[A case of probable catastrophic antiphospholipid syndrome with multi-organ failure presenting as a transient increase of antiphospholipid antibody levels].

A 44-year-old woman was admitted to our hospital with shock, massive pneumonia and respiratory failure, liver and renal dysfunction, and cerebral infarction. Based on these symptoms, we suspected the presence of disseminated intravascular coagulation and multiple organ dysfunctions due to massive pneumonia or catastrophic antiphospholipid syndrome (CAPS). Therefore, the patient was placed on a respirator and was administered ciprofloxacin, doripenem hydrate, thrombomodulin, antithrombin III, and methylprednisolone pulse therapy. Because the patient's antiphospholipid antibody titer was low on the day of admission (day 1), we did not include CAPS in the differential diagnosis and discontinued prednisolone treatment on day 6. However, the anticardiolipin immunoglobulin M antibody titer was found to be elevated on day 7; in addition, a transient increase in the anticardiolipin anti-β2 glycoprotein antibody titer was noted on re-examination. Moreover, on day 8, the thrombopenia and alveolar hemorrhage suddenly exacerbated. We finally diagnosed the patient with CAPS, and therefore resumed methylprednisolone therapy. Subsequently, the inflammation, respiratory failure, and thrombopenia rapidly improved, and the patient was extubated on day 12.