en Infectious diseases and public health Infectious diseases and public health Original article Original article <strong>Introduction</strong>: A simple and sensitive diagnosis method is needed to identify HIV infection in sera of untreated, treated, and drug-resistant patients. The purpose of this study is to determine whether heat shock proteins (Hsp)-27 and -20 and HP91 peptide along with HIV-1 polypeptides can serve as potential biomarkers to distinguish HIV infection in untreated, treated, and drug-resistant individuals compared to HIV-negative subjects. <strong>Methods</strong>: At first, human sera were obtained from 141 participants, including 20 na&iuml;ve HIV-infected, 71 treated, 30 drug-resistant, 20 HIV-negative (healthy/control) individuals. The recombinant Hsp27, Hsp20, and five designed HIV-1 polypeptides were expressed in <em>Escherichia coli</em> and purified by affinity chromatography under denaturing or native conditions. Finally, the antibodies against these antigens were quantified in sera using ELISA. <strong>Results</strong>: Our data showed that HIV-infected patients significantly displayed higher serum levels of anti-Hsp27, anti-HP91, and anti-Nef-Tat-Gp160-P24, anti-Nef-Vpr-Gp160-P24, anti-Nef-Vif-Gp160-P24, anti-Nef-Vpu-Gp160-P24, and anti-Nef-Rev-Gp160-P24 polypeptide antibodies than healthy groups (<em>p </em>< 0.05), but not for anti-Hsp20. Moreover, the serum levels of antibodies against Hsp27, Hsp20, HP91, and HIV-1 polypeptides were not statistically significant between different groups of patients (<em>p</em> > 0.05). <strong>Conclusion</strong>: The levels of anti-Hsp27 and anti-HP91 antibodies in serum increased in HIV-1 seropositive subjects along with antibodies against five HIV-1 polypeptides suggesting their potential value as a diagnostic marker for HIV-1 infections. HIV-1 proteins, Heat shock proteins, HP91 peptide, Antibody detection 113 104 http://jommid.pasteur.ac.ir/browse.php?a_code=A-10-123-6&slc_lang=en&sid=1 Alireza Milani 0000-0003-4931-2753 No Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran Kazem Baesi kbaesi@gmail.com 0000-0001-5483-0008 No Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran Elnaz Agi 0000-0003-3587-2952 No Iranian Comprehensive Hemophilia Care Center, Tehran, Iran Azam Bolhassani azam.bolhassani@yahoo.com 0000-0001-7363-7406 Yes Department of Hepatitis and AIDS, Pasteur Institute of Iran, Tehran, Iran