Inflammatory bowel disease in Shwachman-Diamond syndrome; is there an association?

Shwachman-Diamond syndrome (SDS) is a rare autosomal recessive disease characterized by exocrine pancreatic insufficiency with malabsorption, malnutrition, growth failure and bone marrow failure. Furthermore, duodenal inflammatory enteropathy features may be present. For the first time, we report here a SDS case that is also diagnosed with inflammatory bowel disease (IBD). He was diagnosed with SDS at the age of two based on poor growth, severe exocrine pancreatic insufficiency with steatorrhea, neutropenia, recurrent infections and thoracic skeletal abnormalities. Ileocolonoscopy and histopathology revealed colonic Crohn's disease at the age of sixteen. Our report may encourage further studies elucidating the possible association between the SDS genetic defect and inflammatory bowel disease.

A comparison between cystatin C, plasma creatinine and the Cockcroft and Gault formula for the estimation of glomerular filtration rate.

BACKGROUND: In clinical practice, the glomerular filtration rate (GFR) is often estimated from plasma creatinine. Several studies have shown cystatin C (cys C) to be a better parameter for the diagnosis of impaired renal function. No data are available, however, on the performance of cys C in follow-up of patients, compared with creatinine. Also, comparisons of cys C with the Cockcroft and Gault (C&G) formula for estimation of GFR are few. METHODS: Plasma samples were obtained from 93 consecutive patients seen for GFR determination and from 30 patients with diabetes mellitus type 2, of whom 23 were investigated a second time after 2 years. GFR was determined with [125I]iothalamate. Plasma creatinine was determined enzymatically and the creatinine clearance calculated according to C&G. Cys C was measured with a particle-enhanced immunonephelometric method. RESULTS: GFR correlated with 1/cys C (r = 0.873) as well as with C&G (r = 0.876). The area under the curve (AUC) of the receiver operating curves (ROCs), a measure of diagnostic accuracy, for cys C (0.931) and C&G (0.938) were equal (P = 0.815) and both better than the creatinine AUC (0.848; P = 0.006). Bland and Altman analysis showed that the simple formula GFR = -4.32 + 80.35 x 1/cys C, derived from our data, gave more accurate (P < 0.0001) and more precise (P = 0.024) GFR estimates than obtained with the C&G formula. The day-to-day variation (biological +analytical) for cys C was small (3.1%, SD 2.51%) in diabetic patients. In the follow-up study in diabetic patients, cys C was the parameter which had the best correlation (r = 0.66) with changes in GFR. CONCLUSIONS: Cys C shows a high correlation with GFR. With a very simple formula, cys C gives a good estimate of GFR, more accurate and precise than C&G. Because biological variation is low, cys C gives also a good assessment of GFR changes during follow-up. Cys C is the preferred endogenous parameter for GFR.

Cimetidine improves prediction of the glomerular filtration rate by the Cockcroft-Gault formula in renal transplant recipients.

BACKGROUND: The glomerular filtration rate (GFR) can be predicted from plasma creatinine, age, gender, and body weight, using the formula of Cockcroft and Gault. Cimetidine improved the accuracy of GFR prediction in renal disease and also in diabetes mellitus type 2, due to inhibition of tubular creatinine secretion. We compared the accuracy and precision of GFR prediction from the Cockcroft-Gault formula without cimetidine (CG), with cimetidine (CGcim) and from the creatinine clearance without cimetidine in renal transplant recipients. METHODS: CG and CGcim were calculated from plasma creatinine before and after 2400 mg of oral cimetidine during the 24 hr preceding the GFR measurement. The endogenous creatinine clearance was measured in 24 outpatients from a 24-hr urine collection (Ccr24) before cimetidine. GFR was measured as the urinary clearance of continuously infused 125I-iothalamate. Creatinine was determined with an automated enzymatic assay in plasma and with an alkaline picrate assay in urine. RESULTS: GFR was 47.8+/-16.8 ml/min/1.73 m2 (mean+/-SD), Ccr24 was 71.8+/-23.1 ml/min/1.73 m2, CG was 62.2+/-15.2 ml/min/1.73 m2, and CGcim was 52.8+/-14.9 ml/min/1.73 m2. Ccr24 overestimated GFR in every patient by an average of 23.8 ml/min/1.73 m2 and CG by an average of 14.3 ml/min/1.73 m2, whereas CGcim overestimated GFR significantly less by an average 4.9 ml/min/1.73 m2 (P<0.001). The precision of CGcim was significantly better than that of Ccr24: the SD of the difference from GFR was 9.0 ml/min/1.73 m2 for CGcim and 14.5 ml/min/1.73 m2 for Ccr24 (P<0.05). CONCLUSION: CGcim is useful for GFR prediction in outpatient renal transplant recipients and has a far better accuracy and precision than Ccr24 and also a better accuracy than CG. We propose a strategy after kidney transplantation of one GFR measurement at baseline and follow-up with CGcim.