title: Detection of histidine rich protein & lactate dehydrogenase of Plasmodium falciparum in malaria patients by sandwich ELISA using in-house reagents.
abstract: OBJECTIVE
  Despite major control efforts, malaria remains a major public health problem that still causes high mortality rate worldwide especially in Africa and Asia. Accurate and confirmatory diagnosis before treatment initiation is the only way to control the disease. The present study was undertaken to develop reagents using sandwich ELISA for simultaneous detection of PfHRP2 (Plasmodium falciparum histidine rich protein) and PfLDH (P. falciparum lactate dehydrogenase) antigens in the proven malaria cases.
  
  
  METHODS
  The antibodies were raised against two epitopes of PfHRP2 protein and three unique and unexplored epitopes of PfLDH protein. These antibodies were able to detect PfHRP2 and PfLDH antigens in culture supernatant and parasitized RBC lysate of P. falciparum, respectively up to 50 parasites/μl. The in-house reagents were tested in 200 P. falciparum positive patients residing in Baghpat district of Uttar Pradesh in northern India.
  
  
  RESULTS
  Microsphere (PLGA) with CpG ODN were used to generate high titre and high affinity antibodies against selected peptides of PfHRP-2 and pLDH antigen in mice and rabbit. The peptide specific peak titre varied from 12,800 - 102,400 with an affinity ranging 0.73 - 3.0 mM. The indigenously developed reagents are able to detect PfHRP2 and PfLDH antigens as low as 75 parasites/μl of blood with a very high sensitivity (96-100%) and specificity (100%).
  
  
  CONCLUSIONS
  The study highlight the identification of unique epitopes of PfHRP2 and PfLDH, and the generated antibodies against these antigens were used for quantitative estimation of these two antigens using sandwich ELISA. No corresreactivity with P. vivax infected patients was observed with the sera.
authors: Priyanka
authors: P
authors: Verma
authors: Sukla
authors: S
authors: Biswas
authors: Teena
authors: T
authors: Mohan
authors: Shakir
authors: S
authors: Ali
authors: Department of Biochemistry, All India Institute of Medical Sciences, New Delhi, India.
authors: D N
authors: DN
authors: Rao
mesh_terms: D000818:Animals; D000941:Antigens; D000953:Antigens, Protozoan / Q000302:isolation & purification*; D004797:Enzyme-Linked Immunosorbent Assay; D000939:Epitopes / Q000276:immunology; D006801:Humans; D007194:India; D045022:Lactate Dehydrogenases / Q000302:isolation & purification*; D016778:Malaria, Falciparum / Q000175:diagnosis* / Q000276:immunology / Q000469:parasitology; D051379:Mice; D010963:Plasmodium falciparum / Q000302:isolation & purification* / Q000472:pathogenicity; D015800:Protozoan Proteins / Q000302:isolation & purification*; D011817:Rabbits
chemical_list: D000941:Antigens; D000953:Antigens, Protozoan; D000939:Epitopes; C514457:HRP-2 antigen, Plasmodium falciparum; D015800:Protozoan Proteins; D045022:Lactate Dehydrogenases