Xanthogranulomatous pyelonephritis is associated with higher tissue expression of monocyte chemotactic protein-1.

TOPIC: Xanthogranulomatous pyelonephritis (XGP) is a chronic inflammation of the kidney characterized by destruction and replacement of its parenchyma with granulomatous tissue. It is associated with both chronic urinary obstruction and urinary tract infection (UTI). METHODS: We studied two children with chronic ureteropelvic junction obstruction (UPJO) and recurrent UTI nephrectomized for poor kidney function. An intraoperative renal biopsy was taken to relate the presence of infiltrating monocytes plus tubular atrophy to tissue expression of monocyte chemotactic protein-1 (MCP-1) and epidermal growth factor (EGF). XGP was diagnosed by a pathologist in both cases. RESULTS: MCP-1 expression was significantly higher in the two patients compared with the controls or patients with uncomplicated UPJO. It also correlated with the extent of monocyte infiltration, whereas EGF was only significantly downregulated when compared with the controls. CONCLUSIONS: MCP-1 would seem to play a key role in the pathogenesis of XGP by mediating the recruitment of circulating monocytes or by cells resident in the interstitial space.

Cystinuria type I: identification of eight new mutations in SLC3A1.

BACKGROUND: Cystinuria is a heritable disorder of amino acid transport characterized by the defective transport of cystine and the dibasic amino acids through the brush border epithelial cells of the renal tubule and intestine tract. Three types of cystinuria (I, II, and III) have been described based on the urinary excretion of cystine and dibasic amino acids in obligate heterozygotes. The SLC3A1 gene coding for an amino acid transporter named rBAT is responsible for type I cystinuria, whereas the SLC7A9 gene coding for a subunit (b0,+AT) of rBAT is involved in determining non-type I (types II and III) cystinuria. METHODS: The SLC3A1 gene sequence was investigated in a sample of seven type I/type I, three type I/non-type I, six type I/untyped, and four untyped unrelated cystinuric patients by RNA single-strand conformation polymorphism (RNA-SSCP). RESULTS: Eight new point mutations (S168X, 765+1G>T, 766-2A>G, R452Q, Y461X, S547W, L564F, and C673W) and seven previously reported mutations were detected. These new mutations increase the number of mutated alleles so far characterized in SLC3A1 to 62. CONCLUSIONS: We have found SLC3A1 mutations in 0.739 of the type I chromosomes studied. The relatively high proportion of uncharacterized type I chromosomes suggests either that there may be mutations not yet found in SLC3A1 or that many of the assigned type I chromosomes in mixed type I/non-type I patients may have mutations in SLC7A9. If the hypothesis is excluded in the future, we believe that a third gene may be involved in cystinuria.

[Prognostic value of neonatal pyelectasia diagnosed in utero]. / Valutazione prognostica delle pielectasie neonatali diagnosticate in utero.

Sixty-six children (48 male-18 female) with prenatal diagnosis of pyelectasia that was conformed at birth were examined between 1986-1994. All newborns carried out urinalysis and urine culture and performed a renal sonogram to reconfirm the diagnosis at 1 month of age. After 3 month of life the pelvic dilatation was confirmed in 61 patients while 5 showed a complete disappearance, 61 patients underwent micturitional cystography that evidenced 30 renal units (RU) with moderate to severe vesicoureteral reflux. In the patients without reflux, a scintigraphy was carried out with DTPA or MAG 3 and/or IVP and evidenced a functional junctional pathology in 32 RU and an organic junctional pathology in 24 RU, a primary megaureter with pre-vesical stenosis in 6 RU and a pyelo-ureteral complete double system in 4 RU. The patients with organic stenosis or those patients with parenchymal damage due to the vesicoureteral reflux underwent surgical intervention during the 1st year of life while all the remaining patients are continuously monitored to date with biohumoral exams and echography. With these results we can safely confirm the important role of the sonogram in the initial diagnosis of pyelectasia and to its eventual modifications in order to benefit the patients with a nephro-urological pathology and direct them toward a correct follow up.

Primary hypergammaglobulinemic purpura associated with IgG2 deficiency. A case report.

Hypergammaglobulinemic purpura is a rare disease in children. We report a case of a 12 year-old girl with a history of frequent infections. We found the presence of IgG2 deficiency despite polyclonal hypergammaglobulinemia. An IgG subclass determination should be obtained in every child with polyclonal hypergammaglobulinemia and features of immunodeficiency.