Comparison of C-Reactive Protein in Dried Blood Spots and Saliva of Healthy Adolescents

Abstract

Background/AimDetermining C-reactive protein (CRP) by non-invasive methods is of great interest for research addressing inflammation in young people. However, direct comparisons of such methods applied in children and adolescents are lacking so far. This study aimed to evaluate the association between CRP measured in dried blood spots (DBS CRP) and in saliva (sCRP), two less invasive alternatives to venipuncture, in 12- to 14-year-old adolescents. To evaluate the validity of both measurements in the context of biobehavioral studies, the potential of DBS CRP and sCRP to discriminate between defined BMI subgroups was assessed.Materials and MethodsCRP levels in DBS and saliva collected from 87 healthy adolescents (M = 13.25 years, SD = 0.30, 51.7% females) were determined using high sensitive CRP ELISA for serum and salivary CRP ELISA, respectively. Characteristics and correlation of both measurements were assessed for the total sample and for three subgroups classified by BMI percentile ranges (A: ≤ 25; B: 26–74; C: ≥ 75).ResultsIn the total sample, DBS CRP and sCRP were significantly associated (r = 0.59, p < 0.001). Splitting the sample into BMI-dependent subgroups revealed similarly strong associations of DBS CRP with sCRP for all three groups (A: r = 0.51; B: r = 0.61; C: r = 0.53). However, comparing the mean CRP values per BMI subgroup, one-way ANOVA reported significant differences for DBS CRP, but not for sCRP mean values.ConclusionsThe significant correlation of DBS CRP with sCRP was independent of the investigated BMI range groups, yet BMI-dependent distinction was only provided by DBS CRP mean values. Overall, our results suggest that DBS CRP is likely to reflect systemic inflammation more precisely. Salivary CRP can be alternatively determined in studies with adolescents when conditions require it, given the oral health status is assessed. Considering that DBS CRP and sCRP share only 35% of common variance, further studies should examine their specific validity.

Remote self-collection of capillary blood using upper arm devices for autoantibody analysis in patients with immune-mediated inflammatory rheumatic diseases

“…Mixed data exist on equivalence of capillary blood, regarding liver 37 and kidney function tests 37 54 and complete blood count. 37 55 56 Promising results have been recently published regarding completely non-invasive measurement of CRP via saliva 57 or even continuously real time via a sweat-based wrist wearable. 58 In line with our results, previous studies could demonstrate that UA-based self-sampling is perceived as less painful compared with traditional venous blood collection 28 and finger pricking.…”

“…Mixed data exist on equivalence of capillary blood, regarding liver37 and kidney function tests37 54 and complete blood count 37 55 56. Promising results have been recently published regarding completely non-invasive measurement of CRP via saliva57 or even continuously real time via a sweat-based wrist wearable 58…”

Salivary High-Sensitivity C-Reactive Protein and Its Clinical Relevance in Modern Medicine: A Comprehensive Review

“…Studies have consistently demonstrated a positive correlation between salivary and serum hsCRP levels across various conditions, encompassing MI patients and controls. This suggests that saliva can be an alternative sample for assessing inflammatory markers such as hsCRP [ 5 ]. Saliva collection methods, including passive drool and swab-based techniques, offer standardized protocols for sampling and ease of use, rendering saliva a convenient and noninvasive sample for monitoring health status and detecting systemic disorders [ 5 , 13 ].…”

“…This suggests that saliva can be an alternative sample for assessing inflammatory markers such as hsCRP [ 5 ]. Saliva collection methods, including passive drool and swab-based techniques, offer standardized protocols for sampling and ease of use, rendering saliva a convenient and noninvasive sample for monitoring health status and detecting systemic disorders [ 5 , 13 ]. The secretion of hsCRP in saliva is influenced by systemic inflammation and local oral factors.…”

“…The exploration of salivary hsCRP represents a compelling proposition driven by the limitations associated with traditional blood-based assays. While conventional methods necessitate invasive and often costly blood sampling, saliva offers a noninvasive, easily accessible alternative for biomarker analysis [ 5 ]. This shift in focus toward salivary hsCRP holds promise for overcoming logistical barriers associated with blood sampling, potentially revolutionizing disease detection, monitoring, and management, particularly in scenarios where blood sampling may pose challenges or be undesirable [ 6 ].…”