Relation of interleukin-15 with the severity of primary knee osteoarthritis

Comparison of Inflammatory Biomarkers in Females with and Without Patellofemoral Pain and Associations with Patella Position, Hip and Knee Kinematics, and Pain

Background/Objectives: Patellofemoral pain (PFP) is believed to be a precursor to knee osteoarthritis (OA). The primary purpose of this study was to compare matrix metalloproteinase-9 (MMP-9) levels in young adult females with and without PFP. The secondary purpose was to determine the associations between MMP-9, patella position, hip and knee kinematics, and pain in females with PFP. Methods: Plasma was analyzed for MMP-9. Patellar position was measured using diagnostic ultrasound as the degree of offset (RAB angle) from the deepest aspect of the femoral trochlear groove to the inferior pole of the patella. A positive RAB angle suggested patella lateralization. Hip and knee kinematics during a single-leg squat were measured using 2-dimensional motion analysis and quantified as the dynamic valgus index (DVI), a combined measure of hip and knee motion. A higher DVI suggests increased valgus loading at the patellofemoral joint. Pain was measured using a 10 cm visual analog scale. Results: Females with PFP had significantly higher levels of MMP-9 than controls (72.7 vs. 58.0 ng/mL, p = 0.03). Females with PFP had a significant positive association between MMP-9 and patella lateralization (r = 0.38, p = 0.04), suggesting that greater patellar lateralization may contribute to increased joint inflammation. A significant inverse association was observed between MMP-9 and the DVI (r = -0.50, p = 0.007), indicating that individuals with higher inflammatory marker levels may adopt movement patterns that reduce valgus loading. Conclusions: The significant association between MMP-9 and patella lateralization suggested a potential link between patella alignment and joint inflammation, which may contribute to early joint degeneration. The inverse association between MMP-9 levels and the DVI suggested that subjects with higher MMP-9 levels adjusted their movement pattern as a compensatory mechanism to reduce knee valgus stress to reduce joint degeneration.

Genetic polymorphisms of interleukin-16 in Egyptian patients with primary knee osteoarthritis

Background

The pro-inflammatory cytokine, interleukin 16 (IL-16), has been shown to be secreted in low levels in knee osteoarthritis (KOA). The aim of the study was to examine the relationship between IL-16 polymorphisms and the risk of KOA in the Egyptian population, as well as the clinical and radiographic severity of KOA.

Results

IL16 rs11556218 thymidine triphosphate (T) T G (guanosine triphosphate), GG, TG + GG genotypes, and G allele (odd ratio (OR) = 0.315; 95% confidence interval (CI) = 0.191–0.518; P < 0.001; OR = 0.363; 95% CI = 0.162–0.815, P = 0.014; OR = 0.323; 95% CI = 0.202–0.519, P < 0.001; OR = 0.480; 95% CI = 0.338–0.683, P < 0.001 respectively); rs4778889 cytidine triphosphate (C) T,CC, TC + CC genotypes, and C allele (OR = 0.519, 95% CI = 0.319–0.844, P = 0.008; OR = 0.309, 95% CI = 0.105–0.916, P = 0.034; OR = 0.485, 95% CI = 0.304–0.775, P = 0.002; OR = 0.537, 95% CI = 0.365–0.791, P = 0.001 respectively); and rs4072111 CT, TT, CT + TT genotypes, and T allele (OR = 0.537, 95% CI = 0.323–0.893, P = 0.017, OR = 0.316, 95% CI = 0.096–0.843, P = 0.049, OR = 0.502, 95% CI = 0.309–0.816, P = 0.005; OR = 0.534, 95% CI = 0.353–0.809, P = 0.004 respectively) were associated with a decreased KOA risk, and they were significantly associated with decreased the Western Ontario and McMaster Universities Arthritis Index (WOMAC) and the Kellgren-Lawrence (K/L) scores.

Neither IL-16 serum levels nor IL-16 polymorphisms were associated with the susceptibility to KOA. Low KOA risk was associated with the haplotypes GTC and TCT.

Conclusion

There was no correlation between serum IL-16 levels and KOA susceptibility or IL-16 polymorphisms. GTC and TCT haplotypes were associated with low KOA risk. The variant alleles rs11556218GG, TG + GG; rs4778889 CC, TC + CC; and rs4072111 TT, CT + TT were associated with a reduced risk of KOA.

Association between primary osteoarthritis and ADAMTS14 single nucleotide polymorphism in Egyptian population: a case-control study

Background

Primary osteoarthritis is considered one of the most common and the most studied musculoskeletal disorder. Nevertheless, the risk factors remain unclear. A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) 14 (ADAMTS14) gene is involved in the cleavage of amino-terminal propeptides from type II procollagen, a necessary step in the formation of collagen fibers. The abnormal metabolism of collagen fibers type II leads to a decreased mechanical strength of joint cartilage which is one of the most important contributing factors to joint osteoarthritis. We aimed at investigating the association between primary osteoarthritis and ADAMTS14 gene rs4747096 single nucleotide polymorphism in a sample of Egyptian patients and analyzing the relationship between this genetic polymorphism with the severity of osteoarthritis. Sixty-five Egyptian patients who fulfilled the American College of Rheumatology criteria for primary knee osteoarthritis were compared with thirty-one apparently healthy subjects. Genotyping was performed by TaqMan single nucleotide polymorphism genotyping assay.

Results

There was a statistically significantly higher frequency of AA genotype among osteoarthritis patients compared to the control group (P = 0.004). The number of affected hand joints was significantly higher among patients with ADAMTS14 AA genotype in comparison to patients with ADAMTS14 AG genotype (P = 0.002). In addition, AA genotype was associated with statistically significantly higher Kellgren-Lawrence radiological grades in the knee and hand joints (proximal interphalangeal and thumb interphalangeal joints) (P = 0.037, 0.003, and 0.030 respectively).

Conclusion

The study showed an association between the AA genotype of ADAMTS14 gene rs4747096 single nucleotide polymorphism with knee and hand osteoarthritis and osteoarthritis severity in these joints. The AA genotype of ADAMTS14 gene rs4747096 single nucleotide polymorphism could be implicated in the increased incidence of primary osteoarthritis development and elevated disease severity among the Egyptian population.