From the Guidelines
The investigation of sarcoidosis should begin with a thorough clinical evaluation, chest X-ray, and pulmonary function tests, followed by cardiac MRI or PET scan for suspected cardiac involvement, as recommended by the most recent guidelines 1. The initial workup should include complete blood count, comprehensive metabolic panel, calcium levels, ACE levels, and 24-hour urinary calcium.
- Chest imaging is essential, with chest X-ray as the first step, followed by high-resolution CT scan for better characterization of lung involvement.
- Pulmonary function tests help assess lung function impairment.
- Additional tests based on suspected organ involvement include ophthalmologic examination for ocular involvement, and neuroimaging for neurosarcoidosis.
- Bronchoscopy with transbronchial biopsy is often the preferred method for obtaining tissue samples, with a diagnostic yield of 65-85% 1.
- Mediastinoscopy or surgical lung biopsy may be necessary if bronchoscopy is non-diagnostic.
- The Kveim-Siltzbach test is rarely used now.
- After diagnosis, staging is determined by chest X-ray findings (Stages 0-IV), which helps guide treatment decisions and provides prognostic information 1.
- Regular follow-up with pulmonary function tests and imaging is important to monitor disease progression and treatment response.
- For patients with extracardiac sarcoidosis and suspected cardiac involvement, cardiac MRI is suggested to obtain both diagnostic and prognostic information 1.
- Serum ACE levels can be useful in the diagnosis of sarcoidosis and for evaluating disease activity 1.
From the Research
Sarcoidosis Investigation
- Sarcoidosis is a multisystem inflammatory disease characterized by the formation of noncaseating granulomas in various organs, predominantly lungs, intrathoracic lymph nodes, skin, and eyes 2, 3, 4.
- The diagnosis of sarcoidosis relies on three criteria: a compatible clinical and radiologic presentation, pathologic evidence of noncaseating granulomas, and exclusion of other diseases with similar findings 3.
- Clinical features of sarcoidosis can be quite variable, and a Sarcoidosis Diagnostic Score (SDS) has been developed to summarize the clinical features of patients with possible sarcoidosis 5.
- Imaging techniques such as high-resolution computed tomography (HRCT), fluorodeoxyglucose positron emission tomography (FDG-PET), and magnetic resonance imaging (MRI) can be used to assess the extent of disease and evaluate the clinical management of patients responding or not to treatment 2, 4, 6.
- A diagnosis of sarcoidosis should be suspected in any young or middle-aged adult presenting with unexplained cough, shortness of breath, or constitutional symptoms, especially among blacks or Scandinavians 3.
- The presence of specific clinical features, especially multiorgan involvement, can enhance the diagnostic certainty of sarcoidosis 5.
- Various factors, including infection, genetic predisposition, and environmental factors, are involved in the pathology of sarcoidosis, and exposures to insecticides, herbicides, bioaerosols, and agricultural employment are also associated with an increased risk for sarcoidosis 4.