Estimation of Serum YKL-40 by Real-Time Surface Plasmon Resonance Technology in North-Indian Asthma Patients.
BACKGROUND
Many studies reported for estimating serum YKL-40 using ELISA or RIA methods. This study introduces the plausible utilization of real-time surface plasmon resonance (SPR) technology in investigating the expression of serum YKL-40 protein levels and ELISA method for serum IgE in bronchial asthma.


METHODS
A commercially available BIAcore 2000 instrument, based on SPR technology, was utilized for assessing serum YKL-40 levels in a control sample size of 45 and active sample size of 97. Antibody immobilization was optimized to obtain the best sensor performance and a sensitive analytic detection. A commercially available ELISA kit was utilized for detecting serum IgE to estimate allergic condition-associated asthma.


RESULTS
The results of SPR technology could distinctly classify with highly statistical significance, the asthma severities by estimating the elevated levels of YKL-40 in blood sera of minute quantities (up to 0.33 ng/ml), and thus differentiates superior utility in comparison with ELISA method. No statistically significant correlation of YKL-40 and IgE was observed.


CONCLUSIONS
Serum YKL-40 may be used as a protein marker in classifying asthma severity by applying SPR technology as a reliable, label-free, highly sensitive, and cost-effective tool.
Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Sarla
S
Naglot
Department of Emergency Medicine, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Praveen
P
Aggarwal
Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Sharmistha
S
Dey
Department of Biophysics, All India Institute of Medical Sciences (AIIMS), New Delhi, India.
Krishna
K
Dalal
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000097:blood* / Q000175:diagnosis*; D016022:Case-Control Studies; D000071451:Chitinase-3-Like Protein 1 / Q000097:blood*; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006801:Humans; D007073:Immunoglobulin E / Q000097:blood*; D007194:India; D008297:Male; D008875:Middle Aged; D020349:Surface Plasmon Resonance / Q000379:methods*; D055815:Young Adult
C084533:CHI3L1 protein, human; D000071451:Chitinase-3-Like Protein 1; D007073:Immunoglobulin E

Enzyme linked immunosorbent assay
; Asthma severity; FEV1; Surface Plasmon Resonance technology; YKL-40