Contact sensitization to iron: A potentially underestimated metal allergen and elicitor of complications in patients with metal implants.

BACKGROUND: Little is known about sensitization to iron (Fe) in private, occupational, and medical settings, particulary implantology. OBJECTIVES: To investigate sensitization to metals, particularly to Fe, both in pre-implant individuals with presumed metal allergy and in patients with suspected metal implant allergy. To further characterize Fe-sensitized individuals. METHODS: Analysis of patch test reactions to an Fe (II) sulfate-containing metal series in 183 consecutive patients (41 pre-implant, 142 metal implant bearers). Test readings were on day (D)2, D3, and D6. Evaluation of questionnaire-aided history of metal reactivity patterns and demographics of Fe reactors. RESULTS: Metal reactivity in pre-implant/implant/total group was: to nickel 39%/30%/32%; to cobalt 17%/15%/15%; and to chromium 7%/13%/11%. Co-sensitizations cobalt/nickel (19/58) and cobalt/chromium (11/21) were significant at P < .001; co-sensitizations Fe/nickel (4/10) and chromium/knee arthroplasty (11/73) at P = .03. Ten of 183 (5.5%) reacted to Fe (2 of 41 pre-implant patients, 8 of 142 implant bearers), with 10 reacting only on D6. Fe reactivity was highest in complicated knee arthroplasty (7/73). Further peculiarities of Fe reactors included frequent isolated Fe reactivity (6/10), occupational metal exposure (7/10), previous (par)enteral Fe substitution (6/10). CONCLUSIONS: The 5.5% prevalence of Fe reactions suggests a potentially underestimated role of this metal allergen in general and in implant bearers. The latter also shows a distinct metal sensitization pattern.

Ex vivo confocal laser scanning microscopy: A diagnostic technique for easy real-time evaluation of benign and malignant skin tumours.

Ex vivo confocal laser scanning microscopy (ex vivo CLSM) is a novel diagnostic tool for a quick bedside evaluation of freshly excised tissue, comparable to histology. We aimed to assess the sensitivity and specificity of ex vivo CLSM in detecting malignant features, to validate its reliability in identifying various skin tumours based on a combination of confocal features and to evaluate the digital staining mode (DS). One-hundred twenty freshly excised skin samples from 91 patients were evaluated. Each lesion was screened for the presence of 23 predefined confocal criteria with ex vivo CLSM, followed by a histopathological examination. The diagnostic agreement between ex vivo CLSM and histology was 89.2%. The diagnostic accuracy of ex vivo CLSM in detecting malignancy reached a sensitivity of 98% and a specificity of 76%. Ex vivo CLSM enabled a rapid identification of the most common skin tumours, the tumour dignity and cytological features. The DS demonstrated a close resemblance to conventional histopathology.

Usefulness of lymphocyte transformation test and in vitro cytokine release in differentiating between independent and cross-reacting nickel/palladium allergy.

BACKGROUND: Often concomitant patch test (PT) reactivity to palladium (Pd) and nickel (Ni) is found. OBJECTIVES: To determine whether lymphocyte transformation test (LTT) could be useful in discrimination between cross-reacting or distinct PT results, and to compare the results with in vitro cytokine production upon Pd or Ni stimulation. MATERIALS AND METHODS: The study population consisted of two groups: 13 individuals with Pd PT reactions (10 with concomitant Ni PT reaction, 3 individuals with only Pd PT reactivity) and 10 Ni/Pd PT negative individuals. LTT and assessment of cytokine release (interferon-gamma, interleukin-5 [IL-5], IL-8, IL-17A, tumor necrosis factor alpha) by cytometric bead assay were performed. RESULTS: All 10 patients with positive PT to Ni and Pd showed positive LTT to Ni (P < .05) as compared with the 10 Pd/Ni PT negative patients-but had no significant LTT reaction to Pd. In all, 9 out of 10 Pd/Ni PT negative patients were also LTT negative to Ni and 10 out of 10 to Pd. In the 3 only Pd PT reactors 2 out of 3 remained LTT negative to Ni and 0 out of 3 to Pd. As a major finding, cytokine production gave clearly enhanced IL-5 response to Ni in Ni PT positive individuals (P < .05), whereas Pd PT reactivity was not linked with such enhanced IL-5 production in vitro to Pd. CONCLUSIONS: Pd and Ni sensitization are mostly found concomitantly, and cross-reactivity is questioned. By different LTT reactions and particularly IL-5 production in vitro, predominant Ni sensitization becomes more evident.

The role of antibiotic-loaded bone cement in complicated knee arthroplasty: relevance of gentamicin allergy and benefit from revision surgery - a case control follow-up study and algorithmic approach.

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: Fifteen 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.