Parasites and the Kidney — A Very Long and Tumultuous Relationship
The relationship between kidney disease and parasites dates back to ancient times. The Ebers papyrus (1550 BCE) contained the description of a “bloody urine disease” caused by a “worm” that would later be identified as schistosomiasis. Surprisingly, the papyrus also contained recommendations regarding prophylaxis and treatment of this ailment. A最近的文章published in theAmerican Journal of Kidney Diseasesreviews the evolution of the understanding of parasitic kidney disease since the origins of humanity until the latest discoveries in parasite molecular pathogenesis. Author Dr. Rashad S. Barsoum (RB), from Cairo University in Egypt, discusses his recent review with Dr. Helbert Rondon (eAJKD), eAJKD Contributor.
eAJKD:How did you become interested in parasitic kidney disease?
RB：Soon after I began practicing clinical nephrology in 1969, my colleagues and I at Cairo University and the Naval American Research Unit (NAMRU)-3 in Cairo encountered several cases of a full-blown nephrotic syndrome in patients with hepatosplenic schistosomiasis. This disease typically spares the urinary tract. We obtained kidney biopsies from these patients and found histologic lesions similar to those reported by Brazilian investigators. Our group published several papers on glomerulonephritis in hepatosplenic schistosomiasis, particularly when associated with salmonellosis—a well-known co-morbidity. We later identified a pathogenetic link, established a role of impaired hepatic macrophage function, and implicated Th2 cytokines, particularly IL-10, in the disease process. Finally, we put together a histopathologic classification system of the different glomerular lesions in hepatosplenic schistosomiasis, and correlated them with clinical features and prognosis.
eAJKD:Why is this topic important? Can you comment on the importance of these diseases for physicians in Western countries where they are not frequently seen in clinical practice?
RB：According to the World Health Organization (WHO), one in four individuals living on our planet is infected with one or more parasites. Literally, hundreds of millions are infected, and millions die every year as a direct result of those infections. The prevalence of acute kidney injury (AKI) due to malaria is 10 fold that of all other causes of AKI. Eighty percent of chronic kidney disease (CKD) patients in the world live in areas endemic for parasitic disease with these infections the cause of their kidney disease in an appreciable, yet imprecisely identified, frequency. Colleagues in the West are not commonly aware of the magnitude of this health problem, largely because of the containment of parasitic diseases in Africa, India, South-East Asia, and Central and South America. However, more and more parasitic diseases are being seen in the industrialized world owing to immigration of infected patients and vectors and exposure of Western populations through tourism and ex-partite appointments. Furthermore, the impact of parasitic infection has been seriously magnified by the growing immunocompromised populations including those with HIV infection, malignancy, and immunosuppression for organ transplantation. While many parasites share this scenario, my article is focused only on those which seem to cause the highest morbidity, both in endemic areas and in Western communities.
RB：I have conventionally classified the evolution of our knowledge in this area into 4 stages: a) Ancient scripts, drawings, and embossments dating to about 2500 BCE in Egyptian, Sumerian, Assyrian, Indian, Nok, and other civilizations, followed many centuries later by documentation of the clinical syndromes associated with relevant parasitic diseases by Greek, Roman, and Byzantine philosophers; b) discovery of the causative agents and life cycles during the 19th century; c) discovery of the kidney manifestations of such infections during the 20th century; and d) appreciation of the impact of co-infection with multiple parasites, bacteria, and viruses around the turn of the millennium.
eAJKD:Can you comment on the epidemiology of parasitic kidney disease in Africa and Asia? Is parasitic kidney disease identified as an important cause of CKD or end-stage renal disease in these geographical areas?
eAJKD:我们如何建立因果关系之间的寄生在fection and a specific pattern of kidney disease (i.e., glomerulonephritis) beyond a simple temporal relationship?