Leptospira infection- potential cause of chronic kidney disease of uncertain etiology

"The study's findings, published in the Karger journal Nephron, showed that at least some serovars of Leptospira can lead to CKDu in endemic leptospirosis areas," the researchers wrote. "Leptospirosis is common among agricultural communities, suggesting the association of this infection as a risk factor for CKDu occurrence."

Chronic kidney disease of uncertain etiology is an environmental nephropathy in which etiological factors are not sure. Leptospirosis is a spirochetal infection which is common among agricultural communities. It has been identified as a potential etiology for CKDu beyond environmental nephropathy.

In endemic regions, an increasing number of cases are reported with features indicative of interstitial nephritis without any known reason, with or without background chronic kidney disease, despite CKDu being a chronic kidney disease. Chih-Wei Yang, Chang Gung University, Taoyuan, Taiwan, and colleagues hypothesized that exposure to pathogenic leptospires is one of the causative factors for the occurrence of AINu.

The study included 59 clinically diagnosed AINu patients, 72 healthy controls from the CKDu endemic region (endemic controls [ECs]), and 71 healthy controls from the non-endemic areas of CKDu (non-endemic controls [NECs]).

The authors reported the following findings:

• The seroprevalence of 18.6, 6.9, and 7.0% was observed in the AIN (or AINu), EC, and NEC groups, respectively, from the rapid IgM test.
• Among 19 serovars tested, the highest seroprevalence was observed at 72.9, 38.9, and 21.1% in the AIN (AINu), EC, and NEC groups, respectively, by microscopic agglutination test (MAT), particularly for serovar Leptospira santarosai serovar Shermani. This emphasizes the presence of infection in AINu patients and suggests that Leptospira exposure might play an essential role in AINu.

Exposure to Leptospira infection could be one of the crucial factors for the AINu occurrence.

The authors wrote, "considering the low awareness of exposure to Leptospira among the study groups (3%),... "we propose that leptospirosis may be an underdiagnosed disease in Sri Lanka, specifically in areas with high CKDu incidences and confirmatory tests are not widely available.

"Further studies and prospective studies need to be carried out for the early diagnosis of leptospirosis and to identify the associations between leptospirosis and CKD/CKDu," they concluded.

Reference:

Premarathne SS, Gamage C, Chandrajith R, Ratnatunge NV, Wijetunge S, Wazil A, Chou LF, Ko YC, Huang CT, Yang HY, Fonseka A, Sonnadara T, Herath D, Hewavitharane P, Yang CW, Nanayakkara N. Leptospirosis: A Potential Culprit for Chronic Kidney Disease of Uncertain Etiology. Nephron. 2023 Feb 21:1-10. doi: 10.1159/000528703. Epub ahead of print. PMID: 36809758.