12/06/2024
IgG4-related disease (IgG4-RD) is a chronic inflammatory condition characterized by the infiltration of IgG4-positive plasma cells into various tissues and organs, leading to fibrosis and organ dysfunction. It can affect nearly any organ system, but common sites include the pancreas, bile ducts, salivary glands, kidneys, lungs, and lymph nodes.
# # # Key Features of IgG4-Related Disease:
1. **Inflammation and Fibrosis**: The hallmark of IgG4-RD is a dense lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells and storiform fibrosis (a characteristic pattern of fibrosis).
2. **Elevated Serum IgG4**: Many patients with IgG4-RD have elevated levels of IgG4 in their blood, although this is not universal and not required for diagnosis.
3. **Multiorgan Involvement**: IgG4-RD can involve multiple organs simultaneously or sequentially. Commonly affected organs include:
– **Pancreas**: Leading to autoimmune pancreatitis.
– **Bile Ducts**: Causing sclerosing cholangitis.
– **Salivary and Lacrimal Glands**: Resulting in swelling and dysfunction.
– **Kidneys**: Causing tubulointerstitial nephritis.
– **Lungs**: Leading to various pulmonary manifestations.
– **Lymph Nodes**: Causing lymphadenopathy.
4. **Symptoms**: Symptoms vary depending on the organs involved but can include abdominal pain, jaundice, dry mouth and eyes, and generalized symptoms like weight loss and fatigue.
5. **Diagnosis**: The diagnosis of IgG4-RD is based on a combination of clinical, serological, radiological, and histopathological features. Biopsy of the affected tissue showing characteristic features is often necessary.
6. **Treatment**: Corticosteroids are the mainstay of treatment and are typically effective in reducing inflammation and symptoms. Other immunosuppressive agents, such as rituximab, may be used in refractory cases or to maintain remission.
7. **Prognosis**: With appropriate treatment, many patients achieve remission, but the disease can be chronic and relapsing, requiring long-term management.
IgG4-RD is relatively rare and was only recognized as a distinct clinical entity in the early 21st century. Ongoing research continues to improve understanding of its pathogenesis, diagnosis, and treatment.
IGG4
