Which inflammatory marker is more reliable in diagnosing acute septic arthritis in the pediatric population?

Evaluating the Diagnostic Performance of Systemic Immune-Inflammation Index in Childhood Inflammatory Arthritis: A Focus on Differentiating Juvenile Idiopathic Arthritis from Reactive Arthritis

In pediatric care, the range of potential diagnoses for arthritis can be relatively extensive, primarily involving infectious and inflammatory causes and, to a lesser extent, oncological conditions. Specifically, when addressing inflammatory causes, differentiating between Juvenile Idiopathic Arthritis (JIA) and Reactive Arthritis (ReA) can prove to be challenging during the first weeks, owing to the lack of specific antibodies in several JIA subtypes. This single-center retrospective study of 108 children with arthritis aimed to evaluate in greater detail the complete blood count (CBC) profiles of children with JIA and ReA in greater detail. The most significant differences were noted in terms of the Systemic Immune-Inflammation Index (SII), with higher values in the JIA group. Moreover, within the JIA group, SII displayed a significant positive correlation with conventional inflammatory biomarkers, specifically C-reactive protein (ρ = 0.579) and Erythrocyte Sedimentation Rate (ρ = 0.430). It was the only independent factor associated with the presence of JIA after adjusting for age (p = 0.030). Also, even with the moderate diagnostic value, the discriminating capacity of SII was superior to those of each of its component CBC parameters according to receiver operating characteristic (ROC) analysis. In summary, this study identified elevated SII values in the JIA group compared to the ReA group, indicating the potential utility of SII as an adjuvant discriminatory marker between these two arthritis forms.

Synovial Fluid and Serum Neutrophil-to-Lymphocyte Ratio: Novel Biomarkers for the Diagnosis and Prognosis of Native Septic Arthritis in Adults

BACKGROUND

Septic arthritis (SA) is a musculoskeletal emergency for which prompt diagnosis and treatment are critical. However, traditional diagnostic criteria of a synovial fluid (SF) white blood-cell count (WBC) of >50,000 cells/mm 3 or >90% polymorphonuclear leukocytes (%PMN) are not particularly sensitive or specific for the diagnosis of SA. Furthermore, prognostic markers are lacking. The purposes of this study were to assess the discriminative ability of the SF neutrophil-to-lymphocyte ratio (NLR) in the diagnosis of SA and of the serum NLR in the prognosis of SA.

METHODS

A multi-institution, retrospective study of 598 patients with native shoulder, hip, or knee SA in 2000 to 2018 was conducted. SF-NLR was calculated from the arthrocentesis cell count with differential. Receiver operating characteristic curves were analyzed, and the optimal threshold of SF-NLR for SA diagnosis was determined using the Youden index. Results were compared with traditional SF diagnostic criteria. Similar analyses assessed the association of serum NLR with 90-day treatment failure and mortality for the subset of patients with confirmed hip or knee SA and with serum complete blood-cell counts with differentials (n = 235). Results were compared with traditional serum prognostic markers (WBC, C-reactive protein [CRP], and erythrocyte sedimentation rate [ESR]).

RESULTS

The SF-NLR (area under the receiver operating characteristic curve [AUC], 0.85 [95% confidence interval (CI), 0.82 to 0.88]) was significantly more accurate for an SA diagnosis than SF-WBC (AUC, 0.80 [95% CI, 0.76 to 0.83]; p = 0.002) and SF-%PMN (AUC, 0.81 [95% CI, 0.77 to 0.84]; p = 0.01). The optimal threshold of SF-NLR was 25 (78% sensitivity and 81% specificity), compared with >50,000 cells/mm 3 for SF-WBC (56% sensitivity and 80% specificity) and >90% for SF-%PMN (65% sensitivity and 78% specificity). Elevated serum NLR was independently associated with 90-day treatment failure (odds ratio [OR], 7.04 [95% CI, 3.78 to 13.14]; p < 0.001) and mortality (OR, 7.33 [95% CI, 2.00 to 26.92]; p = 0.003); elevated serum WBC and CRP were also associated with treatment failure, and WBC, CRP, and ESR were not associated with mortality.

CONCLUSIONS

This study provides compelling data on the superior diagnostic and prognostic ability of serum NLR and SF-NLR for SA compared with current clinical standards. Given that this biomarker requires no additional cost or time to return than current laboratory tests already being performed, pending validation, it can readily be used to aid clinicians in the diagnosis and prognostication of SA.

LEVEL OF EVIDENCE

Diagnostic Level IV . See Instructions for Authors for a complete description of levels of evidence.

Septic arthritis of the wrist and the hand: - An Emergency department case study

Joint pain is a common presentation in the Emergency department. There are countless potential causes for pain and swelling in a joint. Septic arthritis is a true joint emergency as it can lead to rapid, irreversible destruction of the joint. If not diagnosed early this infection can lead to considerable functional deficit. Our case is unique in that our patient presented to the Emergency department requesting referral to the fracture clinic for continued management of a suspected scaphoid bone fracture but was found to have Neisseria gonorrhoea causing septic arthritis of the joint. This case highlights the importance of accurate history taking, clinical examination and assessment of the patients presenting with joint pain.