A 32-year-old woman presents to the clinic with a history of three consecutive miscarriages, all occurring in the first trimester. She reports no significant symptoms between pregnancies, though she occasionally experiences mild joint pain. On further questioning, she denies fever, photosensitivity, or Raynaud’s phenomenon. Laboratory investigations show a positive lupus anticoagulant, elevated anticardiolipin antibodies, and a normal ANA titer. Her prothrombin time (PT) and partial thromboplastin time (PTT) are prolonged.
What is the most likely diagnosis?
A. Systemic lupus erythematosus (SLE)
B. Antiphospholipid syndrome (APS)
C. Systemic sclerosis
D. Rheumatoid arthritis
E. Gonococcal arthritis
Correct Answer: B. Antiphospholipid syndrome (APS)
Explanation:
Antiphospholipid syndrome (APS) is a systemic autoimmune disorder characterized by recurrent pregnancy loss, venous or arterial thrombosis, and the presence of antiphospholipid antibodies (aPL). These antibodies include lupus anticoagulant, anticardiolipin antibodies, and anti-beta-2 glycoprotein-I antibodies. APS may occur as a primary condition or secondary to systemic lupus erythematosus (SLE).
In this case, the patient presents with recurrent first-trimester miscarriages, a hallmark of APS. Miscarriages occur due to thrombosis of the placental vasculature, resulting in inadequate fetal development. Additional findings include:
- Positive lupus anticoagulant and anticardiolipin antibodies, fulfilling the diagnostic criteria for APS.
- Prolonged PTT due to interference with phospholipid-dependent clotting assays, despite an increased risk of thrombosis rather than bleeding.
Management involves:
- Anticoagulation therapy: Low-dose aspirin and low-molecular-weight heparin (LMWH) during pregnancy to prevent miscarriage.
- Long-term anticoagulation: In cases of thrombosis, lifelong anticoagulation with warfarin is indicated (avoided in pregnancy).
A. Systemic lupus erythematosus (SLE)
While SLE can be associated with pregnancy complications, recurrent miscarriages alone are insufficient for a diagnosis. Positive ANA and symptoms such as rash, photosensitivity, or renal involvement are typically present. Moreover, APS can occur independently of SLE, as in this case.
C. Systemic Sclerosis
This autoimmune disease primarily affects the skin and internal organs (e.g., lungs, kidneys) with features like Raynaud’s phenomenon, sclerodactyly, and esophageal dysmotility. Pregnancy complications are less common and usually result from vascular changes rather than thrombosis.
D. Rheumatoid Arthritis
Rheumatoid arthritis predominantly affects the joints and does not commonly lead to recurrent miscarriages. While RA can be associated with pregnancy complications, these are generally due to inflammation rather than thrombophilic conditions.
E. Gonococcal Arthritis
This is an infectious arthritis caused by Neisseria gonorrhoeae. It presents with migratory polyarthritis, tenosynovitis, and sometimes a characteristic pustular rash. It is not associated with recurrent pregnancy loss.