“…In the first of these reports, proliferative glomerulonephritis with IgG deposits and undetected kappa light chains in electrophoresis and immunofixation is described, possibly secondary to their low quantity and rapid glomerular fixation, attributed to an immune response to some self or external antigen [ 10 ]. A second case report documented a patient with renal injury, proposing paraproteinemia as a trigger for complement activation or dysregulation and neutrophil activation, leading to a pauci-immune, ANCA-negative mechanism due to the absence of renal deposits [ 11 ]. Finally, a third case of proliferative glomerulonephritis with evidence of IgG3 deposits is described, with its nephrotoxic effects attributed to its high molecular weight, positive charge, and wide complement-fixing capacity.…”