Harshit Singh
Sanjay Gandhi Postgraduate Institute of Medical Sciences, India
Title: Neutrophilic CD64 Expression differentiates between infection versus disease activity in Systemic Lupus Erythematosus patients
Biography:
Abstract:
Purpose: Fever in case of Systemic Lupus Erythematosus (SLE) may be due to disease activity or infection. As of now no biomarker can distinguish fever caused by disease activity or infection. We aimed to determine usefulness of CD64 glycoprotein expression on the surface of neutrophils in distinguishing bacterial infection from disease flare in SLE.
Methods: In this cross sectional, observational study 25 healthy control and 42 adult patients diagnosed of SLE were recruited. Neutrophil CD64 expression was measured by flow cytometry. Total Leucocyte Count (TLC), Erythrocyte Sedimentation Rate (ESR), C-Reactive Protein (CRP) and anti-double stranded DNA (anti-dsDNA) titers were noted. Diagnosis of bacterial infection was documented and appropriateness of first hand antibiotic treatment was established post hoc.
Results: Among 42 adult patients included 17(40.48%) were diagnosed with infection. Percentage of neutrophil with CD64 expression and their mean fluorescence intensity in patients with infection (75.52±12.79, 335.97±96.72 p<0.05) were significantly higher as compared to those without infection (9.65±4.69, 149.94±37.72 p<0.001). CD64 expression identified fever with asensitivity of82.81% and specificity of 82.87%.TLC (15912±8509, 6178±4023) and CRP (11.9±9.1, 1.3±1.8) were significantly higher (p<0.05) in patients with bacterial infection than disease activity, while ESR (78±45, 62±42) and anti-dsDNA levels (145.9±146.4, 219.8±119.5) were non significant.
Conclusion: CD64 expression on neutrophils is helpful marker for early diagnosis of fever in SLE patients.