Detection of Urinary Antibodies and Its Application in Epidemiological Studies for Parasitic Diseases

Abstract

For epidemiological studies of infectious diseases, pathogen-specific antibody levels in an area give us essential and appropriate information. The antibodies against pathogens are usually detected in blood, the drawing of which inconveniences people. Collection of blood increases the risk of accidental infections through blood, and it is difficult to obtain the participation of the target populations, especially the younger generation. On the other hand, urine samples, which contain a high enough level of antibodies for ELISA, can be harmlessly and easily collected and therefore have been used for epidemiological studies for diseases. The antibody examination of urine has been used for the epidemiology of parasitic diseases with a high sensitivity and specificity of serum samples. In this paper, we reviewed antibody assays with urine for seven parasitic diseases that urine diagnostic methods have reported in the past, and these are important infections included in NTDs, caused, for example, by Leishmania donovani, Wuchereria bancrofti, Schistosoma japonicum, Paragonimus westermani, Echinococcus granulosus, Echinococcus multilocularis, Strongyloides stercoralis, and Opisthorchis viverrini. The easy and safe urine surveillance system might be an admirable tool for future epidemiological studies for infectious diseases.

Detecting anti–SARS-CoV-2 antibodies in urine samples: A noninvasive and sensitive way to assay COVID-19 immune conversion

“…When the effect of the timing of urine collection was studied for Wuchereria bancrofti infection, with urine collections in the early morning and later throughout the day, only a small fluctuation in antibody units was observed and all samples remained positive ( 33 , 34 ). In a urine-based ELISA study conducted for H. pylori , it was observed that the urine water content influenced the concentration of antibody in urine; however, the performance of the qualitative assay on post-fasting urine correlated well with those of serum samples ( 33 , 35 ). Various features of urine, beyond retention time, could influence signal strength relative to serum and deserve future investigation.…”

“…Changes in urine pH and the presence of microorganisms had no significant effect on the absorbance value of the H. pylori urine-based ELISA. Moreover, sodium azide is commonly added to prevent changes in urine pH resulting from contamination and growth of bacteria ( 33 , 35 ). Patients with significant proteinuria should be tested with caution as demonstrated for the H. pylori urine-based ELISA ( 35 ).…”

“…It would be important in a future study to determine and fix retention time, as well as for its use in clinical practice. When the effect of the timing of urine collection was studied for Wuchereria bancrofti infection, with urine collections in the early morning and later throughout the day, only a small fluctuation in antibody units was observed and all samples remained positive (33,34). In a urinebased ELISA study conducted for H. pylori, it was observed that the urine water content influenced the concentration of antibody in urine; however, the performance of the qualitative assay on post-fasting urine correlated well with those of serum samples (33,35).…”

Wastewater as a back door to serology?

“…12 However, human antibodies shed in urine and feces have not been targeted as a biomarker in wastewater. Fecal antibody levels are correlated with antibody levels in serum 13 , and antibodies have frequently been demonstrated as a potential biomarker for detection of viral 14 and parasitic infections 15 in human urine samples. Antibody measurements from fecal samples have been highlighted as a non-invasive means to rapidly monitor the immune status of wildlife 16 , and similar measurements are increasingly being used for studying various aspects of human health 17,18 .…”

Diagnostic performance of a urine-based ELISA assay for the screening of human schistosomiasis japonica: A comparative study

“…In contrast, urine-based diagnostic tests involve convenient and completely non-invasive urine sampling, with the limited chance of participants being exposed to biological risks. Previously, urine-based ELISA assays have been suggested as a possible alternative tool to diagnose a number of parasitic helminthiases such as echinococcosis, filariasis, opisthorchiasis, and schistosomiasis ( Itoh et al, 2001 , 2003 ; Sunita et al, 2007 ; Sawangsoda et al, 2012 ; Samad et al, 2013 ; Chirag et al, 2015 ; Eamudomkarn et al, 2018 ; Nagaoka et al, 2021 ; Chungkanchana et al, 2022 ). In this study, we aimed to validate a urine-based SjSAP4 + Sj23-LHD-ELISA assay for the diagnosis of S. japonicum infection in a human cohort recruited from areas in the Philippines moderately endemic for schistosomiasis japonica.…”