MULTICENTRIC CASTLEMAN DISEASE ASSOCIATED WITH THE HHV-8 VIRUS
Multicentric CD associated with the HHV-8 virus is generally found in patients infected with HIV but can also affect other populations, particularly those of Mediterranean or African origin.
It is a disease linked to the HHV-8 virus which can be found in the lymph nodes and the blood.
If left untreated, it can develop rapidly into a serious or even life-threatening form.
Discovery
The disease is usually detected by signs of inflammation: fever, sweats, weight loss, failure to thrive in children or unexplained anaemia. Lymph nodes (adenopathies) can be felt at the side of the neck, the underarm or groin area. In some cases, the spleen may be enlarged (splenomegaly).
In half of all cases, it exists alongside another complication of the HHV-8 infection, namely Kaposi's sarcoma, which produces violet lesions in the skin.
Diagnosis
A diagnosis is made after examining a sample (biopsy) taken from a lymph node. This sample may be taken by a surgeon (minor operation under local anaesthesia) or by a radiologist who inserts a needle into the lymph node. The lesions characteristic of Castleman disease can be detected by analysing this sample and the HHV-8 virus can be detected in the lymph node using a specific technique. The doctor in charge of this analysis (anatomopathologist) will then indicate or confirm the diagnosis.
Initial assessment
Based on the biopsy report which indicates this diagnosis, the doctor in charge will propose various tests to confirm the diagnosis.
- Lesions in the skin typical of Kaposi's sarcoma may be identified in the examination.
- The doctor will be systematically looking for anaemia and signs of inflammation by examining a blood sample. The patient will also be screened for HIV infection. With this form of Castleman disease, the examinations will usually reveal anaemia, signs of inflammation with raised C-reactive protein (CRP) and gammaglobulin levels.
- A radiological examination of the whole body (scan or PET scan) can reveal the affected lymph nodes and investigate the spleen.
In the case of HIV infection, the HIV viral load and the CD4 lymphocyte count are also examined.
Treatment
The reference treatment involves an antibody (immunotherapy) which destroys the cells (B lymphocytes) which contain the HHV-8 virus. The antibody used is rituximab (Mabthera®). It is often associated with treatment with etoposide (vepeside®, celltop®) in an emergency, which quickly brings the symptoms under control.
It must be combined with an antiretroviral treatment in the case of HIV infection.
Relapse is possible but the disease generally responds to a second treatment.
Outcome
The prognosis has improved significantly since the introduction of these new treatments.
There is a risk of the disease developing into a malignant lymph node tumour (lymphoma), but this risk has been significantly reduced since the introduction of rituximab.