People with human herpesvirus 8 associated multicentric Castleman disease (HHV-8-associated MCD) have enlarged lymph nodes in multiple regions and often have flu-like symptoms, abnormal findings on blood tests, and dysfunction of vital organs, such as the liver, kidneys, and bone marrow.

People with HHV-8-associated MCD may experience enlarged lymph nodes in multiple lymph node regions; systemic symptoms, such as fever, night sweats, unintended weight loss, and fatigue; rashes such as cherry hemangiomas or Kaposi sarcoma; enlargement of the liver and/or spleen; and extravascular fluid accumulation in the extremities (edema), abdomen (ascites), or lining of the lungs (pleural effusion).

In particular, HHV-8 infection of immune cells leads to increased levels of Interleukin-6 (IL-6), a cytokine known to play a role in other forms of Castleman disease.

[4] HHV-8-associated MCD is diagnosed based on patient history, physical exam, laboratory testing, radiologic imaging, and microscopic analysis (histology) of biopsied tissue from an enlarged lymph node.

[1][8] Radiologic imaging will demonstrate enlarged lymph nodes in multiple regions, which are typically 18F-fluorodoxyglucose (FDG) avid on positron-emission tomography (PET).

Surgical removal of enlarged lymph nodes, the standard treatment for UCD, is ineffective in HHV-8-associated MCD.

Antiviral medications targeted at HHV-8, such as valganciclovir, may be used in patients with poorly controlled HIV or concurrent Kaposi sarcoma.

[12] Rituximab may be discontinued once clinical and laboratory evidence of active disease resolve or continued as maintenance therapy.

Follow-up visits may include evaluation of symptoms, physical examination, laboratory testing, and radiologic imaging.

[13] There have been no published epidemiologic studies of Castleman disease outside of the United States; however, rates of HHV-8-associated MCD may vary in different populations based on the prevalence of HHV-8 infection.