Overview of STING-Associated Vasculopathy with Onset in Infancy (SAVI) Among 21 Patients

BACKGROUND

Gain-of-function mutations in STING1 underlie a type I interferonopathy termed SAVI (STING-associated vasculopathy with onset in infancy). This severe disease is variably characterized by early-onset systemic inflammation, skin vasculopathy, and interstitial lung disease (ILD).

OBJECTIVE

To describe a cohort of patients with SAVI.

METHODS

Assessment of clinical, radiological and immunological data from 21 patients (17 families) was carried out.

RESULTS

Patients carried heterozygous substitutions in STING1 previously described in SAVI, mainly the p.V155M. Most were symptomatic from infancy, but late onset in adulthood occurred in 1 patient. Systemic inflammation, skin vasculopathy, and ILD were observed in 19, 18, and 21 patients, respectively. Extensive tissue loss occurred in 4 patients. Severity of ILD was highly variable with insidious progression up to end-stage respiratory failure reached at teenage in 6 patients. Lung imaging revealed early fibrotic lesions. Failure to thrive was almost constant, with severe growth failure seen in 4 patients. Seven patients presented polyarthritis, and the phenotype in 1 infant mimicked a combined immunodeficiency. Extended features reminiscent of other interferonopathies were also found, including intracranial calcification, glaucoma and glomerular nephropathy. Increased expression of interferon-stimulated genes and interferon α protein was constant. Autoantibodies were frequently found, in particular rheumatoid factor. Most patients presented with a T-cell defect, with low counts of memory CD8+ cells and impaired T-cell proliferation in response to antigens. Long-term follow-up described in 8 children confirmed the clinical benefit of ruxolitinib in SAVI where the treatment was started early in the disease course, underlying the need for early diagnosis. Tolerance was reasonably good.

CONCLUSION

The largest worldwide cohort of SAVI patients yet described, illustrates the core features of the disease and extends the clinical and immunological phenotype to include overlap with other monogenic interferonopathies.

Frequency and phenotypes of cutaneous vascular malformations in a consecutive series of 417 patients with familial cerebral cavernous malformations

BACKGROUND

Familial cerebral cavernous malformations (FCCM) are vascular malformations inherited as an autosomal-dominant condition. Three genes (KRIT1/CCM1, MGC4607/CCM2, PDCD10/CCM3) have been identified so far. Extra-neurological manifestations include retinal and cutaneous vascular malformations. The cutaneous vascular malformation, which had been more specifically associated with FCCM, is hyperkeratotic cutaneous capillary venous malformation (HCCVM).

OBJECTIVES

To define the frequency of cutaneous vascular malformations in patients with FCCM, to precise their different phenotypes, and to study the association of each cutaneous vascular malformation subtype with the different three mutated CCM genes.

METHODS

Dermatological inquiry was systematically performed in a large series of consecutive FCCM patients. Cutaneous biopsies were reviewed when available. Cutaneous vascular malformations classification was based on predominant anomalous channels, using the current International Society for the Study of Vascular Anomalies classification. Molecular screening of CCM genes was performed. Results Four hundred seventeen consecutive FCCM patients from 182 unrelated families were included. 38 patients (9%) from 25 different families had cutaneous vascular malformations. In these 38 patients, cutaneous vascular malformations were classified as follows: 13 capillary malformations (CM), 15 HCCVM, 8 venous malformations (VM) and 2 unclassified lesions. All patients (92%), but one with CM had a KRIT1/CCM1 mutation. The last patient had no detectable mutation. All of the 15 patients with HCCVM had a KRIT1/CCM1 mutation; 86.7% of cutaneous vascular malformation patients (33 of 38) had a KRIT1/CCM1 mutation.

CONCLUSION

Cutaneous vascular malformations are seen in 9% of FCCM patients. Three distinct major cutaneous vascular malformations phenotypes were identified: HCCVM (39%), CM (34%) and VM (21%). CCM1 is the most frequently mutated gene in cutaneous vascular malformations-FCCM patients.