**5. Malaria antigen detection tests**

There are currently over twenty (20) such tests commercially available (WHO product testing, 2008) and these consist of a group of commercially available tests that allow rapid diagnosis of malaria by unskilled laboratory traditional techniques. The first malaria antigen suitable as target for Rapid Diagnostic Tests (RDTs) was a soluble glycolytic enzyme, Glutamate dehydrogenase. None of the current tests is as sensitive as a thick blood film. A major drawback in the use of all dipstick methods is that the result is essentially qualitative. In many endemic areas of tropical Africa; however, the quantitative assessment of parasitemia is important as a large percentage of the population will test positive. An accurate diagnosis of malaria is becoming more and more important in view of the increasing resistance of *Plasmodium falciparum* and the high price of alternatives to chloroquine. The enzyme pGluDH (parasite Glutamate Dehydrogenase) does not occur in the host red blood cells and was regarded as a marker enzyme for Plasmodium species. The malaria marker enzyme test is suitable for routine work and it's now a standard in most nations afflicted with malaria. The presence of pGluDH is known to represent parasite viability, and a rapid diagnostic test using pGluDH as antigen would have the ability to differentiate live and dead organisms. It is possible to note that a complete RDT with pGluDH as antigen has been developed in China. Glutamate dehydrogenases are ubiquitous enzymes that occupy an important branch point between carbon and nitrogen metabolisms. Both nicotinamide adenine dinucleotide[ (NAD)EC 1.4.1.2] and nicotinamide adenine dinucleotide phosphate (NADP) dependent GluDH [EC1.4.1.4] enzymes are present in plasmodia. The NAD-dependent GluDH is relatively unstable and not useful for diagnostic purposes. Glutamate dehydrogenase provides an oxidizable carbon source used in production of energy as well as a reduced electron carrier, NADH. Glutamate is a principal donor to other amino acids in subsequent transamination reactions. The multiple roles of glutamate in nitrogen balance, make it a gateway between free ammonia and the amino groups of most amino acids. The GluDH activity in *P. vivax*, *P.ovale* and *P. malariae* has been tested, but given the importance of GluDH as a branch point enzyme, every cell must have a high concentration of GluDH. It is well known that enzymes with high molecular weights like GluDH have many isoenzymes which allow strain differentiation (given the right monoclonal antibody).The host produces antibodies against the parasite enzyme, indicating a low sequence identity.

168 Dehydrogenases

and invasiveness.

diagnosis against microscopy.

**5. Malaria antigen detection tests** 

**Kenya** 

and cancer. Because the LDH enzymes found in *P.vivax*, *P. ovale* and *P.malariae*, all exhibit 90% identity to PfLDH; It would be desirable to have new anti-pLDH drugs particularly, ones that are effective against *P*. *falciparum*, the most virulent species of human malaria. Most invasive tumor phenotypes show a metabolic switch (Warburg effect) from oxidative phosporylation to an increased anerobic glycolysis by promoting an up-regulation of the human isoform-5 of lactate dehydrogenase (hLDH-5 or LDH-A), which is normally present in muscles and liver. Hence, inhibition of hLDH-5 may constitute an efficient way to interfere with tumor growth

**4. New enzymatic assay using parasite ldh in diagnosis of malaria in** 

The biochemical basis for this assay is on the fact that human red blood cells do not utilize APAD in the metabolism of glucose. The study subjects were of three different categories: the healthy non-infected individuals staying out of malaria endemic area( controlled GP-1).The non-symptomatic and parasitemic healthy individuals living in endemic regions (both field study –GP 2).The non-parasitemic and parasitemic symptomatic individuals living in endemic region (both clinical study Group 3).In the clinical studies, thin smear microscopy gave the highest sensitivity as 75.6 % for plasma, while the highest specificity was 71.4 %. For red blood cells, the highest sensitivity was 78.4% while specificity was 80 %. In field trials, the highest sensitivity was 89 %) using thin smear microscopy, where as the specificity was 45% for the plasma cut off, using thick smear. For red blood cells, the highest sensitivity was 79% while the specificity was 66.7%. The variations in sensitivity and specificity of this assay in comparison to microscopy is a strong indication that pLDH may even be measuring sequestered parasites that cannot be visualized by microscopy. The results of the study validates the use of pLDH as an alternative objective test for malarial

There are currently over twenty (20) such tests commercially available (WHO product testing, 2008) and these consist of a group of commercially available tests that allow rapid diagnosis of malaria by unskilled laboratory traditional techniques. The first malaria antigen suitable as target for Rapid Diagnostic Tests (RDTs) was a soluble glycolytic enzyme, Glutamate dehydrogenase. None of the current tests is as sensitive as a thick blood film. A major drawback in the use of all dipstick methods is that the result is essentially qualitative. In many endemic areas of tropical Africa; however, the quantitative assessment of parasitemia is important as a large percentage of the population will test positive. An accurate diagnosis of malaria is becoming more and more important in view of the increasing resistance of *Plasmodium falciparum* and the high price of alternatives to chloroquine. The enzyme pGluDH (parasite Glutamate Dehydrogenase) does not occur in the host red blood cells and was regarded as a marker enzyme for Plasmodium species. The malaria marker enzyme test is suitable for routine work and it's now a standard in most
