SLR - September 2017 - Joshua D. Adams

Potential of Circulatory Procalcitonin as a Biomarker Reflecting Inflammation Among South Indian Diabetic Foot Ulcers 

Reference:
Umapathy D, Dornadula S, Rajagopalan A, Murthy N, Mariappanadar V, Kesavan R, Kunka Mohanram R. Potential of Circulatory Procalcitonin as a Biomarker Reflecting Inflammation Among South Indian Diabetic Foot Ulcers. J Vasc Surg. 2017 Jul 20. pii: S0741-5214(17)31127–8.

Scientific Literature Review

Reviewed By: Joshua D. Adams, DPM
Residency Program: North Colorado Medical Center, Greeley, CO

Podiatric Relevance: A large subset of podiatric medicine seeks to limit foot complications associated with diabetes mellitus. Infection control is key to prevent complications, including amputation. Compared to traditional biomarkers of infection (WBC count, ESR, and CRP), procalcitonin increases more predictably in the setting of infected diabetic foot ulcers. Patients with uncontrolled type 2 diabetes mellitus are often immunocompromised and may not generate a traditional immune response. Procalcitonin does not rely on an intact immune response and may be a more reliable biomarker than WBC count, ESR and CRP.

Methods: This cross-sectional study included 185 participants with type 2 diabetes mellitus. Participants were divided into three groups; patients living with diabetes with no foot ulcers as a control (n=75), noninfected diabetic foot ulcer (NIDFU, n=34), and lastly, infected diabetic foot ulcer (IDFU, n=76).  

The IDFU group was further divided into three groups based on the severity of infection using the IDSA guidelines (Grades 2–4). Blood samples were taken from all participants and analyzed using standard laboratory methods for WBC count, ESR, CRP and procalcitonin levels. Outcomes were reported as mean values with standard deviation for each group.

Results: When comparing control, NIDFU and IDFU groups, procalcitonin increased from 0.04, 0.06 and 0.50, respectively. When comparing NIDFU to IDFU, WBC count increased from 10.4, 10.9 and 13.6, respectively. When comparing NIDFU to IDFU with regards to ESR, there was an increase from 44, 64 and 88, respectively. When comparing NIDFU to IDFU, CRP increased from 3.8, 15 and 36.2, respectively. Procalcitonin and WBC count did not increase with severity of infection, whereas ESR and CRP did increase with infection severity.

Conclusions: The authors conclude that procalcitonin is a reliable biomarker for infection based on this pilot cross-sectional study. Based on the results of this study, I conclude that procalcitonin could effectively be used to help determine whether a diabetic foot ulcer is infected. However, this lab test should not replace clinical signs of infection but serves to verify clinically suspicious ulcers. Furthermore, traditional biomarkers still serve a purpose in helping to determine efficacy of treatment, as ESR and CRP change with severity of infection.

This study fails to mention other important factors that need to be considered when potentially routinely ordering serum procalcitonin levels, including cost, availability and other confounding disease processes that could change procalcitonin levels.

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