Challenging differential diagnosis, Unusual setting of medical care, Rare disease
Sihyung Park, Yoo Jin Lee, Yang Wook Kim, Junghae Ko, Jin Han Park, Il Hwan Kim, Hee-Jin Kim, Doyeun Oh, Bong Soo Park
Department of Internal Medicine, Inje University Haeundae Paik Hospital, Busan, South Korea
Am J Case Rep 2020; 21:e922567
Available online: 2020-04-02
Hemolytic uremic syndrome (HUS) can be categorized as primary (typical or atypical) or secondary (with a coexisting diseases). Typical HUS usually means shiga-toxin-medicated and thrombotic thrombocytopenic purpura. Secondary HUS is often initiated by coexisting diseases or conditions such as infections, transplantation, cancer, and autoimmune disease. Atypical HUS (aHUS) is usually induced by genetic mutations of one or several complement-regulating genes and associated with dysregulated complement activation. In the era of compliment-inhibiting therapy, early recognition of aHUS is important for patient prognosis. However, compliment-inhibiting therapy is not always beneficial in patients with secondary HUS.
CASE REPORT: We present a case of a 49-year-old woman with aHUS, which was caused by a novel genetic point mutation of complement factor H gene (p.Gly1110Ala) mimicking secondary HUS with scleroderma. Instead of administering eculizumab treatment for C5 polymorphism, the patient was successfully treated with mycophenolate mofetil.
CONCLUSIONS: HUS has complex and mixed etiologies and requires genetic testing. Attention should be paid to new point mutations in aHUS.
Keywords: Hemolytic-Uremic Syndrome, Mutation, Scleroderma, Diffuse