Hemolytic uremic syndrome associated with novel influenza A H1N1 infection

Sirs, During 2009, a pandemic influenza A H1N1 virus emerged end spread all over the world [1]. Renal involvement in influenza A virus infection is rare, but one case of hemolytic uremic syndrome (HUS) during season influenza has been reported [2]. We present a patient with novel A H1N1 virus complicated with HUS. A previously healthy 11-year-old boy was transferred to our Children’s Clinic with a history of fever, coughing, fatigue, jaundice, and oliguria. He had no diarrhea. On admission his temperature was over 38.5°C, and his blood pressure was 130/80 mmHg. He had no edema. Laboratory investigations revealed a sign of hemolysis (with declining hemoglobin to 6.5 g/l, and reticulocytosis) with thrombocytopenia (38,000 mm) and renal failure (serum creatinine 280 μmol/l, blood urea nitrogen 22 mmol/l). Blood smear showed fragmented and damaged erythrocytes. Serum chemistry showed a high level of total bilirubin (48 μmol/ l) and a very high level of lactate dehydrogenase (LDH 4,800 μ/l, normal range 250–480 μ/l). Alanine and aspartate transferases were slightly elevated. Urine analyses revealed 3+ proteinuria, 3+ hemoglobinuria, and erythrocyte casts. Prothrombin time and activated partial thromboplastin time were normal, D-dimer was elevated, and direct and indirect Coombs tests were negative. C3 and C4 were normal. A chest X-ray showed viral, interstitial pneumonia. Two other family members also started coughing and developed fever and fatigue. Based on the above findings the patient was diagnosed with HUS. On the day of admission he was treated with ceftriaxone 100 mg/kg per day and infusion of low doses of dopamine and furosemide. On his second day in hospital we decided to start plasma therapy, which may be recommended in nondiarrheal/nonpneumococcal HUS. However, a few hours after the first doses of fresh-frozen plasma he showed aggravated hemolytic anemia (hemoglobin level decreased to 5 g/l, LDH severely increased). We stopped plasma infusion, and continued with fluid and diuretics. In the meantime we received his respiratory spacemen test, which was positive for novel influenza A H1N1 by real-time reverse transcriptase PCR. Oseltamivir (75 mg every 12 h) was started, and continued for 6 days. Symptoms subsided in the next few days. He gradually recovered, lost the fever, his urine output increased with improving renal function, and his blood count too. He was discharged after 15 days with serum creatinine 77 μmol/l, normal levels of LDH, and hemoglobin 10 g/l. Usually, influenza A H1N1 turns out to be a benign disease. The association of pneumococcal infection with the current and previous influenza pandemics is well known. Pneumococcal HUS is an uncommon condition, with reports of this complication in patients with invasive infections, but also in one patient during influenza A and pneumococcal coinfection [3, 4]. We did not confirm bacterial super infection in throat swab, sputum and blood culture in our patient. It is E. Golubovic (*) : P. Miljkovic Department of Pediatric Nephrology, Children’s Clinic, University of Nis, Zorana Djindjica 48, 18000 Nis, Serbia e-mail: ema.golubovic@gmail.com