Changes in the immune response related to age

Lymphatic organ development in dogs: major lymphocyte subsets and activity

In the present study, we have characterized lymphocyte subsets and activity in peripheral blood, spleen, mesenteric and popliteal lymph nodes in pups from birth till the age of one month and compared the results with the situation in the group of three adult dogs. In neonatal pups, lower numbers of CD3(+) T-cells were detected in both the spleen and peripheral blood than in lymph nodes. In contrast to the other compartments, CD21(+) B-cells prevailed in the spleen, which resulted in low values (<1) of the CD3(+)/CD21(+) ratio. Low numbers of CD8(+) lymphocytes were characteristic in all compartments immediately after birth; consequently a high CD4(+)/CD8(+) ratio has been calculated. Postnatal development was characterized by an increasing frequency of CD8(+) lymphocytes in all organs studied. Another typical feature of the early period of life was a relative decrease of B-cell numbers, which was compensated by an increasing proportion of T-lymphocytes, particularly in the peripheral blood and spleen. DNA synthesis in newborn pups' cells as measured by in vitro thymidine incorporation was surprisingly high in non-stimulated control samples, notably in the spleen. Further development of lymphocyte activity was characterized by the decline in spontaneous activity in all organs. Stimulation indices upon mitogen-induced proliferation increased proportionally to the decrease in spontaneous activity. Based on our experimental data, we have concluded that pups are born with a relatively competent immune system the structure of which, however, markedly develops during a few postnatal weeks.

Neonatal immunity and immunisation in early age: lessons from veterinary medicine

The objective of this paper is to review adaptive immunity of young animals using examples from my own experience and from the literature. Trials carried out by us with a modified live and inactivated canine parvovirus vaccine in newborn puppies provide evidence of the immune capacity of these puppies. With regard to transfer of immunity from mother to offspring, there is a role for transplacental and colostral immunity. Examples of passive protection of young animals against different infections include passive protection of kittens against the feline immunodeficiency virus. However, passive immunity, though very useful at an early age, varies in duration and makes implementation of standard vaccination schedules difficult. Other experiments demonstrate that, under certain conditions, it is possible to overcome residual maternally-derived antibodies and to induce post-vaccinal immunity.

Geriatric ophthalmology

The threat of vision loss increases with age owing to a combination of the accumulation of untreated or partially managed eye disease (for example, immune-mediated keratoconjunctivitis) as well as the late-in-life onset of certain ocular disorders such as lens subluxation/luxation syndrome and senile/age-related cataracts. In addition, the ophthalmic effects of age-related systemic diseases such as systemic hypertension can be vision threatening as well. The veterinarian must always weigh the potential ophthalmic benefits of contemporary therapy against the potential patient risk, not only when ophthalmic surgery is considered but also with the use of various drugs.

Host response to vaccination

The desired response to vaccination is protection from clinical disease. This article presents several factors, related to both the host and the vaccine, which may result in inadequate protection from clinical disease following vaccination. Also presented is an overview of adverse reactions to vaccines and the response of young animals and pregnant animals to vaccination.