Alkaline phosphatase is useful for predicting giant cell arteritis complications in patients with polymyalgia

Ryo Yamashita1, Yusuke Izumi1, Jun Hiramoto1

  • 1Department of General Medicine, The Jikei University School of Medicine, Daisan Hospital, Tokyo, Japan.

Modern Rheumatology
|November 14, 2024
PubMed
Abstract

Insights

Alkaline phosphatase (ALP) levels are significantly higher in patients with polymyalgia rheumatica (PMR) and giant cell arteritis (GCA) complications. Elevated ALP can help differentiate GCA in PMR patients.

Area of Science:

  • Rheumatology
  • Clinical Biochemistry

Background:

  • Polymyalgia rheumatica (PMR) can present with or without giant cell arteritis (GCA).
  • Distinguishing GCA complications in PMR patients is crucial for timely treatment and preventing irreversible damage.

Purpose of the Study:

  • To investigate the utility of alkaline phosphatase (ALP) in differentiating GCA complications among patients diagnosed with PMR.
  • To evaluate ALP as a predictive biomarker for GCA in the PMR population.

Main Methods:

  • Retrospective analysis of 128 patients diagnosed with PMR between 2014 and 2023.
  • Comparison of ALP levels between isolated PMR and PMR with GCA groups.
  • Logistic regression analysis to identify predictors of GCA complications.

Main Results:

  • Patients with PMR and GCA (n=17) exhibited significantly higher median ALP levels compared to isolated PMR patients (n=111) (242.0 vs. 187.0 U/L, P < .001).
  • An ALP cut-off of 214 U/L demonstrated 88% sensitivity and 55% specificity for GCA diagnosis.
  • Multivariate analysis confirmed ALP as an independent predictor of GCA complications (OR, 25.2; P = .032).

Conclusions:

  • Alkaline phosphatase is a valuable biomarker for distinguishing GCA complications in patients with polymyalgia rheumatica.
  • Elevated ALP levels can aid clinicians in identifying PMR patients who have developed GCA.