Makroprolaktin - racionalna upotreba probirnog testa u dijagnostici hiperprolaktinemije

master's thesis

• Title (english): Macroprolactin - rational use of screening test in diagnostic of hyperprolactinaemia
• Author: Milica Šostarić
• Mentor: Nada Vrkić (mentor)
• Committee member: Nada Vrkić (predsjednik povjerenstva)
• Committee member: Sandra Šupraha Goreta (član povjerenstva)
• Committee member: Olga Gornik (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medical biochemistry and haematology); Zagreb
• Defense date and country: 2018-03-21, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry

Abstract

Određivanje koncentracije prolaktina u serumu ima najveći klinički značaj u diferencijalnoj dijagnostici hiperprolaktinemije. Budući da je fiziologija djelovanja i regulacije lučenja prolaktina u krvi vrlo složena, postoje različiti čimbenici koji utječu na vrijednosti izmjerenih koncentracija. Jedan od glavnih analitičkih interferenata prilikom određivanja koncentracija prolaktina u serumu je povećana prisutnost polimernog oblika, makroprolaktina. Ciljevi ovoga rada bili su ispitati učestalost makroprolaktinemije u ispitivanoj populaciji te utvrditi postoji li statistički značajna razlika u prevalenciji između spolova. Također je napravljena usporedba načina izvještavanja rezultata nakon taloženja makroprolaktina polietilen glikolom te ispitana mogućnost racionalizacije postupka taloženja podizanjem granične vrijednosti na 700 mIU/L, tj. 1000 mIU/L. Wilcoxonovim parnim utvrđeno je postoji li statistički značajna razlika u testu iskorištenja (engl. Recovery) kod ispitanika kojima je postupak taloženja polietilen glikolom ponovljen nakon godinu dana. Ispitivanje je provedeno na 1136 uzoraka seruma odraslih pacijenata prikupljenih u razdoblju od siječnja 2016. do rujna 2017. kojima su koncentracije prolaktina bile iznad gornje granice referentnog intervala. Koncentracije prolaktina prije i nakon taloženja polietilen glikolom izmjerene su elektrokemiluminiscentnom metodom na analizatoru Cobas e601. Koncentracije prolaktina koje su unutar referentnog intervala nakon taloženja smatraju se lažnim hiperprolaktinemijama. Prema rezultatima ispitivanja utvrđena je učestalost makroprolaktinemije u ispitanoj populaciji od 3,26% pri čemu nema statistički značajne razlike između muškaraca i žena u prevalenciji makroprolaktinemije. Usporedbom načina izvještavanja rezultata nakon taloženja makroprolaktina polietilen glikolom uočena je važnost paralelnog prikazivanja postotka iskorištenja uz apsolutne vrijednosti koncentracija prolaktina nakon taloženja i pripadnih post-PEG referentnih intervala. Podizanje graničnih vrijednosti nije opravdano jer bi se propustio veliki broj pacijenata s makroprolaktinemijom, a rezultati Wilcoxonovog parnog testa potvrđuju potrebu za ponavljanjem taloženja polietilen glikolom nakon godinu dana za sve pacijente s hiperprolaktinemijom.

Abstract (english)

Determination of serum prolactin concentration has the highest clinical relevance in the differential diagnosis of hyperprolactinemia. Since the physiological activity and regulation of prolactin secretion is very complex, there are many different factors that affect prolactin serum concentration to consider. Macroprolactin, a polymeric form of prolactin, is the major cause of falsely increased prolactin. Aims of this study were to establish the prevalence of macroprolactinaemia in our study population and to see whether there is a statistically significant difference between men and women. A comparison of the method of reporting the results after the precipitation of macroprolactin with polyethylene glycol was also made, as well as the possibility of rationalizing the precipitation process by increasing the limit value to 700 mIU/L, i.e. 1000 mIU/L. Wilcoxon's paired test was used to determine whether there was a statistically significant difference in recovery in subjects whose polyethylene glycol precipitation was repeated after one year. The study was conducted on 1136 adult patients' sera samples which were collected from January 2016 to September 2017. All samples had prolactin above corresponding upper reference limit. Measurements before and after PEG-precipitation were performed with electrochemiluminescence method on Cobas e601 analyzer. Post-PEG prolactin concentrations that fall within corresponding reference interval are considered false hyperprolactinemia. According to the results of the study, the incidence of macroprolactinemia in the examined population was 3.26%, with no statistically significant difference between men and women. By comparing the method of reporting the results after the precipitation of macroprolactin with polyethylene glycol, the importance of the parallel representation of the percentage of recovery and absolute values of prolactin concentrations after precipitation, along with corresponding post-PEG reference intervals, was observed. Raising the limit values is not justified because a large number of patients with macroprolactinemia would be missed, and Wilcoxon's paired test results confirmed the need to repeat the precipitation with polyethylene glycol after a period of one year for all patients with hyperprolactinaemia.

• Keywords: hiperprolaktinemija; makroprolaktin; taloženje polietilen glikolom; probirni test
• Keywords (english): hyperprolactinaemia; macroprolactin; precipitation with polyethylene glycol; screening test
• Language: croatian
• URN:NBN: urn:nbn:hr:163:610752
• Study programme: Title: Medical biochemistry; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: magistar/magistra medicinske biokemije (magistar/magistra medicinske biokemije)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2018-11-28 15:33:36