Editing Alpha-2-Macroglobulin (section)

==Disease==
α<sub>2</sub>-Macroglobulin levels are increased when the serum albumin levels are low,<ref>{{cite journal | vauthors = Stevenson F, Greene S, Kaysen G | title = Serum alpha 2-macroglobulin and alpha 1-inhibitor 3 concentrations are increased in hypoalbuminemia by post-transcriptional mechanisms. | journal = Kidney International | volume = 53 | issue = 1 | pages = 67–75 | date = January 1998 | pmid = 9453001 | doi = 10.1046/j.1523-1755.1998.00734.x | doi-access = free }}</ref> which is most commonly seen in [[nephrotic syndrome]], a condition wherein the [[kidney]]s start to leak out some of the smaller blood proteins. Because of its size, α<sub>2</sub>-macroglobulin is retained in the bloodstream. Increased production of all proteins means α<sub>2</sub>-macroglobulin concentration increases. This increase has little adverse effect on the health but is used as a diagnostic clue.

An increase in α<sub>2</sub>-Macroglobulin with normal amount of albumin mainly indicates acute and/or chronic inflammation.<ref>{{cite web | title = Protein electrophoresis - serum | url = https://www.mountsinai.org/health-library/tests/protein-electrophoresis-serum | website = Icahn School of Medicine at Mount Sinai }} Last reviewed on: 1/25/2022. Reviewed by: Todd Gersten, MD, and David Zieve, MD</ref>

A common variant (29.5%) ([[polymorphism (biology)|polymorphism]]) of α<sub>2</sub>-macroglobulin may lead to increased risk of [[Alzheimer's disease]].<ref name="Blacker_1998">{{cite journal | vauthors = Blacker D, Wilcox MA, Laird NM, Rodes L, Horvath SM, Go RC, Perry R, Watson B, Bassett SS, McInnis MG, Albert MS, Hyman BT, Tanzi RE | title = Alpha-2 macroglobulin is genetically associated with Alzheimer disease | journal = Nature Genetics | volume = 19 | issue = 4 | pages = 357–360 | date = August 1998 | pmid = 9697696 | doi = 10.1038/1243 | s2cid = 15628847 }}</ref><ref name="Kovacs_2000">{{cite journal | vauthors = Kovacs DM | title = alpha2-macroglobulin in late-onset Alzheimer's disease | journal = Experimental Gerontology | volume = 35 | issue = 4 | pages = 473–479 | date = July 2000 | pmid = 10959035 | doi = 10.1016/S0531-5565(00)00113-3 | s2cid = 54409507 }}</ref> However, findings from meta-analyses have been inconclusive, and the association remains debated.<ref>{{Cite journal | vauthors = Li Z, liu N, Zhang W, Zhu G, Chen H | title = Influence of Alpha-2-Macroglobulin 5bp I/D and Ile1000Val Polymorphisms on the Susceptibility of Alzheimers disease: A Systematic Review and Meta-analysis of 52 Studies | journal = Cell Biochemistry and Biophysics | volume = 70 | issue = 1 | pages = 511–519 | date = 2014-09-01 | pmid = 24756728 | doi = 10.1007/s12013-014-9950-3 | url = https://link.springer.com/article/10.1007/s12013-014-9950-3 | language = en | issn = 1559-0283 | url-access = subscription }}</ref>

α<sub>2</sub>-Macroglobulin binds to and removes the active forms of the [[gelatinase]] ([[MMP-2]] and [[MMP-9]]) from the circulation via scavenger receptors on the phagocytes.