ABSTRACT
Background: Cerebrospinal fluid (CSF) biomarkers are used to diagnose Alzheimer disease (AD), especially in atypical clinical presentations. No consensus currently exists regarding cut-off values. This study aimed, firstly, to define optimal cut-off values for CSF biomarkers, and secondly, to investigate the most relevant diagnostic strategy for AD based on CSF biomarker combinations. Methods: A total of 380 patients were prospectively included: 140 with AD, 240 with various neurological diagnoses (non-AD). CSF biomarkers were measured using ELISA. Univariate and multivariate analyses were performed using random forest and logistic regression approaches. Results: Univariate receiver operating curve curves analysis of T-Tau, P-Tau181, Aß42, Aß40 concentrations, and Aß42/Aß40 ratio levels showed AD cut-off values of ≥355, ≥57, ≤706, ≥10,854, and ≤0.059 ng/L, respectively. Multivariate analysis using random forest and logistic regression found that the algorithm based on P-Tau181, Aß42 concentrations and Aß42/Aß40 ratio yielded the best discrimination between AD and non-AD populations. The cross-validation technique of the final model showed a mean accuracy of 0.85 and a mean AUC of 0.89. Conclusion: This study confirms that the Aß42/Aß40 ratio was more useful than the Aß40 concentration in discriminating AD from non-AD populations in daily practice. These results indicate that the Aß42/Aß40 ratio should be assessed in all cases, independently of Aß42 concentrations.
ABSTRACT
BACKGROUND: Recessive dystrophic epidermolysis bullosa (RDEB), an autosomal-recessive genodermatosis, is one of the more severe forms of the epidermolysis bullosa dystrophica group, and is characterized by generalized blistering of the skin and mucous membranes. Cutaneous squamous cell carcinoma is one of the most serious complications of this disease. METHODS: We report four patients (three females and one male), two of whom were under 20 years of age, suffering from RDEB-Hallopeau-Siemens. RESULTS: All patients developed well-differentiated squamous cell carcinoma. No metastases were detected. All cases were treated surgically. Fatal evolution was noted in one patient. A second tumor was detected in another patient during the follow-up period. No further tumors or metastases were observed in the other patients. CONCLUSIONS: Regular clinical and histologic examination of any nodular lesions or non healing ulcers of all patients suffering from RDEB-Hallopeau-Siemens to detect an early malignancy is recommended.
