Katra R

Charles University

OpenAlex Profile
2
Publications
14
h-index
(657 citations, 52 total works)

Research Topics

Thyroid Cancer Diagnosis and Treatment (19) Helicobacter pylori-related gastroenterology studies (7) MicroRNA in disease regulation (4) Gastroesophageal reflux and treatments (4) Neuroendocrine Tumor Research Advances (4)

PFAPA Syndrome Publications

Polyclonal, newly derived T cells with low expression of inhibitory molecule PD-1 in tonsils define the phenotype of lymphocytes in children with Periodic Fever, Aphtous Stomatitis, Pharyngitis and Adenitis (PFAPA) syndrome.

Dytrych P, Krol P, Kotrova M, Kuzilkova D, Hubacek P , et al.
Molecular immunology •

PFAPA syndrome is a benign, recurrent inflammatory disease of childhood. Tonsillectomy is one of the therapeutic options with a yet unexplained biological mechanism. We tested whether specific lymphocyte subsets recruited from blood to human tonsils participate in PFAPA pathogenesis. Paired tonsils/peripheral blood (PB) samples were investigated (a) from children with PFAPA that successfully resolved after tonsillectomy (n=10) (b) from children with obstructive sleep apnoea syndrome as controls (n=10). The lymphocyte profiles were analysed using 8-colour flow cytometry, immunoglobulin (IGH) and T-cell receptor (TCR) gene rearrangements via PCR and next generation sequencing; a TREC/KREC analysis was performed using qPCR. The PFAPA tonsils in the asymptomatic phase had a lower percentage of B-lymphocytes than controls; T-lymphocyte counts were significantly higher in PB. The percentages of cytotoxic CD8pos T-lymphocytes were approximately 2-fold higher in PFAPA tonsils; the transitional B cells and naïve stages of both the CD4pos and CD8pos T-lymphocytes with a low expression of PD-1 molecule and high numbers of TREC were also increased. With the exception of elevated plasmablasts, no other differences were significant in PB. The expression levels of CXCL10, CXCL9 and CCL19 genes were significantly higher in PFAPA tonsils. The IGH/TCR pattern showed no clonal/oligoclonal expansion. DNA from the Epstein-Barr virus, Human Herpervirus-6 or adenovirus was detected in 7 of 10 PFAPA tonsils but also in 7 of 9 controls. Our findings suggest that the uninhibited, polyclonal response of newly derived lymphocytes participate in the pathogenesis of PFAPA. Because most of the observed changes were restricted to tonsils and were not present in PB, they partly explain the therapeutic success of tonsillectomy in PFAPA syndrome.

View on PubMed → DOI →

PFAPA syndrome: clinical characteristics and treatment outcomes in a large single-centre cohort.

Król P, Böhm M, Sula V, Dytrych P, Katra R , et al.
Clinical and experimental rheumatology •

This paper aims to describe clinical and laboratory features and disease outcome in a single-centre cohort of patients with PFAPA syndrome (Periodic Fever, Aphtous stomatitis, Pharyngitis, and Adenitis) and to test performance of diagnostic and therapeutic algorithms. Patients fulfilling criteria were selected from the fever clinic population. Prospective follow-up together with recruitment of newly diagnosed patients followed pre-defined guidelines. Diagnostic and therapeutic algorithms and definitions of outcome and therapy response were formulated. Paired blood samples during febrile and afebrile periods were compared. Out of 176 patients referred for suspected periodic fever 125 children fulfilled criteria. Their age at onset was 23 months, median episode duration 3.5 days at 4-week intervals. Fever was associated with pharyngitis (91%), cervical adenitis (78%) and aphtae (41%). Among therapeutic options, episodic prednisone proved to be the most common first-line treatment. Administered to 77 patients, it reduced symptoms in 94%. Tonsillectomy led to the full symptom resolution in all 18 patients. Forty-six patients reached disease remission. Distribution of typical symptoms, response to therapies and disease outcome in a large patient cohort were documented. We offer diagnostic and therapeutic algorithms that have proven effective during this prospective trial. Our findings support the general belief of benign nature of this aetiologically unclear condition, despite proportion of patients having persistent disease for years. Maintenance of normal findings in afebrile intervals, striking response to a single dose of prednisone and normal growth and development together with spontaneous tendency towards prolongation of afebrile intervals are important confirmatory features of PFAPA syndrome.

View on PubMed →