Background and Aims

Heat shock protein 70 (HSP-70) is an important part of the intracellular defense system and provide an important immunoregulatory function. Failure of this function may occur in chronic glomerulonephritis (CGN).

Aim was to evaluate HSP70 levels in the urine and renal tissue and the anti-HSP70 antibody levels in CGN.

Methods

76 patients with CGN patients were included: 10 patients with mild proteinuria (<1.0 g/day) and 10 healthy subjects. 34 active CGN with proteinuria >1.0g/day (I group), 42 with nephrotic syndrome (II group). Urinary levels of HSP70, IL10, and serum levels of anti-HSP70 were measured by ELISA. The immunohistochemical peroxidase method was used to study the expression of HSP70 and Foxp3+ in kidney biopsies.

Results

Median urinary HSP70 levels in patients with nephrotic syndrome (NS) group II and group I were higher than in positive and negative controls. Hsp-70 levels in the urine in group II - significantly higher than in group I. HSP70 expression index in tubular cells positively correlated with urinary HSP70 and proteinuria. The number of Treg ^Foxp3+ cells in the kidney interstitium and interleukin-10 excretion were decreased in patients with NS. Anti-HSP70 antibodies serum levels in patients of group II and group I were significantly higher than in positive and negative controls.

Conclusions

Hsp70 urinary and tissue levels increased in patients with active CGN. However, activation of HSP70 did not lead to an increase in tissue levels of Treg^Foxp3+ cells or release of IL-10. These data may indicate an impaired anti-inflammatory function of HSP70 in patients with a severe nephropathy.