“…Table 2 summarizes the methods used for the determinations, the main results, and observations in some of these studies, including the reason for exclusion of several of these studies from the meta-analysis. Reasons for total and partial exclusion included the following: (i) total or partial overlapping with other articles from the same author group [6,21,28,32,39,42,52,54,61,69,78,80]; (ii) lack of a control group [13,38,49,59,75]; (iii) lack of portions of the data in the text, tables or figures [12,55]; (iv) measurement of relative but not absolute values of the variables studied [37,44,62,70]; and (v) inability to obtain the original article [9]. Selected case-control studies reporting CSF concentrations of iron (11 studies), ferritin (five studies), transferrin (two studies), and lactoferrin (one study) are summarized in Table S1.…”