It is a clinical sign, and it deserves a proper look
13 In 1993, The Journal of Clinical Apheresis published a paper detailing the use of TPE as either a first- or second-line therapy to be used with other modalities on disorders such as Raynauds disease, systemic lupus erythematosus, coagulation factor inhibitors, familial hypercholesterolemia, acute Guillain-Barr syndrome, chronic inflammatory demyelinating polyneuropathy, myasthenia gravis, cryoglobulinemia, Goodpastures syndrome, and thrombotic thrombocytopenic purpura
Titov et al
None of these are FDA-approved drugs
These pathways involve complex intracellular signaling cascades, including cAMP production, PKA activation, and modulation of gene expression related to pigmentation and metabolic regulation