The ability of clinical and laboratory findings to predict in-hospital death in patients with thrombotic thrombocytopenic purpura in an internal and emergency medicine department

Introduction: Thrombotic thrombocytopenic purpura (TTP) is a rare, life-threatening syndrome characterized by microangiopathic anemia, thrombocytopenia, diffuse microvascular thrombosis, and ischemia. It is associated with very low levels of ADAMTS-13. Measurement of ADAMTS-13 levels is used for diagnostic and prognostic purposes, but in every-day clinical practice, this type of analysis is not always readily available. In this retrospective study, we evaluated prognostic value of clinical and laboratory findings in patients with TTP. <br />Materials and methods: We retrospectively investigated patients with clinically diagnosed TTP treated in a unit of Internal and Emergency Medicine (1996-2007). Clinical and laboratory findings were collected and analyzed in order to assess their ability to predict in-hospital death. <br />Results: Twelve patients were identified (mean age 59 <span style="text-decoration: underline;">+</span> 22 years; 58% were women). Five (42%) died during the hospitalization, and the variables significantly associated with this outcome were: a delay between diagnosis and symptom onset (HR 1.36; 95% CI 1.04-1.78; p &lt; 0.05); a higher severity score (HR 1.48; 95%CI 1,23-3.86; p &lt; 0.05); hemodynamic instability with hypotension and/or shock (HR 3.35; 95%CI 3.02-9.26; p &lt; 0.01); a higher schistocyte count on blood smear (HR 1.84; 95%CI 1.04-3.27; p &lt; 0.05); and higher lactate values (HR 1.85; 95%CI 1.08- 3.16; p &lt; 0.05). <br />Conclusions: TTP is a rare and potentially fatal disease with protean manifestations. Delayed diagnosis after symptom onset is a major determinant of poor outcome. Hypotension and shock are also prognostically unfavourable. Laboratory evidence of cardiocirculatory compromise (i.e., elevated lactate levels) and extension of the disease process (i.e., schistocyte count &gt; 3) are predictive of in-hospital death, independently of the hemodynamic profile on admission