Salivary inflammatory cytokines echo the low inflammatory burden in liver-transplanted children.

Objectives: The aims of this study were to compare the salivary cytokine profile, as a potential replacement for blood tests, in liver-transplanted children to that of a control group of healthy children, and to correlate the values of commonly tested laboratory blood tests to those of published blood values.

Methods: Liver-transplanted children, and a control group of healthy children of the same sex and age distribution, were recruited for the study. Saliva was collected at the same appointment for routine blood tests for the liver-transplanted children. Saliva was also collected from a control group of healthy children with similar age and sex distributions. Normal healthy blood values were extracted from the literature, for comparison. Cytokine levels in the saliva were quantified with ELISA. The analysis compared serum and saliva values between liver-transplanted and healthy children. In the serum, the values of albumin, GIT, GPT, GGT, CRP, WBC, neutrophils, and lymphocytes were examined, while the levels of IL-6, CXCL1, IL-1b, and IL-10 were measured in the saliva.

Results: Thirty liver-transplanted children and 30 healthy children were included in the study. Compared with published data for healthy children, the liver-transplanted group showed similar hepatic serum levels, yet reduced levels of serum inflammatory markers. Compared with the control group, in the transplanted group, the mean value of IL-6 was lower and the mean value of CXCL1 was similar. Interestingly, the anti-inflammatory IL-10 cytokine was lower in the transplanted group, while the pro-inflammatory IL-1β cytokine was higher.

Conclusion: The salivary inflammatory markers examined showed a similar pattern to the serum inflammatory values, though different markers were examined in the serum and saliva.

Clinical Relevance: The current study stresses the potential of oral fluids as an accessible biofluid, for use as a diagnostic substrate for systemic and oral diseases.

Trial Registration: 0136-16-RMC, Registered on 01 March 2018.