Statistical analysis
Scatter plots were prepared in GraphPad Prism 8 (GraphPad Software, Inc., USA). In scatter plots, whiskers represent 25-75% interquartile range (IQR) with the median shown by a line. Statistical analysis was done in GraphPad Prism 8 (GraphPad Software, Inc., USA), STATISTICA version 10 (StatSoft, Inc., USA) and IBM SPSS Statistics 25 (IBM Corp., USA). The cell fractions were compared between IgA patients, ADPKD and HC. The cytokine concentrations were compared between IgA patients and HC. Since the values were not normally distributed in all groups, comparisons for cell fractions were performed using the Kruskal-Wallis test and for cytokine concentrations Mann-Whitney U test was applied. Significant differences between groups were analyzed using the post hoc multiple comparisons p values (2-tailed) test. P<0.05 was considered statistically significant. Mann-Whitney U test was used to compare laboratory findings on blood parameters between study groups. Linear regression test was applied to determine the relationship between different variables; clinical indexes and cell fractions as well as cytokine levels.