Nejm 2002;347:589; 346:23, 1990;323:1161

Cause:

• Postinfectious or postpartum (Nejm 1985;312:1556) via endotoxin; vero (Shiga) toxin produced by: 0157:H7 E. coli(Ann IM 1995;123:698; Nejm 1995;333:364; 1987;317:1496) infection from petting cows (Nejm 2002;347:555) hamburger and milk results in HUS in 6-30% of those children infected, and also causes TTP; also caused by other E. coli(Nejm 1996;335:635), shigella, pneumococcus, salmonella
• Relapsing
• Drug-induced TTP/HUS syndrome, esp w quinine (Ann IM 2001;135:1047; 1993;119:215)

Pathophys:

(Nejm 2002;346:23) Relapsing type very similar to TTP and assoc w circulating very large vonW factor multimers, but predominant renal involvement (Nejm 1991;325:426). Diarrhea-associated types show a shiga toxin-induced thrombogenesis and vasculitis, with 4 systems involved: kidney, skin, joints, bowel

Tissue plasminogen activator is elevated (Nejm 1993;327:755) because is complexed and inactivated

Drug-induced types probably due to drug-induced antibodies

Increasing incidence; most under age 5 yr where now incidence = 6/100 000; day care clusters occurring. 65% of all types are postinfectious

Sx:

Diarrhea (86%), vomiting (75%), bloody diarrhea (59%), abdominal cramps (50%), fever (49%), seizures (17%)

Postinfectious type may have a h/o viral or bacterial infection 1-2 wk before

Si:As above; oligo/anuria

2-wk average; <5% mortality if supported; ie, is self-limited

Renal failure, 47% require dialysis temporarily and 25+% have long-term renal impairment (Jama 2003;290:1360); shock, cardiac arrest, blindness, CVAs

Lab:

Chem:Elevated BUN and creatinine

Hem:Crit <30%; microangiopathic picture with red cell fragments, platelets <150 000; if wbc's >15 000, prognosis worse. VonW factor cleaving protease function normal (unlike TTP) (Nejm 1998;379:1578). Elevated D-dimer

Urine:Hematuria, proteinuria

Rx:

(Nejm 1991;325:398)

Prevent by avoiding antibiotic rx of O157 E. colidiarrhea (Nejm 2000;342:1930 vs Jama 2002;288:996), and antimotility drugs

Supportive; dialysis; steroids may help by decreasing edema; plasma exchange transfusions help (Am J Med 1999;107:573)

No help: antihistamines, anti-shiga toxin (Jama 2003;290:1337)