Serum Soluble Triggering Receptor Expressed on Myeloid Cells versus 16s rRNA genes detection in early diagnosis of bacteremia in malignant febrile neutropenic patients

Abstract

Febrile neutropenia is the most common risk factor for severe bacterial infections in hematological malignancies. It is the most common life-threatening complication of cancer therapy. Most, if not all, episodes of fever during neutropenia are supposed to be infectious in origin. Infection, however, is documented only in a minority of cases. (Freifeld et al., 2012; Keng and Sekeres ,2013). Despite a great number of clinical studies on these patients, none have found an individual diagnostic test for bacteremia. Likewise, no single list of signs, symptoms, or test values has been discovered that can faithfully identify the condition, especially early (Perman et al., 2012).

Blood culture is the gold standard for the diagnosis of blood stream infection (BSI). A great limitation of blood cultures is the delay at least 2 days before results become available (Magadia and Weinstein, 2010; Michela et al., 2010). Broad-range PCR assays have been developed for the universal detection of bacteria or fungi in blood. They are based on amplification of the 16S rRNA gene of bacteria and the 18S rRNA gene of fungi (Peters et al., 2004). Triggering receptor expressed on myeloid cells-1 (TREM-1) is a recently identified molecule involved in monocytic activation and inflammatory response (Dimopoulou et al., 2012). A soluble form of TREM-1 (sTREM-1) is shed from the membranes of activated phagocytic cells and can be quantified in human body fluids (Nicasio et al., 2010). The aim of this study was to evaluate the utility of sTREM-1 level and 16S rRNA gene detection in early diagnosis of bacteremia in febrile neutropenic patients with hematological malignancies .

This study was conducted on 60 febrile neutropenic patients with different hematological malignancies, admitted to Hematology department at Ain Shams University hospital during the period from August 2012 to May 2013. Blood samples were collected for BACTEC blood cultures, estimation of serum sTREM-1 levels; and 16S rRNA gene detection. Results : * Regarding types of hematological malignancies, it was found that NHL was the most common type {24 (40%) of patients}; MDS and HCL were equal and the least presented types {2 (3.33%) of patients}.