PO8 - Clinical Presentations of Familial Sarcoidosis: A Retrospective Cohort Study from Finland
Sini Koivu (Finland)1; Aino Puhakka (Finland)1; Jari Huovinen (Finland)1 2; Inna Wathén (Finland)1; Joakim Hulkkonen (Finland)1; Terttu Harju (Finland)1 2; Hannu Vähänikkilä (Finland)3; Hanna Jaula (Finland)1 2; Johanna Leppänen (Finland)1 2; Riitta Kaarteenaho (Finland)1 2;
1 - Research Unit of Biomedicine and Internal Medicine, University of Oulu, Oulu, Finland; 2 - Center of Internal and Respiratory Medicine and Medical Research Center (MRC) Oulu, Oulu University Hospital, Oulu, Finland; 3 - Northern Finland Birth Cohorts, Arctic Biobank, Infrastructure for Population studies, Faculty of Medicine, University of Oulu, Oulu, Finland;
Keywords: familial sarcoidosis; systemic disease and lungs; cohort study;
Select the theme: Special Topics in Extrathoracic Sarcoidosis
Type: Original Papers
Presentation: Poster Presentation

Introduction: Familial sarcoidosis is an uncommon form of sarcoidosis characterized by disease clustering among relatives and an increased genetic susceptibility; however, the clinical features and disease course distinguishing familial from sporadic sarcoidosis remain poorly defined.

Objectives: This retrospective cohort study aimed to compare the clinical features, organ involvement, treatment, and outcomes between familial and sporadic sarcoidosis in a well-defined Finnish population.

Materials and Methods: Data from 1,131 patients with confirmed sarcoidosis diagnosed between 2008 and 2022 at Oulu University Hospital and Oulu District Hospital were analyzed. Familial sarcoidosis was defined as disease occurring in at least one first-, second-, or third-degree relative. Clinical characteristics, medication use, pulmonary function and comorbidities were compared between familial (n = 68) and sporadic (n = 1,063) cases, with additional sex-specific analyses performed within the familial group.

Results: Familial sarcoidosis accounted for 6.0% of cases and was more common in women (58.8%) and first-degree relatives (80.9%). Compared with sporadic cases, familial sarcoidosis was associated with increased ocular (P = .003) and renal (P = .019) involvement, more frequent multiorgan disease (≥3 organs: P = .020), and greater oral corticosteroid use (P = .032). Despite broader systemic manifestations, familial patients demonstrated greater pulmonary function improvement; Forced vital capacity (P = .027) and forced expiratory volume in 1 second (P = .0.031) percentages were significantly higher at follow-up. Sex-stratified analyses revealed more systemic involvement and poorer clinical response at follow-up (P = .040) in familial women, whereas men more frequently presented with concurrent pulmonary and lymph node disease (P = .045).

Conclusions: These findings indicate that familial sarcoidosis in the Oulu region represents a distinct clinical phenotype with broader systemic involvement and greater corticosteroid use, likely reflecting an underlying genetic predisposition. This supports recognition of familial sarcoidosis as a distinct entity requiring individualized diagnostic and therapeutic strategies.