Urinary annexin V in children with nephrotic syndrome: a new prognostic marker?

Annexin V has a molecular weight of 32-35 kDa and has been reported to possess anticoagulant activity, inhibition of phospholipase A(2), regulation of membrane transport, proliferation and signal transduction. It is reported that urinary annexin V concentration may be an indicator of apoptosis and acute renal injury related to the urinary protein level. The aim of this study was to define the role of urinary annexin V excretion and serum annexin V concentrations as new prognostic tools and follow-up criteria in children with steroid-sensitive (SSNS) and steroid-resistant nephrotic syndrome (SRNS). Annexin V concentrations were measured in serum and 24-h urine samples in 23 SSNS patients in both relapse and remission periods of each patient and in 22 SRNS patients and 22 healthy controls. Total protein, albumin, blood urea nitrogen (BUN), creatinine, total cholesterol concentrations, and 24-h urinary excretion of protein and creatinine were also measured in each patient. In the SRNS group, median 24-h urinary annexin V levels were significantly higher than for all other groups (5,048.8 ng/g creatinine vs. 2,839.5 ng/g creatinine in SSNS relapse group; 2,500.0 ng/g creatinine in SSNS remission group, and 2,018.3 ng/g creatinine in healthy control group). No significant correlation was found between urinary protein excretion and 24-h urinary annexin V levels in all subjects. Twenty-four-hour urinary annexin V excretion may be a predictor in children with SRNS, and it may be a prognostic marker in children with NS.

Renal amyloidosis in a child with sickle cell anemia.

The kidney is frequently affected in patients with sickle cell syndrome, i.e., homozygous and heterozygous patients, with a consequently large spectrum of renal abnormalities that may range from minimal functional changes to chronic renal failure. Here, we present a 13-year-old boy with sickle cell anemia (SCA) (HbSS) who was referred to our unit with nephrotic syndrome. Renal biopsy revealed AA type amyloidosis on the basis of light microscopic findings, indicating Congo red staining and immunohistochemistry. He had neither a family history of familial Mediterranean fever (FMF) nor any complaint of recurrent abdominal pain, arthritis, and fever, but frequent painful vaso-occlusive crises. The patient was found to have no MEFV gene (Mediterranean feVer) mutations either. Painful episodic attacks might provoke recurrent acute inflammation, leading to repeated stimulation of acute phase responses and cause secondary amyloidosis. To our knowledge, this boy is the first case of SCA complicated by renal amyloidosis observed in childhood.

Low serum apolipoprotein AI levels in amyloidosis related to familial Mediterranean fever.

Amyloidosis (A) related to familial Mediterranean fever (FMF) causes serious morbidity and mortality in children. Our study evaluates serum levels of apolipoprotein (Apo) AI, AII, B, and E and Apo AII/AI ratios as a non-invasive diagnostic tool for amyloidosis in children with FMF and FMF-A. Results were compared with those of patients with childhood nephrotic syndrome (NS) and healthy children (controls). Significantly lower serum levels of Apo AI (90.20+/-28.30 mg/dl) were documented in patients with FMF-A than in all other groups (FMF 126.89+/-51.07 mg/dl, NS 140.38+/-33.73 mg/dl, and controls 134.67+/-12.73 mg/dl) ( P<0.01). Diagnostic sensitivity, specificity, and predictive value for this test were 85%, 80%, and 85%, respectively. Apo AII/AI ratio results were essentially equal in all groups ( P>0.05). It is concluded that a decreased Apo AI serum level, but not Apo AII/AI ratio, is a useful, non-invasive test for the early diagnosis of FMF-A in children.