The onset inflammatory parameters and the Cobb angle in adolescent idiopathic scoliosis: a case-control study

To investigate the association between early inflammatory markers: neutrophil/lymphocyte ratio (NLR), monocyte/lymphocyte ratio (MLR), platelet/lymphocyte ratio (PLR), and C-reactive protein/albumin ratio (CAR) and the Cobb angle in adolescent idiopathic scoliosis (AIS).

This multicenter case-control study (2017-2024) enrolled 419 patients with AIS (Cobb angle >10°) and 381 age- and sex-matched controls (Cobb angle 0°). We collected demographic data, curve characteristics, and laboratory parameters (white blood cells [WBC], NLR, MLR, PLR, and CAR) at the time of initial diagnosis, before treatment initiation or infection. The Cobb angle was measured by two independent radiologists blinded to clinical data.

Compared with controls, AIS patients had significantly higher WBC, neutrophil, lymphocyte, and monocyte counts, CRP, NLR, and CAR, and lower platelets, PLR, and calcium levels (all P<0.05). CAR and NLR values increased with greater Cobb angle. In contrast, mean platelet volume did not differ between the groups.

This is the first study to evaluate CAR in AIS, demonstrating its significant association with the Cobb angle, alongside NLR and MLR. As inexpensive and readily available markers, CAR and NLR may help in diagnosing AIS, but their role in risk stratification and disease monitoring requires confirmation in future prospective studies.