Prediction and prophylactic treatment of type 1 diabetes

Abstract

An in vitro method for predicting the onset of type 1 diabetes (T1D) in a subject, comprises the steps of: (a) measuring the concentration of at least one amino acid, amino acid derivative or amino acid metabolite in a biological sample taken from the subject; (b) determining the subject's HLA genotype; (c) assigning the subject's genetic risk of developing T1D on the basis of the subject's HLA genotype; (d) combining the information obtained in step (a) with the information in step (c); and (e) predicting the likelihood of onset of T1D based upon the combination of step (d). The diagnostic method can be used to select target subjects for T1D prophylactic treatment, and as part of a T1D preventative treatment regime for neonates having a likelihood of developing childhood T1D.

1 . An in vitro method for predicting the onset of type 1 diabetes (T1D) in a subject, comprising the steps of:
 (a) measuring the concentration of at least one amino acid, amino acid derivative or amino acid metabolite in a biological sample taken from the subject;   (b) determining the subject's HLA genotype;   (c) assigning the subject's genetic risk of developing T1D on the basis of the subject's HLA genotype;   (d) combining the information obtained in step (a) with the information in step (c); and   (e) predicting the likelihood of onset of T1D based upon the combination of step (d).   
   
   
       2 . The method of  claim 1 , wherein in step (c) the genetic risk is assigned as “high”, “moderate” or “low” according to the subject's HLA genotype. 
   
   
       3 . The method of  claim 2 , wherein a high risk HLA genotype comprises the genetic markers:
 DRB1*03/*04 (not 0403), DQB1 0302.   
   
   
       4 . The method of  claim 2 , wherein a moderate/medium risk HLA genotype comprises the genetic markers:
 DRB1*04 (not 0403)/*04 (not 0403), DQB1 0302;   DRB1*04 (not 0403)/X, DQB1 0302/DQB1 not 0602-3)   DRB1*03/*03;   DRB1*03/X, DQB1 not 0602-3, not 0301, not 0503;   
     wherein X is not DRB1*03, *04, or 0403. 
   
   
       5 . The method of  claim 2 , wherein a low risk HLA genotype comprises any combination of genetic markers not specified in  claim 3  or  claim 4 . 
   
   
       6 . The method of  claim 1 , wherein the amino acid, amino acid derivative or amino acid metabolite is selected from the group consisting of: alanine, arginine, aspartate, citrulline, glycine, glutamate, glutamine, leucine, isoleucine, methionine, ornithine, phenylalanine, proline, tyrosine and valine. 
   
   
       7 . The method of  claim 1 , wherein in step (a) the concentration of two or more amino acids, amino acid derivatives or amino acid metabolites are measured. 
   
   
       8 . The method of  claim 1 , wherein in step (a) the concentration of essential amino acids is measured. 
   
   
       9 . The method of  claim 1 , wherein in step (a) the concentration of non-essential amino acids is measured. 
   
   
       10 . The method of  claim 1 , wherein in step (a) a total concentration of the amino acids, amino acid derivatives and amino acid metabolites is measured, wherein the amino acid, amino acid derivative or amino acid metabolite is alanine, arginine, aspartate, citrulline, glycine, glutamate, glutamine, leucine, isoleucine, methionine, ornithine, phenylalanine, proline, tyrosine and valine 
   
   
       11 . The method of  claim 10 , wherein in step (e) a total amino acid concentration of less than approximately 1200 μmol/L in combination with a high risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       12 . The method of  claim 10 , wherein a total amino acid concentration of approximately 500-1200 μmol/L in combination with a high risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       13 . The method of  claim 10 , wherein in step (e) a total amino acid concentration of less than approximately 1000 μmol/L in combination with a moderate or low risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       14 . The method of  claim 10 , wherein a total amino acid concentration of approximately 300-1000 μmol/L in combination with a moderate or low risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       15 . The method of  claim 1 , additionally comprising the steps of:
 (a′) measuring the concentration of at least one of: free carnitine, acylcarnitine and total carnitine in a sample taken from said subject; and   (d′) combining the information obtained in step (a′) with the information in step (c); and   (e′) predicting the likelihood of onset of T1D based upon the combination of step (d) and the combination of step (d′).   
   
   
       16 . The method of  claim 15 , wherein in step (a′) the concentrations of free carnitine, acylcarnitine and total carnitine are measured. 
   
   
       17 . The method of  claim 15 , wherein in step (e′) a total carnitine concentration of less than approximately 50 μmol/L in combination with a high risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       18 . The method of  claim 15 , wherein a total carnitine concentration of approximately 20-50 μmol/L in combination with a high risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       19 . The method of  claim 15 , wherein in step (e′) a total carnitine concentration of less than approximately 40 μmol/L in combination with a moderate or low risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       20 . The method of  claim 15 , wherein a total carnitine concentration of approximately 10-40 μmol/L in combination with a moderate or low risk HLA genotype is indicative of the likely future onset of T1D. 
   
   
       21 . The method of  claim 1 , wherein in step (a) said biological sample is a blood sample. 
   
   
       22 . The method of  claim 21 , wherein said blood sample is collected within 3 days (i.e. 72 hours) of the subject's birth. 
   
   
       23 . The method of  claim 1 , wherein step (b) is carried out by genetically screening a portion of said sample used in step (a). 
   
   
       24 . The method of  claim 15 , wherein step (a′) is carried out on the sample used in step (a). 
   
   
       25 . The method of  claim 1 , wherein the subject is a neonate. 
   
   
       26 . A method for identifying a neonatal subject for enrolment onto a potential prophylactic treatment program for T1D, which comprises performing the steps of  claim 1  in a neonate so as to identify a neonate having a likelihood of onset of T1D and enrolling said neonate into a prophylactic treatment program. 
   
   
       27 . A method for the prophylactic treatment for T1D, which comprises the steps of:
 (a) performing the steps of  claim 1 ;   (b) identifying one or more subject having a likelihood of onset of T1D; and   (c) prescribing to said one or more subject a prophylactic treatment for preventing or delaying the onset of T1D.   
   
   
       28 . A method for the prophylactic treatment for T1D, which comprises the steps of:
 (a) performing the steps of  claim 25 ;   (b) identifying one or more subject having a likelihood of onset of T1D; and   (c) prescribing to said one or more subject a prophylactic treatment for preventing or delaying the onset of T1D.   
   
   
       29 . The method of  claim 27 , wherein said prophylactic treatment in step (c) comprises insulin replacement therapy. 
   
   
       30 . The method of  claim 27 , wherein said prophylactic treatment in step (c) comprises immunomodulation therapy. 
   
   
       31 . The method of  claim 29 , wherein the immunomodulation therapy comprises anti-CD3 treatment. 
   
   
       32 . The method of  claim 27 , wherein said prophylactic treatment in step (c) comprises photopheresis. 
   
   
       33 . The method of  claims 28 , wherein said prophylactic treatment in step (c) comprises a dietary supplement. 
   
   
       34 . The method of  claim 32 , wherein said dietary supplement comprises an amino acid, amino acid derivative or amino acid metabolite supplement. 
   
   
       35 . The method of  claim 33 , wherein said dietary supplement comprises a carnitine or acylcarnitine supplement. 
   
   
       36 . The method of  claim 34 , wherein said dietary supplement comprises a carnitine or acylcarnitine supplement. 
   
   
       37 . A method of treating a neonate identified as having a predisposition to T1D, comprising:
 administering a prophylactic composition that comprises one or more amino acid, amino acid derivative or amino acid metabolite in an amount sufficient to increase blood amino acid, amino acid derivative or amino acid metabolite levels to within the normal range.   
   
   
       38 . The method of  claim 37 , wherein said amino acid, amino acid derivative or amino acid metabolite is selected from the group consisting of: alanine, arginine, aspartate, citrulline, glycine, glutamate, glutamine, leucine, isoleucine, methionine, ornithine, phenylalanine, proline, tyrosine and valine. 
   
   
       39 . The method of  claim 37 , wherein said composition comprises all of alanine, arginine, aspartate, citrulline, glycine, glutamate, glutamine, leucine, isoleucine, methionine, ornithine, phenylalanine, proline, tyrosine and valine, in amounts sufficient to restore total blood amino acid, amino acid derivative or amino acid metabolite levels to within the normal range. 
   
   
       40 . The method of  claim 37 , wherein said composition further comprises free carnitine and/or acylcarnitine and said administering comprises administering free carnitine and/or acylcarnitine in amounts sufficient to restore free carnitine, acylcarnitine or total carnitine levels to within the normal range. 
   
   
       41 . The method of  claim 37 , wherein said composition is administered parenterally. 
   
   
       42 . The method of  claim 41 , wherein said administering is in the form of a bolus injection. 
   
   
       43 . The method of  claim 41 , wherein said composition is a slow release composition. 
   
   
       44 . The method of  claim 37 , wherein said composition is administered orally. 
   
   
       45 . The method of  claim 37 , wherein said composition is administered in an amount sufficient to restore to within the normal range the blood level of said one or more amino acid, amino acid derivative or amino acid metabolite and/or said free carnitine and/or acylcarnitine and maintain said normal range for a duration of at least 48 hours. 
   
   
       46 . The method of  claim 37 , wherein said composition is administered in an amount sufficient to restore to within the normal range the blood level of said one or more amino acid, amino acid derivative or amino acid metabolite and/or said free carnitine and/or acylcarnitine and maintain said normal range for a duration of at least 72 hours