Ruxolitinib in Aicardi-Goutières syndrome

A case of severe Aicardi-Goutières syndrome with a homozygous RNASEH2B intronic variant

We report a case of severe Aicardi-Goutières syndrome caused by a novel homozygous RNASEH2B intronic variant, NC_000013.10(NM_024570.4):c.65-13G > A p.Glu22Valfs*5. The patient was born with pseudo-TORCH symptoms, including intracranial calcification, cataracts, and hepatosplenomegaly. Furthermore, the patient exhibited profound intellectual impairment and died at 14 months due to aspiration pneumonia accompanied by interstitial lung abnormalities. The severity of the patient's symptoms underscores the critical role of the C-terminal region of RNase H2B.

TREX-1 related Aicardi-Goutières syndrome improved by Janus kinase inhibitor

Aicardi-Goutières syndrome (AGS) is a genetic interferonopathy classically characterized by early onset of severe neurologic injury with basal ganglia calcifications, white matter abnormalities, and progressive cerebral atrophy, along with lymphocytosis and raised interferon alpha (INFα) in the cerebrospinal fluid (CSF). Here, we report a 31/2 year-old patient born with prenatal onset AGS, first manifesting as intra-uterine growth retardation. Cranial ultrasonography and cerebral MRI revealed ventriculomegaly and periventricular and basal ganglia calcifications, along with cerebral atrophy. Perinatal infections and known metabolic disorders were excluded. Both CSF lymphocytosis and raised INFα were present. Molecular analysis disclosed two already described compound heterozygous pathogenic variants in TREX1 (c. 309dup, p.(Thr104Hisfs*53) and c. 506G > A, p.(Arg169His)). The evolution was marked by severe global developmental delay with progressive microcephaly. Promptly, the patient developed irritability, quadri-paretic dyskinetic movements, and subsequently tonic seizures. Sensorineural hearing loss was detected as well as glaucoma. Initially, he was symptomatically treated with trihexyphenidyl followed by levetiracetam and topiramate. At age 22 months, baricitinib (0.4 mg/kg/day) was introduced, leading to normal serum INFα levels. Clinically, dyskinetic movements significantly decreased as well as irritability and sleep disturbance. We confirmed that baricitinib was a useful treatment with no major side effect.

Type I Interferonopathies: A Clinical Review

This review will discuss when clinicians should consider evaluating for Type I interferonopathies, review clinical phenotypes and molecular defects of Type I interferonopathies, and discuss current treatments.

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.

Treatment response to Janus kinase inhibitor in a child affected by Aicardi-Goutières syndrome

Key Clinical Message

Baricitinib, a Janus kinase inhibitor (JAK-inhibitor), seems to contribute to an improvement of a child affected by Aicardi-Goutières syndrome (AGS), reducing the interferon score and determining a recovery of cognitive, communicative, and relational dysfunctions, while the gross motor deficit persisted.

Abstract

We report the treatment response to baricitinib, a JAK-inhibitor, in a 4-year-old girl affected by Aicardi-Goutières syndrome (AGS2, RNASEH2B mutation). Using quantitative measures, we detected a significant amelioration characterized by a complete recovery of cognitive, communicative, and relational skills after 8 and 16 months from the beginning of therapy.

Aicardi-Goutières syndrome (AGS): recurrent fetal cardiomyopathy and pseudo-TORCH syndrome

Aicardi-Goutières syndrome (AGS) induces innate immune activation. It can present with cerebral calcifications and hepatosplenomegaly mimicking congenital infections. The present case report discusses the diagnosis and treatment of a case of fetal cardiomyopathy whose postnatal symptoms resembled TORCH (toxoplasmosis, other agents, rubella, cytomegalovirus, herpes and syphilis) infection. The mother had a history of two lost pregnancies due to fetal cardiomyopathy and the same was identified in the current pregnancy. At 34 weeks of gestation, the mother delivered a late preterm male neonate due to intrauterine growth restriction weighing 1590 g with respiratory distress and cardiomyopathy at birth. The neonate had cerebral calcifications, hepatosplenomegaly and thrombocytopenia. As the infant's TORCH IgM titre was negative, pseudo-TORCH syndrome similar to AGS was suspected. Clinical exome sequencing of the parents and fetus identified no genes for hydrops fetalis or fetal cardiomyopathy; however, the AGS TREX1 gene was identified in the neonate, while additional symptoms resembled TORCH infection. The neonate was discharged and has shown improvement with oral baricitinib treatment for the last 9 months.

Characteristics and genetic analysis of patients suspected with early-onset systemic lupus erythematosus

BACKGROUND

Systemic lupus erythematosus (SLE) is rarely diagnosed before 5-years-old. Those with disease onset at a very young age are predicted by a higher genetic risk and a more severe phenotype. We performed whole-exome sequencing to survey the genetic etiologies and clinical manifestations in patients fulfilling 2012 SLICC SLE classification criteria before the age of 5.

CASE PRESENTATION

Among the 184 childhood-onset SLE patients regularly followed in a tertiary medical center in Taiwan, 7 cases (3.8%) of which onset ≦ 5 years of age were identified for characteristic review and genetic analysis. Compared to those onset at elder age, cases onset before the age of 5 are more likely to suffer from proliferative glomerulonephritis, renal thrombotic microangiopathy, neuropsychiatric disorder and failure to thrive. Causative genetic etiologies were identified in 3. In addition to the abundance of autoantibodies, patient with homozygous TREX1 (c.292_293 ins A) mutation presented with chilblain-like skin lesions, peripheral spasticity, endocrinopathy and experienced multiple invasive infections. Patient with SLC7A7 (c.625 + 1 G > A) mutation suffered from profound glomerulonephritis with full-house glomerular deposits as well as hyperammonemia, metabolic acidosis and episodic conscious disturbance. Two other cases harbored variants in lupus associating genes C1s, C2, DNASE1 and DNASE1L3 and another with CFHR4. Despite fulfilling the classification criteria for lupus, many of the patients required treatments beyond conventional therapy.

CONCLUSIONS

Genetic etiologies and lupus mimickers were found among a substantial proportion of patients suspected with early-onset SLE. Detail clinical evaluation and genetic testing are important for tailored care and personalized treatment.

Effectiveness and Safety of JAK Inhibitors in Autoinflammatory Diseases: A Systematic Review

Introduction

Autoinflammatory diseases (AID) are rare diseases presenting with episodes of sterile inflammation. These involve multiple organs and can cause both acute organ damage and serious long-term effects, like amyloidosis. Disease-specific anti-inflammatory therapeutic strategies are established for some AID. However, their clinical course frequently includes relapsing, uncontrolled conditions. Therefore, new therapeutic approaches are needed. Janus Kinase inhibitors (JAKi) block key cytokines of AID pathogenesis and can be a potential option.

Methods

A systematic review of the literature in accordance with the PRISMA guidelines was conducted. Three databases (MEDLINE, Embase and Cochrane Central Register of Controlled Trials) were searched for publications regarding the use of JAKi for AID. Data from the included publications was extracted and a narrative synthesis was performed. Criteria for defining treatment response were defined and applied.

Results

We report data from 38 publications with a total of 101 patients describing the effects of JAKi in AID. Data on Type I Interferonopathies, Adult-Onset Still's Disease (AOSD), Systemic Juvenile Idiopathic Arthritis (sJIA), Familial Mediterranean Fever (FMF), and Behçet's Syndrome (BS) was identified. From a total of 52 patients with type I interferonopathies, in seven patients (7/52, 13.5%) a complete response was achieved, most (35/52, 67.3%) showed a partial response and a minority (10/52, 19.2%) showed no treatment response. For AOSD, a complete or a partial response was achieved by eleven (11/26, 42.3%) patients each. Two sJIA patients achieved complete response (2/4, 50%) and in two cases (2/4, 50%) a partial response was reported. Half of FMF patients showed a complete response and the other half had a partial one (3/6, 50.0%). Amongst BS patients most achieved a partial response (8/13, 61.5%). Five patients showed no response to therapy (5/13, 38.5%). Overall, the most frequent AEs were upper respiratory tract infections (17), pneumonia (10), BK virus viremia (10) and viruria (4), herpes zoster infection (5), viral gastroenteritis (2) and other infections (4).

Conclusion

The results from this systematic review show that JAKi can be beneficial in certain AID. The risk of AEs, especially viral infections, should be considered. To accurately assess the risk benefit ratio of JAKi for AID, clinical trials should be conducted.

Analysis of clinical characteristics of children with Aicardi-Goutieres syndrome in China

BACKGROUND

Aicardi-Goutieres syndrome (AGS) is an inflammatory disorder belonging to the type I interferonopathy group. The clinical diagnosis of AGS is difficult, which can lead to a high mortality rate. Overall, there is a lack of large-sample research data on AGS in China. We aim to summarize the clinical characteristics of Chinese patients with AGS and provide clues for clinical diagnostic.

METHODS

The genetic and clinical features of Chinese patients with AGS were collected. Real-time polymerase chain reaction was used to detect expression of interferon-stimulated genes (ISGs).

RESULTS

A total of 23 cases were included, consisting of 7 cases of AGS1 with three prime repair exonuclease 1 mutations, 3 of AGS2 with ribonuclease H2 subunit B (RNASEH2B) mutations, 3 of ASG3 with RNASEH2C, 1 of AGS4 with RNASEH2A mutations, 2 of AGS6 with adenosine deaminase acting on RNA 1 mutations, and 7 of AGS7 with interferon induced with helicase C domain 1 mutations. Onset before the age of 3 years occurred in 82.6%. Neurologic involvement was most common (100%), including signs of intracranial calcification which mainly distributed in the bilateral basal ganglia, leukodystrophy, dystonia, epilepsy, brain atrophy and dysphagia. Intellectual disability, language disability and motor skill impairment were also observed. Skin manifestations (60.87%) were dominated by a chilblain-like rash. Features such as microcephaly (47.62%), short stature (52.38%), liver dysfunction (42.11%), thyroid dysfunction (46.15%), positive autoimmune antibodies (66.67%), and elevated erythrocyte sedimentation rate (53.85%) were also found. The phenotypes of 2 cases fulfilled the diagnostic criteria for systemic lupus erythaematosus (SLE). One death was recorded. ISGs expression were elevated.

CONCLUSIONS

AGS is a systemic disease that causes sequelae and mortality. A diagnosis of AGS should be considered for patients who have an early onset of chilblain-like rash, intracranial calcification, leukodystrophy, dystonia, developmental delay, positive autoimmune antibodies, and elevated ISGs, and for those diagnosed with SLE with atypical presentation who are nonresponsive to conventional treatments. Comprehensive assessment of vital organ function and symptomatic treatment are important.

Phenotypic variability of a TREX1 variant in Aicardi-Goutieres type 1 patients from the Indian subcontinent

Aicardi-Goutieres Syndrome (AGS) is a heterogeneous genetic syndrome, manifesting early as encephalopathy and is associated with abnormal neurologic findings, hepatosplenomegaly, elevated liver enzymes, thrombocytopenia and intracranial calcification. The most severe neonatal type, AGS1, is caused by biallelic disease-causing variants in TREX1. In this study, we describe four patients with TREX1-related AGS1 whose phenotype overlaps with intra-uterine infections and neonatal lupus. Exome sequencing identified a previously reported TREX1 variant, c.223dup (NM_016381.5; p. Glu75GlyfsTer82) in all the four patients belonging to the Indian subcontinent. The functional consequence of the disease-causing variant was predicted by using a new combination of bioinformatics softwares. The recurrence of this pathogenic variant indicates a possible founder effect in TREX1 for AGS1 in this population. The phenotypic variability in those with this founder mutation can mimic intrauterine infections and neonatal lupus, thereby leading to misdiagnosis warranting a targeted genetic testing approach to be a part of the diagnostic workup to obtain a definite, early and cost-effective diagnosis in patients from Indian subcontinent with early onset encephalopathy.

Case Report: Novel Compound Heterozygous RNASEH2B Mutations Cause Aicardi-Goutières Syndrome

Aicardi–Goutières Syndrome (AGS) is a rare disorder characterized by neurological and immunological signs. In this study we have described a child with a phenotype consistent with AGS carrying a novel compound heterozygous mutation in RNASEH2B gene. Next Generation Sequencing revealed two heterozygous variants in RNASEH2B gene. We also highlighted a reduction of RNase H2B transcript and protein levels in all the family members. Lower protein levels of RNase H2A have been observed in all the members of the family as well, whereas a deep depletion of RNase H2C has only been identified in the affected child. The structural analysis showed that both mutations remove many intramolecular contacts, possibly introducing conformational rearrangements with a decrease of the stability of RNase H2B and strongly destabilizing the RNase H2 complex. Taken together, these results highlight the importance of an integrated diagnostic approach which takes into consideration clinical, genetic, and molecular analyses.