Collagen is a tough, glue-like protein that represents 30% of the body protein and shapes the structure of tendons, bones, and connective tissues. Malfunctioning of the immune system can affect blood vessels which in turn affects the connective tissues. Collagen vascular diseases include:
rheumatoid arthritissystemic lupus erythematosusperiarteritis nodosasclerodermadermatomyositispolyarteritis nodosa