Methods for determining drug responsiveness

Abstract

The invention provides a diagnostics assay for measuring the responsiveness to a drug by comparing the mRNA levels of a gene that responds to the drug, such as a steroid, to the mRNA levels of a gene that does not respond to the drug. Methods according to the invention are useful for predicting the ability of a patient (or a tissue, body fluid or cell sample in vitro) to respond to a drug or steroid at any stage of their treatment (i.e., before, during or after), and to monitor the patient (or a tissue, body fluid or cell) over time to assess continued responsiveness to the drug or steroid.

What is claimed is:  
     
         1 . A method for determining steroid responsiveness in a subject, comprising 
 determining the ratio of gene expression levels of a first gene and a second gene in a clinical sample from said subject and comparing said ratio to a predetermined control ratio,    wherein said first gene is a steroid responsive gene and said second gene is a steroid non-responsive gene,    wherein said control ratio is the ratio of gene expression levels of said first gene and said second gene in either a nonresponsive subject or in a responsive subject,    and wherein said subject is steroid responsive if said ratio is higher than the control ratio for a non-responsive subject or is substantially similar to the control ratio for a responsive subject.    
     
     
         2 . A method for determining steroid responsiveness in a subject undergoing steroid treatment, comprising: 
 comparing the expression level ratio of a first gene and a second gene in a clinical sample obtained from said subject prior to steroid administration with the expression level ratio of said first and said second gene in a clinical sample obtained from said subject after administration of a steroid,    wherein said first gene is a steroid responsive gene and said second gene is a steroid non-responsive gene,    and wherein a pre-administration ratio that is less than the post-administration ratio is indicative of steroid responsiveness in said subject, and wherein a pre-administration ratio that is greater than or the same as than the post-administration ratio is indicative of steroid non-responsiveness in said subject.    
     
     
         3 . A method for determining steroid responsiveness in a clinical sample, comprising: 
 comparing the expression level ratio of a first gene and a second gene in said clinical sample obtained prior to in vitro exposure of said sample to a steroid with the expression level ratio of said first and said second gene in said clinical sample obtained after in vitro exposure of said sample to a steroid,    wherein said first gene is a steroid responsive gene and said second gene is a steroid non-responsive gene,    and wherein a pre-exposure ratio that is less than the post-exposure ratio is indicative of steroid responsiveness in said sample, and wherein a pre-exposure ratio that is greater than or the same as than the post-exposure ratio is indicative of steroid non-responsiveness in said sample.    
     
     
         4 . The method according to  claim 1 , wherein said gene expression levels are determined by measuring RNA or protein expression levels.  
     
     
         5  The method according to  claim 4 , wherein said gene expression levels are determined by measuring RNA levels using RT-PCR.  
     
     
         6 . The method according to  claim 1 , wherein at least one said gene expression ratios is determined by in situ detection of RNA expressed from said first and second genes.  
     
     
         7 . The method according to  claim 1 , wherein at least one of said gene expression ratios is determined using a nucleic acid probe array.  
     
     
         8 . The method according to  claim 4 , wherein said gene expression levels are determined by measuring protein levels using an ELISA assay.  
     
     
         9 . The method according to  claim 1 , further comprising monitoring or tracking the steroid responsiveness over time to detect a change in responsiveness.  
     
     
         10 . The method according to  claim 1 , further comprising administering one or more pro-inflammatory and/or anti-inflammatory mediators to the tissue, body fluid or cell.  
     
     
         11 . The method according to  claim 10 , comprising administering one or more pro-inflammatory mediators selected from the group consisting of interleukin 1α (IL-1 α), interleukin-1β (IL-1β), interleukin 6 (IL-6), and tumor necrosis factor (TNF-α).  
     
     
         12 . The method according to  claim 10 , comprising administering one or more anti-inflammatory mediators selected from the group consisting of interleukin 1 receptor antagonist (IL-1RA), tumor necrosis factor receptor antagonist (TNF-RA) or derivatives thereof, soluble TNF receptors, anti-TNF antibodies, and anti-TNF-RA antibodies.  
     
     
         13 . The method according to  claim 1 , further comprising the step of administering one or more cytokines, chemokines, interferons or hormones to said clinical sample.  
     
     
         14 . The method according to  claim 1 , further comprising the step of administering a compound selected from the group consisting of interleukin-8 (IL-8) and vasoactive intestinal peptide (VIP).  
     
     
         15 . The method according to  claim 1 , wherein said sample comprises a fluid selected from the group consisting of blood, serum, plasma, cerebrospinal fluid, ascites fluid, synovial fluid, fluid harvested from a site of inflammation, fluid harvested from a pooled collection site, saliva, semen and bronchial lavage.  
     
     
         16 . The method according to  claim 1 , wherein said sample comprises nucleated cells.  
     
     
         17 . The method according to  claim 16 , wherein said sample comprises cells selected from the group consisting of monocytes, macrophages, neutrophils, T-cells, B-cells, basophils, fibroblasts, endothelial cells and epithelial cells.  
     
     
         18 . The method according to  claim 1 , wherein said sample comprises buccal cells.  
     
     
         19 . The method according to  claim 1 , wherein said first gene encodes serum amyloid A1 (SAA1) and said second gene encodes serum amyloid A2 (SAA2).  
     
     
         20 . The method according to  claim 1 , wherein said first gene comprises a steroid responsive element.