lymphoproliferative disorder
Meaning of lymphoproliferative disorder: A broad label covering uncontrolled growth of immune cells, from harmless reactive swelling through to outright lymphoma.
Definition of lymphoproliferative disorder
A lymphoproliferative disorder is any condition in which lymphocytes, the white blood cells that run the immune response, multiply beyond what the body needs. The group ranges from reactive growth that settles on its own to cancers such as lymphoma and chronic lymphocytic leukemia. Many arise when immune control is weakened by an inherited defect, a virus, or drugs given after an organ transplant.
How is this different from a normal immune response?
Fighting an infection normally makes lymphocytes multiply. Lymph nodes swell, then shrink again once the threat has passed. In a lymphoproliferative disorder the expansion does not stop when it should. Sometimes the growing cells are a mixed population that has simply lost its off switch. Sometimes a single clone has escaped control entirely, and that is what makes a cancer. The line between the two is not always sharp, and a process that begins as reactive can progress into a malignant one.
What are the main groups?
| Group | Example |
|---|---|
| Reactive | Swollen nodes after a viral infection |
| Post-transplant | Growth of virus-infected B cells during immune suppression |
| Inherited immune defect | Failure to control Epstein-Barr virus |
| Malignant | Hodgkin and non-Hodgkin lymphoma |
Why does a weakened immune system matter?
Healthy T cells patrol the body and destroy cells that have been infected by a virus or have started behaving abnormally. Epstein-Barr virus, carried silently for life by most adults, lives inside B lymphocytes and drives them to divide. When T cell surveillance is deliberately suppressed to protect a transplanted organ, or is missing because of an inherited fault or untreated HIV, those infected B cells can expand unchecked. Reducing the immune suppression sometimes lets the immune system regain control on its own, which is unusual among conditions treated like cancer.
How does it show itself?
Painless swelling of lymph nodes is the usual first sign, since nodes are the collecting stations of the lymphatic system where lymphocytes gather. The spleen and liver may enlarge as well. Fever, drenching night sweats, unintended weight loss and marked tiredness often accompany it, and blood counts may be abnormal. Diagnosis rests on removing a whole node or sampling bone marrow, because the appearance of the cells and the pattern of markers on their surface decide which disorder is present and how it is likely to behave.
Also known as
Used in a sentence
The biopsy was reported as a post-transplant lymphoproliferative disorder driven by Epstein-Barr virus.
Good to know
Not every lymphoproliferative disorder is a cancer, and post-transplant cases can regress when the drugs suppressing the immune system are reduced.
Word origin
Where “lymphoproliferative disorder” comes from
Lympho- comes from the Latin lympha, meaning clear water; proliferative comes from proles, offspring, and ferre, to bear.