Comparison of renal function markers in Kuwaiti patients with sickle cell disease.

BACKGROUND: Proteinuria is a common manifestation of renal disease which is a significant cause of morbidity in patients with sickle cell disease (SCD). OBJECTIVE: To evaluate and compare cystatin C, beta(2)-microglobulin, and creatinine as markers of renal disease in relation to the degree of proteinuria and other complications of SCD. METHODS: 24 h urine collections were used for estimation of urine protein and creatinine clearance in 59 patients with SCD. Results were correlated with plasma cystatin C, beta(2)-microglobulin, creatinine, glomerular filtration rate (GFR; derived from plasma creatinine by Cockcroft-Gault, MDRD formulae, and calculated cystatin C clearance), and clinical and haematological variables. RESULTS: Comparing the different methods of GFR, the proportion of patients with hyperfiltration (GFR >140 ml/min) were 30.5% (MDRD), 44.1% (Cockcroft-Gault), and 10.2 % (calculated cystatin C clearance). Cystatin C was the most consistent marker of hyperfiltration. The endogenous markers of GFR showed an increasing trend with increasing proteinuria, but haematological variables were not correlated with cystatin C, beta(2)-microglobulin, or plasma creatinine. Urine protein excretion was correlated with age (r = 0.33) and significant proteinuria was present in 13.6% of patients. Patients with proteinuria had lower haemoglobin concentration (p = 0.027) than those without proteinuria but HbF was not related to the degree of proteinuria or to markers of GFR. CONCLUSIONS: Markers of GFR show variable ability to identify hyperfiltration in patients with SCD, but cystatin C is the best endogenous marker. Proteinuria is associated with age, haemoglobin, and abnormalities of GFR. Routine screening is recommended to allow for early detection and intervention.

Serum concentration of cystatin C is not affected by cellular proliferation in patients with proliferative haematological disorders.

BACKGROUND: Recent reports have shown elevated concentrations of serum cystatin C (CC) in patients with solid tumours. The aim of our study was to investigate whether patients with proliferative haematological disorders have increased serum concentrations of CC compared with normal subjects. METHODS: Full blood count, serum CC, beta2-microglobulin (beta2M) and serum creatinine were determined in 27 apparently healthy subjects and 35 patients with proliferative haematological disorders. Creatinine clearance was calculated using the Cockroft-Gault formula. RESULTS: CC and beta2M showed a significant correlation with each other (r=0.96, P<0.0001). Serum beta2M (P=0.001) and the serum beta2M:CC ratio (P=0.001) were significantly higher in the patients with normal renal function than in controls, but serum CC was not significantly different (P=0.08). CC did not show a significant correlation with blood count parameters. DISCUSSION: Compared with beta2M and the beta2M:CC ratio, serum CC is not influenced by cell proliferation in haematological disorders.

Bilateral pulmonary aspergilloma caused by an atypical isolate of Aspergillus terreus.

A case of bilateral pulmonary aspergilloma caused by an atypical isolate of Aspergillus terreus is described. The diagnosis was established by the presence of septate, dichotomously branched fungal elements in freshly collected bronchoalveolar lavage and sputum specimens and by repeated isolation of the fungus in culture. Specific precipitating antibodies against the A. terreus isolate were demonstrated in the patient's serum. The isolate was atypical as it failed to produce fruiting structures on routine mycological media, but it did so on extended incubation on potato flake agar and produced globose, relatively heavy-walled, hyaline accessory conidia (formerly termed aleurioconidia) on both vegetative and aerial mycelia. Also, it produced an intense yellow diffusing pigment in the medium. The report underscores the increasing importance of A. terreus in the etiology of pulmonary aspergillosis. It is suggested that A. terreus antigen be included in the battery of serodiagnostic reagents to facilitate the early diagnosis of infections caused by this species.