Q: My wife, 28 years old, is having joint pains. The orthopaedic doctor asked for a few tests out of which the AntiDS DNA turned out to be positive. All other tests like Phosphate, Urine test, ESR were normal. Then we consulted a general physician as directed. He asked for a repeat of tests and this time, ANA was mildly positive and AntiDS DNA was negative. Now I am confused. Please advise.

A:In the first instance, an ANA test should have been performed before performing AntiDS DNA test. Because ANA is a screening test usually recommended for detection of rheumatic activities. AntiDs DNA is a specific test usually performed to rule out SLE. Hence in the absence of ANA test, the value of AntiDs DNA is of doubtful significance. In the second part of your query, you have mentioned that a repeat test of ANA and AntiDs DNA were performed. It is mentioned that ANA was mildly positive, this term mildly positive is an ambiguous term, usually not used in standard clinical practice. It could be either positive or negative, at best can be called weakly positive. Nevertheless in some normal individuals ANA positivity is also seen. Negative AntiDs DNA rules out SLE.