New insights on the role of vitamin D in the progression of renal damage.

Several studies indicate a relationship between hypovitaminosis D, survival, vascular calcification and inflammation. In addition to its central role in the regulation of bone mineral metabolism, vitamin D also contributes to other systems, including the immune, cardiovascular and endocrine systems. Vitamin D analogs reduces proteinuria, in particular through suppression of the renin-angiotensin-aldosterone system (RAAS) and exerts anti-inflammatory and immunomodulatory effects. In particular vitamin D deficiency contribute to an inappropriately activated RAAS, as a mechanism for progression of chronic kidney disease (CKD) and/or cardiovascular disease. Human and sperimental models of CKD showed that vitamin D may interact with B and T lymphocytes and influence the phenotype and function of the antigen presenting cells and dendritic cells, promoting properties that favor the induction of tolerogenic T regulators rather than T effectory. Interstitial fibrosis may be prevented through vitamin D supplementation. Renal myofibroblast, an activated fibroblast with expression of a molecular hallmark α-smooth muscle actin (α-SMA), is generally considered the principal matrix-producing effector cells that are responsible for the excess production of extracellular matrix (ECM) components in the fibrotic tissues. It turns out that calcitriol effectively blocks myofibroblast activation from interstitial fibroblasts, as evidenced by suppression of TGF-ß1-mediated α-SMA expression.

Can neutrophil gelatinase-associated lipocalin help depict early contrast material-induced nephropathy?

PURPOSE: To evaluate the utility of serum and urinary neutrophil gelatinase-associated lipocalin (NGAL) in depicting an event of contrast material-induced nephropathy (CIN) in patients who received iodinated contrast media, gadoterate meglumine, or radiopharmaceutical technetium-99m ((99m)Tc) and to evaluate the protective effect exerted by isotonic saline infusion, sodium bicarbonate administration, or N-acetylcysteine administration. MATERIALS AND METHODS: Institutional ethics committee approval was given, and informed consent was obtained. One hundred twenty patients were enrolled in a prospective study and divided into three groups: iomeprol group, magnetic resonance (MR) imaging group (gadoterate meglumine), and renal scintigraphy group ((99m)Tc). They randomly received N-acetylcysteine, physiologic saline, or sodium bicarbonate. Receiver operating characteristic (ROC) analysis, Kaplan-Meier curves, and Cox proportional hazard regression analysis were used. RESULTS: In the MR imaging and renal scintigraphy groups, there were significant changes in serum creatinine and NGAL levels, and there were no cases of CIN. In the iomeprol group, an early rise in NGAL was found, while serum creatinine level changes occurred 24 hours after contrast material administration. At ROC analysis, NGAL showed high sensitivity and specificity (serum NGAL: area under the curve, 0.995; 95% confidence interval [CI]: 0.868, 0.992; urinary NGAL: area under the curve, 0.992; 95% CI: 0.925, 1.000) in identifying CIN 8 hours after iomeprol administration. Regression analysis showed that NGAL independently predicted CIN. Administration of N-acetylcysteine, sodium bicarbonate, or physiologic saline did not influence NGAL level. CONCLUSION: NGAL depicted CIN in patients who received iodinated contrast material within 8 hours of contrast material administration. SUPPLEMENTAL MATERIAL: http://radiology.rsna.org/lookup/suppl/doi:10.1148/radiol.12120578/-/DC1.

Glutamine-supplemented total parenteral nutrition improves immunological status in anorectic patients.

OBJECTIVE: Glutamine is an important substrate for critical cells of the immune system, in particular lymphocytes and macrophages, and it is considered a conditionally essential amino acid. Several studies have indicated that glutamine-enriched total parenteral nutrition improves immunologic status and shortens length of stay of critically ill patients. We investigated the effect of total parenteral nutrition supplemented with glutamine on the immune system in anorectic patients. METHODS: Thirty-six anorectic patients were randomized to receive standard parenteral nutrition or parenteral nutrition supplemented with glutamine 0.18 g kg(-1) d(-1) for 20 d. To evaluate the immune system status, we determined serum levels of neopterin and insulin growth factor-1 and lymphocyte count at baseline and after 10 and 20 d from the beginning of the therapy. RESULTS AND CONCLUSIONS: The results showed a significant increase of the serum levels of neopterin after 10 d of treatment with glutamine (26.44 +/- 3.08 versus 6.75 +/- 1.73 nmol/L, P < 0.001), thus proving a probable stimulating action carried out by glutamine on the immune system, as testified by the increase of lymphocytes.

Hypophosphatemia as unusual cause of ARDS in Cushing's syndrome secondary to ectopic CRH production. A case report.

Hypophosphatemia is an unusual cause of acute respiratory distress syndrome (ARDS). We describe a hypophosphatemia-related ARDS case report of a 50-year-old woman with ACTH dependent Cushing's syndrome secondary to ectopic CRH production. The patient clinically showed hypotension tachypnea and increasing dyspnea. Laboratory data showed carbohydrate intolerance, severe hypokalemia, and hypophosphatemia. Arterial blood gases measurement revealed hypocapnia and elevation in bicarbonate values. Chest X-ray showed diffuse bilateral alveolar infiltrates similar to acute pulmonary edema and Kerley's striae. Chest CT scan evidenced diffuse ground glass opacification, bilateral patchy consolidation, and fibrosis, compatible with the recovery phase of ARDS. Clinical symptoms and laboratory examinations supported the diagnosis of ARDS. The patient was managed with supplemental potassium, octreotide, and oxygen therapy. Hypophosphatemia was managed by treating the underlying disorder. Successive surgical removal of the adrenal gland led to complete resolution of Cushing's syndrome. In conclusion, although rare and associated with specific risk factors, hypophosphatemia should be suspected in patients who develop unexplained ARDS.