Cancer Treatment Today

 Immunoglobulin G4-related systemic disease (IgG4-RSD) is a recently defined emerging entity characterized by a diffuse or mass forming inflammatory reaction rich in IgG4-positive plasma cells associated with fibrosclerosis and obliterative phlebitis. IgG4-RSD usually affects middle aged and elderly patients, with a male predominance. It is associated with an elevated serum titer of IgG4, which acts as a marker for this recently characterized entity. The prototype is IgG4-related sclerosing pancreatitis or autoimmune pancreatitis (AIP). Other common sites of involvement are the hepatobiliary tract, salivary gland, orbit, and lymph node, however practically any organ can be involved, including upper aerodigestive tract, lung, aorta, mediastinum, retroperitoneum, soft tissue, skin, central nervous system, breast, kidney, and prostate. Fever or constitutional symptoms usually do not comprise part of the clinical picture. Laboratory findings detected include raised serum globulin, IgG and IgG4. An association with autoantibody detection (such as antinuclear antibodies and rheumatoid factor) is seen in some cases. A set of Japanese consensus guidelines for the management of AIP has defined certain indications for glucocorticoid treatment. These include obstructive jaundice, abdominal pain, and back pain, and the presence of symptomatic extrapancreatic lesions. Patients with extrapancreatic manifestations of IgG4-RSD also appear to respond well to glucocorticoids. These guidelines would not consider  treatment necessary in this case. Steroid therapy comprises the mainstay of treatment.

Rtuxan was reported to produce partial remission in several case reports. The recent review by Khroshani et al says this: “Confirmation and refinement of these findings in large studies are required in order to clarify this potential improvement in IgG4-RSD. Mechanistic studies in patients with rituximab, aiming to understand how rituximab achieves its effectiveness in this condition, may elucidate some aspects of pathogenesis of IgG4-RSD. The optimal regimen and frequency of rituximab treatment are not clear and require larger prospective studies of patients with different IgG4-RSD presentations.”

References:

Mukul Divatia et al, IgG4-Related Sclerosing Disease, an Emerging Entity: A Review of a Multi-System Disease.  Yonsei Med J. 2012 Jan 1; 53(1): 15–34.

Arezou Khosroshahi; John H. Stone, Treatment Approaches to IgG4-related Systemic Disease. Curr Opin Rheumatol. 2011;23(1):67-71.

Kamisawa T, Okazaki K, Kawa S, et al. Japanese consensus guidelines for management of autoimmune pancreatitis: III. Treatment and prognosis of AIP. J Gastroenterol 2010; 45:471–477.