Clinical Trial: Retrospective Study for Diagnosis of Undetected IgG4 Related Diseases in Patients With High Serum IgG4 Levels.
Study Status: Completed
Recruit Status: Unknown status
Study Type: Observational
Official Title: A Survey of Patients With Elevated Serum IGG4 With Unknown IGG4-related Disease to Whom Biopsy Was Performed for Other Reasons and Performance of Subsequent Specific Stain
Brief Summary:
Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized syndrome of unknown etiology comprised of a collection of disorders that share specific pathologic, serologic, and clinical features.
Histopathological analysis of biopsy specimens remains the cornerstone in the diagnosis of IgG4- related disease. Elevated concentrations of IgG4 in tissue and serum are helpful in diagnosing IgG4-related disease, but neither one is a specific diagnostic marker. Correlation with specific histopathological findings is essential, regardless of the serum IgG4 concentration, the number of IgG4-positive plasma cells in tissue, or the ratio of IgG4 to IgG in tissue. Misdiagnoses of IgG4-related disease are increasingly common because of excessive emphasis on moderate elevations of serum IgG4 concentration and overreliance on the finding of IgG4-positive plasma cells in tissue.
Detailed Summary:
IgG4 is a unique antibody in both structure and function. This molecule accounts for less than 5% of the total IgG in healthy persons and is the least abundant IgG subclass. In contrast to IgG1, IgG2, and IgG3, serum IgG4 concentrations among ostensibly healthy people vary by a factor of more than 100 (normal range, 0.01 to 1.4 mg per milliliter), but IgG4 concentrations within individual persons are generally stable.
Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized syndrome of unknown etiology comprised of a collection of disorders that share specific pathologic, serologic, and clinical features.
These different conditions were previously thought to be unrelated [2-4]. The commonly shared features include tumor-like swelling of involved organs, a lymphoplasmacytic infiltrate enriched in IgG4-positive plasma cells, and variable degrees of fibrosis that has a characteristic "storiform" pattern. In addition, elevated serum concentrations of IgG4 are found in 60 to 70 percent of patients with IgG4-RD.
Two major presentations of this condition, which often affects more than one organ, are type 1 autoimmune pancreatitis (IgG4-related pancreatitis) and salivary gland disease; the later may present as salivary gland enlargement or as sclerosing sialadenitis (formerly termed "Mikulicz disease" and Küttner's tumor, respectively). These conditions often resemble Sjögren's syndrome but are pathophysiologically distinct from this disorder. The preferred name for the overall condition is IgG4-related disease.
The presence of IgG4-bearing plasma cells is required for a diagnosis of IgG4- related disease, but IgG4-positive cells are found in a wide variety of inflammatory infiltrates,
Sponsor: Meir Medical Center
Current Primary Outcome: serum level of IGG4 [ Time Frame: 6 months ]
Original Primary Outcome: Same as current
Current Secondary Outcome: specific staining for IGG4 to biopsy samples [ Time Frame: six months ]
Original Secondary Outcome: Same as current
Information By: Meir Medical Center
Dates:
Date Received: August 28, 2014
Date Started: October 2014
Date Completion: September 2015
Last Updated: August 29, 2014
Last Verified: August 2014
