In part 2 of important laboratory findings in chronic wounds we will take a look at serologies that are often considered when you are suspecting an ulcer due to “immune” causes. These include:

Anti-nuclear antibody

This test assesses for antibodies produced against cell nuceli. This is a powerful test for diagnosing a wide array of autoimmune conditions.  A positive ANA needs to be further evaluated with additional serology to arrive to a final autoimmune process

• Positive ANA associated with: Systemic lupus erythematosus , Lupus-like syndrome (drug induced lupus), Raynaud’s disease, Sjogren’s syndrome, antiphopholipid antibody syndrome and others
• Certain major laboratories such as Quest Diagnostics offer cascading ANA panels (ANAChoice) that automatically order the appropriate follow-up testing to help make a more specific diagnosis

Rheumatoid factor

Rheumatoid factor (RF) when present complexes with IgG (immunoglobulin G) and forms an immune complex which can illicit an inflammatory cascade.

• A positive RF does not necessarily mean a patient has rheumatoid arthritis. Clinical findings must also be consistent

Antiphospholipid antibodies

These antibodies are associated with the formation of both venous and arterial thrombi. Lupus anticoagulant and Anticardiolipin are the 2 most common antiphosphospholipid antibodies

Cryoglobulins

Cryoglobulins or cold agglutinin antibodies are abnormal immunoglobulins which are cold sensitive. At temperatures below 98.6 F of 37.0C they form immune complexes, precipitate out of the blood stream and cause micro-thrombi to form in sensitive areas such as the feet, hands and face

• A common and often missed cause of cryoglobulinemia is hepatitis C.