Function:

Phospholipids are a class of lipids that are a major component of all cell membranes. They play a role in the formation of lipid bilayers. Most phospholipids contain a diglyceride, a phosphate group, and a simple organic molecule such as choline.

Antibodies Appear:

- Antiphospholipid Syndrome[1, 4]

- NIDDM [7]

- Systemic Lupus Erythematosus [3, 6]

Known Cross-Reactions:

- Anti-ribosomal P protein antibodies [1]

- DNA [2]

- Cardiolipin [2]

Clinical Significance:

Antibodies against phospholipids may have an important role in mediating platelet destruction in autoimmune disorders. Anti-phospholipid antibodies (anti-PL) have been shown to bind to the membrane of activated platelets; thus it has been postulated that this may result in increased destruction of platelets by the reticuloendothelial system. [3]

Anti-PL have been demonstrated in patients with autoimmune thrombocytopenia (AITP) and Systemic lupus erythematosus (SLE). [3]

Anti-PL are directed against a diverse group of phospholipids and phospholipid-binding proteins; among these, anti-cardiolipin (anti-CL), anti-beta-2-glycoprotein I (b2-GP-I) and anti-prothrombin antibodies seem to be the most relevant from the clinical viewpoint. [1]

Anti-PL have been found in moderate and severe noninsulin-dependent diabetes mellitus patients, and thus may suggest that autoimmune nerve destruction may be involved in diabetic neuropathy in NIDDM patients. [7]

Anti-phospholipid antibody syndrome may appear as a stand-alone syndrome or associated with major connective tissue disease such as SLE and may manifest in a number of neurological conditions. [1]

Widespread thrombosis and infarction of placentas obtained from women with antiphospholipid syndrome (APS) was actually reported both in first and second trimester abortions. [4] There is evidence from in vitro studies that anti-PL may induce pro-coagulant state at the placental level, thus playing a pathogenic role of thrombotic events in anti-PL-associated pregnancy. [4]

It can be concluded that impaired endothelial fibrinolysis is a potential prothrombotic mechanism in subjects with antiphospholipid antibodies. [5]

References:

1. Caponi, et al. Antibodies directed against ribosomal P proteins cross-react with phospholipids. Clin exp Immunol, 2007; 150:140–143.

2. Koike, et al. Antibodies cross-reactive with DNA and cardiolipin in patients with systemic lupus erythematosus. Clin exp Immunol, 1982; 50:298-302.

3. Lipp, et al. Antibodies against platelet glycoproteins and antiphospholipid antibodies in autoimmune thrombocytopenia. Eur J Haemotol, 1998; 60:283-288.

4. Meroni, et al. Anti-phospholipid antibody mediated fetal loss: still an open question from a pathogenic point of view. Lupus, 2010; 19:453-456.

5. Patterson, et al. The influence of anti-endothelial/antiphospholipid antibodies on fibrin formation and lysis on endothelial cells. Br J Haematol, 2006; 133:323–330.

6. Petri. Update on anti-phospholipid antibodies in SLE: the Hopkins’ Lupus Cohort. Lupus, 2010; 19:419-423.

7. Shigeta, et al. Serum Autoantibodies Against Sulfatide and Phospholipid in NIDDM Patients With Diabetic Neuropathy. Diabetes Care, 1997; 20(12): 1896-1899.