Association between blood counts-related parameters and disease activity
in patients with rheumatoid arthritis
Background: Erythrocytes and platelets have been demonstrated to play a
critical role in inflammatory processes. However, little is known about
the diagnostic value of these indices in RA patients. The aim of this
study was to evaluate the clinical significance of blood counts-related
parameters such as counts of red blood cells (RBCs) and platelets
(PLTs), hemoglobin (Hb), red blood cells-platelet ratio (RPR) and
hemoglobin-platelet ratio (HPR) in rheumatoid arthritis (RA) and their
association with disease activity. Methods: Clinical and laboratory data
from 178 RA patients and 164 healthy controls were collected and
analyzed. RA patients were divided into inactive group and active group
according to disease activity score in 28 joints based on C-reactive
protein (DAS28-CRP). The relationship between blood RBC, Hb, PLT, RPR
and HPR and DAS28-CRP was detected by Spearman correlation method.
Receiver operating characteristic (ROC) curve was used to assess the
diagnostic value of these parameters. The predictive role of these
indices for RA disease activity was evaluated by logistical regression
analysis. Results: Active RA patients exhibited lower levels of blood
RBC counts, Hb, HCT, RPR and HPR but significantly higher level of PLT
counts compared with those in inactive groups (P < 0.01).
Spearman analysis showed that blood RBC counts, HCT, RPR and HPR were
negatively but PLT counts were positively related with DAS28-CRP (P
< 0.001) in RA. ROC curve analysis revealed that the AUC of
RBC and Hb was higher than that of ESR, RF and CCP for distinguishing
active RA from inactive group. Logistical regression analyses showed
that PLT is an independent predictor for RA disease activity.
Conclusion: Blood RBC counts, Hb, RPR and HPR were negatively but PLT
counts were positively related with RA disease activity. Blood PLT may
act as a novel inﬂammatory factor for predicting disease activity in RA.