BADURDEEN, Z*1 , Ratnatunga, N2 , Abeysekera, T3 , Wazil, A4 , Gunerathne, L5 , Nishantha, N4
1 Faculty of Medicine- University of Peradeniya. Center for Education Research and Training on Kidney Diseases CERTKiD Kandy Sri Lanka, 2 Faculty of Medicine- University of Peradeniya Pathology Kandy Sri Lanka, 3 Faculty of Medicine- University of Peradeniya- Center for Education Research and Training on Kidney Diseases CERTKiD Kandy Sri Lanka, 4 Teaching Hospital- Kandy Renal Transplant and Dialysis Unit- Kandy Sri Lanka, 5 District Hospital- Giradurukotte Renal Unit Giradurukotte Sri Lanka.
Introduction: The epidemics of chronic kidney disease of uncertain etiology (CKDu) are affecting agricultural communities living in Tropical countries. This is a primary tubulointerstitial disease presenting with minimal proteinuria. CKDu cases either present with end stage renal failure or asymptomatic cases detected at screening. Despite, an acute presentation of CKDu have been reported from Sri Lanka and Nicaragua. Renal biopsies of acute CKDu cases have been described as an acute interstitial nephritis (AIN) (1, 2).
Ultrasound (US) is a convenient tool to estimate kidney size and parenchyma in renal diseases. US bipolar length of kidney (BPL) is clinically reliable and well correlate with renal function (3). Nadeeshani S. et al (2015) reported that mean kidney length of 285 healthy adult farmers with mean age 44 years and normal renal function (no proteinuria and GFR >60ml/min/1.73m2) from CKDu endemic region of Sri Lanka is 9.83( 1.49) cm for males and 9.46 ( 1.63) cm for females. Though small kidneys are routinely encounter in patients with CKDu, progressive changes of kidney size are not evaluated. 1. Badurdeen Z, Nanayakkara N, Ratnatunga NV, Wazil AW, Abeysekera TD, Rajakrishna PN, et al. Chronic kidney disease of uncertain etiology in Sri Lanka is a possible sequel of interstitial nephritis! Clinical nephrology. 2016;86(7):106. 2. Fischer RS, Vangala C, Truong L, Mandayam S, Chavarria D, Llanes OMG, et al. Early detection of acute tubulointerstitial nephritis in the genesis of Mesoamerican nephropathy. Kidney international. 2018;93(3):681-90. 3. Meola M, Samoni S, Petrucci I. Imaging in chronic kidney disease. Ultrasound Imaging in Acute and Chronic Kidney Disease. 188: Karger Publishers; 2016. p. 69-80.
Methods: We reviewed the clinic records of CKDu cases who were continuum of acute (AIN) to chronic CKDu, followed up in the Nephrology unit in Kandy, Sri Lanka from 2012 to 2017. Biopsy proven AIN cases that is not attributable to any traditional risk factors from CKDu endemic regions were selected. Out of these patients, who had been reviewed with repeat US scan, at 36 months since first diagnosis were included. US scans were done by Nephrologist who is well trained and experienced in renal ultrasonography. Measurements were taken from a single machine placed in the clinic. Patients’ clinical data were retrieved with ethical approval.
Results: There were 45 cases who full filled inclusion criteria. One post renal transplant case was excluded. Patients’ clinical profile at acute presentation (AIN) is depicted in table 1. At 36 months, number of cases according to CKD stage were 3 stage-I, 13 stage-ii, 24 stage-iii and 4 stage-iv. Mean bipolar length (M-BPL) of kidneys were reduced from 9.6(0.7) cm at acute presentation to 8.7(0.8) cm at 36 months of follow up, P¼0.00 (95%CI: 0.60-1.03). The correlation between MBPL and mean serum creatinine (MSCr) at 36 months was -0.4 with p¼0.005. Serial changes of MSCr and MBPL are graphically illustrated in image 1
Conclusions: In CKDu, kidneys may shrink significantly in early stages of the disease. Clinicians may encounter difficulties to perform renal biopsies when indicated even in early stages of CKD, to rule in patients with CKDu.