Lymphopenia in systemic lupus erythematosus patients: Is it more than a laboratory finding?

Aim of the work: To investigate the relation between lymphopenia and clinical manifestations, laboratory findings, disease activity and damage index in systemic lupus erythematosus (SLE) patients.Patients and methods: 124 SLE patients were recruited from the Rheumatology Department in-patient and outpatient clinic, Faculty of medicine, Cairo University Hospitals. SLE disease activity index (SLEDAI) and the systemic lupus international collaborating clinics damage index (SLICC-DI) were assessed. Patients were divided into two groups according to presence or absence of lymphopenia (lymphocyte count <= 1500 cells/mm(3)), and were compared as regards different disease parameters.Results: The 124 patients were 113 females (91.1%) and 11 males (8.9%). Their mean age was 28.54 +/- 8.25 years and median disease duration was 48 (24-105) months. 86 (69.4%) had renal involvement, complement C3 was consumed in 84 (67.7%) and C4 in 44 (35.5%). All were receiving steroids and a high dose was more frequent in those with lymphopenia (17 (29.8%) compared to those without (in 9 (13.4%). Lymphopenia was found in 57 (46%) patients. Lymphopenic patients had higher frequency of renal involvement (p = 0.002) (OR = 3.37, CI = 1.5-7.8), complement consumption (p = 0.03), 24 h urinary proteins (p = 0.034), higher steroid doses (p = 0.012) and cyclophosphamide administration (p = 0.03). SLEDAI was severe in 29.8% of lymphopenic patients (p = 0.16), and SLICC-DI median was 2 in both groups (p = 0.4).Conclusion: Lymphopenia is a common finding in SLE patients and was significantly associated with lupus nephritis, complement consumption, higher steroid doses and cyclophosphamide administration. Lymphopenia might be a promising marker for renal involvement in SLE. Publishing services provided by Elsevier B.V. on behalf of Egyptian Society of Rheumatic Diseases.