False Positive ANA Testing In The Setting Of Hypovitaminosis D

Abstract

Vitamin D deficiency has been associated with autoimmune diseases, which include systemic lupus erythematosus, and may affect the outcome and activity of these diseases that result from aberrant activation of the immune system. Patients with the systemic autoimmune diseases may have a positive blood test for Antinuclear Antibodies (ANA). The ANA test is very sensitive for the diagnosis of autoimmune diseases but results in many false positives. It has been reported that up to 15% of completely healthy individuals have a positive ANA test without an autoimmune disease and that ANAs are measurable in approximately 25% of the population. Only about 10-13% of persons with a positive ANA test are found to have lupus. Vitamin D insufficiency/deficiency is prevalent in patients with autoimmune disease and vitamin supplementation has a therapeutic effect on disease severity and progression. Though there are many studies supporting the clinical picture that lupus patients are more prone to vitamin D deficiency, there are only a few articles that have considered the possibility that hypovitaminosis D is associated with false positive ANA testing. A case of an anemic patient who was initially evaluated and managed as a case of lupus is presented.