Kikuchi-Fujimoto Disease and COVID-19 vaccination: pharmacovigilance approach.

Summary: Background. Kikuchi-Fujimoto Disease (KFD) or histiocytic necrotizing lymphadenitys is a rare disorder characterized by subacute necrotizing regional lymphadenopathy. It is usually presented as painful cervical nodes and associated with fever, headache, night sweats, nausea, vomiting and sore throat. Etiology of KFD is still unclear, two theories have been proposed: infections and autoimmune origin. Due to recent reports of KFD related to COVID-19 vaccination, the novelty of the mechanism of these vaccines and the immunomodulated role of both matters, a literature and adverse event databases review was carried out in order to shed light on the relationship between these two matters. Methods. A search in the Spanish and the European adverse events databases (FEDRA and Eudravigilance) was performed. Search criteria were any drug and the diagnosis "Histiocytic necrotizing lymphadenitis" according to the Medical Dictionary for Medical Activities version 25.0. All adverse events registered as June 2, 2022, were included. Results. FEDRA encompassed two KFD reports, one related to a mRNA COVID-19 vaccine. Eudravigilance included a total of 62 KFD cases, 14 of them associated to COVID-19 vaccines and eight to other vaccines. Conclusions. Pharmacovigilance is of utter importance in detecting adverse events caused by new vaccines. More research is needed to establish a final connection between KFD and COVD-19 vaccines, but due to the physiopathology of the condition, how vaccines stimulate the immune system and the high number of reported KFD cases with vaccines given its rare incidence, it is plausible to think that both entities are related.

[Clinical-biological differences between invasive ductal carcinomas and breast lobular carcinomas. Preliminary results]. / Diferencias clínico-biológicas entre carcinomas infiltrantes de tipo ductal y lobulillar de mama. Resultados preliminares.

In order to know the biological differences between both histological types, we have analyzed some clinical and biological parameters in tissues of women having infiltrating carcinomas (247 ductal (IDCs) 17 and lobular (ILCs) of the breast. Our preliminary results led us to suggest the following. 1) In negative axillary lymph node involvement (N-) patients, ILCs were more frequently associated with diploidy and the existence of multiple foci; likewise, they had higher pS2 cytosolic levels than IDC; 2) in N+ patients, ILC were associated with multicentricity and had higher concentrations of progesterone receptors and 3) these findings could help to explain us the clinical and biological peculiarities, as well as, the clinical outcome of both histological types.

[Absence of correlation between the concentrations of carcinoembryonic antigen (CEA) and the tumor growth factor beta 2 (TGFB2) in the two main types of breast macrocysts]. / Ausencia de correlación entre las concentraciones del antígeno carcinoembrionario (CEA) y del factor de crecimiento tumoral beta 2 (TGFB2) en los dos tipos principales de macroquistes mamarios.

In order to study the possible correlation between carcinoembryonic antigen (CEA) and cellular proliferation, we assayed the concentrations of this substance in the fluid of 77 bening macrocysts of the breast classified according to their Na+/K+ ratio and compared them with those of transforming growth factor beta 2. CEA levels correlated positively and significantly with the cationic ratio, the concentrations of albumin, glucose, Cl- and pH and were higher (range: 2.5-81.5, median 12.8 vs range: 0.4-41.5, median 3.2 ng/ml (p: 0.00000) in type 2 (Na+/K+ > 3) than in type 1 (Na+/K+ < 3) cysts. There was no correlation between CEA and TGFb2, nor between the former and dehydroepiandrosterone sulphate levels. These results led us to suggest that the high CEA concentrations in type 2 cysts seem to be the consequence of loos of cellular differentiation and disruption of the cyst wall lining as well as the acquisition of embryonary properties by the latter as a consequence of a reduced hormonal microenvironment.