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Urmila Anandh @AnandhUrmila

Urmila Anandh is a senior consultant and head of nephrology in Yashoda Hospitals and is part of a large multiorgan transplant unit. Her area of interests include diabetic kidney disease, transplantation, and critical care nephrology.

Competitors for the Parasites Region

Malaria vs Leishmaniasis

Schistosomiasis vs Filariasis

Copyright: Kateryna Kon / Shutterstock

Parasites (aka moochers) are organisms which thrive in another organism. The phenomenon of parasitism is as old as life on earth. Based on the parasite, its host, and the environment, the parasite can either be “benign” or can cause life-threatening illness. This ambiguity in their impact on human health perhaps makes us overlook these sinister organisms. And secondly, they move around mostly in remote parts of the world (mostly in low and low-medium income countries), and hence, mostly away from social media glare!

But the 4 parasites in contention are no pushovers: when they infect a human host, they cause life-threatening acute kidney injury (malaria), progressive disease leading to malignancy (schistosomiasis), progressive chronic kidney disease and debility (leishmaniasis), and progressive disfigurement (filariasis). Not to mention they inhabit major chunks of the world.

Table 1: Relative Impact of Malaria, Leishmaniasis, Schistosomiasis, and Filariasis

AUA: Asymptomatic Urinary Abnormalities; AKI: Acute Kidney Injury; AGN: Acute Glomerulonephritis; NS: Nephrotic Syndrome; CKD: Chronic Kidney Disease; + seen occasionally, ++ seen sometimes, +++ common manifestation

By their sheer global outreach and impact on humans, malaria is by far the most dangerous. Even though schistosomiasis is prevalent in equally large parts of the world, the renal injury and mortality in malaria is more consequential as far as human health is concerned.

This year’s NephMadness Parasites Region is well-represented by four significant players. The renal involvement is myriad in all these four parasites and in this the malarial parasite top in their ability to cause severe acute kidney injury (AKI). AKI in malaria is multifactorial – see figure below:

Infographic by @nephromythri adapted from da Silva, Junior, et al

The combination of hemodynamic instability, intravascular coagulation, and an abnormal immune response makes malarial AKI (MAKI) a difficult to manage clinical condition. Dialysis is required in about 40-70% of MAKI cases and about 60% show renal recovery. This leads to the concern of progressive chronic kidney disease in MAKI patients. Malaria was also the first parasite infection which was shown to be associated with glomerular disease. Immune complex glomerulonephritis (GN) is a common phenomenon with P.malariae infection. It is important also to realize that the treatment of malaria is very cost-intensive, making the parasite a double whammy in resource-challenged areas of the world.

The next player of significance is as different from malaria as chalk is from cheese, but no less menacing. Schistosomiasis invades the human host and causes chronic life-threatening illnesses. Intestinal schistosomiasis is responsible for chronic liver disease which itself is a risk factor for AKI. Renal involvement is most common in S.hematobium which leads to both glomerular and urinary tract involvement. Direct glomerular injury is because of immune complex deposition containing S.hematobium and S.mansoni worm antigens. Glomerular involvement can be in the form of mesangioproliferative GN, focal segmental glomerulosclerosis (FSGS), membranous nephropathy (MN), and membranoproliferative GN (MPGN). Exudative proliferative GN is seen with co-existent salmonella infection. Amyloidosis is noted after prolonged chronic infection. The pathophysiology of the glomerular involvement is given in the figure below. Most of the chronic sequelae are irreversible leading to end-stage kidney disease (ESKD).

Infographic by @nephromythri based on information from Barsoum

The major concern is the S.hematobium involvement of the urinary tract. Bladder involvement is common manifesting as hematuria and dysuria. Polyps, bladder wall nodularity, ulceration scarring, and calcification of the bladder wall ensues over a period of time. The scarred low-capacity bladder is complicated with the development of vesico-ureteric reflux, hydronephrosis, acute pyelonephritis, and rarely, chronic kidney disease. It is very important to note that the bladder lesions are precancerous. Vesical cancer is a dreaded complication of long-standing S.hematobium infection.

Safe effective treatment and extensive chemoprophylaxis programs in endemic areas has reduced the prevalence and mortality associated with schistosomiasis.

The other two players in the parasite region are no less treacherous, but usually perceived as the “lesser among the equals” in the kidney community. This is mostly because the systemic involvement of both leishmaniasis and filariasis far overshadows their renal involvement. Still, a nephrologist needs to be informed about these “exotic” parasitic illnesses and their therapy.

Parasites causing renal injury teams are long overdue in being featured in NephMadness and I strongly believe that the nephrology community should offer them their due recognition as deserved. These players continue to create havoc and their voices are subdued and don’t reach “people who matter” as they reside in resource-constrained settings of the world. Emphasis of their role in renal injury will go a long way in alleviating the misery of those less fortunate worldwide.

– Guest Post written by Urmila Anandh @AnandhUrmila

As with all content on the AJKD Blog, the opinions expressed are those of the author of each post, and are not necessarily shared or endorsed by the AJKD Blog, AJKD, the National Kidney Foundation, Elsevier, or any other entity unless explicitly stated.

Click to read the full Parasites Region

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