The importance of inflammatory biomarkers in non-specific acute and chronic low back pain: a systematic review.

OBJECTIVE: The purpose of this study was to systematically review the evidence on inflammatory biomarkers as analytic predictors of non-specific low back pain (NsLBP). Low back pain (LBP) is the number one cause of disability globally, posing a major health problem that causes an enormous social and economic burden, and there is an increasing interest on the importance of biomarkers in quantifying and even emerge as potential therapeutic tools to LBP. METHODS: A systematic search was conducted on July 2022 in Cochrane Library, MEDLINE and Web of Science for all the available literature. Cross-sectional, longitudinal cohort or case-control studies that evaluated the relationship between inflammatory biomarkers collected from blood samples and low back pain in humans were considered eligible for inclusion, as well as prospective and retrospective studies. RESULTS: The systematic database search resulted in a total of 4016 records, of which 15 articles were included for synthesis. Sample size comprised a total of 14,555 patients with LBP (acute LBP (n = 2073); chronic LBP (n = 12482)) and 494 controls. Most studies found a positive correlation between classic pro-inflammatory biomarkers and NsLBP, namely C-reactive protein (CRP), interleukin 1 (IL-1) and IL-1ß, interleukin 6 (IL-6) and tumour necrosis factor α (TNF-α). On the other hand, anti-inflammatory biomarker interleukin 10 (IL-10) demonstrated a negative association with NsLBP. Four studies have made direct comparisons between ALBP and CLBP groups regarding their inflammatory biomarkers profile. CONCLUSIONS: This systematic review found evidence of increased levels of pro-inflammatory biomarkers CRP, IL-6 and TNF-α and decreased levels of anti-inflammatory biomarker IL-10 in patients with LBP. Hs-CRP was not correlated with LBP. There is insufficient evidence to associate these findings with the degree of pain severity or the activity status of the lumbar pain over time.

Efficacy of Hounsfield Units Measured by Lumbar Computer Tomography on Bone Density Assessment: A Systematic Review.

STUDY DESIGN: Systematic review. OBJECTIVE: This work aimed to compare the Hounsfield units (HU) value obtained from computed tomography and the t score of dual-energy x-ray absorptiometry (DXA) in the prediction of the lumbar spine bone mineral density (BMD). SUMMARY OF BACKGROUND DATA: Several reports have found a correlation between HU and BMD values based on DXA. Using HUs to infer bone quality has a thorough clinical relevance as it could triage patients at risk for osteoporotic and fragility fractures or modify surgical indications. METHODS: A systematic review in Cochrane Library, Medline, Scopus and Web of Science was performed, using the following query: "hounsfield units" AND ("osteoporosis" OR "spine" OR "bone mineral density" OR "dual x-ray absorptiometry"). We included 18 cohort studies that compared HU value obtained from computed tomography and t score of DXA for predicting regional BMD. RESULTS: A total of 18 studies were included, enrolling 5307 patients. The HU measurement was most frequently made at L1 (N = 3; 18.8%). The mean HU values differentiated based on BMD measured through DXA were reported in seven studies, with values from 54.7 to 130 for osteoporotic, 78.8 to 146 for osteopenic, and from 120.8 to 230 in normal patients. Eight studies identified thresholds for diagnosing osteoporosis through receiver-operating characteristic (ROC) curves, with values ranging from 0.66 to 0.96. Medium HU values reported as diagnostic of osteoporosis ranged between 110 and 150, after exclusion of the two papers presenting outlier values. We infer an HU interval value of 90.9 to 138.7 (95% CI, P  < 0.001) for the diagnosis osteoporosis. CONCLUSIONS: Present data evidence favorable results regarding the possibility of establishing a threshold value for osteoporosis diagnosis from CT measurements of HU. Prospective large-scale studies are needed to more robustly infer the possibility of quantifying BMD based on CT as a screening test and infer a prognostic value of the CT-based evaluation.Level of Evidence: 2.

Neointimal Hyperplasia.

Neointimal hyperplasia is a physiologic healing response to injury to the blood vessel wall, involving all the three arterial layers and it occurs in the presence of internal (endovascular) or external (surgical) injury. It is a highly complex process involving several tissues (perivascular, vessel wall, and blood) and numerous cell lineages with multiple molecular signaling networks. So, there is a number of possible targets for inhibition of this process. There are known risk factors for Intimal Hyperplasia, such as diabetes, female gender, presence of systemic inflammation, type of arteries treated, types of surgical and endovascular materials, presence of turbulent flow and genetic status. The present paper discusses the pathophysiology of neointimal hyperplasia and the strategies to prevention and treatment of it.