincemia/Hypercalprotectinemia (Hz/Hc) syndrome, is a recently described, rare auto-inflammatory disorder caused by specific deleterious variants in the PSTPIP1 gene (p.E250K and p.E257K). The disease is characterized by chronic systemic inflammation, cutaneous and osteoarticular manifestations, hepatosplenomegaly, anemia, and neutropenia. Increased blood levels of MRP 8/14 and zinc distinguish this condition from other PSTPIP1-associated inflammatory diseases (PAID). The aim of this systematic review is to provide a comprehensive overview of the disease phenotype, course, treatment, and outcome based on reported cases. This systematic review adheres to the PRISMA guidelines (2020) for reporting. A literature search was performed in Embase, Medline, and Web of Science on 13 October 2022. The quality of the case reports and case series was assessed using the JBI checklists. Out of the 43 included patients with PAMI syndrome, there were 24 females and 19 males. The median age at onset was 3.9 years. The main clinical manifestations included anemia (100%), neutropenia (98%), cutaneous manifestations (74%), osteoarticular manifestations (72%), splenomegaly (70%), growth failure (57%), fever (51%), hepatomegaly (56%), and lymphadenopathy (39%). Systemic inflammation was described in all patients. Marked elevation of zinc and MRP 8/14 blood levels were observed in all tested patients. Response to treatment varied and no consistently effective therapy was identified. The most common therapeutic options were corticosteroids (N = 30), anakinra (N = 13), cyclosporine A (N = 11), canakinumab (N = 6), and anti-TNF (N = 14). Hematopoietic stem cell transplantation has been recently reported to be successful in five patients. Our review highlights the key characteristics of PAMI syndrome and the importance of considering this disease in the differential diagnosis of patients presenting with early-onset systemic inflammation and cytopenia.

Variant in the PLCG2 Gene May Cause a Phenotypic Overlap of APLAID/PLAID: Case Series and Literature Review

Background: Variants in the phospholipase C gamma 2 (PLCG2) gene can cause PLCG2-associated antibody deficiency and immune dysregulation (PLAID)/autoinflammation and PLCG2-associated antibody deficiency and immune dysregulation (APLAID) syndrome. Linking the clinical phenotype with the genotype is relevant in making the final diagnosis. Methods: This is a single center case series of five related patients (4−44 years), with a history of autoinflammation and immune dysregulation. Clinical and laboratory characteristics were recorded and a literature review of APLAID/PLAID was performed. Results: All patients had recurrent fevers, conjunctivitis, lymphadenopathy, headaches, myalgia, abdominal pain, cold-induced urticaria and recurrent airway infections. Hearing loss was detected in two patients. Inflammatory parameters were slightly elevated during flares. Unswitched B-cells were decreased. Naïve IgD+CD27− B-cells and unswitched IgD+CD27+ B-cells were decreased; switched IgD-CD27+ B-cells were slightly increased. T-cell function was normal. Genetic testing revealed a heterozygous missense variant (c.77C>T, p.Thr26Met) in the PLCG2 gene in all patients. Genotype and phenotype characteristics were similar to previously published PLAID (cold-induced urticaria) and APLAID (eye inflammation, musculoskeletal complaints, no circulating antibodies) patients. Furthermore, they displayed characteristics for both PLAID and APLAID (recurrent infections, abdominal pain/diarrhea) with normal T-cell function. Conclusion: The heterozygous missense PLCG2 gene variant (c.77C>T, p.Thr26Met) might cause phenotypical overlap of PLAID and APLAID patterns.

Der klinische Versorgungspfad zur multiprofessionellen Versorgung seltener Erkrankungen in der Pädiatrie – Ergebnisse aus dem Projekt TRANSLATE-NAMSE

Hintergrund

Seltene Erkrankungen (SE) manifestieren sich ganz überwiegend im Kindes- und Jugendalter, sind heterogen, multisystemisch, haben meist einen chronischen Verlauf und stellen eine große Herausforderung für alle Beteiligten dar. Finanziert durch den Innovationsfonds des G‑BA hatte das Versorgungsprojekt TRANSLATE-NAMSE das Ziel, Vorschläge zur besseren Versorgung von Menschen mit SE zu entwickeln und zu erproben.

Fragestellung

Für Patienten aller Altersgruppen mit einer Verdachtsdiagnose aus einer von 5 Gruppen definierter Indikatorerkrankungen (seltene Anämien, Endokrinopathien, Autoinflammationserkrankungen, primäre Immundefekte und Stoffwechselerkrankungen) sollte ein generischer Versorgungspfad entwickelt werden, der den Weg von der Konfirmationsdiagnostik bis hin zur Langzeitbetreuung dieser Patienten abbildet.

Methodik

Der Versorgungspfad wurde als allgemeines Ablaufschema dargelegt; die Prozessschritte wurden in eine Checkliste übertragen, inhaltlich ausformuliert und an 6 universitären Standorten an 587 Personen mit der Verdachtsdiagnose einer Indikatorerkrankungen erprobt.

Ergebnisse

Für 369 (62,9 %) Fälle mit der Verdachtsdiagnose einer Indikatorerkrankung konnte eine Diagnose gestellt werden, davon in 25,2 % mit innovativer genetischer Diagnostik; 104 (17,7 %) Verdachtsdiagnosen erwiesen sich als falsch-positiv; 114 (19,4 %) Fälle blieben ungeklärt. An Fallkonferenzen zur multiprofessionellen Versorgung nahmen im Median 4 Spezialisten teil. Die Versorgung (Diagnoseeröffnung, Schulung, Beratung, Information) begann im Median am Tag des Diagnostikergebnisses. In einer externen Evaluation erwies sich die Zufriedenheit der Sorgeberechtigten mit dem Versorgungspfad als hoch.

Schlussfolgerungen

Im bisher in Deutschland einzigartigen TRANSLATE-NAMSE-Projekt wurde ein Versorgungspfad für SE in der Pädiatrie entwickelt und erfolgreich erprobt. Zur Verstetigung dieser Versorgungsform ist eine auskömmliche Finanzierung in der Regelversorgung anzustreben.

A comprehensive interaction study provides a potential domain interaction network of human death domain superfamily proteins

Human death domain superfamily proteins (DDSPs) play important roles in many signaling pathways involved in cell death and inflammation. Disruption or constitutive activation of these DDSP interactions due to inherited gene mutations is closely related to immunodeficiency and/or autoinflammatory diseases; however, responsible gene mutations have not been found in phenotypical diagnosis of these diseases. In this study, we comprehensively investigated the interactions of death-fold domains to explore the signaling network mediated by human DDSPs. We obtained 116 domains of DDSPs and conducted a domain-domain interaction assay of 13,924 reactions in duplicate using amplified luminescent proximity homogeneous assay. The data were mostly consistent with previously reported interactions. We also found new possible interactions, including an interaction between the caspase recruitment domain (CARD) of CARD10 and the tandem CARD-CARD domain of NOD2, which was confirmed by reciprocal co-immunoprecipitation. This study enables prediction of the interaction network of human DDSPs, sheds light on pathogenic mechanisms, and will facilitate identification of drug targets for treatment of immunodeficiency and autoinflammatory diseases.

NLRC4 GOF Mutations, a Challenging Diagnosis from Neonatal Age to Adulthood

The NLRC4 inflammasome is part of the human immune innate system. Its activation leads to the cleavage of pro-inflammatory cytokines IL-1β and IL-18, promoting inflammation. NLRC4 gain-of-function (GOF) mutations have been associated with early-onset recurrent fever, recurrent macrophagic activation syndrome and enterocolitis. Herein, we describe two new patients with NLRC4 mutations. The first case presented with recurrent fever and vasoplegic syndrome, gut symptoms and urticarial rashes initially misdiagnosed as a severe protein-induced enterocolitis syndrome. The second case had recurrent macrophage activation syndrome (MAS) and shock, suggesting severe infection. We identified two NLRC4 mutations, on exon 4, within the nucleotide-binding protein domain (NBD). After a systematic review of NLRC4 GOF mutations, we highlight the wide spectrum of this disease with a limited genotype-phenotype correlation. Vasoplegic shock was only reported in patients with mutation in the NBD. Diagnosing this new entity combined with gastrointestinal symptoms and vasoplegic shocks is challenging. It mimics severe allergic reaction or sepsis. The plasma IL-18 level and genetic screening are instrumental to make a final diagnosis.

Ocular involvement in monogenic autoinflammatory disease

OBJECTIVE

Monogenic Autoinflammatory diseases (AIDs) are a broad spectrum of rare hereditary diseases whose ocular involvement has not been well characterized yet. This systematic review aims to provide an overview of the current knowledge about ocular findings in AIDs.

METHODS

A systematic literature review was conducted using 2 electronic databases, according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines. A combination of AIDs and ophthalmology-related search terms were used. All articles were screened by 2 independent reviewers for title, abstract and full text level. We included solely studies that investigated ocular findings in AIDs.

RESULTS

198 papers of 4268 records were retained. Data about 1353 patients with a diagnosis of autoinflammatory disease and ocular involvement were collected (680 CAPS, 211 FMF, 138 TRAPS, 238 Blau, 32 MKD, 21 SIFD, 7 Aicardi Goutières, 3 CANDLE, 8 DADA2, 9 HA20, 6 APLAID). Conjunctivitis was significantly more frequent in CAPS (p < 0.00001), uveitis in Blau, MKD, HA20 and CANDLE (p < 0.00001), papillitis/papilledema in CAPS (p < 0.00001), optic neuritis in Aicardi and DADA2 (p < 0.008), retinal vasculitis in FMF (p < 0.00001), progressive reduction in choroidal thickness in FMF and DADA2 (p < 0.00001), periorbital oedema in TRAPS (p < 0.00001) and retinitis in SIFD (p < 0.00001). Among AIDs with uveitis, granulomatous inflammation was more common in Blau syndrome (p < 0.00001).

CONCLUSION

This systematic literature review characterized the ocular involvement of several AIDs, and the present data may encourage to consider a timely ophthalmological screening program for these rare diseases.

Syndrome of Undifferentiated Recurrent Fever (SURF): An Emerging Group of Autoinflammatory Recurrent Fevers

Syndrome of undifferentiated recurrent fever (SURF) is a heterogeneous group of autoinflammatory diseases (AID) characterized by self-limiting episodes of systemic inflammation without a confirmed molecular diagnosis, not fulfilling the criteria for periodic fever, aphthous stomatitis, pharyngitis and adenopathy (PFAPA) syndrome. In this review, we focused on the studies enrolling patients suspected of AID and genotyped them with next generation sequencing technologies in order to describe the clinical manifestations and treatment response of published cohorts of patients with SURF. We also propose a preliminary set of indications for the clinical suspicion of SURF that could help in everyday clinical practice.