ABSTRACT
Cryoglobulinaemia consists of circulating monoclonal and/or polyclonal immunoglobulins with rheumatoid factor (RF) activity that precipitate at temperatures <37°C. Cryoglobulinaemic syndrome, characterised by clinical signs of systemic vasculitis, is associated with chronic infection of hepatitis C virus (HCV) and might evolve in B-cell malignancies. In about one third of all HCV infection cases, serum autoantibodies are commonly found. This is probably due directly to the transformation of infected B cells but, also, indirectly, to the viral chronic stimulation of a pool of autoreactive B cells. The pattern of IgG subclasses seems to contribute to the worsening progression of HCV infection into lymphoproliferative and/or autoimmune diseases. Many evidences showed that B cells circulating in patients with HCV-associated mixed cryoglobulinaemia (MC) are profoundly abnormal;moreover, in most of cases, normal B cells are replaced by expanded clonal B cells characterised by the low expression of CD21. After viral eradication, these cells persist in circulation and their occurrence does not correlate with serum cryoglobulins nor with vasculitis response or relapse. It is probably due to the persistence of monoclonal B cells producing RF, that in course of MC can be reactivated by circulating immune complexes, highly produced during infections or tumours. Here, we aimed to review current literature focusing the pathogenesis of MC referring to specificity and immunochemical characteristics of the immunoglobulins involved in cryoprecipitation.
ABSTRACT
The involvement of gastrointestinal system in SARS-CoV2 related disease, COVID-19, is increasingly recognized. COVID-19 associated pancreatic injury has been suggested, but its correlation with pancreatic disease is still unclear. In this case report, we describe the detection of SARS-CoV2 RNA in a pancreatic pseudocyst fluid sample collected from a patient with SARS-CoV2 associated pneumonia and a pancreatic pseudocyst developed as a complication of an acute edematous pancreatitis. The detection of SARS-CoV2 within the pancreatic collection arise the question of whether this virus has a tropism for pancreatic tissue and whether it plays a role in pancreatic diseases occurrence.