title: Substance P expression correlates with severity of diarrhea in cryptosporidiosis.
abstract: Cryptosporidiosis, caused by Cryptosporidium parvum, is self-limited in immunocompetent hosts but may cause chronic diarrhea in patients with acquired immunodeficiency syndrome (AIDS). Substance P (SP), a neuropeptide belonging to the tachykinin family, is expressed in gastrointestinal tract and can cause electrogenic chloride anion secretion. Therefore, we studied SP mRNA and protein expression in jejunal tissue samples of patients with AIDS with naturally occurring chronic cryptosporidiosis and healthy volunteers with mild cryptosporidiosis or asymptomatic infection after experimental C. parvum challenge. SP mRNA was associated with symptoms in cryptosporidiosis. SP protein levels were greater in symptomatic than asymptomatic volunteers. Similarly, greater expression of SP mRNA and protein were noted in patients with AIDS with chronic cryptosporidiosis versus immunocompetent volunteers with self-limited infection. This study demonstrates a direct correlation between SP levels and disease severity and may imply that SP plays a role in diarrhea mediation.
authors.affiliation: Infectious Diseases Section, Department of Medicine, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA. premar@bcm.tmc.edu
authors.forename: Prema
authors.initials: P
authors.lastname: Robinson
authors.forename: Pablo C
authors.initials: PC
authors.lastname: Okhuysen
authors.forename: Cynthia L
authors.initials: CL
authors.lastname: Chappell
authors.forename: Joel V
authors.initials: JV
authors.lastname: Weinstock
authors.forename: Dorothy E
authors.initials: DE
authors.lastname: Lewis
authors.forename: Jeffrey K
authors.initials: JK
authors.lastname: Actor
authors.forename: A Clinton
authors.initials: AC
authors.lastname: White
mesh_terms: D017088:AIDS-Related Opportunistic Infections / Q000150:complications / Q000235:genetics; D000163:Acquired Immunodeficiency Syndrome / Q000150:complications / Q000235:genetics; D000293:Adolescent; D000328:Adult; D000818:Animals; D002908:Chronic Disease; D003457:Cryptosporidiosis / Q000150:complications* / Q000235:genetics; D016785:Cryptosporidium parvum; D003967:Diarrhea / Q000150:complications* / Q000235:genetics* / Q000382:microbiology / Q000503:physiopathology; D005260:Female; D005786:Gene Expression Regulation; D020022:Genetic Predisposition to Disease / Q000235:genetics; D006801:Humans; D007583:Jejunum / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D013373:Substance P / Q000235:genetics* / Q000378:metabolism*
chemical_list: D012333:RNA, Messenger; D013373:Substance P