A challenging feature of MeN is that, because the pathophysiology of disease remains relatively poorly understood, the case definition remains broad and likely will include many cases of undiagnosed kidney diseases that ultimately prove to be unrelated to MeN. Recent efforts to provide a case definition have focused on the following features: * Suspected disease: * Estimated GFR (eGFR) 2 * Absence of diabetes, hypertension, autoimmune disease, glomerular disease, congenital kidney disease, obstructive kidney disease as a clear cause of kidney disease (these comorbidities may be present but cannot account for disease development) * Residing in a hotspot region * Proteinuria 2 on 3 month or longer repeat measurement * Relative hypokalemia and/or hyperuricemia * Kidney ultrasound with loss of corticomedullary differentiation or bilateral small kidney size, without cystic disease or large stone burden * Kidney biopsy showing primary tubulointerstitial disease without alternative cause of kidney disease in evidence This case definition may not be as useful for disease outside of<unk>  while there are many similarities between clinical aspects of CKDu in India, Sri Lanka, and MeN in<unk>  there are some important differences as well. Individuals affected in<unk> are younger (aged 20–40 as opposed to 20-60 at the age of onset of CKD). Both regions demonstrate a high male-to-female ratio and significant familial concordance, but the degree of male predominance appears to be greater in<unk>  Most affected individuals in both regions live in rural poverty and work in occupations involving physical labor, including agriculture, fishing, and aquaculture. Hypokalemia, hyponatremia, minimal proteinuria, and sterile pyuria are highly prevalent. Individuals in<unk> often have hyperuricemia and urate crystalluria, but this is observed less frequently India or Sri Lanka, . Kidney biopsy in individuals with MeN demonstrates some consistent features across regions. Biopsies are generally chronic glomerular and tubulointerstitial damage with glomerulosclerosis and chronic glomerular ischemia, without positive findings on immunofluorescence or definitive evidence of primary glomerular lesions. Glomerular enlargement may be observed. Ultrastructural changes evaluated with electron microscopy were mostly consistent with the light microscopic observations. Large dysmorphic lysosomes within tubular epithelial cells have been proposed as a distinctive feature but at present are not considered pathognomonic. In kidney biopsies from individuals with acute kidney injury (AKI) among high-risk patients for MeN, considered possibly a contributing stage to disease, the main findings were described as tubulointerstitial nephritis with varying degrees of acute inflammation and chronic tubulointerstitial changes. In some cases, neutrophils have been found in the tubular lumen of both chronic and acute MeN/CKDu patients, but urine cultures from these patients have been negative.
Mesoamerican nephropathy
IgA nephropathy
Malarial nephropathy
Balkan endemic nephropathy
Sickle cell nephropathy
Uddanam nephropathy
HIV-associated nephropathy
Analgesic nephropathy