Značaj određivanja koncentracije komponente komplementa C1q u pacijenata sa sistemskim eritemskim lupusom

master's thesis

• Title (english): The significance of determining complement component C1q concentration in patients with systemic lupus erythematosus
• Author: Lovro Ljubić
• Mentor: Désirée Coen Herak (mentor)
• Committee member: Desiree Coen Herak (predsjednik povjerenstva)
• Committee member: Željka Vogrinc (član povjerenstva)
• Committee member: Ana Kozmar (član povjerenstva)
• Granter: University of Zagreb; Faculty of Pharmacy and Biochemistry; (Department of medical biochemistry and haematology); Zagreb
• Defense date and country: 2024-10-07, Croatia
• Scientific / art field, discipline and subdiscipline: BIOMEDICINE AND HEALTHCARE; Pharmacy; Medical Biochemistry

Abstract

Sustav komplementa čini više od 30 proteina prisutnih u plazmi i na staničnim membranama, čije funkcije
uključuju moduliranje imunosnog odgovora, liziranje stanica patogena te uklanjanje staničnog otpada i
imunokompleksa. Komponenta komplementa C1q prepoznaje imunokomplekse nastale kao dio imunosnog
odgovora te započinje klasičan put aktivacije sustava komplementa. Sistemski eritemski lupus (SLE) je
multisistemska autoimuna bolest koju karakterizira nastanak te odlaganje imunokompleksa u različitim organima.
Najteža komplikacija SLE koja nastaje nakupljanjem imunokompleksa u bubrezima naziva se lupusni nefritis. Cilj
ovog istraživanja bio je utvrditi važnost određivanja koncentracije komponente komplementa C1q kao
potencijalnog biomarkera u serumu pacijenata sa SLE te povezanost s komponentama komplementa C3 i C4 koje
su dio redovne obrade i praćenja bolesnika. Istraživanje je provedeno u 101 ispitaniku, od kojih 33 zdravih i 68
oboljelih od SLE. Na temelju izmjerenih koncentracija komponente komplementa C1q u serumu zdravih
ispitanika, izračunat je referentni interval koji iznosi 20,7 - 33,4 mg/dL, te se razlikovao od referentnog intervala
predloženim od proizvođača (15,7 - 30,6 mg/dL). Usporedbom vrijednosti koncetracija C1q dobivenih u uzorcima
zdravih i bolesnik ispitanika, utvrđena je statisitički značajno niža vrijednost koncetracije C1q u serumu bolesnih
ispitanika (P<0,001). U skupini bolesnih ispitanika utvrđena je statistički značajna korelacija između koncentracije
komponente komplementa C1q i koncetnracije komponenata komplementa C3 (r=0,450; P=<0,001) i C4
(ρ=0,460; P=<0,001). Dobiveni rezultati podudarni su s dosadašnjim spoznajama o SLE i literaturnim navodima.
Utvrđene značajne razlike i trendovi pokazuju kako se komponenta komplementa C1q može smatrati potencijalnim
biomarkerom, ali je istraživanje potrebno nadopuniti upotrebom različitih analitičkih sustava te većim brojem
ispitanika.

Abstract (english)

The complement system consists of more than 30 proteins present in plasma and on cell membranes, whose
functions include modulation of the immune response, lysis of pathogen cells, and removal of cellular debris and
immune complexes. The complement component C1q recognizes immune complexes formed as part of the
immune response and initiates the classical pathway of complement activation. Systemic lupus erythematosus
(SLE) is a multisystem autoimmune disease characterized by the formation and deposition of immune complexes
in various organs. The most severe complication of SLE resulting from the accumulation of immune complexes in
the kidneys is termed lupus nephritis. The aim of this study was to determine the significance of measuring the
concentration of complement component C1q as a potential biomarker in the serum of patients with SLE, as well
as its correlation with complement components C3 and C4, which are part of routine patient evaluation and
monitoring. The study was conducted on 101 participants, including 33 healthy individuals and 68 patients with
SLE. Based on the measured concentrations of complement component C1q in the serum of healthy subjects, a
reference interval was calculated to be 20.7 - 33.4 mg/dL, which differed from the reference interval proposed by
the manufacturer (15.7 - 30.6 mg/dL). Comparison of C1q concentrations obtained from healthy and patient
samples revealed a statistically significant lower concentration of C1q in the serum of patients (P<0.001). In the
patient group, a statistically significant correlation was found between the concentration of complement
component C1q and the concentrations of complement components C3 (r=0.450; P<0.001) and C4 (ρ=0.460;
P<0.001). The obtained results are consistent with existing knowledge regarding SLE and literature references.
The identified significant differences and trends suggest that complement component C1q may be considered a
potential biomarker; however, further research is necessary, incorporating various analytical systems and a larger
number of participants.

• Keywords: komponenta komplementa C1q; sistemski eritemski lupus; lupusni nefritis; nefelometrija
• Keywords (english): C1q complement component; systemic lupus erythematosus; lupus nephritis; nephelometry
• Language: croatian
• URN:NBN: urn:nbn:hr:163:259524
• Study programme: Title: Medical biochemistry - integrated undergraduate and graduate - university study; Study programme type: university; Study level: integrated undergraduate and graduate; Academic / professional title: sveučilišni magistar medicinske biokemije i laboratorijske medicine (sveučilišni magistar medicinske biokemije i laboratorijske medicine)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Open access
• Created on: 2025-01-31 13:43:23