Mycobacterium tuberculosis as a sarcoid factor? A case report of family sarcoidosis

Patient: Male, 26 Final Diagnosis: Sarcoidosis Symptoms: Disseminated lung parenchymal changes Medication: — Clinical Procedure: — Specialty: Pulmonology OBJECTIVE: Rare disease BACKGROUND: Sarcoidosis is a granulomatous inflammatory disease that is induced by unknown antigen(s) in a genetically susceptible host. Although the direct link between Mycobacterium tuberculosis (MTB) infection and sarcoidosis can be excluded on the basis of a current knowledge, the non-infectious mechanisms may explain the causative role of mycobacterial antigens. The co-incidence of tuberculosis (TB) and sarcoidosis, and higher incidence of mycobacterial DNA in biological samples of sarcoid patients, have been reported by many authors. CASE REPORT: We present a case in which MTB infection in 1 family member triggered a sarcoid reaction in the infected subject and 2 other non-infected family members. We discuss different aspects of diagnosis and differentiation, as well as up-to-date hypotheses on the possible mechanisms leading to sarcoid inflammation in patients exposed to MTB. CONCLUSIONS: This case series documents the possibility of familial spreading of sarcoidosis, and points to MTB as a potential etiological factor.