Moot Point

We are following that long road to FDA licenses with our two drugs.  One will be used to treat horses with EPM.  The second drug will be used for horses that didn’t fully respond to EPM treatment or are suffering what is commonly referred to as a “relapse”.  To accomplish our goals we conduct field studies.

Our studies are listed on our web pages and some common questions are answered there, if you have questions, please email us and we’ll answer by email.  One concern is about the placebo.  Some placebo controlled studies are required by FDA.  In these studies, two out of every three horses will get the test drug and one will get the placebo.  Before the horse is enrolled into the study the owner must fill out and sign the Owner Consent Form.  The form will clearly state if the trial involves a placebo, but the form won’t indicate which drug is being given.  We have a statistician determine the enrollment into each treatment group and that eliminates bias.

The treatment is given for 10 or 14 days.  At the end of 10 days of treatment, the veterinarian will decide what the next steps are for each animal.  The continuing education program we initiated has prepared the vet  to handle the cases to the utmost of our research--they are up to date on our emerging technology.

You can decide what study would best suit your particular case by evaluating the inclusion and exclusion criteria. We have a computer programed to evaluate the submission and  data and help guide the study decisions.  Sometimes horses just don’t fit.

The inclusion and exclusion criteria are important.  We won’t take any horses into the study that are down and unable to stand.  These horses have special needs that won’t be met participating in the study —but call us, we are most happy to share our expertise in these cases.  The serum samples from these horses are very valuable to us, even in the unfortunate circumstance the horse is lost.  The data from these horses can’t fulfill our FDA obligations, but we use the samples to develop new protocols that can help others.  We will include horses with a Grade 2-4 on the gait assessment just as it is defined on the submission form.  The next criteria is to determine the presence or absence of serum antibodies to S. neurona. The antibody will help us decide if the horse has Idiopathic encephalomyelitis or if the provisional diagnosis suggests S. neurona as the cause.

 

This is Ranger Scherer.  He lived on a farm that had a horse with EPM.  He was tested even though he is “pretty normal” for a 5-year old gangly teenage boy--lots of energy, a little bit naughty, but quite sweet!”  He sent in his vote:  No on CSF!  Here’s why:

We determined in 2002 (and published the data in 2003) that specific antibody testing can eliminate the need for collecting and testing spinal fluid (CSF) in experimentally challenged horses, in this study we published data from 6 horses.  Further studies that were blinded--we used board certified veterinary neurologists to do the clinical exams gave us more information.  We the split samples of serum and CSF from 57 of the challenged horses and compared our SAG 1 ELISA results (for serum and CSF) with testing run by the folks in Kentucky.  They got samples pre-challenge and every 30 days for 4 months.  The statistician analyzed the data and determined two things.  First, the antibody levels are consistent with duration of infection and not the number of organisms in the animal.  And second, that there was no statistical difference in determining disease by testing CSF.  We now employ two additional, highly specific antigens in our ELISA’s to determine the phenotype of the infection—CSF is not required for these tests either.  We will measure the antibody in CSF if you submit it to us, but we don’t require it.

If you choose to use alternate testing for entry into our studies, you may do so.  Any antibody test that is recognized in the veterinary community as useful in the diagnosis of EPM can be used for entry into the studies.  Recently, in a Brief Communication, J Vet Intern Med 2013:27:596-599, Johnson, Morrow and Sweeney determined that when evaluating IFAT and SAG 2, 4/3 “using serum results alone was least accurate for both test types.  The more accurate methods, such as the SAG2, 4/3 ELISA serum: CSF ratio, should be used.”  These thoughts were reiterated in J Vet Intern Med 2013;27:1193-1200.  We stand by their recommendations and will accept this test that they reported as more meaningful to detect exposure to S. neurona:  a serum/ CSF ratio.  The IFAT (serum) disagreed with the SAG 2 4/3 ELISA (serum) in one third of the samples, not unlike the results we obtained from EBI in our studies.  The published recommendation is that the IFAT should also be supported by CSF testing.

The reason we won’t go into depth on these papers, as we have done in the past, the point is moot.  We realize that a significant part of EPM is mediated by inflammation.  IgG tests don’t discern inflammation, thus don’t discern EPM.  An ELISA that detects S. neurona antibodies can determine past and current S. neurona infections and that is a start.  These infections can lead to EPM, but they aren’t diagnostic.  The SAG 1, 5, 6 ELISA is rapid, specific, non-invasive testing that can get the animal enrolled into the study.  The treatment duration is short, 10 days, possibly faster than the turn around for the more invasive tests.

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