Frozen lung aspirates were thawed, centrifuged to pellet down the cells and pellets were used to isolate RNA. Total RNA was extracted from PBMCs and lung aspirate cells by using Ribopure Kit (Ambion) as per the manufacturer's instructions. RNA was eluted in 100 ml elution buffer, quantitated using Nanodrop (ND-1000) and processed for quality check in Agilent bioanalyzer (Agilent, U.S.A). Equal quantities of RNA (500 ng) with $7 RIN value were processed further for cDNA synthesis using High Capacity cDNA Reverse Transcription Kit (Applied Biosystems, U.K.). All cDNAs were tested in real time PCR assay using TaqMan primers and probe for 18S rRNA (Applied Biosystems, U.K.) to ensure efficient cDNA synthesis. cDNAs were mixed with equal volumes of TaqMan 2X PCR master mix from one-step RT-PCR kit (Applied Biosystems) and 125 ng (RNA equivalent) cDNAs were loaded per port of the TaqMan Low Density Array card (TLDA) of the Human Immune panel (Applied Biosystems, U.K.) and run on 7900HT Fast Real-Time PCR system (Applied Biosystems, U.K.). Relative gene expression values were obtained employing comparative Ct method using Applied Biosystems' Relative Quantification (RQ) Manager Software v1.2. cDNAs from six healthy individuals processed similarly were considered as calibrators. 18s RNA was used as an endogenous control. Relative quantitation values of each study group were used to calculate mean RQ values. For cluster analysis, relative quantitation values were log2 transformed and hierarchically clustered with analysis software (Cluster 3.0) [9] .