No abstract

Background: Retrospective case series suggest that abnormalities in fluid, electrolyte, and acid-base homeostasis may occur among infants with a febrile urinary tract infection. Potentially inaccurate laboratory methods of sodium testing have often been used. Methods: Between January 2009 and June 2016, we managed 80 previously healthy infants (52 males and 28 females) ≥4 weeks to ≤24 months of age with their first episode of acute pyelonephritis. Ionized sodium, ionized potassium and ionized chloride were determined by direct potentiometry, as recommended by the International Federation of Clinical Chemistry. Bicarbonate was calculated from pH and carbon dioxide pressure. Results: Electrolyte or acid-base abnormalities were disclosed in 59 (74%) of the 80 infants: hyponatremia (n = 54), hypobicarbonatemia (n = 18), hyperkalemia (n = 14), hyperbicarbonatemia (n = 6), hypochloremia (n = 3), hypokalemia (n = 3), and hyperchloremia (n = 1). None of the patients was found to be hypernatremic. Patients with and without electrolyte or acid-base abnormalities did not differ with respect to age, sex distribution, and whole blood glucose. Blood tonicity was lower and poor fluid intake, frequent regurgitations or loose stools more common among infants with electrolyte or acid-base abnormalities. Conclusions: This prospective cross-sectional study shows that electrolyte or acid-base abnormalities, most frequently hyponatremia, occur in approximately 3 quarters of infants with acute pyelonephritis.

The first study on sodium level measured by the direct potentiometry in infants with bronchiolitis points out that the prevalence of hyponatremia is two-fold higher than so far reported.

Angioedema due to acquired deficiency of the inhibitor of the first component of complement (C1-INH) is a rare disease known as acquired angioedema (AAE). About 70% of patients with AEE display autoantibodies to C1-INH, the remaining patients have no antibodies to C1-INH. The clinical features of C1-INH deficiency include recurrent, self-limiting local swellings involving the skin, the gastrointestinal tract, and the upper respiratory tract. Swelling is due to accumulation of bradykinin released from high molecular weight kininogen. Patients with angioedema due to acquired C1 inhibitor deficiency (AEE) often have an associated lymphoproliferative disease including Non-Hodgkin Lymphomas (NHL). Among AAE patients with NHL, splenic marginal zone lymphoma (SMZL) has a higher prevalence (66%) compared to general population (2%) In the present study, we focused on patients with SMZL in AAE. We found 24 AAE patients with NHL and, among them 15 SMZL (62.5% of all NHL). We found NOTCH 2 activation in 4 /15 patients (26.6%) with SMZL, while no patients carried MYD 88 or BIRC3 mutations. Restricted immunoglobulin gene repertoire analysis showed that the IGHV1-2*04 allele was found to be over-represented in the group of patients with or without lymphoproliferative disease presenting with autoantibodies to C1-INH (41 of 55 (75%) of patients; p value 0.011) when compared to the control group of patients with AEE without antibodies to C1-INH, (7 of 27 (26%) of patients). Immunophenotyping failed to demonstrate the presence of autoreactive clones against C1-inhibitor. Taken together, these findings suggest a role for antigenic stimulation in the pathogenesis of lymphomas associated with AEE.