[Lyme nephritis in humans: Physio-pathological bases and spectrum of kidney lesions]. / La néphrite de Lyme chez l'homme : bases physiopathologiques et spectre lésionnel rénal.

Known in less than half a century, borreliosis, or Lyme disease, is a zoonosis caused by the tick bite. It is the most common vector disease in Europe and the United States. Borrelia burgdorferi sensu lato, the bacterium in question, is fitted with a "cunning device" that allows it to trick the immune system and implant the infection chronically. It causes multi-system tissue damage mediated by the inflammatory response of the host. Renal involvement is rarely reported and is better known in dogs as Lyme nephritis. The first case of kidney impairment in the human being was described in 1999, and since then eight other cases have been reported. The involvement is preferentially glomerular; the histological forms vary between immune complex nephropathy and podocytopathy. The pathophysiological mechanisms appear to be triple: immune complex deposits, podocytic hyper-expression of the B7-1 membrane protein, and renal infiltration of inflammatory cells. On the basis of the accumulated knowledge of the disease in just over 40 years, this review aims at establishing the physio-pathological hypotheses of renal involvement in order to better define the histological lesions.

Chronic tubulointerstitial nephropathy induced by glucosamine: a case report and literature review.

Glucosamine is a glycosylated amine and a slow-acting symptomatic treatment for osteoarthritis. Some experimental animal studies have shown that glucosamine can cause apoptosis in kidney tubular and mesangial cells as well as overexpression of transforming growth factor ß1 (TGF-ß1) and connective-tissue growth factor (CTGF), which are potent inducers of mesangial and interstitial tubulointerstitial fibrosis. We report the case of a 67-year-old patient who presented with non-proteinuric renal insufficiency and a reduction of the glomerularfiltration rate (GFR) from 86 to 46 mL/min within 3 months. A kidney biopsy showed noninflammatory 40 - 50% fibrosis of the renal cortex associated with acute tubular necrosis. The etiological investigation was negative apart from taking 1,200 mg of glucosamine daily for 3 years to treat osteoarthritic knee pain. Three weeks after stopping glucosamine, GFR increased from 47.5 to 60 mL/min. Reintroduction of glucosamine resulted in loss of kidney function after 3 weeks, with GFR reduced from 60 to 53 mL/ min. Thus, glucosamine was shown to cause renal toxicity. Referring to other reported cases, we conclude that toxicity is rare but may also be underreported.