(Castlemen'' Disease)

Castleman disease is a group of rare disorders that involves lymph nodes that get bigger, called enlarged lymph nodes, and a wide range of symptoms. The most common form of the disorder involves a single enlarged lymph node. This lymph node is usually in the chest or neck, but it can occur in other areas of the body as well. This form of the disorder is called unicentric Castleman disease (UCD).

Multicentric Castleman disease (MCD) involves multiple regions of enlarged lymph nodes, inflammatory symptoms and problems with organ function. There are three types of MCD:

• HHV-8-associated MCD. This type is linked to human herpes virus type 8, called HHV-8, and human immunodeficiency virus (HIV).

• Idiopathic MCD. The cause of this type is unknown. This also is called HHV-8-negative MCD.

  The most serious form of this type of MCD is known as iMCD-TAFRO. This condition gets its name from the symptoms it causes.

• POEMS-associated MCD. This type is linked to another condition called POEMS syndrome. POEMS syndrome is a rare blood disorder that damages nerves and affects other parts of the body.

                    Enlarged lymph follicle in Castlemen's Disease

Idiopathic Multicentric Castleman Disease (iMCD): The first-line treatment is typically an anti-interleukin-6 (IL-6) monoclonal antibody.

Siltuximab (brand name Sylvant) is the only FDA-approved medication for iMCD and is the preferred initial therapy.
Tocilizumab (brand name Actemra), another anti-IL-6 agent, is also used, particularly in Japan or if siltuximab is unavailable.
Corticosteroids may be used in severe cases, often in combination with other therapies, to control inflammation quickly.
For patients who do not respond to anti-IL-6 therapy, second-line options include other immunomodulators (e.g., sirolimus, bortezomib) or chemotherapy regimens.

HHV-8-associated Multicentric Castleman Disease: This form is strongly linked to the human herpesvirus 8 (HHV-8) and often occurs in patients with HIV.
Rituximab (brand name Rituxan), a B-cell-targeting antibody, is generally the highly effective first-line treatment.
Antiviral drugs to block the activity of HHV-8 or HIV (such as antiretroviral therapy for HIV-positive patients) are often included.
Chemotherapy may be combined with rituximab for severe, life-threatening cases.
POEMS-associated Multicentric Castleman Disease: Treatment is directed at the underlying plasma cell disorder that drives the syndrome. This may involve radiation therapy for localized disease or chemotherapy-based regimens for more widespread disease. 
Due to the complexity and rarity of the disease, it is highly recommended to consult a physician or a center with expertise in Castleman disease. 

The Castleman Disease Collaborative Network (CDCN) offers resources and information on expert centers. The Castleman Disease Collaborative Network plays a crucial role in advancing research and treatment for Castleman disease. Through innovative studies, patient support initiatives, and a commitment to collaboration, the CDCN is making strides in improving outcomes for those affected by this rare condition. For more information, you can visit their official website at CDCN. 

Castleman Disease Collaborative Network | CDCN