PSTPIP1-associated myeloid-related proteinemia inflammatory syndrome: A rare cause of childhood neutropenia associated with systemic inflammation and hyperzincemia

[Autoinflammatory diseases associated with IL-18]

Autoinflammatory diseases (AIDs) are conditions characterized by dysfunction of innate immunity, causing systemic inflammation and various clinical symptoms. The field of AIDs has expanded due to improved comprehension of pathophysiological mechanisms and advancements in genomics techniques. A new emerging category of AIDs is characterized by a significant increase in interleukin 18 (IL-18), a pro-inflammatory cytokine synthesized in macrophages and activated by caspase 1 via various inflammasomes. IL-18 plays a role in the regulation of innate and adaptive immunity. IL-18 is involved in various functions, such as the proliferation, survival, and differentiation of immune cells, tissue infiltration of immune cells, polarization of immune responses, and production of other pro-inflammatory cytokines. This review analyzes the literature on IL-18 regarding its functions and its implications in the diagnosis and treatment of AIDs. IL-18-associated AIDs comprise Still's disease and diseases associated with mutations in NLRC4, XIAP, CDC42, and PSTPIP1, as well as IL-18BP deficiencies. With the exception of PSTPIP1-associated diseases, these conditions all carry a risk of macrophagic activation syndrome. Measuring IL-18 levels in serum can aid in the diagnosis, prognosis, and monitoring of these diseases. Therapies targeting IL-18 and its signaling pathways are currently under investigation.

[Monogenic auto-inflammatory diseases associated with actinopathies: A review of the literature]

Auto-inflammatory diseases (AIDs) are diseases resulting from an inappropriate activation of innate immunity in the absence of any infection. The field of monogenic AIDs is constantly expanding, with the discovery of new pathologies and pathophysiological mechanisms thanks to pangenomic sequencing. Actinopathies with auto-inflammatory manifestations are a new emerging group of AIDs, linked to defects in the regulation of the actin cytoskeleton dynamics. These diseases most often begin in the neonatal period and combine to varying degrees a more or less severe primary immune deficiency, cytopenias (especially thrombocytopenia), auto-inflammatory manifestations (especially cutaneous and digestive), atopic and auto-immune manifestations. The diagnosis is to be evoked essentially in front of a cutaneous-digestive auto-inflammation picture of early onset, associated with a primary immune deficiency and thrombocytopenia or a tendency to bleed. Some of these diseases have specificities, including a risk of macrophagic activation syndrome or a tendency to atopy or lymphoproliferation. We propose here a review of the literature on these new diseases, with a proposal for a practical approach according to the main associated biological abnormalities and some clinical particularities. However, the diagnosis remains genetic, and several differential diagnoses must be considered. The pathophysiology of these diseases is not yet fully elucidated, and studies are needed to better clarify the inherent mechanisms that can guide the choice of therapies. In most cases, the severity of the picture indicates allogeneic marrow transplantation.

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.

Update on autoinflammatory diseases

PURPOSE OF REVIEW

Although the concept of systemic autoinflammatory diseases (SAIDs) is still very young, our knowledge about them is exponentially growing. In the current review, we aim to discuss novel SAIDs and autoinflammatory pathways discovered in the last couple of years.

RECENT FINDINGS

Advances in immunology and genetics have led to the discovery of new pathways involved in autoinflammation, as well as several new SAIDs, including retinal dystrophy, optic nerve edema, splenomegaly, anhidrosis, and migraine headache (ROSAH syndrome), vacuoles, E1 enzyme, X-linked autoinflammatory somatic (VEXAS) syndrome, TBK1 deficiency, NEMO deleted exon 5 autoinflammatory syndrome (NDAS), and disabling pansclerotic morphea. Progress in immunobiology and genetics has also brought forth novel treatments for SAIDs. Personalized medicine has made significant progress in areas such as cytokine-targeted therapies and gene therapies. However, much work remains, especially in measuring and improving the quality of life in patients with SAIDs.

SUMMARY

In the current review, we discuss the novelties in the world of SAIDs, including mechanistic pathways of autoinflammation, pathogenesis, and treatment. We hope this review helps rheumatologists to gain an updated understanding of SAIDs.

Pediatric autoimmune myelofibrosis: Experience from a large pediatric tertiary care center

Autoimmune myelofibrosis (AIMF) is a rare disorder characterized by cytopenias and autoimmunity, with characteristic bone marrow findings that include lymphocytic infiltration and fibrosis. AIMF is described predominantly in adult populations who have systemic lupus erythematosis (SLE), with scant pediatric cases described mainly in older adolescents with SLE. Here, we described the largest single-center pediatric experience of pediatric autoimmune myelofibrosis (PAIMF) series, demonstrating both similarities and distinctions from the adult experience. Patients overall respond well to steroid therapy, but these patients were significantly younger, infrequently carried a diagnosis of SLE, and causative genetic lesions were identified in many cases.

Strong inflammatory signatures in the neutrophils of PAMI syndrome

PSTPIP1 (proline-serine-threonine phosphatase-interactive protein 1)–associated myeloid-related proteinemia inflammatory (PAMI) syndrome is a rare autoinflammatory disease caused by heterozygous gain-of-function mutation in PSTPIP1. As one of the PSTPIP1-associated inflammatory diseases (PAIDs), neutropenia is a distinct manifestation to separate PAMI syndrome from other PAIDs. This study aimed to investigate the potential role of neutrophils and inflammatory signatures in the pathogenesis of PAMI. PAMI neutrophils displayed markedly increased production of interleukin-1β (IL-1β) and IL-18 by enzyme linked immunosorbent assay (ELISA) assay and intracellular cytokine staining. ASC speck formation and lactic dehydrogenase (LDH) release are also increased in patient neutrophils suggesting elevated pyrin inflammasome activation followed by upregulated cell death in PAMI neutrophils. RNA sequencing result showed strong inflammatory signals in both nuclear-factor kappa B (NF-κB) pathway and interferon (IFN) pathway in patient neutrophils. This study highlighted that elevated proinflammatory cytokines IL-1β and IL-18, increased pyrin inflammasome activation, and upregulation of NF-κB and IFN signaling pathways in neutrophils play important roles in pathogenicity of PAMI syndrome.

PSTPIP1-associated myeloid-related proteinaemia inflammatory (PAMI) syndrome; a case presenting as a perinatal event with early central nervous system involvement?

BACKGROUND

We report a three-year-old girl with a potentially unique phenotype of perinatal onset and neurovascular features who was found to have PAMI syndrome. We also compare her case to those previously reported and review the differences between the PSTPIP1-associated inflammatory diseases (PAID) phenotypes and genotypes.

CASE PRESENTATION

The patient was found to have a heterozygous pathogenic variant in PSTPIP1 (c.748G > A p.E250K). This variant was shown to be absent in both parents and therefore de novo in the patient. A literature review was carried out through multiple databases using the terms PSTPIP1, PAID, PAPA syndrome and PAMI syndrome. This information was collected and used to form comparisons between the current literature and our reported case.

CONCLUSIONS

Our case contributes to the literature on PAMI syndrome whilst providing an example of a potentially unique clinical phenotype, giving insight into the pre-symptomatic phase of the condition. We highlight the importance of considering PAMI syndrome in the differential for early onset unexplained inflammation. In addition, we explore the possibility that perinatal neurovascular events could be an early feature of PAMI syndrome.

Clinical and genetic characteristics of PSTPIP1-associated myeloid-related proteinemia inflammatory syndrome

OBJECTIVE

To summarise the clinical and genetic characteristics of three children with PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome.

METHODS

This study retrospectively analysed the clinical and genetic data of three children with PAMI syndrome in our hospital between April 2018 and January 2020.

RESULTS

One male and two female children were 6 years and 5 months, 8 years and 7 months, and 13 years and 3 months of age. All three patients had a recurrent blood trilineage hypoplasia and splenomegaly. Patient 1 had pyoderma gangrenosum, and Ludwig's angina. Patient 2 had pyogenic arthritis, and pyoderma gangrenosum. Patient 3 had hepatomegaly, pyogenic arthritis, and pulmonary hypertension. Laboratory tests revealed that all three children had elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). Patient 1: C-antineutrophilic cytoplasmic antibodies(c-ANCA), positive; antiglobulin test (Coombs), positive. Patient 2: blood zinc, 4.38 mg/L (elevated). Patient 3: Antinuclear antibodies (ANA), 1:100, β2 glycoprotein I, positive; Coombs test, positive; RF, 28.3 U/ml (elevated); C3, 0.77 g/L (decreased). Genetic testing showed that all 3 patients had PSTPIP1 c.748G > A (p.E250K) spontaneous heterozygous mutations, suggesting the diagnosis of PAMI syndrome. Patient 1 was treated with a combination of methylprednisolone and cyclosporine for 8 months. The patient did not develop new skin lesions. The blood count showed mild neutropenia. The spleen was considerably retracted and the CRP became normal. Patient 2 was treated with etanercept and methylprednisolone. The patient had no further arthralgias and pyoderma gangrenosum showed improvement. The spleen was smaller than before. White blood cells were shown to be approximately 2-3 × 10⁹/L. The haematocrit, platelets, CRP, and AESR were normal. Patient 3 was treated with methylprednisolone, methotrexate, and infliximab 4 times. The patient's joint symptoms disappeared gradually and the liver retracted markedly. The pulmonary artery pressure returned to normal. Moreover, Coombs test result was negative. CRP and AESR were lower than before.

CONCLUSION

PAMI syndrome can manifest as pyogenic arthritis, pyoderma gangrenosum, acne, and trilineage hypoplasia, as well as autoimmune diseases. Glucocorticoid and immunosuppressive therapy are partially effective and cytokine antagonists can be used in refractory cases. Whole-exome genetic testing is helpful to confirm diagnosis.

PAMI syndrome: A rare cause that can be easily misdiagnosed

PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome caused by mutations in PSTPIP1 is a rare inflammatory disorder that can be easily misdiagnosed. It is characterized by anemia, arthritis, cutaneous inflammation, recurrent infections, growth failure, hepatosplenomegaly, lymphadenopathy, hyperzincemia/hypercalprotectinemia, neutropenia, thrombocytopenia, and elevated inflammatory indicators. This study describes the cases of two pediatric female patients with long-standing recurrent arthralgia in different parts of the extremities and severe anemia, respectively, who were misdiagnosed and treated for aseptic necrosis of the femoral head and severe autoimmune hemolytic anemia, respectively. High-throughput sequencing analysis revealed a de novo heterozygous missense mutation (c.748G > A, p. Glu250Lys) in exon 11 of PSTPIP1 (NM_003978.5) in both patients, which supported a diagnosis of PAMI. The patients were treated with prednisone and etanercept, which improved their symptoms, but neutropenia remained unchanged. These cases highlight the importance of genetic assessment for the accurate diagnosis of PAMI and to ensure adequate and timely treatment of these patients.

Hemolysis and Neurologic Impairment in PAMI Syndrome: Novel Characteristics of an Elusive Disease

PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome is a rare early-onset autoinflammatory disease associated with various hematologic findings, including chronic neutropenia and pancytopenia. We report a unique case of PAMI syndrome in a toddler with transfusion-dependent hemolytic anemia, hepatosplenomegaly, failure to thrive, developmental delay, and multiple malformations. Because of acute inflammatory-driven decompensation, anakinra was started with dramatic improvement of both the hematologic and neurologic involvement. A customized next-generation sequencing panel later identified a de novo pathogenic variant in the PSTPIP1 gene, confirming the diagnosis. Our case illustrates the broad spectrum of phenotypes associated with PAMI syndrome, which should be considered in any case of unexplained cytopenias associated with autoinflammatory stigmata. It is also one of the few reports of neurologic involvement in PSTPIP1-associated inflammatory diseases. Increased awareness of this rare disease and early performance of genetic testing can correctly diagnose PAMI syndrome and prevent disease complications.

Rare cases of PAMI syndrome in both father and son with the same missense mutation in PSTPIP1 gene and literature review

PSTPIP1-associated myeloid-related proteinaemia inflammatory (PAMI) syndrome has been described as a rare and distinct clinical phenotype of PSTPIP1-associated inflammatory diseases. We report PSTPIP1 mutation in both father and son who have leukopenia and acne-like lesions. Through whole-exome sequencing on blood DNA, it is found a heterozygous mutation of PSTPIP1 gene c.748G>A on the father and son. The diagnosis of PAMI is made based on DNA sequencing results and clinical characteristics of typical lesions, leukopenia, and the markedly increased serum S100A8/A9 (calprotectin).

Actin Remodeling Defects Leading to Autoinflammation and Immune Dysregulation

A growing number of monogenic immune-mediated diseases have been related to genes involved in pathways of actin cytoskeleton remodeling. Increasing evidences associate cytoskeleton defects to autoinflammatory diseases and primary immunodeficiencies. We reviewed the pathways of actin cytoskeleton remodeling in order to identify inflammatory and immunological manifestations associated to pathological variants. We list more than twenty monogenic diseases, ranging from pure autoinflammatory conditions as familial Mediterranean fever, mevalonate kinase deficiency and PAPA syndrome, to classic and novel primary immunodeficiencies as Wiskott-Aldrich syndrome and DOCK8 deficiency, characterized by the presence of concomitant inflammatory and autoimmune manifestations, such as vasculitis and cytopenia, to severe and recurrent infections. We classify these disorders according to the role of the mutant gene in actin cytoskeleton remodeling, and in particular as disorders of transcription, elongation, branching and activation of actin. This expanding field of rare immune disorders offers a new perspective to all immunologists to better understand the physiological and pathological role of actin cytoskeleton in cells of innate and adaptive immunity.

Actin Remodeling Defects Leading to Autoinflammation and Immune Dysregulation

A growing number of monogenic immune-mediated diseases have been related to genes involved in pathways of actin cytoskeleton remodeling. Increasing evidences associate cytoskeleton defects to autoinflammatory diseases and primary immunodeficiencies. We reviewed the pathways of actin cytoskeleton remodeling in order to identify inflammatory and immunological manifestations associated to pathological variants. We list more than twenty monogenic diseases, ranging from pure autoinflammatory conditions as familial Mediterranean fever, mevalonate kinase deficiency and PAPA syndrome, to classic and novel primary immunodeficiencies as Wiskott-Aldrich syndrome and DOCK8 deficiency, characterized by the presence of concomitant inflammatory and autoimmune manifestations, such as vasculitis and cytopenia, to severe and recurrent infections. We classify these disorders according to the role of the mutant gene in actin cytoskeleton remodeling, and in particular as disorders of transcription, elongation, branching and activation of actin. This expanding field of rare immune disorders offers a new perspective to all immunologists to better understand the physiological and pathological role of actin cytoskeleton in cells of innate and adaptive immunity.

HSCT is effective in patients with PSTPIP1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome

BACKGROUND

Proline-serine-threonine phosphatase-interacting protein 1-associated myeloid-related proteinemia inflammatory (PAMI) syndrome is a novel genetic disorder, causing hypercalprotectinemia and hyperzincemia with inflammatory complications accompanied by cytopenia. Immunosuppressive and/or anticytokine therapy is of limited effect.

OBJECTIVES

Because of cytokine production in nonhematopoietic tissues, the potential therapeutic effect of allogeneic hematopoietic stem cell transplantation (HSCT) in autoinflammatory disorders, including PAMI syndrome, has remained uncertain.

METHODS

Five patients with PAMI syndrome underwent allogeneic HSCT with myeloablative (4) or reduced-intensity (1) conditioning regimens. Lack of PAMI disease control served as indication for the HSCT in 4 patients and myelodysplastic syndrome development in 1.

RESULTS

All 5 patients engrafted; however, 1 patient at day +13 developed hemophagocytic syndrome, followed by graft rejection at day +17. After 5.5 months, a second HSCT was performed from an alternative donor. A further patient at day +116 developed an intense inflammatory syndrome with significant serositis and severe mitral and aortic valve regurgitation, controlled with adalimumab, tacrolimus, and prednisone. No other noninfectious inflammatory episodes, or acute or chronic graft-versus-host disease, occurred in any patient. At the last follow-up (median, 2.2 years), all 5 patients have predominantly or complete donor chimerism and adequate immune recovery and are free of any PAMI symptoms.

CONCLUSIONS

Allogeneic HSCT seems to be an effective option to cure cytopenia and severe autoinflammation in PAMI syndrome and may be a curative option for other proline-serine-threonine phosphatase-interacting protein 1-associated inflammatory disorders with poor therapeutic control.

Phenotypic Associations of PSTPIP1 Sequence Variants in PSTPIP1-Associated Autoinflammatory Diseases

Pathogenic variants in the PSTPIP1 gene cause pyogenic sterile arthritis, pyoderma gangrenosum, and acne (PAPA) syndrome. They were also identified in a broad spectrum of phenotypes. As their interpretation is sometimes challenging, we discuss the genotype-phenotype association in PSTPIP1-associated autoinflammatory diseases (PAIDs) in light of a recent consensus classification of variant pathogenicity. Only 7 of 39 (18%) of the PSTPIP1 variants found in all reported cases and our national reference center (161 patients [114 probands]) were pathogenic. They were clearly associated with PAPA and PSTPIP1-associated myeloid-related proteinemia inflammatory syndrome (PAMI), reflecting a variable clinical expression of PAIDs.

A Next-Generation Sequencing Test for Severe Congenital Neutropenia: Utility in a Broader Clinicopathologic Spectrum of Disease

Severe congenital neutropenia (SCN) is a collection of diverse disorders characterized by chronically low absolute neutrophil count in the peripheral blood, increased susceptibility to infection, and a significant predisposition to the development of myeloid malignancies. SCN can be acquired or inherited. Inherited forms have been linked to variants in a group of diverse genes involved in the neutrophil-differentiation process. Variants that promote resistance to treatment have also been identified. Thus, genetic testing is important for the diagnosis, prognosis, and management of SCN. Herein we describe clinically validated assay developed for assessing patients with suspected SCN. The assay is performed from a whole-exome backbone. Variants are called across all coding exons, and results are filtered to focus on 48 genes that are clinically relevant to SCN. Validation results indicated 100% analytical sensitivity and specificity for the detection of constitutional variants among the 48 reportable genes. To date, 34 individuals have been referred for testing (age range: birth to 67 years). Several pathogenic and likely pathogenic variants have been identified, including one in a patient with late-onset disease. The pattern of cases referred for testing suggests that this assay has clinical utility in a broader spectrum of patients beyond those in the pediatric population who have classic early-onset symptoms characteristic of SCN.

ISSAID/EMQN Best Practice Guidelines for the Genetic Diagnosis of Monogenic Autoinflammatory Diseases in the Next-Generation Sequencing Era

BACKGROUND

Monogenic autoinflammatory diseases are caused by pathogenic variants in genes that regulate innate immune responses, and are characterized by sterile systemic inflammatory episodes. Since symptoms can overlap within this rapidly expanding disease category, accurate genetic diagnosis is of the utmost importance to initiate early inflammation-targeted treatment and prevent clinically significant or life-threatening complications. Initial recommendations for the genetic diagnosis of autoinflammatory diseases were limited to a gene-by-gene diagnosis strategy based on the Sanger method, and restricted to the 4 prototypic recurrent fevers (MEFV, MVK, TNFRSF1A, and NLRP3 genes). The development of best practices guidelines integrating critical recent discoveries has become essential.

METHODS

The preparatory steps included 2 online surveys and pathogenicity annotation of newly recommended genes. The current guidelines were drafted by European Molecular Genetics Quality Network members, then discussed by a panel of experts of the International Society for Systemic Autoinflammatory Diseases during a consensus meeting.

RESULTS

In these guidelines, we combine the diagnostic strength of next-generation sequencing and recommendations to 4 more recently identified genes (ADA2, NOD2, PSTPIP1, and TNFAIP3), nonclassical pathogenic genetic alterations, and atypical phenotypes. We present a referral-based decision tree for test scope and method (Sanger versus next-generation sequencing) and recommend on complementary explorations for mosaicism, copy-number variants, and gene dose. A genotype table based on the 5-category variant pathogenicity classification provides the clinical significance of prototypic genotypes per gene and disease.

CONCLUSIONS

These guidelines will orient and assist geneticists and health practitioners in providing up-to-date and appropriate diagnosis to their patients.

PAPA spectrum disorders

Pyogenic arthritis, pyoderma gangrenosum (PG) and acne (PAPA) syndrome is an autosomal dominant autoinflammatory syndrome due to mutations in proline-serine-threonine phosphatase interacting protein 1 (PSTPIP1) gene and presenting with cutaneous and articular manifestations. Other autoinflammatory syndromes caused by mutations in PSTPIP1 gene or characterized by clinical findings overlapping with those found in PAPA syndrome have been recently included in the group of PAPA spectrum disorders. These disorders are PASH (PG, acne and hidradenitis suppurativa [HS]), PAPASH (PASH associated with pyogenic sterile arthritis), PsAPASH (PASH combined with psoriatic arthritis [PsA], PASS (PG, acne, ankylosing spondylitis, with or without HS), PAC (PG, acne and ulcerative colitis [UC]) and PAMI syndrome (PSTPIP1-associated myeloid-related-proteinemia inflammatory syndrome). Except for PAPA and PAMI, no specific pathogenetic mutations have been identified in these syndromes. Dermatologists should be aware that PG, acne and HS may represent cutaneous signs hiding the presence of these rare entities. Systemic corticosteroids, a number of immunosuppressants and biologics, such as interleukin (IL)-1 antagonists and tumour necrosis factor (TNF) α inhibitors, are nowadays therapy for these diseases. A pathogenesis-driven treatment is the near future in the management of these conditions.

The expanding pathways of autoinflammation: a lesson from the first 100 genes related to autoinflammatory manifestations

AutoInflammatory Diseases (AIDs) are a group of innate immune system disorders characterized by sterile inflammation without evidence of pathogenic autoantibodies or auto-reactive T lymphocytes. An expanding spectrum of genes and molecular pathways are associated with AIDs. Inflammasomopathies are secondary to dysregulation of multi-protein complexes, called inflammasomes, leading to an excessive maturation and secretion of IL1β and IL18. Patients present with persistent or recurrent systemic inflammation, abdominal and chest pain, skin rashes and are sensible to IL1 inhibitors. Unfolded proteins response causes a small number of AIDs that we propose to call immuno-proteinopathies, characterized by recurrent fevers and deep tissues inflammation. Other inflammatory conditions can occur in case of abnormalities of actin polymerization and the term of immuno-actinopathies is proposed. Generalized pustular psoriasis is a marker of autoinflammation mainly affecting the keratinocytes. Specific treatment targeting the p40 subunit of IL12 and IL23 or IL-17 are usually effective. Granulomatous inflammation characterizes AIDs related to NOD2 signaling defects. Defects in the ubiquitin-proteasome system cause a group of relopathies and some interferonopathies related to defect of the proteasome function (CANDLE syndrome). Gain of function of proteins regulating the production of type I interferons lead to severe inflammatory conditions, called interferonopathies. The JAK/STAT inhibitors are usually effective in these latter conditions. In conclusions, the identification of the main intracellular pathways involved in rare monogenic AIDs allows not only the proper classification of different conditions, but also highlight a pivotal role of possible novel therapeutic targets for the future.

Neutropenia in the age of genetic testing: Advances and challenges

Identification of genetic causes of neutropenia informs precision medicine approaches to medical management and treatment. Accurate diagnosis of genetic neutropenia disorders informs treatment options, enables risk stratification, cancer surveillance, and attention to associated medical complications. The rapidly expanding genetic testing options for the evaluation of neutropenia have led to exciting advances but also new challenges. This review provides a practical guide to germline genetic testing for neutropenia.