Definition
Lymphocyte count on FBC in an adult patient that is below the lower limit of the normal range.
Lymphopenia is a common finding, especially in elderly patients. It is rarely of clinical significance. No further investigation is advised in an elderly patient with a lymphocyte count > 0.5 x109/l in the absence of any concerning symptoms.
Lymphopenia may reflect a response to stress such as an acute infection, recent surgery or be iatrogenic secondary to medication, especially immunosuppressant drugs such as steroids. Most cases are reversible and do not require specialist evaluation.
Lymphopenia in adults is a common and usually non-specific finding:
it is important to exclude HIV and persistent unexplained lymphopenia is an HIV indicator condition.
C.M & L.W 26-06-23
Who to refer:
- Lymphocyte count <1 x 109/l in addition to the presence of weight loss, fever or drenching night sweats.
- Patients with lymphadenopathy (nodes > 1 cms) and/or splenomegaly.
- Symptomatic patients with persistent lymphopenia (<1 x109/L) with other symptoms should be referred to the most appropriate specialty based on clinical and laboratory features.
Who not to refer:
- Anyone who does not meet the referral criteria above
How to refer:
SCI Gateway– Department of Haematology at WGH, RIE or St John’s.
Primary care investigations
- FBC
- Blood film
- B12 and folate. Treat if deficiency is detected
- Quantitative immunoglobulins + protein electrophoresis
- Offer HIV testing in moderate to severe lymphopenia (lymphocyte count <1 x 109/l, and < 0.5 x 109/l in over 70).
If additional clinical features suggest a diagnosis of SLE, RA or other connective tissue disorder check CCP, ANF, dsDNA (if ANF positive).
- Caird FL et al, Cancer Research 2009;69:5383-91. The leucocyte count in old age.
- Brass D et al, BMJ 2014;348:g1721.
