JD, VC and CI participated in data collection, literature selleckchem search and data interpretation. AK, TC, TT and MC participated in revising the bibliography, and correcting and editing the manuscript. All the authors have read and approved the final manuscript.AcknowledgementsThe Lancardis Foundation in Sion (Switzerland) granted partial support for this study. No other sources have influenced the study design, data analysis or decision to submit the manuscript for publication.
The incidence of sepsis has dramatically increased over the past decade. It is estimated that 1.5 million people in the USA and another 1.5 million people in Europe present annually with severe sepsis and/or septic shock: 35 to 50% of them die.

The enormous case-fatality had led to an intense research effort to understand the complex pathogenesis of sepsis and to apply the acquired knowledge in therapeutic interventions of immunomodulation [1]. The majority of trials of application of immunomodulatory therapies have failed to disclose clinical benefit probably as a result of the incomplete understanding of the mechanisms of pathogenesis [2]. Populations of patients enrolled in these trials were heterogeneous regarding the type of underlying infection.Sepsis is accompanied by considerable derangements of both the innate and adaptive immune systems. Changes such as apoptosis of CD4-lymphocytes and of B-lymphocytes and immunoparalysis of monocytes are well recognized among septic patients [3-6]. However, all studies performed so far consider all septic patients to have similar changes of their immune response irrespective of the type of infection that stimulated the septic reaction.

If the immune response between septic patients differs in relation to the underlying infection, then many of the disappointing results of clinical trials of immunomodulation may be explained.The present study was a prospective study undertaken by departments participating in the Hellenic Sepsis Study Group [7]. The aim of the study was to identify if the early statuses of the innate and adaptive immune systems of septic patients differ in relation to the underlying type of infection stimulating the septic response.Materials and methodsStudy designThis prospective multicenter study was conducted in 18 hospital departments across Greece between January 2007 and January 2008.

Participating departments were: seven ICUs; six departments of internal medicine; one department of pulmonary medicine; three departments of surgery; and one department of urology. A total of 505 patients were enrolled. Written informed consent was provided by the patients or their first-degree relatives for patients unable to consent. The study protocol was approved by the Ethics Committees of the hospitals of the participating Cilengitide centers. Every patient was enrolled once in the study. Patients admitted to the emergency departments, hospitalized in the general ward or the ICU were eligible for the study.