Janus Kinase Inhibitors in the Treatment of Type I Interferonopathies: A Case Series From a Single Center in China

Baricitinib Treatment in RNU7-1-Associated Aicardi-Goutières Syndrome in a South African Child: A Case Report

Aicardi-Goutières syndrome (AGS) is a rare monogenic type I interferonopathy. Janus kinase (JAK) inhibition has emerged as a potential treatment for AGS. RNU7-1 is one of the most recently discovered genes for AGS, and the clinical effects of JAK inhibition in these patients have not been reported. Here, we describe the diagnosis and treatment of a South African infant with RNU7-1-related AGS. The patient presented with developmental delay at age 5 months and was diagnosed with cerebral palsy due to a suspected congenital infection. By 18 months of age, he had a vasculitic rash, prominent generalized dystonia, persistent transaminitis, recurrent stomatitis, moderate-range global developmental delay, and difficulty sleeping. AGS was considered after finding neuroimaging features of the disease; the diagnosis was confirmed when genetic investigations revealed two likely pathogenic RNU7-1 compound heterozygous variants in the patient. Elevated interferon gene expression was noted in the patient and his mother who was a carrier of one RNU7-1 variant. Baricitinib treatment was started, leading to modest, transient improvements in some clinical manifestations and a reduction in interferon-stimulated gene expression. Liver function, dystonia, and neurological function did not improve even after increasing the baricitinib dose. Baricitinib was discontinued due to persistent and worsening adverse effects.

DNA-RNA hybrids in inflammation: sources, immune response, and therapeutic implications

Cytoplasmic DNA-RNA hybrids are emerging as important immunogenic nucleic acids, that were previously underappreciated. DNA-RNA hybrids, formed during cellular processes like transcription and replication, or by exogenous pathogens, are recognized by pattern recognition receptors (PRRs), including cGAS, DDX41, and TLR9, which trigger immune responses. Post-translational modifications (PTMs) including ubiquitination, phosphorylation, acetylation, and palmitoylation regulate the activity of PRRs and downstream signaling molecules, fine-tuning the immune response. Targeting enzymes involved in DNA-RNA hybrid metabolism and PTMs regulation offers therapeutic potential for inflammatory diseases. Herein, we discuss the sources, immune response, and therapeutic implications of DNA-RNA hybrids in inflammation, highlighting the significance of DNA-RNA hybrids as potential targets for the treatment of inflammation.

A rare case of late-onset spondyloenchondrodysplasia with immune dysregulation presenting as adult-onset monogenic lupus

BACKGROUND

Spondyloenchondrodysplasia is classified as an interferonopathy resulting from recessive mutations in the ACP5 gene and manifests with various clinical features, including distinctive skeletal dysplasia, neurological abnormalities, immune dysfunction resembling systemic lupus erythematosus (SLE) and Sjogren's syndrome. While SLE is typically considered multifactorial and more prevalent in adulthood, a subset of approximately 10%-25% of childhood cases arise from monogenic form. Among these, spondyloenchondrodysplasia accounts for only a rare fraction of monogenic lupus cases, with only 22 reported instances in the literature.

CASE REPORT

This paper presents a new case of spondyloenchondrodysplasia-immune dysregulation (SPENCDI) in an adult patient born to nonconsanguineous parents. The patient was diagnosed with SPENCDI and exhibited immune neutropenia, anti-dsDNA positivity, platyspondyly, immune deficiency, and a homozygous variant (c.155 A > C, p. Lys52Thr) in the ACP5 gene, previously classified as pathogenic. Notably, the patient achieved successful clinical management through the initiation of baricitinib treatment, a Janus kinase inhibitor.

CONCLUSION

SPENCDI represents an uncommon cause of SLE in adulthood. Clinicians should be vigilant of underlying Mendelian inheritance when encountering patients with associated features. While treatments for both Mendelian and non-Mendelian SLE are similar, Janus kinase inhibitors like baricitinib show potential for managing interferon-signature monogenic SLE cases.

Aicardi-Goutières syndrome type 6: report of ADAR variant and clinical outcome after ruxolitinib treatment in the neonatal period

BACKGROUND

Aicardi-Goutières Syndrome is a monogenic type 1 interferonopathy with infantile onset, characterized by a variable degree of neurological damage. Approximately 7% of Aicardi-Goutières Syndrome cases are caused by pathogenic variants in the ADAR gene and are classified as Aicardi-Goutières Syndrome type 6. Here, we present a new homozygous pathogenic variant in the ADAR gene. Currently, Janus Kinase inhibitors have been proposed to treat selected interferonopathies such as Aicardi-Goutières Syndrome, although limited information is available on its use and results in the neonatal presentation of this disease.

CASE PRESENTATION

We present two siblings, a male neonate with congenital petechial rash, severe thrombopenia and generalized hypotonia and his deceased sister who had normal development until 5 months of age, when she suffered acute encephalopathy. We describe the clinical course, complementary examinations and follow-up with early treatment of the newborn with ruxolitinib. The homozygous variant c.2908G > A (p.Ala970Thr) in the ADAR gene was found in both siblings, parents were heterozygous carriers.

CONCLUSIONS

The homozygous variant c.2908G > A (p.Ala970Thr) in the ADAR gene causes Aicardi-Goutières Syndrome type 6. Intrafamilial phenotypic spectrum of the disease varies among individuals with the same pathogenic variant. Early initiation of ruxolitinib improved systemic signs but did not prevent the progression of neurological disease.

A case of STING-associated vasculopathy with onset in infancy with novel STING1 variant

STING-associated vasculopathy with onset in infancy (SAVI) is a rare, monogenic interferonopathy caused by gain-of-function variants in STING1 (TMEM173) characterized by systemic inflammation, cutaneous vasculopathy, and interstitial lung disease. We report a case of SAVI attributed to a novel STING1 p.R284T variant who demonstrated characteristic cutaneous features including telangiectasias, livedo and acrocyanotic changes on face and extremities, as well as saddle nose deformity, failure to thrive, inflammatory arthritis and notable lack of pulmonary disease or autoantibody positivity. Due to the risk for progressive and irreversible lung and tissue damage and evolving therapeutic landscape involving the use of Janus kinase inhibitors, it is critical to recognize variable clinical phenotypes to diagnose and consider treatment options for SAVI patients early in their disease course.

Neuropathologic Impacts of JAK Inhibitor Treatment in Aicardi-Goutières Syndrome

Aicardi-Goutières syndrome (AGS) is a genetic interferonopathy characterized by upregulation of type I interferon response. It is associated with increased mortality and severe disabilities. Janus Kinase (JAK) inhibitors have shown effectiveness in treatment of AGS through blocking the downstream effects of interferon activation. We illustrate post-mortem histopathologic findings in a patient with AGS who received baricitinib treatment for a duration of over 4 years, initiating at a remarkably young age of 2 months. We observed global cerebral atrophy, markedly diminished white matter, abundant calcifications involving supratentorial white matter, basal ganglia, dentate nuclei, and brainstem. This study showed profound central nervous system (CNS) sequelae despite early initiation of treatment. Our findings highlight the potential necessity for therapeutic options with enhanced CNS bioavailability.

Case report: Refractory Evans syndrome in two patients with spondyloenchondrodysplasia with immune dysregulation treated successfully with JAK1/JAK2 inhibition

Biallelic mutations in the ACP5 gene cause spondyloenchondrodysplasia with immune dysregulation (SPENCDI). SPENCDI is characterized by the phenotypic triad of skeletal dysplasia, innate and adaptive immune dysfunction, and variable neurologic findings ranging from asymptomatic brain calcifications to severe developmental delay with spasticity. Immune dysregulation in SPENCDI is often refractory to standard immunosuppressive treatments. Here, we present the cases of two patients with SPENCDI and recalcitrant autoimmune cytopenias who demonstrated a favorable clinical response to targeted JAK inhibition over a period of more than 3 years. One of the patients exhibited steadily rising IgG levels and a bone marrow biopsy revealed smoldering multiple myeloma. A review of the literature uncovered that approximately half of the SPENCDI patients reported to date exhibited increased IgG levels. Screening for multiple myeloma in SPENCDI patients with rising IgG levels should therefore be considered.

A rare manifestation of STING-associated vasculopathy with onset in infancy: a case report

BACKGROUND

STING-associated vasculopathy with onset in infancy (SAVI) is a rare type I interferonopathy caused by heterozygous variants in the STING gene. In SAVI, STING variants confer a gain-of-function which causes overactivation of type I interferon (IFN) signaling leading to autoinflammation and various degrees of immunodeficiency and autoimmunity.

CASE PRESENTATION

We report the case of a 5 year old child and his mother, both of whom presented with systemic inflammatory symptoms yet widely varying organ involvement, disease course and therapeutic response. Genetic testing revealed a heterozygous STING variant, R281Q, in the child and his mother that had previously been associated with SAVI. However, in contrast to previously reported SAVI cases due to the R281Q variant, our patients showed an atypical course of disease with alopecia totalis in the child and a complete lack of lung involvement in the mother.

CONCLUSIONS

Our findings demonstrate the phenotypic breadth of clinical SAVI manifestations. Given the therapeutic benefit of treatment with JAK inhibitors, early genetic testing for SAVI should be considered in patients with unclear systemic inflammation involving cutaneous, pulmonary, or musculoskeletal symptoms, and signs of immunodeficiency and autoimmunity.

Case report: JAK1/2 inhibition with baricitinib in the treatment of STING-associated vasculopathy with onset in infancy

BACKGROUND

Gain-of-function mutations in STING1 (also known as TMEM173) which result in constitutive activation of STING, have been reported to cause STING-associated vasculopathy with onset in infancy (SAVI). Although a wider spectrum of associated manifestations and perturbations in disease onset have been observed since its description, the genotype-phenotype correlations are not definite, and there is no established treatment protocol for SAVI.

CASE PRESENTATION

Herein, we report a kindred, heterozygous STING mutation (p.V155M) in which the 2-year-old proband suffered from severe interstitial lung disease (ILD) while her father was initially misdiagnosed with connective tissue disease associated with ILD at an adult age. Baricitinib was initiated after the diagnosis of SAVI in the proband combined with steroids, and during the 14-month follow-up, the respiratory symptoms were improved. However, as the improvement of laboratory indicators was limited, especially in autoimmune indices, and the lung CT images remained unaltered, it seems that JAK1/2 inhibition was unsatisfactory in completely controlling the inflammation of the disease in our study.

CONCLUSIONS

Baricitinib was shown to elicit some effect on the ILD but failed to control the inflammation of the disease completely. Further exploration of JAK inhibitors or other therapeutic strategies are needed to more optimally treat this inflammatory disease.

Efficacy and safety of thalidomide in children with monogenic autoinflammatory diseases: a single-center, real-world-evidence study

BACKGROUND

Monogenic autoinflammatory diseases (AIDs) are rare inflammatory diseases caused by genetic variants. The pathogenesis is complex and treatment options are limited. This study aimed to describe the safety and efficacy of thalidomide in the treatment of monogenic AIDs.

METHODS

This was a single-center, single-arm, real-world study. From September 2016 to August 2021, patients with monogenic AIDs who met the inclusion and exclusion criteria were given thalidomide for 12 months. There was a 3-month run-in period before dosing. The efficacy and adverse events were evaluated and recorded every 3 months. After 3 and 12 months of thalidomide treatment, clinical manifestations, disease activity score, inflammatory markers, and background medication adjustments were compared with baseline for efficacy analyses.

RESULTS

A total of 16 patients entered this study, including 3 with Aicardi-Goutières syndrome (AGS), 4 Blau syndrome, 2 chronic infantile neurologic cutaneous articular syndrome (CINCA), 2 A20 haploinsufficiency (HA20), 1 adenosine deaminase 2 deficiency(DADA2), 1 familial Mediterranean fever (FMF),1 tumor necrosis factor (TNF) receptor-associated periodic syndrome (TRAPS), 1 PLCγ2-associated antibody deficiency and immune dysregulation (PLAID), and 1 stimulator of interferon genes-associated vasculopathy with onset in infancy(SAVI). The efficacy rate in the 16 patients after 3-month and 12-month thalidomide treatment in patients was 56.3%. Twelve patients completed the study, the fever improved in all of them, rash improved in 7 patients, and 5 patients stopped using glucocorticoids or other immunosuppressive agents. C-reactive protein was normal in 8 patients and erythrocyte sedimentation rate was normal in 11 patients. Anorexia and nausea occurred in 2 cases, with no other reported drug-related adverse reactions.

CONCLUSION

The largest cohort of monogenic AIDs with the treatment of thalidomide demonstrated that thalidomide can help reduce disease activity and inflammation, reduce the dosage of glucocorticoids, and improve clinical outcomes. Thalidomide is relatively safe in monogenic AIDs.

Aicardi-Goutières syndrome: A monogenic type I interferonopathy

Aicardi-Goutières syndrome (AGS) is a rare monogenic autoimmune disease that primarily affects the brains of children patients. Its main clinical features include encephalatrophy, basal ganglia calcification, leukoencephalopathy, lymphocytosis and increased interferon-α (IFN-α) levels in the patient's cerebrospinal fluid (CSF) and serum. AGS may be caused by mutations in any one of nine genes (TREX1, RNASEH2A, RNASEH2B, RNASEH2C, SAMHD1, ADAR1, IFIH1, LSM11 and RNU7-1) that result in accumulation of self-nucleic acids in the cytoplasm or aberrant sensing of self-nucleic acids. This triggers overproduction of type I interferons (IFNs) and subsequently causes AGS, the prototype of type I interferonopathies. This review describes the discovery history of AGS with various genotypes and provides the latest knowledge of clinical manifestations and causative genes of AGS. The relationship between AGS and type I interferonopathy and potential therapeutic methods for AGS are also discussed in this review.

TREX1 cytosolic DNA degradation correlates with autoimmune disease and cancer immunity

The N-terminal domain of Three Prime Repair Exonuclease 1 (TREX1) is catalytically active and can degrade dsDNA or ssDNA in the cytosol, whereas the C-terminal domain is primarily involved in protein localization. TREX1 deficiency induces cytosolic DNA accumulation as well as activation of the cGAS-STING-IFN signaling pathway, which results in tissue inflammation and autoimmune diseases. Furthermore, TREX1 expression in cancer immunity can be adaptively regulated to promote tumor proliferation, making it a promising therapeutic target.

Breaking down the cellular responses to type I interferon neurotoxicity in the brain

Since their original discovery, type I interferons (IFN-Is) have been closely associated with antiviral immune responses. However, their biological functions go far beyond this role, with balanced IFN-I activity being critical to maintain cellular and tissue homeostasis. Recent findings have uncovered a darker side of IFN-Is whereby chronically elevated levels induce devastating neuroinflammatory and neurodegenerative pathologies. The underlying causes of these 'interferonopathies' are diverse and include monogenetic syndromes, autoimmune disorders, as well as chronic infections. The prominent involvement of the CNS in these disorders indicates a particular susceptibility of brain cells to IFN-I toxicity. Here we will discuss the current knowledge of how IFN-Is mediate neurotoxicity in the brain by analyzing the cell-type specific responses to IFN-Is in the CNS, and secondly, by exploring the spectrum of neurological disorders arising from increased IFN-Is. Understanding the nature of IFN-I neurotoxicity is a crucial and fundamental step towards development of new therapeutic strategies for interferonopathies.

Use of Tofacitinib for infant-onset STING-associated vasculopathy: A case report from China

BACKGROUND

Stimulator of interferon gene (STING)-associated vasculopathy with onset in infancy (SAVI), caused by gain-of-function mutations in human transmembrane protein 173 (TMEM173), is characterized by widespread chronic inflammation primarily affecting the skin and lungs. Although SAVI is an inflammatory disease, typical anti-inflammatory agents have limited or no effect.

METHODS AND RESULTS

A 1-year-old boy presented with recurrent facial rashes since he was 8 months. Moreover, he suffered from recurrent oral ulcers, chronic cough, and failure to thrive. Laboratory parameters showed elevated erythrocyte sedimentation rate (ESR) and immunoglobulin levels. Chest high-resolution computed tomography (HRCT) showed interstitial lung disease (ILD). Whole-exome sequencing revealed a heterozygous mutation in the TMEM173 gene (c.463G > A, p.V155M). Ultimately, the patient was diagnosed with SAVI. Tofacitinib was initiated at the age of 19 months, resulting in the alleviation of facial rashes and improvement of ILD within 3 months.

CONCLUSION

SAVI is a difficult-to-treat type I interferonopathy. We hope that JAKi treatment will prove valuable for SAVI patients.

Treatment of severe COVID-19: an evolving paradigm

INTRODUCTION

The pathogenesis of severe COVID-19 is due, in part, to dysregulation of the human immune system in response to SARS-CoV-2 infection. Immune cells infected with SARS-CoV-2 can trigger a hyperinflammatory response of both the adaptive and innate immune system that has been associated with severe disease, hospitalization, and death, and better treatment options are urgently needed.

AREAS COVERED

A mainstay of therapy for COVID-19 involves an antiviral agent, remdesivir, in combination with a systemic corticosteroid, dexamethasone.

EXPERT OPINION

The addition of a second immunomodulator, such as an interleukin-6 inhibitor or a Janus kinase inhibitor, has been associated with clinical benefit in a subset of patients with moderate-to-severe disease, but their use remains controversial. This manuscript reviews what is known about the approach to treatment of severe COVID-19 and examines how immunomodulators such as infliximab and abatacept may alter clinical management and COVID-19 research in the years ahead based on the results of randomized, controlled trials.

Phenotypic spectrum in recessive STING-associated vasculopathy with onset in infancy: Four novel cases and analysis of previously reported cases

Gain-of-function variants in the stimulator of interferon response cGAMP interactor 1 (STING1) gene cause STING-Associated Vasculopathy with onset in Infancy (SAVI). Previously, only heterozygous and mostly de novo STING1 variants have been reported to cause SAVI. Interestingly, one variant that only leads to SAVI when homozygous, namely c.841C>T p.(Arg281Trp), has recently been described. However, there are no entries in public databases regarding an autosomal recessive pattern of inheritance. Here, we report four additional unrelated SAVI patients carrying c.841C>T in homozygous state. All patients had interstitial lung disease and displayed typical interferon activation patterns. Only one child displayed cutaneous vasculitis, while three other patients presented with a relatively mild SAVI phenotype. Steroid and baricitinib treatment had a mitigating effect on the disease phenotype in two cases, but failed to halt disease progression. Heterozygous c.841C>T carriers in our analysis were healthy and showed normal interferon activation. Literature review identified eight additional cases with autosomal recessive SAVI caused by c.841C>T homozygosity. In summary, we present four novel and eight historic cases of autosomal recessive SAVI. We provide comprehensive clinical data and show treatment regimens and clinical responses. To date, SAVI has been listed as an exclusively autosomal dominant inherited trait in relevant databases. With this report, we aim to raise awareness for autosomal recessive inheritance in this rare, severe disease which may aid in early diagnosis and development of optimized treatment strategies.

Acrofacial necrotic ulcers in an infant: An undiagnosed presentation

Acral necrotic ulcers in infancy are rare but have been described in type I interferonopathies. Herein, we present a case of an 8-year-old child who presented at the age of one month with severe ulceronecrotic lesions on the face and limbs with exacerbations following exposure to cold weather. Despite extensive investigation the case remains undiagnosed to this day. We hypothesize that this case represents a novel and yet unknown autoinflammatory disease.