Analysis of 8 Cases of Blau Syndrome/Early-onset Sarcoidosis——Clinical Manifestations, Histopathology Features and Gene Mutation Diversity

  Objective  To summarize the clinical manifestations, pathological features and gene mutation diversity of Blau syndrome/early-onset sarcoidosis.

  Methods  We collected general data, clinical manifestations, and auxiliary examination results from 8 patients who were diagnosed of Blau syndrome/early-onset sarcoidosis and treated in our hospital from January 2011 to December 2022, and then summarized and analyzed their characteristics and diversity.

  Results  Among the 8 patients, 4 were males and 4 were females. The onset age was 3 to 8 months old. Rash was the first symptom in 7 patients(87.5%). 6 patients(75.0%) had papules and erythema.3 cases(37.5%) had arthritis. 2 cases(25.0%) had uveitis and other eye inflammation. 4 cases (50.0%) also showed intermittent fever. 3 cases (37.5%) showed symptoms in nerve and respiratory system, and hypertension respectively. The skin histopathology of 8 patients showed non-caseous granuloma formation. In laboratory detection, CRP and TNF-α were significantly increased before treatment, while IL-6, IL-8, TNF-α and IL-2 receptor(IL-2R) were significantly decreased in 5 patients after glucocorticoid therapy. The results of genetic testing showed that 4 of the 7 patients had p.R334W(c.1000C > T) mutation, 1 had p.H313R(c.938A > G) and p.R471C(c.1411C > T)double mutation, and 1 had p.476_477del (c.1427_1429delcct).

  Conclusions  Blau syndrome/early-onset sarcoidosis has significant features in clinical manifestations, histopathology and gene mutation, but it also has diversity.