Additionally, in one study,  mutations of genes encoding several complement regulatory proteins were detected in 8 of 36 (22%) patients diagnosed with STEC-HUS. However, the absence of an identified complement regulatory gene mutation does not preclude aHUS as the cause of the TMA, as approximately 50% of patients with aHUS lack an identifiable mutation in complement regulatory genes.Diagnostic work-up supports the differential diagnosis of TMA-causing diseases. A positive Shiga-toxin/EHEC test confirms a cause for STEC-HUS, and severe ADAMTS13 deficiency (i.e., ≤5% of normal ADAMTS13 levels) confirms a diagnosis of TTP. Prevention
The effect of antibiotics in shiga toxin producing E. coli is unclear. While some early studies raised concerns more recent studies show either no effect or a benefit. Treatment
Treatment involves supportive care and may include dialysis, steroids, blood transfusions, and plasmapheresis.While eculizumab is being used to treat atypical hemolytic uremic syndrome, no evidence as of 2018 supports its use in the main forms of HUS. Scientists are trying to understand how useful it would be to immunize humans or cattle. Prognosis
Acute renal failure occurs in 55–70% of people with STEC-HUS, although up to 70–85% recover renal function. With aggressive treatment, more than 90% of patients survive the acute phase of HUS, and only about 9% may develop ESRD. Roughly one-third of persons with HUS have abnormal kidney function many years later, and a few require long-term dialysis. Another 8% of persons with HUS have other lifelong complications, such as high blood pressure, seizures, blindness, paralysis, and the effects of having part of their colon removed.
Melanonychia is a black or brown pigmentation of the normal nail plate, and may be present as a normal finding on many digits in Afro-Caribbeans, as a result of trauma, systemic disease, or medications, or as a postinflammatory event from such localized events as lichen planus or fixed drug eruption. : 790 : 665 There are two types, longitudinal and transverse melanonychia. : 671  Longitudinal melanonychia may be a sign of subungual melanoma (acral lentiginous melanoma), although there are other diagnoses such as chronic paronychia, onychomycosis, subungual hematoma, pyogenic granuloma, glomus tumour, subungual verruca, mucous cyst, subungual fibroma, keratoacanthoma, carcinoma of the nail bed, and subungual exostosis. See also
Nail anatomy
List of cutaneous conditions


== References ==