DIAGNOSTIC AND PROGNOSTIC VALUE OF SERUM LEPTIN LEVEL IN CRITICALLY ILL PEDIATRIC PATIENTS WITH SEPSIS

Abstract

Sepsis is a systemic inflammatory reaction that is triggered by an infective agent (such as bacteria, viruses, fungi or parasites), It is one of the major health concerns worldwide and also the predominant reason for intensive care unit (ICU) admission), With the rapidly increasing incidence, high mortality rates, complex pathophysiology and overall difficulties in its treatment, sepsis is becoming an important focus for researchers and clinicians. Infections and sepsis are accompanied by clinical signs such as leukocytosis, changes in body temperature and the development of tachycardia. However, these classic indicators of systemic inflammation are neither sensitive nor specific for sepsis. They have only moderate sensitivity and specificity and are not early markers due to the time taken to produce a reaction. Therefore, early markers are useful for the diag¬nosis and treatment of sepsis and are crucial for overcoming sepsis associated mortality. Leptin, a hormone mainly generated by adipocytes (adipokine) acts centrally in the hypothalamus to regulate body weight and energy expenditure, has vascular function, bone and cartilage growth as well as the immune system and systemic inflammatory response. Several activating effects towards T cells, monocytes, endothelium cells and cytokine production have been reported suggesting a protective role of leptin in the setting of an acute systemic inflammation. The aim of this study was to evaluate the role of serum leptin in early diagnosis of sepsis and its possible prognostic value in critically ill patients with sepsis for early intervention to improve the outcome. Our study included thirty critically ill patients fulfilling the criteria of sepsis admitted to the Pediatric Intensive Care Unit, Children Hospital, Ain Shams University over a period of 9 months. The mean age for the study population was 46.07 + 57.23 months. Ten of them (33.3%) were males and twenty patients (66.6%) were females. patients were compared with 24 apparently healthy children with no clinical signs or laboratory evidence of sepsis for whom sampling was required for another purpose. Patients were classified into two groups: Group I: Patients having sepsis (n= 22) with mean age45.13  62.47 months, 15 of them were females and 7 were males. Group II: Patients having severe sepsis (n=8) defined as (Sepsis associated with organ dysfunction, hypotension or hypoperfusion), their mean age was 53.34  35.03 months, 5 of them were females and 3 were males . Patients were further classified according to their fate into either survivors or non-survivors. The study also included twenty four age and sex matched healthy children as controls for comparison. Patients were followed up as regards their general, inflammatory, haemodynamic and organ dysfunction variables. Measurement of plasma concentration of serum leptin on diagnosis and 72 hours later was done. Our results revealed that most of the patients were having pneumonia (n=16, 53.3%), gastroenteritis (n=9, 30%), renal (n=3, 10%) while hematological and neurological representing less common clinical presentation (n=1, 3.3% for each presentation). There was no statistical significant difference between patients with sepsis and patients with severe sepsis as regards their measured parameters except for higher serum creatinine in severe sepsis patients. There was a statistical significant higher mean leptin among patients than controls. There was no statistical significant difference in mean leptin on day (1) and day (3) between sepsis and severe sepsis. There was positive correlation between CRP and leptin at day (1) in patients group. There was positive correlation between PIM II and leptin at day (1, 3) in patients group. The predictive ability of leptin on day (1) to diagnose sepsis is more reliable than leptin on day (3) P<0.05. Receiver operating characteristic analyses examining leptin for sepsis prediction demonstrated leptin (on day 1) cutoff level of 6.2 or greater (provided a sensitivity of 92%, a specificity of 80% and a positive predictive value of 68% and a negative predictive value of 100%) is the best choice. There was a statistical significant higher mean leptin on day (3) among non survivors when compared to survivors P<0.05. The predictive ability of leptin on day (3) for mortality is more accurate than leptin on day (1) P<0.0001.