Clinical Features of Acute Respiratory Viral Infections in Infants with Thymomegaly

Abstract

Introduction. Peculiarities of acute respiratory viral infections (ARVI) in children with increased size of the thymus are associated with the presence of more or less significant immunodeficiency and dyshormonosis with manifestations of adrenal insufficiency. Objective — to study the features of acute respiratory viral infections and to investigate adrenal function in infants with thymomegaly. Material and methods. 41 children aged 1 month to 3 years with thymomegaly and complicated forms of ARVI were involved in clinical studies. Etiological decoding of ARVI has been carried out with the use of paired serum samples. The content of cortisol in the blood plasma was determined by immunoenzyme method. 36 children with thymomegaly without ARVI manifestations within at least 3 months were in comparison group. Results. Analysis of the anamnesis in patients with thymomegaly showed that most of them experienced adverse conditions at different stages of antenatal, intrapartum and postnatal development. Analysis of the data on the size of the thymus gland showed that 3rd — 4th degree of thymomegaly is often observed in children with signs of constrictive laryngotracheitis (75.0 %). 23.5 % of patients with obstructive bronchitis had 1st degree thymomegaly, the rest — 3rd and 4th degrees. In case of nonobstructive lesions of the bronchi, the opposite trend took place: the least degree of thymomegaly was diagnosed in 62.5 %, and 3rd and 4th — in 37.5 % (p < 0.05) of patients. The lowest supply of cortisol was noted in the acute period of constrictive laryngotracheitis (409.4 ± 10.2 nmol/ml against 537.7 ± 11.5 nmol/ml in the comparison group; p < 0.05). In the acute period of ARVI complicated by bronchitis, cortisol levels were not increased — 432.3 ± 32.3 nmol/ml. In the group of patients with pneumonia, we have recorded reliable, probably compensatory increase of cortisol level (787.3 ± 2.0 nmol/ml, p < 0.05). In the acute period of obstructive bronchitis, only tendency towards increasing of cortisol concentration in the blood (562.9 ± 18.9 nmol/ml) was observed. Restoration of adrenocortical function during recovery of infants with thymomegaly was inhomogeneous too. Parameters of children who recovered from acute bronchitis were most significantly closer to physiological parameters. Cortisol supply in patients with pneumonia at the time of recovery did not differ from baseline in children with thymomegaly. The amount of cortisol increased fastest in the dynamics of constrictive laryngotracheitis (up to 528.5 ± 22.6 nmol/ml). Conclusion. Children with thymomegaly are at risk for the development of bronchopulmonary complications of acute respiratory viral infections.

Keywords

• acute respiratory viral infections
• children
• thymomegaly