Author/Editor     Ginter, Katharina; Ahsan, Dalia Melina; Bizjak, Mojca; Krause, Karoline; Maurer, Marcus; Altrichter, Sabine; Terhorst, Dorothea
Title     Cryoglobulins, cryofibrinogens, and cold agglutinins in cold urticaria
Type     članek
Vol. and No.     , št. [Vol.] 12
Publication year     2021
Volume     str. 1-9
ISSN     1664-3224 - Frontiers in immunology
Language     eng
Abstract     Introduction: Cryoproteins, such as cryoglobulins, cryofibrinogens and cold agglutinins, precipitate at low temperatures or agglutinate erythrocytes and dissolve again when warmed. Their pathogenetic and diagnostic importance in cold urticaria (ColdU) is unclear. In this study, we aimed to characterize the prevalence of cryoproteins in patients with ColdU. Methods: We conducted 3 analyses: i) a systematic review and meta-analysis of published data using an adapted version of the Johanna Briggs Institute's critical appraisal tool for case series, ii) a retrospective analysis of 293 ColdU patients treated at our Urticaria Center of Reference and Excellence (UCARE) from 2014 to 2019, and iii) a prospective observational study, from July 2019 to July 2020, with 49 ColdU patients as defined by the EAACI/GA2LEN/EDF/UNEV consensus recommendations. Results: Our systematic review identified 14 relevant studies with a total of 1151 ColdU patients. The meta-analyses showed that 3.0% (19/628), 1.1% (4/357) and 0.7% (2/283) of patients had elevated levels of cryoglobulins, cryofibrinogens, and cold agglutinins, respectively. Our retrospective analyses showed that cryoproteins were assessed in 4.1% (12/293) of ColdU patients. None of nine ColdU patients had cryoglobulins, and one of 5 had cold agglutinins. In our prospective study, none of our patients had detectable cryoglobulins (0/48) or cryofibrinogens (0/48), but 4.3% (2/46) of patients had cold agglutinins (without any known underlying autoimmune or hematological disorder). Conclusion: Our investigation suggests that only very few ColdU patients exhibit cryoproteins and that the pathogenesis of ColdU is driven by other mechanisms, which remain to be identified and characterized in detail.
Descriptors     Urticaria
Retrospective studies
Urtikarija
Retrospektivne študije
Keywords     urtikarija zaradi mraza
koprivnica
krioglobulini
kriofibrinogeni
hladni aglutinini
retrospektivna analiza
cold urticaria
cryoglobulins
cryofibrinogens
cold agglutinins
retrospective analysis