New Sarcoidosis Guideline Bringing Light to the Darkness

Nothing about sarcoidosis is easy. First identified in 1877, it is quite common. In the United States, lifetime risk is 2.4% and 0.85% for African American persons and White persons, respectively. Still, it remains an enigma. Despite study of its genetics and immunopathology, we don't know its cause. Diagnosis is challenging because noncaseating granulomas, the tissue finding associated with sarcoidosis, aren't specific for the disease. With the exception of Löfgren syndrome, a well-described sarcoid presentation that portends an excellent prognosis, initial signs and symptoms are variable and disease course is unpredictable. Alas, because sarcoid affects the lungs in more than 90% of patients, the general pulmonologist is left carrying the bag as the "sarcoidologist."

The inherent heterogeneity of sarcoid makes it challenging to study. In the modern era of evidence-based medicine, it's hard to say much about it with certainty. The American Thoracic Society (ATS) is one of just a few, premier organizations that creates respiratory medicine guidelines. In 1999, they published a sarcoid consensus statement with the European Respiratory Society (ERS), another outstanding and influential respiratory medicine organization, and the World Association of Sarcoidosis and other Granulomatous Disorders (WASOG). For the past 20 years, I've been referring trainees to this document for guidance on managing their patients with sarcoid.

Twenty years later, sarcoid remains frustrating and mysterious, but much has changed. Our methods for evaluating evidence and creating guidelines are now based on the GRADE criteria. Now that we have easy access to advanced technologies such as endobronchial ultrasound, obtaining tissue for diagnosis is easier. Our study of sarcoid itself has advanced, with large cohorts providing data on phenotyping, new immunosuppressants being used for treatment, and an improved understanding of cardiac sarcoidosis. In short, we're in need of a sarcoidosis guideline for the 21st century.

Within in the past 18 months, the ATS and ERS have delivered updated guidelines for diagnosis and treatment. Despite the advancements cited above, sarcoid remains difficult to study. So predictably, neither document issues earth-shattering conclusions. Truth be told, well-done guidelines rarely do. They do provide several important updates that physicians managing patients with sarcoid should note.

The guideline on diagnosis provides recommendations for routine monitoring after diagnosis. Many practicing clinicians took from the 1999 ATS/ERS/WASOG consensus statement that all patients with sarcoid needed to be seen annually. At pulmonary clinics where I've worked, we've defaulted to annual follow-up for everyone, usually with chest radiography, lab testing, electrocardiography, and referral to ophthalmology. Because a majority of patients with sarcoid will remain asymptomatic or experience spontaneous remission, this practice never really seemed cost-effective or clinically efficient. The new guidelines are far more proscriptive on what monitoring is required, grade requirements at specific levels of certainty, and often advise symptom-based assessments in lieu of reflexive annual testing.

The ERS guideline on treatment provides a thoughtful discussion of corticosteroid indications and dosing, broken down by underlying disease severity (assessed by lung function abnormalities and imaging). It also recognizes that two of the most common sarcoid symptoms are fatigue and dyspnea, which are both inherently nonspecific. In practice, proving these symptoms are directly attributable to sarcoid is challenging. The treatment guideline allows for flexibility in these cases, with shared decision-making and trials of low-dose steroids recommended. This seems an excellent hedge against over treatment with immunosuppressive medications that have harmful side effects.

The ATS and ERS guidelines are not without controversy. Their approach to cardiac sarcoid differs slightly from that recommended by a commonly cited Heart Rhythm Society consensus statement, and despite discussing treatment options, the section on fatigue is quite limited. These two facts and other limitations largely reflect differing interpretations of the limited data; they do not detract from the overall importance of the ATS and ERS guidelines. Sarcoid remains an enigma, but little by little the outstanding academic physicians at the ATS and ERS are providing clarity.

Aaron B. Holley, MD, is an associate professor of medicine at Uniformed Services University and program director of pulmonary and critical care medicine at Walter Reed National Military Medical Center. He covers a wide range of topics in pulmonary, critical care, and sleep medicine.

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