The patients, aged between 5 and 12 years, exhibited the phenotypic variability associated with TMEM173-activating mutations,2-4 with lung disease and systemic inflammation being the major features ...in patient 1 (P1) and patient 3 (P3), while in patient 2 (P2) skin involvement was most prominent (Fig 1; see Supplemental Text and Table E1 in this article's Online Repository at www.jacionline.org). Modest and incomplete downregulation of ISG was recently described in splenic B cells of mice treated with tofacitinib, a JAK1/3 inhibitor, with differential signaling effects suggesting currently poorly understood facets of IFN regulation.9 In this regard, our kinetic ex vivo experiments provide insights into the rapid dynamic changes in IFN signaling secondary to JAK1 blockade.
Background Gain-of-function mutations in transmembrane protein 173 (TMEM173) encoding stimulator of interferon genes (STING) underlie a recently described type I interferonopathy called ...STING-associated vasculopathy with onset in infancy (SAVI). Objectives We sought to define the molecular and cellular pathology relating to 3 individuals variably exhibiting the core features of the SAVI phenotype including systemic inflammation, destructive skin lesions, and interstitial lung disease. Methods Genetic analysis, conformational studies, in vitro assays and ex vivo flow-cytometry were performed. Results Molecular and in vitro data demonstrate that the pathology in these patients is due to amino acid substitutions at positions 206, 281, and 284 of the human STING protein. These mutations confer cGAMP-independent constitutive activation of type I interferon signaling through TBK1 (TANK-binding kinase), independent from the alternative STING pathway triggered by membrane fusion of enveloped RNA viruses. This constitutive activation was abrogated by ex vivo treatment with the janus kinase 1/2 inhibitor ruxolitinib. Conclusions Structural analysis indicates that the 3 disease-associated mutations at positions 206, 281, and 284 of the STING protein define a novel cluster of amino acids with functional importance in the regulation of type I interferon signaling.
The CEC count was persistently higher at day 30 in patients with VE (median = 98/mL; range: 1-548) as compared to patients without VE (median = 4/mL; range: 2-52; P = .002) (Fig 1, A). ...the ...increase of CEC counts was significantly higher in patients with VE during the first month post-transplant (median δD0-D30 = 92; range: 16.5-547; P = .007) as compared to patients without (Fig 1, B).  No vascular event (n = 23) Vascular event (n = 11) Total patients (n = 34) Sex ratio female/male 9/14 3/8 12/22 Age: median (range) 3 y (0.5-14 y) 0.9 y (0.25-9 y) 3 and 5 y (0.25-14 y) Diagnosis    SCID 6 2 8 CID 8 5 13 HLH 5 3 8 Neutrophil disorders 3 1 5 Donor    Matched sibling donor 7 0 7 MUD 7 5 12 MMUD 4 2 6 Haploidentical donor 5 4 9 Defibrotide conditioning regimen 8 9 17 Bu/Flu/ATG 16 6 22 Bu/Flu/ThioTEPA/ATG 6 5 11 Mel/Flu/Alemtuzumab 1 0 1 Graft characteristics    In vitro T-depletion 5 6 11 No in vitro T-depletion 18 5 23 CD34 cell dose (106/kg) 8.2 (1.4-24.2) 13 (5-24.2) 10.5 (1.4-24.2) Engraftment day 19 (9-49) 18.5 (13-31) 19 (9-49) Rejection 2 1 3 GVHD 8 3 11 Grade 1-2 6 1 7 Grade 3-4 2 2 4 Time onset (days) 16.5 (2-60) 27 (10-47) 17 (2-60) CMV systemic replication 4 3 7 Severe sepsis 2 1 3 Duration of hospitalization post-HSCT (days) 78 (38-212) 92 (56-155) 83 (38-212) Death 3 5 8 Table I Hematopoietic transplantation characteristics For CD34 number, engraftment, time of onset of GVHD, and duration of post-HSCT hospitalization, median time is indicated with range in brackets.ATG, Antithymocyte globulin; Bu, busulfan; CID, combined immunodeficiency; CMV, cytomegalovirus; Flu, fludarabine; HLH, hemophagocytic lymphohistiocytosis; Mel, Melphalan; MMUD, mismatched unrelated donor; MUD, matched unrelated donor; SCID, severe combined immunodeficiency.
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