Lymphatic filariasis (LF) is a severe form of filariasis (see this term), caused by the parasitic worms <i>Wuchereria bancrofti</i>, <i>Brugia malayi</i> and <i>Brugia timori</i>, and the most common cause of acquired lymphedema worldwide. LF is endemic to tropical and subtropical regions. The vast majority of infected patients are asymptomatic but it can also cause a variety of clinical manifestations, including limb lymphedema, genital anomalies (hydrocele, chylocele), elephantiasis in later stages of the disease (frequently in the lower extremities), and tropical pulmonary eosinophilia (nocturnal paroxysmal cough and wheezing, weight loss, low-grade fever, adenopathy, and pronounced blood eosinophilia). Renal involvement (hematuria, proteinuria, nephritic syndrome, glomerulonephritis), and mono-arthritis of the knee or ankle joint have also been reported.

Nephrotic syndrome is a collection of findings resulting from glomerular dysfunction with an increase in glomerular capillary wall permeability associated with pronounced proteinuria. Nephrotic syndrome refers to the constellation of clinical findings that result from severe renal loss of protein, with Proteinuria and hypoalbuminemia, edema, and hyperlipidemia.