MICROVESICLES CARRYING SHIGA TOXIN TYPE 2 (MVS-STX2) AS A NEW CLINICAL BIOMARKER FOR THE RAPID DIAGNOSIS OF PATIENTS AT RISK OF DEVELOPING HEMOLYTIC UREMIC SYNDROME (HUS)

GOMEZ, FERNANDO DANIEL; SACERDOTI, FLAVIA; GIRON REYES, CLAUDIO DANIEL; PASCUALE, CARLA A.; LOMBARDO, TOMAS; PIAZZA FONTES, ROXANE MARIA; ALCONCHER, LAURA; AMARAL, MARÍA M.

Mar del Plata

Congreso; Reunion anual de Sociedades de Biociencias (SAIC-SAB-AAFE-ACCyTAL); 2023

SAIC-SAB-AAFE-ACCyTAL

In Argentina, Hemolytic Uremic Syndrome (HUS) caused by Shiga toxin (Stx)-producing Escherichia coli (STEC-HUS) infection is anendemic disease and one of the most common causes of acute kidneyinjury in children. Negligible amounts of free toxin are present inthe circulation during HUS, and it circulates mainly bound to bloodcells and microvesicles (MVs). Platelets and leukocytes derivedMVs were detected in the plasma of STEC-HUS patients. In thissense, preliminary, we successfully identified circulating MVs carryingStx2 (MVs-Stx2) in two STEC-HUS patients. In this study, ourobjective was to analyze the presence of MVs-Stx2 in blood samplesof six STEC-HUS patients, between 3 and 17 years old, thatwere admitted to the Hospital Penna-Bahía Blanca. Blood sampleswere collected and underwent sequential ultracentrifugation to obtaina suspension enriched with MVs. Then, MVs were labeled withAnnexin V-FITC and MVs-Stx2 were detected by a monoclonal anti-Stx2 antibody and a secondary antibody conjugated to Alexa Fluor647. Finally, MVs were analyzed by flow cytometry. Data are expressedas the percentage of positives MVs-Stx2. Ten age-matchedhealthy controls were also recruited and a cut-off point for MVs-Stx2was established. Medical history of patients indicated that to the dayof hospitalization, three of them exhibited aqueous diarrhea, twoshowed bloody mucous diarrhea and the other had no diarrhea. ForStx2 PCR analysis, 50% of them were positive. Anti-LPS antibodieswere positive for O145 IgM/IgG in three patients and for O157IgG in one of them. All patients showed a significant percentageof MVs-Stx2 in circulation compared to controls (3.4%, 7%, 13.7%,6%, 3.6% and 13.8% vs 1.76 ± 0.74 %, n=10, (p