www.ksmf.org/arhimed
arhimed@ksmf.org
[5/9/2025 11:49:19 PM]http://www.ksmf.org/arhimed/poglej.asp?id=79
Splenektomija in imunski odziv
Avtor: Ana Kotnik
Mentor: prof. dr. Vladimir Kotnik, dr. med. in prof. dr. Andrej Baraga, dr. med.
Izhodišca. Po odstranitvi vranice je odpornost operirancev za okužbo zmanjšana. Najpogostejša je okužba s pnevmokoki. Zato moramo operirance primerno zašcititi. Najprimernejši nacin je preventivno cepljenje s 23-valentnim pnevmokoknim cepivom. Zanimalo nas je, ob katerem casu ima cepljenje najvecji ucinek. Proucevali smo naslednje možnosti: cepljenje tik pred splenektomijo, cepljenje en dan po splenektomiji in cepljenje sedem dni po splenektomiji, ko si je bolnik že opomogel po operaciji. Naša hipoteza je bila, da je najustreznejše cepljenje tik pred ali takoj po splenektomiji.
Metode. Prospektivno raziskavo smo izvedli na tridesetih miškah, razdeljenih v šest skupin. Operacijsko smo jim odstranili vranico in jih cepili ob razlicnih casih. Prvi skupini mišk vranice nismo odstranili, cepili pa smo jih s pnevmokoknim cepivom. Drugo skupino smo cepili tik pred splenektomijo, tretjo skupino 1 dan po splenektomiji in cetrto skupino 7 dni po operaciji. Peti skupini smo odstranili vranico, ne da bi jih cepili. Šesta skupina so bile zdrave, necepljene miške. Med poskusom smo miškam štirikrat odvzeli vzorce krvi. Z encimsko-imunskim testom smo opazovali spreminjanje množine za Streptococcus pneumoniae specificnih protiteles razredov IgM in IgG. Z metodo mikroprecipitacije v kapilari smo izmerili množino precipitacijskih za pnevmokoke specificnih protiteles v njihovem krvnem serumu. Poskus smo zakljucili z nadzorovano okužbo mišk s pnevmokoki.
Rezultati. Množina IgG, IgM in precipitacijskih protiteles je bila pri vseh odvzemih najvecja pri skupini mišk, ki so bile imunizirane, ne pa splenektomirane (skupina 1). V primerjavi te skupine mišk in vseh ostalih skupin smo našli statisticno znacilno razliko (p < 0,05). Od splenektomiranih mišk so najvecjo množino specificnih protiteles sintetizirale miške, ki so bile imunizirane 1 dan po splenektomiji (skupina 3). Vendar med to skupino in skupino mišk imuniziranih tik pred splenektomijo (skupina 2), nismo našli statisticno znacilne razlike (p > 0,05). Najmanjšo množino specificnih protiteles med imuniziranimi miškami so proizvedle miške, imunizirane 7 dni po splenektomiji (skupina 4). Med skupino 4 in ostalimi skupinami imuniziranih mišk smo našli statisticno znacilno razliko (p < 0,05). Podobne rezultate smo dobili tudi po nadzorovani okužbi mišk s pnevmokoki. Štiri od petih mišk so poginile v skupini zdravih mišk (skupina 6) in v skupini splenektomiranih mišk, imuniziranih 7 dni po operaciji. Nobena miška pa ni poginila v skupini imuniziranih nesplenektomiranih mišk in v skupini splenektomiranih mišk, imuniziranih tik pred splenektomijo. Navkljub veliki množini specificnih protiteles sta v skupini splenektomiranih mišk, imuniziranih 1 dan po splenektomiji, umrli dve od petih mišk.
Zakljucki. Na osnovi naših rezultatov lahko potrdimo, da imunizacija sproži sintezo specificnih protiteles. Splenektomija zmanjša zmožnost sinteze specificnih protiteles, zmanjšanje pa je odvisno od casa med splenektomijo in imunizacijo. Najvecja zmožnost sinteze se ohrani pri operiranih miškah, ki jih imuniziramo tik pred ali 1 dan po posegu. Rezultati potrjujejo našo hipotezo, da je cepljenje s pnevmokoknim cepivom najucinkovitejše, ce živali cepimo tik pred ali takoj po splenektomiji.
[Abstract / English version]
Splenectomy and the immune response
Author: Ana Kotnik
Mentor: prof. dr. Vladimir Kotnik, dr. med. in prof. dr. Andrej Baraga, dr. med.
Backgrounds. Removal of the spleen reduces resistance of the patient to infections, most frequently those caused by pneumococci. The most effective way of protecting these patients is vaccination with a 23-valent pneumococcal vaccine. The aim of our research was to establish at what time after splenectomy vaccination is most effective. Different possibilities were studied: vaccination just before splenectomy, vaccination one day after and seven days after splenectomy. Our hypothesis was that vaccination just before splenectomy has the best protective effect from infection.
Methods. The prospective study was carried out on thirty mice divided into six groups. Their spleens were surgically removed and they were vaccinated at different times before or after the operation. The first group was vaccinated, without splenectomy. The second group was vaccinated just before splenectomy, the third group 1 day after and the fourth group 7 days after surgery. The fifth group had their spleens removed without vaccination. The sixth group consisted of healthy, unvaccinated mice. During the study, the mice had their blood drawn four times. With an enzyme-linked immunosorbent assay, the changing of the amount of specific IgM and IgG antibodies directed against pneumococcal antigens was measured. The amount of precipitating antibodies in the blood serum of mice was measured with a microprecipitation capillary test. The study was concluded with a supervised infection of mice with live pneumococci.
Results. The amount of IgG, IgM and precipitating antibodies was at all times highest in the group of immunized unsplenectomized mice (group 1). A statistically significant difference was found between this and all other groups (p<0.05). Between the splenectomized groups of mice, mice immunized 1 day after splenectomy (group 3) produced the highest amount of specific antibodies against Streptococcus pneumoniae. However there was no statistically significant difference found between group 3 and the group of mice immunized just before splenectomy (group 2) (p>0.05). The lowest amount of specific antibodies was produced in the group of mice immunized 7 days after splenectomy (group 4). There was a statistically significant difference found between group 4 and other groups of immunized mice (p<0.05). Simmular results were obtained after a supervised infection of mice with live pneumococci. Four out of five mice died in the group of healthy mice (group 6) and in group 4. No mice died in the groups of only vaccinated mice and mice vaccinated just before splenectomy. Inspite of the high quantity of specific antibodies in the group of mice vaccinated 1 day after splenectomy, two out of five mice died.
Conclusion. We conclude that vaccination with a pneumococcal vaccine triggers synthesis of specific antibodies. Splenectomy lowers the ability of this synthesis. The lowering depends on the time between splenectomy and vaccination. The highest ability of synthesis of specific antibodies was in operated mice vaccinated just before and 1 day after surgery. Our results confirm the hypothesis that vaccination with a pneumococcal vaccine is most effective if mice are vaccinated just before or very soon after splenectomy.