Author contributions:
Martin Holek – study design, data collection, analysis/statistics,
drafting article
Jiri Kettner – study design, data analysis, critical revision of
article
Janka Franekova – study design, laboratory diagnostics, statistics
Antonin Jabor - study design, laboratory diagnostics, statistics
Marian Pindak – study design
Hynek Riha – study design
Josef Kautzner – approval of article
Ivan Netuka — approval of article
Jan Pirk – approval of article