Background and aims Recent studies revealed that intracellular chaperones, heat shock protein 70 kD family (constitutive Hsc70 and inducible Hsp70), may have specific role in brain development when they released into extracellular compartment (eHsc70 and eHsp70) since neurons and glial cells can take them up from blood circulation. The assessment of atypical brain development in high risk children require more precise quantitative developmental quotient (DQ) measures than qualitative categorical outcomes. The aim of this study was to determine the correlation between the expression of circulating eHsc70 and eHsp70 and the DQ in children who were born preterm.

Methods A total of 21 eligible preterm infants were studied prospectively. The expression of eHsc70, eHsp70 and eHsc+p70 (eHsc70+eHsp70) was determined on the basis of blood samples taken from umbilical artery at birth. The DQ was assessed using The Cognitive Adaptive Test/Clinical Linguistic and Auditory Milestone Scale (CAT/CLAMS) at the corrected age of 18 months; it was expressed as CAT-DQ, CLAMS-DQ and Full Scale (FS)-DQ. Statistical analysis using correlation test, with p < 0.05 being considered significant.

Results Individual expression of eHsc70 and eHsp70 was not correlates with either CAT-DQ, CLAMS-DQ or FS-DQ. However, simultaneously expression of eHsc+p70 correlates significantly with CAT-DQ (r = 0.470; p = 0.031), CLAMS-DQ (r = 0.509; p = 0.018) and FS-DQ (r = 0.496; p = 0.022).

Conclusions This study supports the concept that circulating eHsc70 and eHsp70 at birth may have specific effects in brain development when they were expressed simultaneously. Possibly these proteins may function as a marker for cellular intervention in preterm-born children who show abnormal DQ.