TY - JOUR
T1 - Use of the CD19 count in a primary care laboratory as a screening method for B-cell chronic lymphoproliferative disorders in asymptomatic patients with lymphocytosis
AU - te Raa, G. Doreen
AU - Fischer, Kathelijn
AU - Verweij, Wim
AU - van Houte, Arend J.
AU - Kater, Arnon P.
AU - Biesma, Douwe H.
PY - 2011
Y1 - 2011
N2 - Detection of absolute and relative lymphocytosis in otherwise asymptomatic elderly patients is very common in the primary care setting and frequently results in referral for screening of lymphoproliferative disorders. Since many B-cell chronic lymphoproliferative disorders (B-CLPD) are indeed asymptomatic at diagnosis in most patients with lymphocytosis, no sign of such a disorder is usually detected. Currently, specific guidelines for screening of patients with lymphocytosis are lacking. We investigated the practicability and clinical value of a single colour CD19 count performed by a primary care laboratory in order to improve the diagnostic follow-up of patients with lymphocytosis in a primary care laboratory. The capability of detecting monoclonal B-cell lymphocytosis and B-CLPD by CD19, was first confirmed in patient samples with known B-CLPD. Next, in a previously defined geographic area, a CD19 count was performed on all samples for patients aged ≥40 years with relative or absolute lymphocytosis but without neutropenia. Clinical follow-up, with a median of 4 years, was performed using both a survey among the requesting general practitioners and by analysis of the records of the referral hospitals within the borders of the defined area. A total of 520 cases with asymptomatic lymphocytosis were identified. In all cases, the CD19 count was performed; 207 (40%) showed increased values and 313 (60%) showed normal values. An increase in CD19 proved highly sensitive for detection of B-CLPD (98%, 95% CI; 94%-100%) with a high positive predictive value (57%, 95% CI; 50%-63%). The area under curve, the receiver-operating characteristic curve of the CD19 count (0.93, 95% CI; 0.91-0.96), was significantly higher compared to the absolute lymphocyte count (0.86, 95% CI; 0.83-0.89), especially in patients with moderate lymphocytosis. This study indicates that the CD19 count, performed by a primary care laboratory, is feasible and a promising tool for initial screening of lymphocytosis to discriminate B-CLPD from benign causes of lymphocytosis
AB - Detection of absolute and relative lymphocytosis in otherwise asymptomatic elderly patients is very common in the primary care setting and frequently results in referral for screening of lymphoproliferative disorders. Since many B-cell chronic lymphoproliferative disorders (B-CLPD) are indeed asymptomatic at diagnosis in most patients with lymphocytosis, no sign of such a disorder is usually detected. Currently, specific guidelines for screening of patients with lymphocytosis are lacking. We investigated the practicability and clinical value of a single colour CD19 count performed by a primary care laboratory in order to improve the diagnostic follow-up of patients with lymphocytosis in a primary care laboratory. The capability of detecting monoclonal B-cell lymphocytosis and B-CLPD by CD19, was first confirmed in patient samples with known B-CLPD. Next, in a previously defined geographic area, a CD19 count was performed on all samples for patients aged ≥40 years with relative or absolute lymphocytosis but without neutropenia. Clinical follow-up, with a median of 4 years, was performed using both a survey among the requesting general practitioners and by analysis of the records of the referral hospitals within the borders of the defined area. A total of 520 cases with asymptomatic lymphocytosis were identified. In all cases, the CD19 count was performed; 207 (40%) showed increased values and 313 (60%) showed normal values. An increase in CD19 proved highly sensitive for detection of B-CLPD (98%, 95% CI; 94%-100%) with a high positive predictive value (57%, 95% CI; 50%-63%). The area under curve, the receiver-operating characteristic curve of the CD19 count (0.93, 95% CI; 0.91-0.96), was significantly higher compared to the absolute lymphocyte count (0.86, 95% CI; 0.83-0.89), especially in patients with moderate lymphocytosis. This study indicates that the CD19 count, performed by a primary care laboratory, is feasible and a promising tool for initial screening of lymphocytosis to discriminate B-CLPD from benign causes of lymphocytosis
U2 - https://doi.org/10.1515/CCLM.2011.018
DO - https://doi.org/10.1515/CCLM.2011.018
M3 - Article
C2 - 21054188
SN - 1434-6621
VL - 49
SP - 115
EP - 120
JO - Clinical chemistry and laboratory medicine
JF - Clinical chemistry and laboratory medicine
IS - 1
ER -