Our four year old son was diagnosed with type�1 diabetes last fall, and we had his eight and six year old brothers tested for antibodies. So far, the six year old tested positive, but his sugars are still okay. What is known about the predictive value of this test?

The answer rather depends on exactly what antibody test(s) your six year old son had. If this was the old immunofluorescent islet cell antibody test, the best way to get a prognosis for a large Caucasian population would be to contact Professor R. B. Elliott, who looked at a large group of New Zealand children who were controls in a study of the value of nicotinamide in preventing or delaying insulin dependence.

The only figures so far available in the U.S. are old and with a small sample, but unofficial figures for the control group in the national DPT-1 trial, are that if the test comprised all three immunoassays of anti-GAD, ICA512, and anti-insulin antibodies, then the prognosis depends on the number of antibodies that are positive. If only one antibody was positive in your son’s case, then the chances of developing clinical diabetes within five years is between 10 and 20%, but if all three antibodies were positive, than the figure would be 80 to 90%.

DOB