IgG4-Related Sialoadenitis with a Skin Lesion and Multiple Mononeuropathies Suggesting Coexistent Cryoglobulinemic Vasculitis

IgG4-related sialadenitis complicated with type III mixed cryoglobulinemia: A case report

RATIONALE

IgG4-related disease (IgG4-RD) is a systemic autoimmune disease and mixed cryoglobulinemia may be caused by autoimmune diseases. However, so far only 1 case of IgG4-RD complicated with mixed cryoglobulinemia is reported. Our case further confirms the close relationship between these 2 diseases.

PATIENT CONCERNS

A 55-year-old female was admitted because of dry mouth and teeth falling off.

DIAGNOSES

The patient was diagnosed as IgG4-related sialadenitis (IgG4-RS) complicated with type III mixed cryoglobulinemia. IgG4-RS was confirmed by elevated serum IgG4 levels and diffuse IgG4 plasmocyte infiltration and storiform fibrosis in the interstitium of labial gland. Type III mixed cryoglobulinemia was confirmed by positive serum cryoglobulins and no monoclonal immunoglobulin in serum and urine.

INTERVENTIONS AND OUTCOMES

After treatment with prednisone and cyclophosphamide, serum cryoglobulins rapidly turned negative with the remission of IgG4-RS.

LESSONS

Type III mixed cryoglobulinemia can be caused by IgG4-RS, and the underlying mechanisms need to be further explored.

IgG4-related disease coexisting with autoimmune haemolytic anaemia

An 85-year-old man presented with a pale appearance and generalised pruritic papules. Laboratory investigations disclosed eosinophilia, autoimmune haemolytic anaemia, mixed hyperbilirubinaemia, cholestasis and elevated serum IgG4 levels. Abdominal sonography and CT showed progressive dilatation of biliary trees, with diffuse pancreatic enlargement and a subtle capsule-like low-density rim around the pancreatic head and body. Endoscopic retrograde cholangiopancreatography found no stone-related biliary obstruction, while endoscopic transpapillary biopsy demonstrated chronic inflammation only. Nevertheless, the diagnosis of IgG4-related disease with coexisting autoimmune haemolytic anaemia was presumed. The clinical picture and laboratory abnormalities improved after administration of moderate dose of methylprednisolone.

Neurological Manifestations of IgG4-Related Disease

OPINION STATEMENT

IgG4-related disease (IgG4-RD) is a multisystem inflammatory disorder. Early recognition of IgG4-RD is important to avoid permanent organ dysfunction and disability. Neurological involvement by IgG4-RD is relatively uncommon, but well recognised-hypertrophic pachymeningitis and hypophysitis are the most frequent manifestations. Although the nervous system may be involved in isolation, this more frequently occurs in conjunction with involvement of other systems. Elevated circulating levels of IgG4 are suggestive of the condition, but these are not pathognomonic and exclusion of other inflammatory disorders including vasculitis is required. Wherever possible, a tissue diagnosis should be established. The characteristic histopathological changes include a lymphoplasmacytoid infiltrate, storiform fibrosis and obliterative phlebitis. IgG4-RD typically responds well to treatment with glucocorticoids, although relapse is relatively common and treatment with a steroid-sparing agent or rituximab may be required. Improved understanding of the pathogenesis of IgG4-RD is likely to lead to the development of more specific disease treatments in the future.