“Proteomics” refers to the systematic analysis of proteins. It complements other “omics” technologies such as genomics and transcriptomics in elucidating the identity of proteins of an organism, and understanding their functions. Proteomics is used in many areas of research such as discovery of markers for diagnosis and vaccine candidates, understanding pathogenic mechanisms, in the study of expression patterns at different time points and in response to different stimuli, and in elucidating functional protein networks. Proteomics analysis involves sample preparation, protein separation and protein identification. The ‘heart’ of current proteomics is mass-spectrometry, with LC-MS/MS and MALDI-TOF/TOF being commonly used equipment. However, the high costs of the equipment, software, databases and the need for skilled personnel limit the wide utilization of this technology in the less developed countries. Therefore, there need to be sharing of facilities, better networking and collaborations among our scientists and laboratories to take advantage of this powerful technology.

INTRODUCTIONStrongyloidiasis is one of the most commonly neglected but clinically important parasitic infections worldwide, especially among immunocompromised patients. Evidence of infection among immunocompromised patients in Malaysia is, however, lacking. In this study, microscopy, real-time polymerase chain reaction (PCR) and enzyme-linked immunosorbent assays (ELISAs) were used to detect Strongyloides stercoralis (S. stercoralis) infection among cancer patients in a Malaysian hospital.

METHODSA total of 192 stool and serum samples were collected from cancer patients who were receiving chemotherapy with or without steroid treatment at a hospital in northeastern Malaysia. Stool samples were examined for S. stercoralis using parasitological methods and real-time PCR. Serology by ELISA was performed to detect parasite-specific immunoglobulin G (IgG), IgG4 and immunoglobulin E (IgE) antibodies. For comparison, IgG4- and IgG-ELISAs were also performed on the sera of 150 healthy individuals from the same area.

RESULTSOf the 192 samples examined, 1 (0.5%) sample was positive for S. stercoralis by microscopy, 3 (1.6%) by real-time PCR, 8 (4.2%) by IgG-ELISA, 6 (3.1%) by IgG4-ELISA, and none was positive by IgE-ELISA. In comparison, healthy blood donors had significantly lower prevalence of parasite-specific IgG (2.67%, p < 0.05) and IgG4 (2.67%, p < 0.05) responses.

CONCLUSIONThis study showed that laboratory testing may be considered as a diagnostic investigation for S. stercoralis among immunocompromised cancer patients.

Adolescent ; Adult ; Aged ; Aged, 80 and over ; Animals ; Antibodies, Helminth ; blood ; Child ; Child, Preschool ; Cross-Sectional Studies ; Enzyme-Linked Immunosorbent Assay ; Female ; Healthy Volunteers ; Hospitalization ; Humans ; Immunocompromised Host ; Immunoglobulin E ; blood ; Immunoglobulin G ; blood ; Malaysia ; Male ; Middle Aged ; Neoplasms ; complications ; parasitology ; Real-Time Polymerase Chain Reaction ; Strongyloides stercoralis ; Strongyloidiasis ; blood ; complications ; diagnosis ; Young Adult

Objective: To determine the true prevalence of soil-transmitted helminth infections in the Malaysian aborigines using real-time PCR. Methods: A total of 122 aborigines from seven tribes were recruited from settlements and nearby hospitals which served the communities, located in four states in Peninsular Malaysia. The stool samples were examined for the presence of soil-transmitted helminth using real-time PCR and microscopy. The latter included the direct wet mount and formalin-ether concentration technique (FECT). The infection load in FECT-positive samples was determined by the Kato-Katz method. Rotorgene real-time analyzer detected five helminth species using two sets of assays. Results: The real-time PCR detected soil-transmitted helminth in 98.4% samples (n=122), which were 1.56 times higher than by microscopy. Ascaris lumbricoides and Trichuris trichiura were detected in more than 90% of the samples, while hookworm was detected in 46.7% (Necator americanus) and 13.9% (Ancylostoma sp.) of the samples. Comparison with previous reports on the Malaysian aborigines showed that the real-time PCR markedly improved the detection of Ascaris lumbricoides, hookworm and Strongyloides stercoralis. The real-time PCR detected poly-helminths in 92.6% of the samples compared to 28.7% by microscopy. In addition, 27 samples (22.1%) showed amplification of Strongyloides stercoralis DNA. Conclusions: The real-time PCR showed very high prevalence rates of soil-transmitted helminth infections in the aborigines and is the recommended method for epidemiological investigation of soil-transmitted helminth infections in this population.