Histopathological alterations and Immunoglobulin G levels in Cryptococcosis induced in mus musculus balb/c at different times of infection

Abstract

The present study had the purpose of evaluate histopatological alterations and IgG levels in induced criptococosis in Mus musculus BALB/c "mouse" at different times of infection. For that it was worked with a culture of Cryptococcus neoformans and 45 specimens of Mus musculus BALB/c of both sexes, of 45 days of age and approximately 25g weigh, in 5 of those randomly chosen natural infection by C.neoformans was discarded by means of the test of negative tint with 10% nigrosine in brain samples and lungs, the 40 remaining were distributed at random in control group and experimental group of 20 especimens each one and were subdivided in 4 subgroups of 5 specimens each one. The mice of the experimental group were inoculated intraperitoneally with 0,5 mL of a suspension from the fungus in a similar concentration to the tube Nº 3 of of Mac Farland's Nefelometer, and for the control group it was used 0,5 mL of sterile physiologic saline solution (SSF). At the 10, 15, 20 and 25 days of the inoculation, there were taken samples of blood to evaluate the levels of IgG in serum, and after the sacrifice there were extracted the encephal, lungs, spleen, liver and kidneys for their macroscopic and histological evaluation after their conservation in 10% formol and were later colorated with Hematoxylin. eosin. In relation to the control group in the organs of the experimental group were observed macroscopic changes as: size Increase in longitude presenting marked hepatomegalia and esplenomegalia, change of color, hemorrhagic aspect and presence of abscesses that went increasing in number at more time of infection and histopatological alterations were also observed at the days 10 and 15 as hiperemia in meninxes, chronicle inflammatory infiltration in meninxes, alveolus and interstice in lung, liver and kidney; edema in cerebral cortex; necrosis in cerebral cortex, spleen, liver and kidney; areas of hemorrhages in brain, lung, and perirrenal adipose tissue; tendency to form granuloma in lung, and liver; hiperplasia of lymphatic nodules and megacarioblastos in spleen; proliferation of lymphocytes in spleen, sinusoids dilation in liver; Cryptococcus in meninxes, brain in bilateral form, lung, liver and kidney. At the 20 and 25 days of infection besides the histopatological alterations observed at the days 10 and 15, it was observed granulomatose chronic inflammatory Infiltration in meninxes and lung; hiperemy in cerebral cortex; chronicle inflammatory infiltration in spleen; multiple necrosis focuses in liver and kidney; abundant Cryptococcus in meninxes, brain, spleen, lung, liver and kidney. The evaluation of the levels of anticriptococosic IgG of experimental group and control was carried out by means of ELISA'S test, being the control group negative for anticriptococosic IgG, and the experimental group positive with titles of 1/80, 1/320, 1/160, 1/160 corresponding to the 10, 15, 20, and 25 days of infection. It was concluded that at more times of infection bigger histopatological alterations were presented in the evaluated organs and the levels of IgG increases until the 15 days of infection and then they diminish starting from the 20 days of infection. The test of correlation of Pearson was used, to determine if there is relationship between the size of the evaluated organs and the time of infection with C. neoformans, and it was found that it is highly significant, and the test of Chi squared to determine the dependence relationship between the histopalogical alterations and the levels of Ig G and it was found that dependence relationship exists.