Pleural effusion after plasmapheresis in Waldenström's macroglobulinemia

Transudative pleural effusion developed after plasmapheresis in a patient with Waldenström's macroglobulinemia and hyperviscosity. When albumin was added to the apheresis, the effusion resolved. We therefore suspect that rapid removal of high-molecular-weight IgM led to an abrupt decrease in intravascular colloid oncotic pressure and transudation of fluid into the pleural space. Plasmapheresis can cause pleural effusions in patients who were previously hemodynamically compensated at high levels of colloid oncotic pressure.