Is Procalcitonin Helpful In The Diagnosis of Toxic Shock Syndrome?

Background:Procalcitonin (PCT) is a serologic biomarker used in identification of severe bacterial infections. Toxic shock syndrome (TSS) is a type of severe bacterial infection resulting in multi-organ system failure and often death. Early identification and treatment are critical for favorable outcomes, but diagnosis is difficult. CDC guideline criteria establish a diagnosis by including clinical and laboratory evaluations. To the best of our knowledge, there are few case reports evaluating PCT and association with TSS diagnosis. Our study planned to see if patients with TSS have elevated PCT levels, and if PCT may be valuable in diagnosing TSS.

Methods:Retrospective study of adult patients admitted to Santa Barbara Cottage Hospital in Santa Barbara California between 2009-2014. Charts of patients with ICD-9 code of TSS were reviewed. Only those with a confirmed diagnosis based on CDC criteria for either Staphylococcal TSS-1 or Streptococcal TSS-2 were included. Maximum PCT within the first 48 hours of admission was used.

Results: Nineteen patients fulfilled the CDC criteria for TSS. Age ranged from 18 to 80 years, mean of 43, 8/19 male, 11/19 female. PCT was elevated in all 19 patients, ranging from 0.11 to 482.7 ng/ml. Eighteen (95%) had PCT greater than 0.2 and 14 had PCT greater than 2.0. All patients with a PCT greater than 100 had a creatinine level greater than two times normal, ranging 2.3-6.7.

Conclusion:PCT is heralded as the biomarker holding promise for bloodstream infections in sepsis, but the correlation with TSS is uncertain. PCT above 2.0 is generally interpreted as positive, indicating a severe systemic bacterial infection. In our study, all 19 patients had an elevated PCT and 74% of patients had a PCT of 2.0 or more. 26 percent had PCT greater than one hundred. All patients with confirmed TSS had a detectable PCT, with three quarters of our patients having a PCT more than 2. These results show promise in searching for a correlation between PCT and TSS, however the association has yet to be determined. We were unable to find statistical significance for the use of PCT and did not find a correlation differentiating PCT in TSS-1 or TSS-2. An elevated PCT may support the diagnosis of TSS, however our study was unable to prove this correlation due to the small sample size. Prospective studies with larger patient size are needed to investigate the utility of PCT in TSS.