Mixed Connective Tissue Disease-related ILD

Mixed connective tissue disease (MCTD) is an overlap syndrome including features of systemic lupus erythematous (SLE), systemic sclerosis (SSc), and polymyositis (PM).¹ Up to 80% of MCTD patients present with pulmonary manifestations, including ILD (sometimes fibrotic), pleural effusion, and pulmonary arterial hypertension (PAH).² The defining clinical feature of MCTD is the presence of high titers of anti-U1 ribonucleoprotein antibody.¹

Overlap syndrome:

• SLE
• SSc
• PM

MCTD EPIDEMIOLOGY

In the United States, prevalence is estimated to be 32,000, and the annual incidence is around 6500 individuals.^3,4

Onset of disease typically occurs in individuals between 15-30 years of age.⁵

RISK FACTORS AND MORTALITY⁵

RISK FACTORS:

• Females are 3 times more likely to develop MCTD

MORBIDITY/MORTALITY:

• 10-year survival ^~80%
• Prognosis is worse in patients with signs of SSc and/or PM

Pulmonary hypertension is the most common MCTD-related cause of death.

SYMPTOMS

Symptoms of MCTD:^1,5

• Raynaud’s phenomenon
• Puffy or swollen fingers
• Arthritis
• Prone to developing PAH

Many nonspecific symptoms may come before these more obvious signs — frequent fatigue, myalgias, arthralgias, low-grade fevers.⁵

MCTD-ILD EPIDEMIOLOGY⁶

• Just as MCTD is underdiagnosed, the associated ILD is also likely underrecognized
• An estimated 40% of people with MCTD have signs of ILD on HRCT
• ILD affects survival of patients with MCTD