Detection of histidine rich protein & lactate dehydrogenase of Plasmodium falciparum in malaria patients by sandwich ELISA using in-house reagents.

Background & objectives: 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%). Interpretation & 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.

Success of antiviral therapy in chronic hepatitis C infection relates to functional status of myeloid dendritic cells.

The pure recombinant and synthetic antigens used in modern day vaccines are generally less immunogenic than older style live/attenuated and killed whole organism vaccines. One can improve the quality of vaccine production by incorporating immunomodulators or adjuvants with modified delivery vehicles viz. liposomes, immune stimulating complexes (ISCOMs), micro/nanospheres apart from alum, being used as gold standard. Adjuvants are used to augment the effect of a vaccine by stimulating the immune system to respond to the vaccine, more vigorously, and thus providing increased immunity to a particular disease. Adjuvants accomplish this task by mimicking specific sets of evolutionary conserved molecules which include lipopolysaccharides (LPS), components of bacterial cell wall, endocytosed nucleic acids such as dsRNA, ssDNA and unmethylated CpG dinucleotide containing DNA. This review provides information on various vaccine adjuvants and delivery vehicles being developed to date. From literature, it seems that the humoral immune responses have been observed for most adjuvants and delivery platforms while viral-vector, ISCOMs and Montanides have shown cytotoxic T-cell response in the clinical trials. MF59 and MPL® have elicited Th1 responses, and virus-like particles (VLPs), non-degradable nanoparticle and liposomes have also generated cellular immunity. Such vaccine components have also been evaluated for alternative routes of administration with clinical success reported for intranasal delivery of viral-vectors and proteosomes and oral delivery of VLP vaccines.

Current practices in laboratory monitoring of HIV infection.

After a diagnosis of HIV infection is made, the patient needs to be monitored using both clinical assessment and laboratory markers. HIV/AIDS monitoring is essential in guiding when to recommend initiation of therapy. Clinical monitoring will include staging of the HIV/AIDS disease using either the presence or absence of HIV-related signs and symptoms using the WHO staging system. Various laboratory methods can be used to monitor the disease progression and to guide whether the patient will need antiretroviral therapy or not. Laboratory monitoring for patients who are not on drugs is done to provide information about the stage of illness; to enable the clinician to make decisions on treatment and to give information on prognosis of the patient. Patients on drugs are monitored to assess their response to treatment with antiretroviral drugs and to detect any possible toxicity and improvement associated with the antiretroviral drugs.