Immunological status of White Leghorn chicks hatched from eggs inoculated with ochratoxin A (OTA)

This study was designed to evaluate the immunological status of chicks hatched from the ochratoxin A (OTA)-contaminated eggs. For this purpose, 900 fertile White Leghorn (WL) layer breeder eggs were divided into eight groups (A-H). Group A was maintained as untreated control, whereas Group B was kept as sham control (10 µL of 0.1 M NaHCO₃). Groups C, D, E, F, G, and H were injected with 0.01, 0.03, 0.05, 0.10, 0.50, and 1.00 µg OTA/egg, respectively. Eggs were incubated at 37.5 °C and 65% relative humidity. Hatched chicks from each group were then maintained separately under standard environmental conditions. At Day 18-of-age, chicks (n = 10) from each group were used for lymphoblastogenic response against an intradermal administration of phytohemagglutinin P (PHA-P). At Day 30-of-age, abdominal macrophages, collected from 15 chicks in each group, were utilized for determination of phagocytic potential using sheep red blood cells (SRBC) as particulate antigen and for nitrite production in response to lipopolysaccharide. Antibody (Ab) titers (i.e. total antibodies, IgG, and IgM) against SRBC were determined at 7 and 14 days after primary (at Day 13-of-age) and booster (given 14 days after primary) intravenously administered SRBC doses. The lymphoblastogenic responses of the chicks hatched from OTA-contaminated eggs in response to PHA-P administration were significantly lower at 24, 48, and 72 h after PHA-P injection when compared with responses by control chicks. The percentage of abdominal macrophages displaying phagocytosis of SRBC, the number of SRBC/macrophage, and nitrite production were each significantly lower in cells from chicks in the OTA-administered groups. Total Ab, IgG, and IgM titers against SRBC showed significant reductions in the groups that had been hatched from eggs injected with the higher doses of OTA (as compared with titers associated with chicks in control eggs). These findings suggested that there are substantive immunosuppressive risks in chicks that could be exposed to OTA in ovo.