Hi and thank you so much for this query. Plaquenil is used to treat rheumatoid arthritis. This is largely considered an auto immune disease but not all patients would show immunologic evidence on testing. There are a set of criteria that are being followed and only one of them is the positive immunologic testing. In all, a positive test adds more weight to the diagnosis but not mandatory for making the diagnosis. For this reason, there is no justification to stop plaquenil based on a single test and not the global context. I hope you find this useful. I wish you well. Feel free to request for more information and ask ore questions should need be. Thanks.