Thrombotic Microangiopathies and their Connection to Rheumatic Diseases

Thrombotic microangiopathies (TMAs) are disorders characterized by damage to the endothelium of blood vessels, leading to vascular occlusions and potential renal failure and mortality. TMAs can be associated with certain rheumatologic conditions such as Antiphospholipid Syndrome and can occur with other factors like infections, malignancies, autoimmune disorders, and severe hypertension. The shared phenotype of TMAs includes fragmented red blood cells, low platelet count, elevated LDH, and decreased haptoglobin. While TMAs like Thrombotic Thrombocytopenic Purpura (TTP) and Hemolytic Uremic Syndrome (HUS) have established treatments, new therapies are being explored. TTP is characterized by low ADAMTS13 levels and can occur in lupus patients. Rapid recognition and initiation of treatment, like plasmic exchange, are crucial. HUS, more common in pediatrics, is associated with acute kidney injury and may require complement inhibition with Eculizumab. Anaphospholipid Syndrome, often overlapping with TMAs, can manifest as catastrophic APS, presenting with microangiopathic hemolytic anemia and multiple organ involvement. Triple therapy (anticoagulation, plasma exchange or IVIG, and steroids) is the standard treatment for catastrophic APS. Diagnostic advancements and targeted therapies offer hope for improved outcomes in TMAs associated with rheumatic diseases.