Our immune systems aren't really overactive - they are malfunctioning. It's more that if you already have one thing going on, the autoimmune disease activity in this case lupus, the immune system's resources are less capable of dealing with anything additional.
The autoimmune disease provides an opportunity for infections that would otherwise be more readily resisted, in much the same way that bacterial infections often follow viral infections.
HTH
Clare
The autoimmune disease provides an opportunity for infections that would otherwise be more readily resisted, in much the same way that bacterial infections often follow viral infections.
HTH
Clare