PPIB and Sjogren syndrome: One characteristic feature of this disease is hypergammaglobulinemia, defined by the presence of tissue-specific autoantibodies, the surge in the levels of immunoglobulins, circulating autoantibodies against ribonuclear proteins (anti-52 and 60-kDa Sjögren’s syndrome A; SS-A/Ro, anti-Sjögren’s syndrome B; SSB/La), cellular proteins like carbonic anhydrase II, cellular receptors (e.g., β-adrenergic, muscarinic cholinergic), secreted proteins, and detectable Rheumatoid Factor (RF) [7,8].