A comparative perspective on brucellar, pyogenic, and tuberculous spondylodiscitis.

OBJECTIVE: Non-specific features of spondylodiscitis lead to a delay and challenge in the diagnosis/differential diagnosis/treatment processes, and thus, serious complications may arise. This study aims to compare brucellar, pyogenic, and tuberculous types of spondylodiscitis, considering their demographic, clinical, and laboratory differences. This may provide more rapid management and good outcomes. PATIENTS AND METHODS: A total of 131 patients with infectious spondylodiscitis were included in the study. The patients were divided into brucellar (n=63), pyogenic (n=53), and tuberculous (n=15) types of spondylodiscitis and compared for demographic, clinical, laboratory, and imaging features. RESULTS: Tuberculous spondylodiscitis had higher scores for weight loss, painless palpation, thoracic spine involvement, and psoas abscess formation than other spondylodiscitis. Also, tuberculous spondylodiscitis had higher rates of neurologic deficit and lower rates of lumbar involvement than brucellar spondylodiscitis. Pyogenic spondylodiscitis is more likely to occur in patients who have a history of spine surgery compared to other forms of spondylodiscitis. Also, pyogenic spondylodiscitis had higher rates of fever, erythema, paraspinal abscess, white blood cell (WBC), and erythrocyte sedimentation rate (ESR) than brucellar spondylodiscitis. On the other hand, brucellar spondylodiscitis had higher rates of rural living and sweating than pyogenic spondylodiscitis. CONCLUSIONS: Weight loss, painless palpation, involved thoracic spine, psoas abscess, and neurologic deficit are symptoms favoring tuberculous spondylodiscitis. History of spine surgery, high fever, skin erythema, and paraspinal abscess are findings in favor of pyogenic spondylodiscitis. Rural living, sweating, and involved lumbar spine are symptoms that indicate brucellar spondylodiscitis. These symptoms can be used to distinguish the types of spondylodiscitis.

Early Diagnosis and Successful Empirical Treatment of L1-L2 Spondylodiscitis in a 21-Month-Old Girl: A Case Report.

BACKGROUND Infantile spondylodiscitis is a rare condition with a varied clinical presentation. Microbial infection may not always be identified, but early diagnosis and management are required to prevent long-term and irreversible complications, including spinal deformities and vertebral instability. CASE REPORT This report is of a 21-month-old girl with a 3-week history of difficulty in walking and constipation due to L1-L2 spondylodiscitis following a gluteal skin burn. The family had sought medical advice multiple times, but results of all investigations were unremarkable. Her initial spine X-ray was negative but her spine magnetic resonance imaging (MRI) showed a picture suggestive of spondylodiscitis, which then responded to empiric treatment with broad-spectrum antibiotics. The patient showed complete resolution of clinical symptoms and her bowel habits came back to normal after 6 months of complete antibiotics treatment. Her repeat spine MRI showed a significant improvement of her spondylodiscitis. CONCLUSIONS This report has highlighted the importance of rapid diagnosis and management of infantile spondylodiscitis and the challenging approach to treatment when no infectious organism can be identified, as well as the early initiation of antibiotics therapy when appropriate in pediatric patients to avoid serious neurological complications associated with spondylodiscitis. Thus, it is essential to assess children with refusal to walk, gait problems, or back discomfort, especially when they are associated with high inflammatory markers.

Bacterial and Viral Infectious Disease of the Spine.

Spinal infections are a diverse group of diseases affecting different compartments of the spine with variable clinical and imaging presentations. Diagnosis of spinal infections is based on a combination of clinical features, laboratory markers, and imaging studies. Imaging plays a pivotal role in the diagnosis and management of spinal infections. The characteristic imaging manifestations of bacterial and viral infections in the spine are discussed with key teaching points emphasized.

Differentiation of Native Vertebral Osteomyelitis: A Comprehensive Review of Imaging Techniques and Future Applications.

Native vertebral osteomyelitis, also termed spondylodiscitis, is an antibiotic-resistant disease that requires long-term treatment. Without proper treatment, NVO can lead to severe nerve damage or even death. Therefore, it is important to accurately diagnose the cause of NVO, especially in spontaneous cases. Infectious NVO is characterized by the involvement of 2 adjacent vertebrae and intervertebral discs, and common infectious agents include Staphylococcus aureus, Mycobacterium tuberculosis, Brucella abortus, and fungi. Clinical symptoms are generally nonspecific, and early diagnosis and appropriate treatment can prevent irreversible sequelae. Advances in pathologic histologic imaging have led physicians to look more forward to being able to differentiate between tuberculous and septic spinal discitis. Therefore, research in identifying and differentiating the imaging features of these 4 common NVOs is essential. Due to the diagnostic difficulties, clinical and radiologic diagnosis is the mainstay of provisional diagnosis. With the advent of the big data era and the emergence of convolutional neural network algorithms for deep learning, the application of artificial intelligence (AI) technology in orthopedic imaging diagnosis has gradually increased. AI can assist physicians in imaging review, effectively reduce the workload of physicians, and improve diagnostic accuracy. Therefore, it is necessary to present the latest clinical research on NVO and the outlook for future AI applications.

An Uncommon Cause of Nocturnal Crying and Discomfort: A Case of a 15-month-old Girl With Spondylodiscitis.

Nocturnal crying in toddlers has a broad spectrum of causes, including psychosocial and somatic causes, whereby the majority are self-limiting and do not need referral to specialist medical care. Although uncommon, atypical presentations of nocturnal crying-such as spondylodiscitis-require referral to specialist medical care, especially when combined with discomfort. In this case report, we present a case of a 15-month-old girl with an atypical presentation of nocturnal crying in combination with back pain.

The importance of the bacterial spectrum in the clinical diagnostics and management of patients with spontaneous pyogenic spondylodiscitis and isolated spinal epidural empyema: a 20-year cohort study at a single spine center.

BACKGROUND: Personalized clinical management of spondylodiscitis (SD) and isolated spinal epidural empyema (ISEE) is challenging due to limited evidence of microbiologic findings and their clinical impact during the clinical course of the disease. We aimed to characterize clinico-microbiological and imaging phenotypes of SD and ISEE to provide useful insights that could improve outcomes and potentially modify guidelines. METHODS: We performed chart review and collected data on the following parameters: bacterial antibiogram-resistogram, type of primary spinal infection, location of spinal infection, source of infection, method of detection, clinical complications (sepsis, septic embolism, and endocarditis), length of hospital and intensive care unit (ICU) stay, relapse rate, and disease-related mortality in patients with proven pyogenic SD and ISEE treated surgically in a university hospital in Germany between 2002 and 2022. RESULTS: We included data from 187 patients (125 SD, 66.8% and 62 ISEE, 33.2%). Gram-positive bacteria (GPB) were overall more frequently detected than gram-negative bacteria (GNB) (GPB: 162, 86.6% vs. GNB: 25, 13.4%, p < 0.001). Infective endocarditis was caused only by GPB (GPB: 23, 16.5% vs. GNB: 0, 0.0%, p = 0.046). Methicillin-susceptible Staphylococcus aureus was the most frequently isolated strain (MSSA: n = 100, 53.5%), occurred more frequently in the cervical spine compared to other bacteria (OB) (MSSA: 41, 41.0% vs. OB: 18, 20.7%, p = 0.004) and was most frequently detected in patients with skin infection as the primary source of infection (MSSA: 26, 40.6% vs. OB: 11, 16.7%, p = 0.002). Streptococcus spp. and Enterococcus spp. (SE: n = 31, 16.6%) were more often regarded as the cause of endocarditis (SE: 8, 27.6% vs. OB: 15, 11.4%, p = 0.037) and were less frequently detected in intraoperative specimens (SE: 19, 61.3% vs. OB: 138, 88.5%, p < 0.001). Enterobacterales (E: n = 20, 10.7%) were identified more frequently in urinary tract infections (E: 9, 50.0% vs. OB: 4, 3.6%, p < 0.001). Coagulase-negative Staphylococci (CoNS: n = 20, 10.7%) were characterized by a lower prevalence of sepsis (CoNS: 4, 20.0% vs. OB: 90, 53.9%, p = 0.004) and were more frequently detected in intraoperative specimens (CoNS: 20, 100. 0% vs. OB: 137, 82.0%, p = 0.048). Moreover, CoNS-associated cases showed a shorter length of ICU stay (CoNS: 2 [1-18] days vs. OB: 6 [1-53] days, median [interquartile range], p = 0.037), and occurred more frequently due to foreign body-associated infections (CoNS: 8, 61.5% vs. OB: 15, 12.8%, p = 0.008). The presence of methicillin-resistant Staphylococcus aureus (MRSA) prolonged hospital stay by 56 [24-58] days and ICU stay by 16 [1-44] days, whereas patients with Pseudomonas aeruginosa spent only 20 [18-29] days in the hospital and no day in the ICU 0 [0-5] days. CONCLUSIONS: Our retrospective cohort study identified distinct bacterial-specific manifestations in pyogenic SD and ISEE regarding clinical course, neuroanatomic targets, method of pathogen detection, and sources of infection. The clinico-microbiological patterns varied depending on the specific pathogens.

Pyogenic spondylodiscitis in HIV-positive patients under antiretroviral therapy: A case series.

Background: The incidence of pyogenic spondylodiscitis has been increasing in countries of Europe and North America, probably due to an increasing number of persons with risk factors for this infection. It is unclear whether HIV infection in the era of antiretroviral therapy (ART) increases the risk for spondylodiscitis. Method: We present 7 cases of pyogenic spondylodiscitis of the cervical, thoracic, and lumbar spine in six individuals living with HIV under ART with suppressed viral load. Results: All patients presented with severe non-radicular pain and elevated inflammatory markers. Diagnosis was confirmed by magnetic resonance imaging (MRI) scan and isolation of the pathogen. Staphylococcus aureus was the causative pathogen in five patients. One patient suffered from an infection with Klebsiella pneumoniae followed by a mixed infection with Cutibacterium acnes and Bacillus circulans 18 months later. All patients needed surgical intervention, and the mean duration of antibiotic treatment was 17 weeks (range 12-26). Five patients recovered fully, including two persons who also suffered from endocarditis. One patient died from multi-organ failure. Conclusion: Spondylodiscitis may be seen more frequently in persons living with HIV as they grow older and suffer from comorbidities which put them at risk for this infection. HIV physicians should be aware of the infection and its risk factors.

Candida spondylodiscitis: a systematic review and meta-analysis of seventy two studies.

OBJECTIVES: Knowledge of Candida spondylodiscitis is limited to case reports and smaller case series. Controversy remains on the most effective diagnostical and therapeutical steps once Candida is suspected. This systematic review summarized all cases of Candida spondylodiscitis reported to date concerning baseline demographics, symptoms, treatment, and prognostic factors. METHODS: A PRISMA-based search of PubMed, Web of Science, Embase, Scopus, and OVID Medline was performed from database inception to November 30, 2022. Reported cases of Candida spondylodiscitis were included regardless of Candida strain or spinal levels involved. Based on these criteria, 656 studies were analyzed and 72 included for analysis. Kaplan-Meier curves, Fisher's exact, and Wilcoxon's rank sum tests were performed. RESULTS: In total, 89 patients (67% males) treated for Candida spondylodiscitis were included. Median age was 61 years, 23% were immunocompromised, and 15% IV drug users. Median length of antifungal treatment was six months, and fluconazole (68%) most commonly used. Thirteen percent underwent debridement, 34% discectomy with and 21% without additional instrumentation. Median follow-up was 12 months. The two year survivorship free of death was 80%. The two year survivorship free of revision was 94%. Younger age (p = 0.042) and longer length of antifungal treatment (p = 0.061) were predictive of survival. CONCLUSION: Most patients affected by Candida spondylodiscitis were males in their sixties, with one in four being immunocompromised. While one in five patients died within two years of diagnosis, younger age and prolonged antifungal treatment might play a protective role.

Treatment of Spinal Infections.

The treatment of spinal infections is not well defined, and a cursory review of the literature can lead to conflicting treatment strategies. To add to the complexity, infections can include primary infection of the spine, infection secondary to another primary source, and postoperative infections including epidural abscesses, discitis, osteomyelitis, paraspinal soft-tissue infections, or any combination. Furthermore, differing opinions often exist within the medical and surgical communities regarding the outcomes and effectiveness of varying treatment strategies. Given the paucity of defined treatment protocols and long-term follow-up, it is important to develop multidisciplinary treatment teams and treatment strategies. This, along with defined protocols for the treatment of varying infections, can provide the data needed for improved treatment of spinal infections.

Abiotrophia defectiva triple threat: A rare case of infective spondylodiscitis, endocarditis, and brain abscess.

Abiotrophia defectiva is a pathogen of the oral, gastrointestinal, and urinary tracts that can cause significant systemic disease with uniquely negative blood cultures depending on the growth medium. Prior cases note possible seeding from relatively common procedures such as routine dental work and prostate biopsies, however case literature describes prior infectious complications to include infective endocarditis, brain abscess formation, and spondylodiscitis. While prior cases describe some aspects of these presentations, we highlight a case of a 64-year-old male who presented to the emergency department (ED) f5or acute onset of low back pain with fever symptoms four days after an outpatient transrectal ultrasound-guided needle biopsy of the prostate, with a prior dental extraction described four weeks prior to arrival. Findings on initial ED presentation and subsequent hospitalization revealed infective spondylodiscitis, endocarditis, and brain abscess formation. This is the only cases noted in literature with all three infection locations with dual risk factors of dental and prostate procedures prior to symptom onset. This case highlights the multifocal illness that can complicate Abiotrophia defectiva infections, and the importance of thorough ED evaluation and multiservice approach for consultation and treatment.

Epidemiological trends of pyogenic spondylodiscitis in Germany: an EANS Spine Section Study.

Pyogenic spondylodiscitis presents significant diagnostic and therapeutic challenges. In Germany, a comprehensive understanding of its epidemiology and inpatient management outcomes is limited, hindering the optimisation of therapeutic strategies. This study aimed to characterise the evolving epidemiological trends of pyogenic spondylodiscitis in Germany, and concurrently evaluate inpatient management strategies and outcomes. We performed a retrospective population-based study of spondylodiscitis cases in Germany from 2005 to 2021, utilising data from the German Federal Statistical Office database. The parameters assessed were incidence trends, demographic characteristics, inpatient management strategies, and inpatient mortality. The study found a significant rise in the population-adjusted incidence of spondylodiscitis in Germany from 2005 to 2021, increasing by 104% from 5.4 to 11.0 cases per 100,000 individuals (p < 0.001). The highest number of diagnoses was recorded in 2019. Age group-adjusted data revealed the largest relative changes in the "90 + " age group, followed by the "80-89" and "70-79" age groups. These increases were not solely attributable to population changes but were also confirmed after calculating the age-group-adjusted incidence rates. Additionally, our statistical analysis demonstrated that both age and year significantly influenced the incidence of spondylodiscitis. Over the same period, inpatient mortality also surged significantly by 347% (p < 0.001), with the highest increase recorded in the 90 + age group, observing a 2450% rise (p < 0.001). The mean length of inpatient stay decreased by 15% (p < 0.05). Concurrently, there was a significant increase in surgical interventions using spinal stabilisation procedures (p < 0.001), which might suggest a shift in the treatment paradigm for spondylodiscitis. The results underscore a concerning rise in spondylodiscitis incidence and mortality in Germany, particularly affecting the ageing population. A notable shift towards surgical intervention was observed. The data highlights the urgent necessity for high-level evidence studies comparing surgical versus conservative treatment, thereby guiding optimised therapeutic strategies.

Understanding the management of pediatric spondylodiscitis based on existing literature; a systematic review.

BACKGROUND: Spondylodiscitis (SD), a rare disease in children, poses diagnostic challenges due to non-specific presenting symptoms, scarcity in incidence, and difficulty expressing pain in non-verbal children. METHOD: A comprehensive search was conducted on three databases, including PubMed/Medline, Web of Science, and Scopus until March 2023. The inclusion criteria were studies that investigated the clinical characteristics, treatment, and complications of children's spondylodiscitis. Full text of cross-sectional and cohort studies were added. The quality assessment of cohort studies was conducted using the Newcastle-Ottawa Quality Assessment Scale. The search, screening, and data extraction were performed by two researchers independently. RESULT: Clinical manifestations of discitis in children are nonspecific, such as back pain, fever, reduced ability or inability to walk or sit, limping, and reduced range of movements. The mean delay in the time of diagnosis was 4.8 weeks. The most affected site of all the studies was the lumbar spine. 94% of studies reported increased inflammatory markers such as white blood cell count, C-reactive protein, and erythrocyte sedimentation rate. Less than 30% of patients had positive blood cultures and biopsy findings. The most common microbiological results (64%) were Staphylococcus Aureus and Kingella kingae. In radiographic evaluation, intervertebral disk narrowing, lumbar lordosis reduction, loss of disk height, and destruction of the vertebral body have been reported. In all studies, antibiotic therapy was initiated; in 52% immobilization was employed, and 29% of studies reported surgery was performed, and the follow-up period differed from 1.5 months to 156 months. 94% of studies reported complications such as vertebral body destruction, back pain, kyphosis, reduced range of movement, scoliosis, and neurological complications. CONCLUSION: Spondylodiscitis is an uncommon, heterogeneous, multifactorial disease with resulting difficult and delayed diagnosis. Due to its morbidity, it is essential to investigate children with refusal to walk, gait disturbances, or back pain, particularly when associated with elevated inflammatory markers.

Metagenomic next-generation sequencing identifying a rare case of Mycobacterium xenopi discitis.

Mycobacterium xenopi is a non-tuberculous mycobacterium (NTM) that sporadically causes infections in humans and can cause rare bone and joint infections in immunocompromised hosts with history of spinal surgery. This slow-growing mycobacterium takes 8-12 weeks to grow on culture. Metagenomic next-generation sequencing (MNGS) is a highly sensitive and specific plasma-based microbial cell-free DNA test that can detect M. xenopi weeks prior to culture growth. We present a case of M. xenopi lumbosacral discitis with presacral abscess in an immunocompromised woman without history of spinal surgery which was detected by MNGS 8 weeks prior to culture growth. The patient's discitis resolved with an M. xenopi-directed regimen of ethambutol, rifampin and azithromycin. This case illustrates the utility of next-generation sequencing tests in rapid diagnosis of rare and opportunistic infections, as compared with traditional diagnostic tests, with supporting contextual clinical and diagnostic findings.

A clinical prediction model to differentiate tuberculous spondylodiscitis from pyogenic spontaneous spondylodiscitis.

BACKGROUND: Microbiological diagnosis of tuberculous spondylodiscitis (TS) and pyogenic spontaneous spondylodiscitis (PS) is sometime difficult. This study aimed to identify the predictive factors for differentiating TS from PS using clinical characteristics, radiologic findings, and biomarkers, and to develop scoring system by using predictive factors to stratify the probability of TS. METHODS: A retrospective single-center study. Demographics, clinical characteristics, laboratory findings and radiographic findings of patients, confirmed causative pathogens of PS or TS, were assessed for independent factors that associated with TS. The coefficients and odds ratio (OR) of the final model were estimated and used to construct the scoring scheme to identify patients with TS. RESULTS: There were 73 patients (51.8%) with TS and 68 patients (48.2%) with PS. TS was more frequently associated with younger age, history of tuberculous infection, longer duration of symptoms, no fever, thoracic spine involvement, ≥3 vertebrae involvement, presence of paraspinal abscess in magnetic-resonance-image (MRI), well-defined thin wall abscess, anterior subligamentous abscess, and lower biomarker levels included white blood cell (WBC) counts, erythrocyte-sedimentation-rate (ESR), neutrophil fraction, and C-reactive protein (all p < 0.05). Multivariate logistic regression analysis revealed significant predictors of TS included WBC ≤9,700/mm3 (odds ratio [OR] 13.11, 95% confidence interval [CI] 4.23-40.61), neutrophil fraction ≤78% (OR 4.93, 95% CI 1.59-15.30), ESR ≤92 mm/hr (OR 4.07, 95% CI 1.24-13.36) and presence of paraspinal abscess in MRI (OR 10.25, 95% CI 3.17-33.13), with an area under the curve of 0.921. The scoring system stratified the probability of TS into three categories: low, moderate, and high with a TS prevalence of 8.1%, 29.6%, and 82.2%, respectively. CONCLUSIONS: This prediction model incorporating WBC, neutrophil fraction counts, ESR and presence of paraspinal abscess accurately predicted the causative pathogens. The scoring scheme with combination of these biomarkers and radiologic features can be useful to differentiate TS from PS.

Determining threshold values for success after surgical treatment of lumbar spondylodiscitis using quality of life scores.

OBJECTIVE: This study aimed to determine threshold values of validated quality of life (QoL) scores, including Oswestry Disability Index (ODI) and Core Outcome Measures Index (COMI), for predicting a successful outcome following surgical treatment of lumbar spondylodiscitis (LS). METHODS: Patients with lumbar spondylodiscitis (LS) undergoing surgery in a tertiary referral hospital were included prospectively from 2008-2019. Data were collected both before surgery (T0) and one year after surgery (T1). QoL was measured using ODI and COMI. The successful clinical outcome was defined by the combination of the following four criteria: no recurrence of spondylodiscitis, back pain ≤4 on visual analogue scale or relief of ≥3 points, absence of LS-related neurological deficit, and radiological fusion of the affected segment. For subgroup analysis, group 1 consisted of patients with a favorable treatment outcome (meeting all four criteria), while group 2 included patients with unfavorable treatment outcome (meeting ≤3 criteria). RESULTS: Ninety-two LS patients (median age = 66 years; age range = 57-74) were analyzed. QoL scores improved significantly. Threshold values for the ODI and COMI were calculated at 35 and 4.2 points, respectively. The area under curve for the ODI was 0.856 (95%-CI 0.767- 0.945; P<0.001) and 0.839 (95% CI-0.749-0.928; P<0.001) for the COMI score. Eighty percent of patients achieved a favorable outcome. CONCLUSION: Objective measurement and evaluation of successful surgical treatment of spondylodiscitis require defined thresholds of quality of life scores. We were able to define such thresholds for Oswestry Disability Index and Core Outcome Measures Index. These can be useful to assess clinically relevant changes and therefore allow a more precise estimation of the post-surgical outcome. LEVEL OF EVIDENCE: Level II, Prognostic study.

[Spondylodiscitis]. / Spondylodiszitis.

Spondylodiscitis is a severe infectious disease of the spine that affects the intervertebral discs and adjacent vertebrae. It can lead to nonspecific pain, limited mobility, and destruction of spinal structures. Various pathogens, such as bacteria, fungi, or parasites, can trigger the disease. An early diagnosis and targeted treatment are crucial to reduce the risk of serious complications. Magnetic resonance imaging (MRI) with contrast agent and blood tests are essential for the diagnosis and assessing the course of the disease. The treatment includes conservative and surgical approaches. Conservative treatment consists of a minimum 6­week antibiotic course and immobilization of the affected area. Surgical interventions, along with several weeks of antibiotic therapy, are indicated for instabilities or complications in order to eliminate the infection focus and to restore spinal stability.

Case series of aspergillus spondylodiscitis from a tertiary care centre in India.

Aspergillus spondylodiscitis is a rare entity reported in the literature. In tuberculosis endemic regions like India, more often it could be misdiagnosed as tuberculous spondylodiscitis. Herein we report a case series of three patients with Aspergillus spondylodiscitis presenting with chronic low backpain and clinically diagnosed as tuberculosis spine. Culture and histopathological examination of the debrided tissue provided a definite diagnosis. Interestingly, one of the cases had coexisting tuberculosis spine. All three patients underwent surgical intervention-debridement, decompression and fusion of spine and combined medical management with voriconazole with successful outcome.

Determining the prevalence and risk factors for positive bacterial culture in canine discospondylitis: 120 cases.

BACKGROUND: Identification of the aetiologic agent in canine discospondylitis is infrequent; and risk factors for a positive bacterial culture have not previously been reported. METHODS: Medical records at three institutions were searched to identify clinical features of dogs with discospondylitis diagnosed via radiography or cross-sectional imaging. Inclusion in this retrospective case-control study required culture of one or more samples. Multivariable binary logistic regression identified features associated with a positive culture. RESULTS: Fifty (42%) of 120 dogs had one or more positive culture results obtained from either urine (28/115), blood (25/78), intervertebral disc aspiration (10/34) or cerebrospinal fluid (1/18). A positive culture was associated with higher bodyweight (p = 0.002, odds ratio [OR] = 1.054, 95% confidence interval [CI]: 1.019-1.089), more sample types cultured (p = 0.037, OR = 1.806, 95% CI: 1.037-3.147) and institution (p = 0.021). The presence of possibly associated preceding events (e.g., surgery), pyrexia, number of disc sites affected and serum C-reactive protein result, among other features, were not statistically significant. LIMITATIONS: All isolates cultured were included since differentiation of true aetiologic agents from contaminants was not possible without histological confirmation and culture from surgical or postmortem biopsies. CONCLUSIONS: Clinical features typically associated with infection were not identified as risk factors for positive culture in canine discospondylitis. The statistical significance of the institution suggests that standardisation of sampling protocols is necessary.

Elevated regulatory T cells after antibiotic treatment of infectious spondylodiscitis as biomarker of recovery?

Dysregulated systemic immune responses during infectious spondylodiscitis (IS) may impair microbial clearance and bone resorption. Therefore, the aim of the study was to examine whether circulating regulatory T cells (Tregs) are elevated during IS and whether their frequency is associated with alterations in T cells and the presence of markers of bone resorption in the blood. A total of 19 patients hospitalized with IS were enrolled in this prospective study. Blood specimens were obtained during hospitalization and 6 weeks and 3 months after discharge. Flow cytometric analysis of CD4 and CD8 T cell subsets, the percentage of Tregs and serum levels of collagen type I fragments (S-CrossLap) were performed. Out of 19 enrolled patients with IS, microbial etiology was confirmed in 15 (78.9%) patients. All patients were treated with antibiotics for a median of 42 days, and no therapy failure was observed. Next, a significant serum C-reactive protein (S-CRP) decrease during the follow-up was observed, whereas the frequencies of Tregs remained higher than those of controls at all-time points (p < 0.001). In addition, Tregs demonstrated a weak negative correlation with S-CRP and S-CrossLap levels were within the norm at all-time points. Circulating Tregs were elevated in patients with IS and this elevation persisted even after the completion of antibiotic therapy. Moreover, this elevation was not associated with treatment failure, altered T cells, or increased markers of bone resorption.