RESUMO
BACKGROUND: Accurate diagnosis and classification of von Willebrand disease (VWD) are essential for optimal management. The von Willebrand factor multimers analysis (VWF:MM) is an integral part of the diagnostic process in the phenotypic classification, especially in discrepant cases. The aim of this study was to evaluate the performance of a new Hydragel 11VWF multimer assay (H11VW). METHODS: Analytical performance characteristics such as repeatability (intra-assay variability, in gel between track variation), reproducibility (inter-assay variability, between gel variation), sensitivity, EQA performance and differences between two commercially available VWF:MM kits (H5VW and H11VW) were analysed in healthy volunteers' plasmas using in-house prepared reference plasma. RESULTS: Repeatability and reproducibility results of H11VW demonstrated acceptable and equivalent performance with previously verified H5VW. Participation in EQA was successful. No statistically significant difference was detected between H5VW and H11VW kits for different fractions of multimers: LMWM p=0.807; IMWM p=0.183; HMWM p=0.774. CONCLUSIONS: H11VW demonstrated acceptable analytical performance characteristics. H11VW kit conveniently offers a more significant number of samples on a single gel. H5VW and H11VW kits can be used in daily practice interchangeably.
RESUMO
BACKGROUND Pseudolymphoma is a rare disorder that can mimic lymphoma both clinically and histologically. It usually affects middle-aged females. Since pseudolymphoma is a rare disorder not only is diagnosing the condition difficult, but there is also a lack of standardized treatment guidelines. In the literature, anti-CD20 monoclonal antibody rituximab is described as an effective treatment option. CASE REPORT 46-year-old female fell ill suddenly with swelling and enlargement of her chin. Multiple skin biopsies were done, which were re-evaluated multiple times as well. Each ended with a new diagnosis for the patient. Finally, in the last revision of biopsy material, pseudolymphoma was confirmed. The patient received multiple courses of corticosteroid treatments - locally and systemically - without long lasting effect. After diagnosis of pseudolymphoma, the patient was started on intravenous rituximab and this treatment was effective. CONCLUSIONS Cutaneous pseudolymphoma is a diagnostic challenge. Rituximab is a treatment option for refractory pseudolymphoma. Since there are no treatment guidelines for pseudolymphoma, more clinical studies are needed to establish best treatment options for these patients. Therefore, each reported clinical case is important.
