Acute intoxication with single oral dose of ochratoxin A (OTA) causes leukopenia, heteropenia, lymphopenia and lymphoid depletion in the bursa of Fabricius in broiler chicks

Abstract

Ochratoxin A (OTA) is a mycotoxin produced by species of Penicillium and Aspergillus, agricultural product contaminants. Chronic and sub-chronic OTA intoxication by chickens ingesting contaminated feed, leads to health damages due to its hepatotoxic, nephrotoxic, cytotoxic, immunotoxic, gastrotoxic, and possibly carcinogenic effects. As there are few data on acute intoxication, the present study evaluated the effects of a single acute OTA intoxication dose on immunological and hematological parameters in chicks. Sixteen one-day-old chicks were used, separated into two groups (n=8). A single dose of OTA (1400 µg kg-1 body weight) was administered, via gavage, for the OTA group and one dose of sterile PBS for the control group. On the 13th day, blood samples were collected to assess hematological and biochemical parameters, and on the 14th day, euthanasia and collection of lymphoid organs were performed. The animals of the OTA group demonstrated a significant decrease in total circulating leukocytes (p<0.001) with heteropenia (p<0.001) and lymphopenia (p=0.023), decrease hematocrit (p=0.020), hemoglobin (p=0.032), and plasma IgA (p =0.044), and increased plasma uric acid level (p=0.045), in relation to the control group. In addition, the animals intoxicated with OTA showed depletion of lymphoid cells in the bursa of Fabricius (p=0.016), but not in the thymus or spleen (p>0.05), compared to the control. For the other parameters: total plasma proteins, plasma IgY levels, and anti-Newcastle Disease Virus (NDV) vaccine titers from matrices, there were no significant differences between the analyzed groups (p>0.05), although there was a worsening tendency in contaminated animals. In conclusion, even a single acute OTA intoxication at a high dose, leads to the suppression of the systemic immune response, also affecting some hematological or biochemical parameters in chicks.