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Introduction Periprosthetic fibroblast-like cells (PPFs) play an important role in aseptic loosening of arthroplasties. Various studies have examined PPF behavior in monolayer culture systems. However, the periprosthetic tissue is a three-dimensional (3D) mesh, which allows the cells to interact in a multidirectional way. The expression of bone remodeling markers of fibroblast-like cells in a multilayer environment changes significantly versus monolayer cultures without the addition of particles or cytokine stimulation. Gene expression of bone remodeling markers was therefore compared in fibroblast-like cells from different origins and dermal fibroblasts under transwell culture conditions versus monolayer cultures. Methods PPFs from periprosthetic tissues (n = 12), osteoarthritic (OA) synovial fibroblast-like cells (SFs) (n = 6), and dermal fibroblasts (DFs) were cultured in monolayer (density 5.5 × 103/cm2) or multilayer cultures (density 8.5 × 105/cm2) for 10 or 21 days. Cultures were examined via histology, TRAP staining, immunohistochemistry (anti-S100a4), and quantitative real-time PCR. Results Fibroblast-like cells (PPFs/SFs) and dermal fibroblasts significantly increased the expression of RANKL and significantly decreased the expression of ALP, COL1A1, and OPG in multilayer cultures. PPFs and SFs in multilayer cultures further showed a higher expression of cathepsin K, MMP-13, and TNF-α. In multilayer PPF cultures, the mRNA level of TRAP was also found to be significantly increased. Conclusion The multilayer cultures are able to induce significant expression changes in fibroblast-like cells depending on the nature of cellular origin without the addition of any further stimulus. This system might be a useful tool to get more in vivo like results regarding fibroblast-like cell cultures.

After decades of rising prevalence of atopic and airway-related diseases, studies showed stagnating prevalence in western industrialised countries. Objective of this study is to analyse the time trend of prevalence of atopic diseases and airway-related symptoms among Bavarian children before starting primary school.Five cross-sectional studies from 2004/2005, 2006/2007, 2012/2013, 2014/2015 and 2016/2017 took place in urban and rural regions in Bavaria, Germany. Using standardized parent questionnaires children's atopic diseases and airway-related symptoms were surveyed. Logistic regression analysis (Bonferroni correction: adjusted significance level 0.005) was performed to analyse prevalence of symptoms and diseases from 2004 to 2017 for time trends.The surveys included 27384 Bavarian children aged 5-6 years (52.6% male). In all children the calculated 12-month prevalence of symptoms '≥four episodes of wheeze' (p-value = .0880) and 'rhinoconjunctivitis' (p-value = .3994) reported by parents stagnated, whereas 'wheeze' (p-value.0001; OR = 0.97; CI = [0.96-0.98]) and 'rhinitis' (p-value = .0007; OR = 0.98; CI = [0.97-0.99]) decreased. In all children the calculated lifetime prevalence of physician-diagnosed 'asthma' (p-value = .5337), and 'hay fever' (p-value = .8206) stagnated, whereas of 'bronchitis' (p-value.0001; OR = 0.98; CI = [0.98-0.99]) decreased over time. The calculated lifetime prevalence of physician-diagnosed 'atopic eczema' (p-value = .0002; OR = 0.98; CI = [0.97-0.99]) decreased in all children, whereas the calculated 12-month prevalence of the symptom 'itchy rash' increased (p-value = .0033; OR = 1.07; CI = [1.05-1.08]) over time.Several calculated prevalence of children's atopic diseases and airway-related symptoms reported by parents stagnated in a subgroup of Bavarian children before starting primary school between 2004 and 2017. The time trend of prevalence in 'wheeze', 'rhinitis' and 'bronchitis' decreased. Prevalence of 'atopic eczema' decreased over time, whereas 'itchy rash' increased.

Background Antibiotic-loaded (particularly gentamicin) bone cement (BC) is widely used in total joint arthroplasty (TJA) to prevent periprosthetic infections (PPIs), but may itself cause implant failure. In light of a complete lack in literature, the objective was to assess the clinical relevance of gentamicin allergy for failure of cemented total knee arthroplasties in 25 out of 250 patients with positive patch test reactions to gentamicin and otherwise unexplained symptoms by evaluating benefits from revision with change to gentamicin-free cement. Methods 15 of these 25 patients and their treating orthopaedic surgeons agreed to a re-assessment. They were surveyed regarding interim course of therapy and symptoms, including re-assessment of the Knee Injury and Osteoarthritis Outcome Score (KOOS), and underwent follow-up clinical and radiographic investigations. The initial use of gentamicin-loaded BC was reaffirmed by review of the primary implantation operative reports and respective implant passports. Primary and follow-up KOOS scores were analyzed regarding benefits from revision surgery by comparing nine patients with revision to six without revision. Results Mean follow-up time was 38 months. The entirety of patients experienced an improvement of self-reported symptoms, with revision surgery (i.e. switching to gentamicin-free BC or uncemented total knee arthroplasty) yielding significantly greater improvement (p=0.031): the nine revised patients reported a significant symptom relief (p=0.028), contrary to the six unrevised patients (p=0.14). Interestingly, the decision to proceed with revision surgery was significantly correlated with higher symptom severity (p=0.05). Conclusion In symptomatic total knee arthroplasty with gentamicin allergy, uncemented revision arthroplasty or change to gentamicin-free BC provides significant symptom relief.

Background and purpose — Metal sensitivity might provoke complications after arthroplasty. Correspondingly, coated “hypoallergenic” implants are of interest but long-term follow-up data are missing. Thus, we assessed immunological and clinical parameters in such patients. Patients and methods — 5 years’ follow-up data were obtained from 3 centers, which used either a standard total knee replacement (TKR) or the identical implant with multilayer surface zirconium nitride based coating. Of the 196 patients (mean age 68 years (44–84), 110 females) 97 had arthroplasty with a coated surface, and 99 were treated by a standard TKR of the same type. Investigations were Knee Society Score (KSS), Knee injury and Osteoarthritis Outcome Score (KOOS), radiographic analysis, and cytokine measurement in peripheral blood. Pro- and anti-inflammatory cytokines were evaluated by cytometric beads assay and RT-PCR. Results — Survival rate (Kaplan–Meier) was 98% for coated and 97% for uncoated implants after 5 years. Mechanical axis and KSS pain score (42 vs. 41 (0–50)) were comparable. Most serum cytokine levels were comparable, but mean interleukin-8 and interleukin-10 levels were higher in the group with an uncoated implant. IL-8: 37 (SD 7.5) pg/mL vs. 1.1 (SD 4.3) (p < 0.001); IL-10: 3.6 (SD 2.5) vs. 0.3 (SD 1.8) pg/mL (p < 0.001). Interpretation — There was similar clinical outcome 5 years after standard and surface-coated TKR. In peripheral blood there was an increased pro-inflammatory status, i.e., significant elevation of IL-8 and the anti-inflammatory IL-10, after standard uncoated prosthesis. Any long-term effects of these cytokine changes are unknown.

The effect of Actovegin® was investigated on PMA- and LPS-induced human peripheral blood mononuclear cells (PBMCs).PBMCs (1 × 10Stimulation of cells by PMA or LPS (without Actovegin®) significantly increased the secretion of IL-1beta, IL-6, IL-10 and TNF-α from PBMCs, compared to controls. Pre-treatment of cells with Actovegin® (1, 5, 25, 125 µg/ml) plus PMA significantly decreased the secretion of IL-1beta from PBMCs, compared to controls (PMA without Actovegin®). In contrast, addition of Actovegin® (1, 5, 25, 125 and 250 µg/ml) plus LPS did not alter the IL-1beta production, compared to controls (LPS without Actovegin®). TNF-α, IL-6 and IL-10 do not contribute to the reduction of inflammatory reactions with Actovegin®.Actovegin® can reduce the PMA-induced IL-1beta release and the ROS production from PBMCs. These findings may help to explain the clinically known positive effects of Actovegin® on athletic injuries with inflammatory responses (e.g., muscle injuries, tendinopathies).

Co-culture studies investigating the role of periprosthetic fibroblasts (PPFs) in inflammatory osteoclastogenesis reveal contrary results, partly showing an osteoprotective function of fibroblasts and high OPG expression in monolayer. These data disagree with molecular analyses of original periosteolytic tissues. In order to find a more reliable model, PPFs were co-cultivated with peripheral blood mononuclear cells (PBMCs) in a transwell system and compared to conventional monolayer cultures. The gene expression of key regulators of osteoclastogenesis (macrophage colony-stimulating factor (MCSF), receptor activator of NF-&kappa, B ligand (RANK-L), osteoprotegerin (OPG), and tumor necrosis factor alpha (TNF&alpha, )) as well as the ability of bone resorption were analyzed. In monolayer co-cultures, PPFs executed an osteoprotective function with high OPG-expression, low RANK-L/OPG ratios, and a resulting inhibition of osteolysis even in the presence of MCSF and RANK-L. For transwell co-cultures, profound changes in gene expression, with a more than hundredfold decrease of OPG and a significant upregulation of TNF&alpha, were observed. In conclusion, we were able to show that a change of culture conditions towards a transwell system resulted in a considerably more osteoclastogenic gene expression profile, being closer to findings in original periosteolytic tissues. This study therefore presents an interesting approach for a more reliable in vitro model to examine the role of fibroblasts in periprosthetic osteoclastogenesis in the future.

Immobilization of proteins has been examined to improve implant surfaces. In this study, titanium surfaces were modified with nanofunctionalized denosumab (cDMAB), a human monoclonal anti-RANKL IgG. Noncoding DNA oligonucleotides (ODN) served as linker molecules between titanium and DMAB. Binding and release experiments demonstrated a high binding capacity of cDMAB and continuous release. Human peripheral mononuclear blood cells (PBMCs) were cultured in the presence of RANKL/MCSF for 28 days and differentiated into osteoclasts. Adding soluble DMAB to the medium inhibited osteoclast differentiation. On nanofunctionalized titanium specimens, the osteoclast-specific TRAP5b protein was monitored and showed a significantly decreased amount on cDMAB-titanium in PBMCs + RANKL/MCSF. PBMCs on cDMAB-titanium also changed SEM cell morphology. In conclusion, the results indicate that cDMAB reduces osteoclast formation and has the potential to reduce osteoclastogenesis on titanium surfaces.

Background Psoriasis is a systemic immune-mediated chronic inflammatory disease. In the skin, the antimicrobial proteins koebnerisin (S100A15) and psoriasin (S100A7) are overexpressed in the epidermis of psoriatic lesions and mediate inflammation as chemoattractants for immune cells. Their role for systemic inflammation in circulating leukocytes is unknown. Objective The aim of the study was to identify circulating leukocyte populations as a source of koebnerisin and psoriasin. Further, immune-stimulatory effects of these S100A proteins on circulating leukocytes were evaluated and their role as therapeutic response markers in patients with psoriasis was analyzed upon UVB treatment. Methods The expression and production of koebnerisin and psoriasin by leukocytes were assessed by quantitative real-time PCR (qRT-PCR) and immunoblotting. The S100A protein mediated regulation of proinflammatory cytokines by peripheral blood mononuclear cells (PBMCs) was measured with qRT-PCR and cytometric bead assay. Results We identified circulating leukocytes as novel sources of koebnerisin (S100A15) and psoriasin (S100A7). Circulating leukocytes (PBMCs) of patients with psoriasis produced increased levels of koebnerisin and psoriasin compared to healthy individuals. Both S100A proteins further acted as ‘alarmins’ on PBMC to induce proinflammatory cytokines implicated in the pathogenesis of psoriasis, such as IL-1β, TNF-α, IL-6 and IL-8. Koebnerisin levels were suppressed in PBMC of psoriatic patients when effectively treated with narrow-band UVB. Conclusions Data suggest that koebnerisin and psoriasin are systemic pro-inflammatory mediators and koebnerisin acts as a therapeutic response marker in psoriasis.

Generalized pustular psoriasis (GPP) is the most severe psoriasis variant. Mutations in the IL-36 antagonist IL36RN, in CARD14 or AP1S3 provide genetic evidence for autoinflammatory etiology but cannot explain its pathogenesis completely. Here we demonstrate that unopposed IL-36 signaling promotes antigen-driven and likely pathogenic T-helper type 17 (Th17) responses in GPP. We observed that CD4

BACKGROUND Patch test (PT) is the gold standard to reveal nickel (Ni) allergy. In vitro tests are under discussion. We aimed to establish a cytokine based in vitro assay to detect Ni sensitization. METHODS From 15 patients with positive (13f, 42-78 years) and 15 with negative PT to Ni (controls, 3f, 31-82 years) within a consecutive patient series, peripheral blood mononuclear cells (PBMC) were obtained. Six-day stimulation with three concentrations of NiSO4 was performed. Proliferative response (uptake of tritiated thymidine) and production of the cytokines IL-1β, IL-4, IL-5, IL-6, IL-8, IL-10, IL-17A, TNF-α, IFN-γ (cytometric bead array) were assessed. RESULTS Twelve of fifteen Ni PT-positive patients also had positive LTT, and all control patients were PT and LTT negative. The mean SI differed between Ni allergics and controls (P

Hypersensitivity reactions to titanium (Ti) are very rare. Thus, we assessed the proinflammatory response and also potential tolerance favoringin vitroreactivity of human blood lymphocytes and monocytes (PBMC) to Ti in healthy individuals (14 without, 6 with complication-free dental Ti implants). The proliferation index (SI) in lymphocyte transformation test (LTT) and production of cytokines linked to innate immune response (IL-1β, IL-6, and TNFα) or immune regulation (IL-10) were assessed in response to TiO2particles or Ti discs. In both groups, the Ti-LTT reactivity was not enhanced (e.g.,SI<3). The control antigen tetanus toxoid (TT) gave adequate reactivity (median SI individuals without/with implant:20.6±5.97/19.58±2.99). Individuals without implant showed higher cytokine response to Ti materials than individuals with symptom-free implants; for example, TiO2rutile particle induced increase of IL-1β70.27-fold/8.49-fold versus control medium culture. PBMC of 5 of the 6 individuals with complication-free Ti implants showed anex vivoongoing production of IL-10 (mean4.18±2.98 pg/mL)-but none of the 14 controls showed such IL-10 production. Thusin vitroIL-1β-, IL-6-, and TNF-αproduction reflects “normal” unspecific immune response to Ti. This might be reduced by production of tolerogenic IL-10 in individuals with symptom-free Ti dental implants.

BACKGROUND: Key factors for successful porous polyethylene (PPE) implantation are rapid vascularization and low inflammatory response. Dermal fibroblasts produce a variety of pro-angiogenic and immunmodulatory factors. OBJECTIVE: The aim of this tissue engineering study was to investigate whether coating PPE implants with dermal fibroblasts in vitro is sustainable in vivo and whether the kinetics of blood vessel ingrowth and immunological responses are hereby affected. METHODS: PPE implants were cultured with syngeneic GFP-transfected dermal fibroblasts. Cells on the biomaterial were quantified before implantation into dorsal skinfold chamber preparations of C57Bl/6 mice. Uncoated implants served as controls. Angiogenic activity and leukocyte-endothelial cell interactions were repeatedly analyzed. After 10 days, mechanical integration was measured and surviving fluorescently labeled fibroblasts were quantified. Expression of inflammatory cytokines was assessed by quantitative real time-reverse transcription PCR. RESULTS: PPE implants were successfully coated with dermal fibroblasts in vitro and 69% of the cells were still detectable at the end of observation. Angiogenic parameters increased during the observation period in both groups. IL-2, IL17A and IL-10 tended to be increased in coated implants, but did not affect leukocyte-endothelial cell interactions. CONCLUSIONS: Dermal fibroblast-coating of porous polyethylene implants is feasible and sustainable in vivo. Alone it does not improve biocompatibility but may be beneficial in combination with specific growth factor supplements.

SummaryBackground The patch test is considered to be the gold standard for diagnosing nickel (Ni) allergy. The lymphocyte transformation test (LTT) can also be used to detect Ni sensitization. However, little is known about the correlation between patch test and LTT reactions to Ni. Objective To establish and validate an LTT for Ni sensitization by comparison with patch test reaction and history. Methods Fifty individuals without self-reported ‘Ni allergy’ (controls) and 50 patients with self-reported suspicion of Ni allergy were included. A questionnaire-aided history was taken, and patch tests with at least the baseline series and LTTs with various NiSO4 dilutions were performed. Results In the patch tests, 2 of 50 controls and 18 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to Ni. In the LTTs, 2 of 50 controls and 26 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to NiSO4 2.5 × 10−5 m, and 2 of 50 controls and 17 of 50 patients with self-reported suspicion of Ni allergy showed positive reactions to NiSO4 1 × 10−5 m. Sixteen of the 18 history-positive and patch test-positive patients (i.e. 88% sensitivity) were also LTT-positive, in contrast to only 2 positive LTT reactors within the 48 PT and history negative individuals (i.e. 96% specificity). [Correction added on 16 February 2017, after first online publication: The preceding sentence has been edited for language and this has been amended in this version.] Conclusion Performing the LTT with optimized stimulating conditions might be a useful additional tool for the diagnosis of Ni allergy if non-sensitized controls are included.

Nickel, chromium, and cobalt in stainless steel and Cobalt-chrome-molybdenum (CoCrMo) alloys may induce allergy. The objectives of this study were to evaluate surface coating regarding ion release, patch test reactivity, and arthroplasty performance. Materials and methods included patch test in 31 patients with metal allergy and 30 patients with no allergy to stainless steel and CoCrMo disks that are uncoated or coated by titanium nitride/zirconium nitride (TiN/ZrN). Assessment include atomic absorption spectrometry of released nickel, cobalt, and chromium from the disks after exposure to distilled water, artificial sweat and culture medium. Results showed that both coatings reduced the nickel and chromium release from stainless steel and CoCrMo disks and mostly the cobalt release from the disks (maximally 11.755 µg/cm 2 /5 d to 1.624 by Ti-N and to 0.442 by ZrN). Six of the 31 patients with metal allergy reacted to uncoated disks, but none reacted to the coated disks. The current authors report on exemplary patients with metal allergy who had symptom relief by revision with surface-coated arthroplasty. The authors concluded that the surface coating may prevent cutaneous and peri-implant allergic reactions. [ Orthopedics . 2016; 39(3):S24–S30.]

This study was undertaken to screen periprosthetic tissues (PPTs) under specified conditions for a series of molecular components and describe them in bone remodeling processes within aseptic loosening. PPT samples were obtained from patients undergoing revision surgery of endoprostheses (n = 24) and synovial tissues from patients with OA (control) (n = 18), patients with any form of inflammatory arthritides were excluded. Tissue samples were examined via microbiology, histology (HE, TRAP), immunohistochemistry (CD68/anti-S100a4), quantitative real-time PCR (ALP, COL1A1, cathepsin K, M-CSF, MMP13, OPG, RANK, RANKL, TNF-α, and TRAP) and an endotoxin-assay. PPT samples contained a variety of cellular components and stained positive for TRAP (56%), CD68 (100%), and S100a4 (100%). Wear debris were found in cells staining positive for CD68 and S100a4. In PPTs significantly higher ALP, COL1A1, MMP-13, RANK, RANKL, and TRAP expression were found along with a significantly higher RANKL/OPG ratio and a significantly lower OPG expression. No significant difference was observed for M-CSF, TNF-α, cathepsin K, and endotoxin levels. In conclusion we found osteogenic proteins (ALP, COL1A1), a proteolytic enzyme (MMP-13), markers for osteoclast differentiation (RANK, RANKL), and osteoclast activity (TRAP) to be increased in PPT, whereas OPG expression decreased significantly in comparison to control. We present data about a large series of molecular components in PPT and describe novel and key findings about their expression levels in regards to aseptic implant loosening. © 2016 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:248-257, 2017.

We report the case of a 60-year-old man with localized erythema and edema, caused by an implanted cardioverter defibrillator (ICD).An infection could be excluded by clinical examination, para clinical parameters and clinical chemistry. The histologic examination was indicative for hypersensitivity reaction. Patch test was negative but nickel sensitization was seen by lymphocyte transformation test and nickel could be measured in the pacemaker eluate.Based on the synopsis of negative patch testing, the hypersensitivity resembling histology and the corresponding in vitro analysis, the assumed cause for the dermatitis is a contact allergy to nickel as pacemaker component. After explantation, complete restitution of the skin could be observed.Unusual skin reactions in patients with cardiac pacemakers are mostly referred to as "Pacemaker dermatitis". There are various potential causes: first, an infection needs to be excluded. Then, the possibility of both "pressure damage" caused by the pacemaker and the mostly symptom free "pacemaker erythema with telangiectasia" - synonym "post implantation erythema" - needs to be considered. When suspecting an incompatibility of the implant, further allergologic testing is required. Often, the removal of the pacemaker is inevitable.

Arthroplasty patients with complications may be sensitized to implant components.To quantify patch test reactions to implant materials in aseptic cemented arthroplasty patients with complications, and to evaluate the benefit of late patch test reading at D6.Analyses of patch test reactions to baseline series and bone cement components and of the questionnaire-aided histories of 250 consecutive patients with suspected implant allergy were performed. Patch tests were read at D2, D3, and D6.There were 187 positive reactions to the 29 allergens of the baseline series, and 52 to the seven allergens of the bone cement series. Forty-nine of 250 patients reacted to the bone cement series. In contrast to 'early allergens' such as fragrance mix, late reading at D6 increased the number of positive reactions by 11/32 for nickel, 1/5 for cobalt, and 2/4 for chromium. With bone cement components, most reactions were to gentamicin (25 of 250 patients), and 17 of 25 appeared only at D6.Late reading is useful for patch tests with metals and bone cement components. With only D2/D3 readings, 32 reactions to nickel, cobalt, chromium and bone cement components would have been missed. This underlines the utility of late reading in general and in complicated cemented arthroplasty patients, given the unexpectedly high number of gentamicin reactions.

We performed a combined approach to identify suspected allergy to knee arthroplasty (TKR): patch test (PT), lymphocyte transformation test (LTT), histopathology (overall grading; T- and B-lymphocytes, macrophages, and neutrophils), and semiquantitative Real-time-PCR-based periprosthetic inflammatory mediator analysis (IFNγ, TNFα, IL1-β, IL-2, IL-6, IL-8, IL-10, IL17, and TGFβ). We analyzed 25 TKR patients with yet unexplained complications like pain, effusion, and reduced range of motion. They consisted of 20 patients with proven metal sensitization (11 with PT reactions; 9 with only LTT reactivity). Control specimens were from 5 complicated TKR patients without metal sensitization, 12 OA patients before arthroplasty, and 8 PT patients without arthroplasty. Lymphocytic infiltrates were seen and fibrotic (Type IV membrane) tissue response was most frequent in the metal sensitive patients, for example, in 81% of the PT positive patients. The latter also had marked periprosthetic IFNγexpression. 8/9 patients with revision surgery using Ti-coated/oxinium based implants reported symptom relief. Our findings demonstrate that combining allergy diagnostics with histopathology and periprosthetic cytokine assessment could allow us to design better diagnostic strategies.

Background: The peripheral blood mononuclear cells (PBMC) of individuals with nickel contact allergy are reported to proliferate to a varying degree upon nickel stimulation in vitro. Different phenotypes of the T cells involved are described. With regard to preferential use of the T-cell receptor (TCR), analysis of the several families of the TCR-γ gene allows rearrangement evaluation of all T cells regardless of predominant surface expression of TCR α/β. Methods: The PBMC of 10 nickel-allergic and five nonallergic individuals were cultured for 4 days in the presence of either medium, PHA, NiSO4, or tetanus toxoid (TT). Proliferation was measured by radioactive thymidine uptake and expressed as stimulation index (SI). T-cell clonality was assessed by analysis of the TCR-γ chain gene, including the use of PCR with a primer combination covering the four main groups (Vγ1-8, Vγ9, Vγ10, and Vγ11) of the variable region of the TCR-β chain gene. Results: In the allergic individuals, proliferation to NiSO4 was significantly (P

Background: Differentiation between septic and aseptic loosening of joint replacements is essential for successful revision surgery, but reliable markers for the diagnosis of low-grade infection are lacking. The present study was performed to assess intra-articular and systemic levels of antimicrobial peptides and proinflammatory cytokines as diagnostic markers for periprosthetic joint infection. Methods: Fifteen consecutive patients with staphylococcal periprosthetic joint infections and twenty control patients with aseptic loosening of total hip and knee replacements were included in this prospective, single-center, controlled clinical trial. Expression of the antimicrobial peptides human β-defensin-2 (HBD-2), human β-defensin-3 (HBD-3), and cathelicidin LL-37 (LL-37) was determined by ELISA (enzyme-linked immunosorbent assay) in serum and joint aspirates. Proinflammatory cytokines were assessed in serum and joint aspirates with use of cytometric bead arrays. C-reactive protein in serum, microbiology, and histopathology of periprosthetic tissue served as the “gold standard” for the diagnosis of infection. Results: The antimicrobial peptides HBD-3 and LL-37 were significantly elevated in joint aspirates from patients with periprosthetic joint infection compared with patients with aseptic loosening, and the area under the curve (AUC) in a receiver operating characteristic curve analysis was equal to 0.745 and 0.875, respectively. Additionally, significant local increases in the proinflammatory cytokines interleukin (IL)-1β, IL-4, IL-6, IL-17A, interferon (IFN)-γ, and tumor necrosis factor (TNF)-α were observed to be associated with infection. Logistic regression analysis indicated that the combination of an antimicrobial peptide with another synovial fluid biomarker improved diagnostic accuracy; the AUC value was 0.916 for LL-37 and IL-4, 0.895 for LL-37 and IL-6, 0.972 for HBD-3 and IL-4, and 0.849 for HBD-3 and IL-6. In contrast, the only antimicrobial peptides and cytokines in serum that showed a significant systemic increase in association with infection were HBD-2, IL-4, and IL-6 (all of which had an AUC value of

Background: Some nickel (Ni) allergic patients develop complications following Ni-containing arthroplasty. In the peri-implant tissue of such patients, we had observed lymphocyte dominated inflammation together with IFN-γ and IL-17 expression. Objectives: To determine whether Ni stimulation of peripheral blood mononuclear cells (PBMCs) of such patients would lead to a different cytokine pattern as compared to Ni-allergic patients with symptom-free arthroplasty. Patients and Methods: Based on history and patch testing in 15 Ni-allergic patients (five without implant, five with symptom-free arthroplasty, five with complicated arthroplasty) and five non-allergic individuals, lymphocyte transformation test (LTT) was performed using PBMC. In parallel in vitro cytokine response to Ni was assessed by real-time reverse transcriptase-polymerase chain reaction (RT-PCR). Results: All 15 Ni-allergic individuals showed enhanced LTT reactivity to Ni (mean SI = 8.42 ± 1.8) compared to the non-allergic control group. Predominant IFN-γ expression to Ni was found both in the five allergic patients without arthroplasty and also in the five allergic, symptom-free arthroplasty patients. In contrast, in the five Ni-allergic patients with arthroplasty-linked complications a predominant, significant IL-17 expression to Ni was seen but not in patients with symptom-free arthroplasty. Conclusions: The predominant IL-17 type response to Ni may characterize a subgroup of Ni-allergic patients prone to develop lymphocytic peri-implant hyper-reactivity.

Locally destructive soft tissue pseudotumor has been reported in patients following metal-on-metal hip resurfacing arthroplasty (MoMHRA). A delayed hypersensitivity reaction type IV to nickel (Ni), chromium (Cr), or cobalt (Co) has been suggested to play a role in its aetiology. The aim of this study was to investigate the incidence and level of metal-induced systemic hypersensitivity in patients with MoMHRA, both with and without pseudotumor by measuring lymphocyte proliferation responses to metals. A total of 92 patients were investigated: (1) MoMHRA patients with pseudotumors (nine female, one male); (2) MoMHRA patients without pseudotumors (30 female, 30 male); and (3) age-matched control subjects without metal implants (9 female, 13 male). The venous blood samples were collected for serum Ni, Co, and Cr ion level measurements and lymphocyte transformation tests (LTT). A higher incidence and level of enhanced lymphocyte reactivity only to Ni was found in patients with MoMHRA compared to the patients without MoM implants, reflecting exposure and immune reactivity. However, lymphocyte reactivity to Co, Cr, and Ni did not significantly differ in patients with pseudotumors compared to those patients without pseudotumors. This suggests that systemic hypersensitivity type IV reactions, as measured by lymphocyte proliferation response to these metals, may not be the dominant biological reaction involved in the occurrence of the soft tissue pseudotumors.

Nickel, chromium, and cobalt released from stainless steel and CoCrMo alloys have been postulated to trigger hypersensitivity reactions. The objective of this study was to assess the ion release from a CoCrMo alloy and stainless steel in vitro and the cutaneous reactivity to it by patch test. 52 metal-allergic patients and 48 non-allergic controls were patch tested to stainless steel and CoCrMo discs. In addition, using atomic absorption spectrometry, the release of nickel, cobalt, and chromium from both materials was assessed upon 2-day exposure to distilled water, artificial sweat (AS), and cell culture medium. There was low nickel ion release from stainless steel (0.3-0.46 microg/cm(2)/2 days) and CoCrMo discs (up to 0.33 microg/cm(2)/2 days) into the different elution media. Chromium release from the 2 materials was also very low (0.06-0.38 microg/cm(2)/2 days from stainless steel and 0.52-1.36 microg/cm(2)/2 days from CoCrMo alloy). In contrast, AS led to abundant cobalt release (maximally 18.94 microg/cm(2)/2 days) from the CoCrMo discs, with concomitant eczematous reaction upon patch testing: 0 of the 52 metal-allergic patients reacted to stainless steel discs and 5 of the 52 patients to CoCrMo discs (all 5 patients were cobalt allergic and 3 also nickel and chromium allergic). None of the controls reacted to the discs. Apart from nickel being a focus of allergological research, our results point to the possibly underestimated association of cobalt release and potential hyperreactivity to CoCrMo alloy.

There are very few reports on hypersensitivity reactions in association with titanium-based materials so that the existence of allergy to titanium is still put in question. We report on a patient in whom impaired fracture healing and eczema localized to the perioperative area developed upon titanium-based osteosynthesis. Patch testing gave no reactions to titanium nor to nickel, chromium, or cobalt. However, in the lymphocyte transformation test, the patient's lymphocytes showed markedly enhanced proliferation in vitro to titanium. After removal of the titanium material, fracture healing was achieved and the eczema cleared. Parallel to this, in vitro hyperreactivity to titanium disappeared. Although contact allergic reactions to titanium have been very rarely reported, these findings support a diagnosis of titanium allergy in our patient.

Background: We report on a 37-year-old man without history of previous allergic disease who developed an aseptic intolerance reaction to a chromium-cobalt alloy, with local discomfort, loosening, and absence of fracture healing. Both in vivo and in vitro allergoimmunologic diagnostic tests were performed. Methods: Patch testing was done with a European standard series. Specific serum IgE was measured by CAP-FEIA. In addition to immunohistology (APAAP method), peri-implantar tissue was further analyzed by PCR to determine T-cell-receptor-γ rearrangement and thus the potential clonal (antigen-driven) T-cell repertoire. The actual tissue mRNA expression for IL-4, IL-6, and IFN-γ was visualized by RT-PCR. Results: Skin testing gave a delayed-type reaction to dichromate. Specific serum IgE to natural rubber latex and grass pollen was found – but without clinical symptoms. Immunohistology revealed a monocytic and dense T-cell infiltrate. The latter, instead of being random, showed an oligoclonal T-cell receptor rearrangement. In addition, there was TH1-type mediator expression (IL-6 and IFN-γ, but not IL-4). Conclusions: Skin test, examination of peri-implantar tissue, and the prompt healing after replacement of the osteosynthesis material suggest an allergic reaction. PCR analysis of peri-implantar tissue can further help to identify and understand allergy-mediated implant intolerance reactions.