Editing Primary biliary cholangitis (section)

==Epidemiology==
Epidemiologic studies report heterogeneous incidence rates of 0.33 to 5.8 per 100,000 inhabitants per year, and prevalence rates of 1.9 to 40.2 per 100,000 inhabitants. Such figures, in particular the prevalence, have shown some increase in the last decades. Improvement of diagnostic tools, increasing disease awareness, and digitised patient registration with facilitation of case-findings, along with improved survival, likely contributed to the rising prevalence rates.
The disease has been described worldwide, though North America and Northern Europe have shown the highest incidence and prevalence rates. Whether a true variation in disease prevalence exists among populations of different geographical areas and of different ethnicity or if this is a consequence of a difference in study quality is unknown.<ref name="pmid22245904">{{cite journal | vauthors = Boonstra K, Beuers U, Ponsioen CY | title = Epidemiology of primary sclerosing cholangitis and primary biliary cirrhosis: a systematic review | journal = Journal of Hepatology | volume = 56 | issue = 5 | pages = 1181–1188 | date = May 2012 | pmid = 22245904 | doi = 10.1016/j.jhep.2011.10.025 | doi-access = free }}</ref><ref name="pmid10421645">{{cite journal | vauthors = James OF, Bhopal R, Howel D, Gray J, Burt AD, Metcalf JV | title = Primary biliary cirrhosis once rare, now common in the United Kingdom? | journal = Hepatology | volume = 30 | issue = 2 | pages = 390–394 | date = August 1999 | pmid = 10421645 | doi = 10.1002/hep.510300213 | s2cid = 25248575 }}</ref> PBC is more common in women, with a female:male ratio of at least 9:1.  The peak incidence of PBC is in the fifth decade of life. In some areas of the US and UK, the prevalence is estimated to be as high as one in 4,000. This is much more common than in South America or Africa, which may be due to better recognition in the US and UK.<ref name="pmid22245904"/><ref name="pmid10421645"/> First-degree relatives may have as much as a 500 times increase in prevalence, but if this risk is greater in the same-generation relatives or the one that follows is debated.

PBC is considered a prime example of the female preponderance in autoimmunity with a female to male ratio of up to 9:1, confirmed by large cohort studies, although some recent data, using administrative registries, suggest an increasing male prevalence. Major defects of sex chromosomes, i.e. enhanced monosomy X in female patients and an enhanced Y chromosome loss in male patients, have been described and might well explain the greater female predisposition to develop PBC.<ref name="pmid 14975617">{{cite journal | vauthors = Invernizzi P, Miozzo M, Battezzati PM, Bianchi I, Grati FR, Simoni G, Selmi C, Watnik M, Gershwin ME, Podda M | display-authors = 6 | title = Frequency of monosomy X in women with primary biliary cirrhosis | journal = Lancet | volume = 363 | issue = 9408 | pages = 533–535 | date = February 2004 | pmid = 14975617 | doi = 10.1016/S0140-6736(04)15541-4 | s2cid = 5309 }}</ref>

An association of a greater incidence of PBC at latitudes more distant from [[the Equator]] is similar to the pattern seen in [[multiple sclerosis]].<ref>{{cite journal | vauthors = Webb GJ, Ryan RP, Marshall TP, Hirschfield GM | title = The Epidemiology of UK Autoimmune Liver Disease Varies With Geographic Latitude | journal = Clinical Gastroenterology and Hepatology | volume = 19 | issue = 12 | pages = 2587–2596 | date = December 2021 | pmid = 33493696 | doi = 10.1016/j.cgh.2021.01.029 | pmc = 8661127 | doi-access = free }}</ref>

Typical disease onset is between 30 and 60 years, though cases have been reported of patients diagnosed at the ages of 15 and 93. Prevalence of PBC in women over the age of 45 years could exceed one in an estimated 800 individuals.