Factors associated with the time required for CRP normalization in pyogenic spondylitis: A retrospective observational study

Takuya Takahashi; Hiroyuki Inose; Takashi Hirai; Yu Matsukura; Shingo Morishita; Satoru Egawa; Jun Hashimoto; Kunihiko Takahashi; Toshitaka Yoshii

doi:10.1016/j.xnsj.2023.100301

Factors associated with the time required for CRP normalization in pyogenic spondylitis: A retrospective observational study

N Am Spine Soc J. 2023 Dec 4:17:100301. doi: 10.1016/j.xnsj.2023.100301. eCollection 2024 Mar.

Authors

Takuya Takahashi¹, Hiroyuki Inose^{2

3}, Takashi Hirai¹, Yu Matsukura¹, Shingo Morishita¹, Satoru Egawa¹, Jun Hashimoto¹, Kunihiko Takahashi⁴, Toshitaka Yoshii¹

Affiliations

¹ Department of Orthopedic Surgery, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
² Department of Orthopedic and Trauma Research, Graduate School, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan.
³ Department of Orthopaedic Surgery, Dokkyo Medical University Saitama Medical Center, 2-1-50 Minamikoshigaya, Koshigaya-shi, Saitama 343-8555, Japan.
⁴ Department of Biostatistics, M&D Data Science Center, Tokyo Medical and Dental University, 2-3-10 Kanda Surugadai, Chiyoda-ku, Tokyo 101‑0062, Japan.

Abstract

Background: Treatment for pyogenic spondylitis tends to be prolonged; however, few studies have examined the factors associated with the time required for infection control. Therefore, we analyzed a consecutive cohort of patients to identify factors associated with the time required to control infection in pyogenic spondylitis. This study aimed to clarify the factors linked to the duration necessary for achieving infection control in cases of pyogenic spondylitis, using C-reactive protein (CRP) normalization as an indicator.

Methods: In this retrospective observational study, we investigated 108 patients diagnosed with pyogenic spondylitis. We evaluated the number of days from the first visit to CRP normalization; for cases wherein CRP did not normalize, the number of days to the date of final blood sampling was evaluated. In the present study, infection control in pyogenic spondylitis was defined as a CRP falling within the normal range (≤0.14 mg/dL). We performed univariate and multivariate Cox regression analyses to identify various factors associated with the time required for CRP normalization in pyogenic spondylitis.

Results: The mean time required for CRP normalization was 148 days. Univariate Cox regression analysis showed that the serum creatinine level, estimated glomerular filtration rate (eGFR), lymphocyte percentage, neutrophil percentage, CRP level, CRP-albumin ratio, and neutrophil-to-lymphocyte ratio were significantly associated with the time required to control infection. Multivariate Cox regression analysis showed that a higher neutrophil percentage, diabetes mellitus, and a lower eGFR were the independent factors associated with a longer infection control time.

Conclusions: We found that a higher neutrophil percentage, diabetes mellitus, and a lower eGFR were significantly associated with a longer time for CRP normalization in pyogenic spondylitis. These findings may help identify patients with pyogenic spondylitis who are at a high risk for an extended infection control period.

Keywords: C-reactive protein; Diabetes mellitus; Estimate glomerular filtration rate; Neutrophil; Risk factors; pyogenic spondylitis.