How do you approach weakly positive PL-7 antibody in a patient who initially presented with muscle weakness, rhabdomyolysis and non specific muscular edema on MRI that resolved with IV fluids?

During an episode of rhabdomyolysis, muscle MRI isn't reliable since it would be positive regardless of the underlying cause. So, monitoring the trajectory of CPK levels and serial muscle exams to evaluate for weakness would offer a more reliable assessment for true myositis. Positive antibody results during an episode of rhabdomyolysis can yield false positive results, which would be difficult to interpret. So, the question is to determine if PL7 is a true or false positive result.

Since myositis-specific antibodies remain positive in most cases, even during remission, then can repeat the labs, especially given the fact that in the case of PL-7+ antisynthetase syndrome, it typically manifests primarily as ILD, with muscle weakness being a ...