Nodular glomerulosclerosis in cystic fibrosis mimics diabetic nephropathy.
OBJECTIVE
Despite the cystic fibrosis gene product, the cystic fibrosis transmembrane conductance regulator, being widely expressed throughout the kidney, there is no clearly defined renal phenotype in patients with cystic fibrosis. As patients with cystic fibrosis survive longer progressive pancreatic destruction may lead to abnormal glucose tolerance and diabetes mellitus, which in the kidney may be associated with the characteristic changes of nodular glomerulosclerosis.


METHODS
The adult cystic fibrosis service at the Alfred hospital consists of a cohort of 200 patients. We describe 3 cystic fibrosis patients with impaired renal function who had renal biopsies performed as part of their diagnostic work-up. All patients had fasting plasma glucose levels, oral glucose tolerance tests and measurements of HbA1c performed to assess for the presence of cystic fibrosis-related diabetes mellitus.


RESULTS
The renal biopsies of all 3 patients showed histological changes characteristic of diabetic nephropathy. In all cases described characteristic Kimmelstiel-Wilson nodules were present. However, in all 3 patients the presence of impaired glucose tolerance and diabetes mellitus was excluded using standard biochemical diagnostic criteria.


CONCLUSIONS
We describe 3 adult CF patients, who on renal biopsy had histological evidence of nodular glomerulosclerosis in the absence of abnormal glucose metabolism. We speculate that the pro-inflammatory cytokine profile, typical of cystic fibrosis, predisposes to the lesions described.
Westall
Glen P
GP
Department of Respiratory Medicine, The Alfred Hospital and Monash Medical School, Monash University, Melbourne, Vic, Australia.
Binder
John
J
Kotsimbos
Tom
T
Topliss
Duncan
D
Thomson
Napier
N
Dowling
John
J
Wilson
John W
JW
D000328:Adult; D003550:Cystic Fibrosis / Q000150:complications*; D003928:Diabetic Nephropathies / Q000175:diagnosis*; D003937:Diagnosis, Differential; D005921:Glomerulonephritis / Q000209:etiology / Q000473:pathology*; D006801:Humans; D007668:Kidney / Q000000981:diagnostic imaging / Q000473:pathology; D008297:Male; D008854:Microscopy, Electron; D014463:Ultrasonography