The Functional State of Neutrophil (PMN) Correlates with Severity in children with the Hemolytic Uremic Syndrome (HUS)

FERNANDEZ G.C; GOMEZ S.A; RAMOS M.V; LANDONI V.I; EXENI R; GRIMOLDI I; ALDUNCIN M; ISTURIZ M.A; PALERMO M.S

Cordoba Argentina

Congreso; VII Congreso Latinoamericano de Inmunología; 2005

THE FUNCTIONAL STATE OF NEUTROPHILS (PMN) CORRELATES WITH SEVERITY IN CHILDREN WITH HEMOLYTIC UREMIC SYNDROME (HUS) Gabriela C. Fernández*, Sonia Gómez*, Victoria Ramos*, Verónica Landoni*, Ramón Exeni#, Irene Grimoldi#, Marta Alduncín#, Martín Isturiz*, Marina Palermo*. *Inmunología, IIHEMA, Academia Nacional de Medicina, #Nefrología, Hospital Municipal del Niño, San Justo, Buenos Aires, Argentina. Activated PMN contribute to endothelial damage in HUS, the main cause of pediatric acute renal failure. We have demonstrated that HUS PMN are partially deactivated, as a consequence of a postactivation exhaustion process. Here, we investigated whether the activation state of PMN correlates with the severity of renal impairment. The expression of activation markers, PMAinduced reactive oxygen species (ROS) generation and spontaneous apoptosis were evaluated by flow cytometry on circulating PMN from at least 20 HUS patients during the acute period and healthy children (HC,n=12). According to Gianantonio’s criteria, patients were classified in mild, moderate or severe cases (0, <7 or >7 days of anuria, respectively). HC HUS Mild HUS Moderate HUS Severe Correlation with severity Number (PMNx109/L) 3.8±0.3 8.7±0.9* 10.4±1.2* 15.3±1.2*§# r=0.6,p=0.001 MFI CD16   151.1±16.4 55.0±8.3* 60.8±10.1* 39.8±7.0* No correlation CD11b 184.0±26.1 124.1±19.2* 80.1±11.2* 62.3±7.9*§ r=0.37,p=0.01 CD66b 184.6±32.3 156.8±16.5 81.2±16*§ 103.3±14*§ r=0.35,p=0.01 Myeloperox. 166.7±24.0 160.3±23.0 99.3±17.1§ 96.0±19.3*§ r=0.51,p=0.01 ROS 99.0±10.1 113.6±21.7 123.3±34.0 37.7±17*§# r=0.50,p=0.02 % apoptosis 54.6±3.3 45.7±4.2 41.05±16.5 25.1±2.9*§ r=0.51,p=0.01 Results expressed as mean±SE. *p<0.05 vs. HC; §p<0.05 vs. Mild; #p<0.05 vs. Moderate. The expression of all markers, ROS production and apoptosis were profoundly diminished in severe cases, suggesting that a higher PMN count and a more pronounced deactivation state at presentation indicates a worse outcome.