Definition
Lymphocyte count on FBC in an adult patient that is greater than the upper limit of the normal range: please only refer if above 10 X 109, unless the patient has other symptoms in which case the threshold is lower (see below).
T cell Lymphocytosis is common and is usually a reactive response that does not require any intervention. It occurs in viral infections, autoimmune disorders including connective tissue disorders, thyroiditis, diabetes etc. It can also been seen in smokers and post splenectomy.
C.M & L.W 31-07-23
Who to refer:
Please refer:
- Symptomatic patients (weight loss, fever, drenching night sweats) with a lymphocyte count >5 x 109/l
- Patients with lymphadenopathy (nodes > 1 cms) and/or splenomegaly and/or cytopenias (Hb <100, neutrophils <1.0, platelets <100) with a lymphocyte count >5 x 109l
- Patients with a lymphocyte count >10 x 109/l for >3 months
- Patients with clonal B cell lymphocytosis.
Please refer URGENTLY:
- symptomatic patients or presence of lymphadenopathy or splenomegaly.
Who not to refer:
- Asymptomatic patients with a single lymphocyte count >10 x 109/l. Instead repeat FBC in 3 months.
- Asymptomatic patients with a lymphocyte count of 5 – 10 x 109/l. Instead repeat FBC in 6 months and if minimal change repeat FBC annually thereafter. Consider referral if lymphocyte >10 x 109/l.
How to refer:
SCI Gateway to the Department of Haematology WGH or SJH.
- FBC
- Blood film.
- Liver Function tests.
- Viral serology for EBV (IgM), CMV, HIV & Hepatitis viruses (HepBs Ag, HepB core Ab, HepC Ab)
- Immunophenotyping if lymphocytosis >10 x 109/l for longer than 3 months (this may be done by reflex in the laboratory). If requesting from primary care, please take samples Monday –Thursday. This reflex testing generates a report which gives an interpretative result and advises action to be taken, including if referral is indicated.
The significance of lymphocytosis in routine clinical practice: data from the South East Scotland Cancer Network
Gabrielle E. Clark, Christopher Mullen, Laura E. McGlinchey, Victoria Campbell.
