Cystatin C levels in bronchial asthma variants

Mineev V.N., Vasilieva T.S., Galkina O.V., Trofimov V.I.

I.P. Pavlov State Medical University, Saint-Petersburg, Russia

Introduction. The possibility of chronic kidney disease (CKD) development in asthma patients was previously shown using an assessment of the glomerular filtration rate. It has been demonstrated that cystatin C can be considered as an indicator of glomerular filtration rate, however, the results of using cystatin C as a predictor of possible CKD development in bronchial asthma are not clear and require further research.

The aim of the study is to determine serum cystatin C levels in different variants of asthma and to compare them with clinical, functional, and laboratory parameters characterizing bronchial asthma and CKD.

Patients and methods.A total of 52 asthma patients were examined (30 patients with allergic variant of asthma, 22 patients with non-allergic variant). Glomerular filtration rate (eGFR) was calculated using CKD-EPI. The concentration of cystatin C in blood serum was determined by immunoturbidimetry, using a reagent kit for the determination of specific proteins "Cystatin C FS" (Diasys, USA).

Results. It was established that the serum cystatin C level was within normal values in both bronchial asthma variants, and the average eGFR values were significantly lower in nonallergic variant compared to allergic variant of asthma.

A significant inverse correlation between cystatin C and eGFR levels was revealed only in the nonallergic variant of asthma. Correlation analysis allowed to reveal inverse correlation of cystatin C levels and a number of indices of external respiratory function, first of all, with velocity indices (MEF50, MEF75). Multidirectional correlation of cystatin C level with the level of total IgE was established: direct correlation in allergic variant and inverse correlation in nonallergic variant of bronchial asthma. Besides, direct correlation between cystatin C level and a course dose of parenteral glucocorticoid medication was revealed.

Conclusion. The data obtained suggest that evaluation of cystatin C level as an indicator of GFR in bronchial asthma seems to be reasonable only in non-allergic variant of the asthma.