MALDI-TOF analysis of blood serum proteome can predict the presence of monoclonal gammopathy of undetermined significance.

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell dyscrasia that can progress to malignant multiple myeloma (MM). Specific molecular biomarkers to classify the MGUS status and discriminate the initial asymptomatic phase of MM have not been identified. We examined the serum peptidome profile of MGUS patients and healthy volunteers using MALDI-TOF mass spectrometry and developed a predictive model for classifying serum samples. The predictive model was built using a support vector machine (SVM) supervised learning method tuned by applying a 20-fold cross-validation scheme. Predicting class labels in a blinded test set containing randomly selected MGUS and healthy control serum samples validated the model. The generalization performance of the predictive model was evaluated by a double cross-validation method that showed 88% average model accuracy, 89% average sensitivity and 86% average specificity. Our model, which classifies unknown serum samples as belonging to either MGUS patients or healthy individuals, can be applied to clinical diagnosis.

Langerhans cell histiocytosis mimicking molluscum contagiosum: A case series.

Langerhans cell histiocytosis (LCH) is a disorder characterized by accumulation of Langerhans-like cells in one or various organs. A correct staging work-up is essential since there are multiorgan presentations with a poor prognosis. We report three patients with LCH skin lesions mimicking molluscum contagiosum in association with both high and low risk organ involvement. This peculiar cutaneous presentation can be a clue for the diagnosis of LCH, a disease with potentially severe systemic involvement.