Evaluating High Mobility Group Box 1 (HMGB1) as a prognostic biomarker for mortality in canine systemic inflammatory response syndrome.

PICO question: In canine patients with infectious systemic inflammatory response syndrome (SIRS), how do increased levels of High Mobility Group Box 1 (HMGB1) protein, compared to low levels, relate to mortality outcomes? Clinical bottom line: Category of research: Prognosis. Number and type of study designs reviewed: Three studies were critically reviewed. All three studies were prospective observational studies. Strength of evidence: Weak. Outcomes reported: All three studies included in this Knowledge Summary evaluated canine patients with SIRS, encompassing both infectious and non-infectious causes. The second and third paper both found a significant association between elevated serum HMGB1 levels and increased mortality in dogs with SIRS. The first paper, while focusing specifically on infectious SIRS, did not find a statistically significant correlation between HMGB1 levels and mortality, although HMGB1 levels were elevated in SIRS cases compared to healthy controls. Variability in the timing of HMGB1 measurements, along with differences in study design, population heterogeneity, and small sample sizes, may have contributed to inconsistencies in the findings. Overall, the evidence suggests a potential association between higher HMGB1 levels and increased mortality in dogs with SIRS, but further standardised research is needed to strengthen this conclusion. Conclusion: While two studies identified an association between elevated HMGB1 and mortality, the findings are inconclusive. The strength of evidence is restricted by diagnostic and methodological limitations, making for weak quality evidence overall. Future research should prioritise standardised measurement timing, larger and more homogeneous populations, and explore HMGB1's role in disease progression to fully establish its utility as a prognostic marker in canine SIRS. How to apply this evidence in practice The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient's circumstances and owners' values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.