Introduction 11 21 1 20 The aim of this study was to determine the clinical features and long-term evolution of HCV infection in a group of children who had never received treatment with antiviral drugs. Patients and methods Thirty-seven children (16 females, 21 males) with positive antibodies to hepatitis C (anti-HCV) were investigated retrospectively. These patients were followed-up for a period of 5 years. None had received treatment with antiviral drugs for viral hepatitis or had a history of intravenous drug abuse. All subjects made regular visits to our outpatient clinic, and the serum levels of alanine aminotransferase (ALT), albumin, prothrombin time, antinuclear antibodies (ANA), anti-mitochondrial antibodies (AMA), anti-smooth muscle antibodies (SMA), liver-kidney anti-microsomal antibodies type I (LKM), anti-gastric parietal cells antibodies (GPCA), rheumatoid factor, thyroxine (T4), thyroid stimulating hormone (TSH), anti-thyroid antibodies, anti-HCV and HCV-RNA were determined at least on five consecutive occasions at 1-year intervals. Hepatitis B virus (HBV) surface antigen (HBsAg), antibodies to HBV surface antigen (anti-HBs), antibodies to HBV core antigen (Anti-HBc), human immunodeficiency virus (HIV) and antibodies to hepatitis E (anti-HEV) were investigated in all patients during one visit. Hepatitis G virus-RNA (HGV-RNA) and antibodies to HGV (anti-HGV) were determined in 26 patients. Genotypes of HCV were performed in 21 viremic children. The duration of infection was calculated as the interval between the presumed date of infection and the date of the last visit to the clinic. Liver biopsies were obtained in 17 patients. Repeated biopsies were performed in three patients. Viral markers for HBV, HCV and HIV were tested by third generation ELISA (Axsym; Abbott Diagnostics, Chicago, Ill.). Anti-HEV was detected by a commercially available ELISA (Bioelisa HEV IgG; Biokit, Barcelona, Spain). HGV-RNA and anti-HEV antibodies were detected using commercial tests (Roche Diagnostics, Mannheim, Germany). HCV-RNA was detected by PCR (Amplicor HCV PCR test, Roche Diagnostics), and HCV genotyping was performed by a second generation line probe assay (INNO-LIPA HCV; Innogenetics, Ghent, Belgium). 12 5 Results Mean chronological age for the 37 patients (21 males and 16 females) at the last follow-up evaluation was 20.1 years (range: 9–30 years). Most of the subjects were diagnosed among patients who were screened for HCV infection after receiving transfusions of blood products for heart surgery, hematological diseases or casual injuries before 1992. Thus, most of the patients included in the study presented with other diseases that were unrelated to HCV infection: 16 patients had a congenital heart disease, seven had various hematological disorders, three had neurological diseases, one had vesicoureteral reflux and one had Turner syndrome associated to IgA deficiency. 1 Table 1 Characteristics and biologic data of children with HCV infection   n n a 18 (9–26) 20 (9–30) a 14 (6–23) 16 (5–30) Route of infection  Parenteral 10 24  Vertical 0 2  Unknown 0 1 Alanine aminotransferase (U/l)  First visit Last visit n  10 7 14 n  b 0 6 7 n  0 5 5 n  0 9 1 Non-organ specific antibodies  Antinuclear antibody 0 2  Anti-mitochondrial antibodies 1 0  Anti-smooth muscle antibodies 0 1  Liver-kidney anti-microsomal antibody type 1 1 1  Gastric parietal cell antibodies 0 1 HCV genotype  1a  8  1b  12  2a  1  Unknown  6 HBV 0 0 HIV 1 0 n 1/0 4/2 Anti-HEV 0 0 a b Group 1 The once-yearly PCR analysis revealed that ten patients had positive anti-HCV and negative viremia, which reflected an ongoing or past infection with HCV. These patients were asymptomatic, and the liver function tests remained normal in all but two who had been diagnosed with congestive heart failure; the liver abnormalities of these two patients were normalized after their cardiac condition had improved. One female patient presented persistent positive AMA for 3 years, which then normalized and remained negative during the subsequent 9-year follow-up period. Throughout this period the patient was asymptomatic, and liver tests were normal. Two years after the laboratory tests were negative for antibodies, the patient presented with psoriasis. Another patient had persistent high titers (1:620) of anti-LKM. Fifteen years after acquiring the infection this patient lost the anti-HCV but the anti-LKM remained positive for two more years. During the follow-up this patient did not present liver abnormalities or other diseases. During the follow-up span of this study, another female patient became persistently anti-HCV negative 12 years after she was infected. At the time of writing, eight patients remain anti-HCV-positive and HCV-RNA-negative, and they show no evidence of liver disorders. Group 2 HCV-RNA was detectable in the blood of 27 patients, two of whom became HCV-RNA-negative. The age of exposure to the infection and the type of exposure could not be established in one patient; following the detection of HCV in the blood serum, this patient was followed for 11 years and was positive for HCV up to and including the last follow-up visit. All patients, with one exception, were asymptomatic. The exception had been diagnosed with leukemia in 1987 and received transfusions of blood products on several occasions. She underwent chemotherapy and had a cholestatic hepatitis; liver tests revealed persistent abnormalities. Anti-HCV and HCV-RNA were detected in 1991. The patient presented portal hypertension and progressive liver failure, and when she was 8 years old, in 1993, she received a liver transplant. 1 The presence of non-organ-specific autoantibodies (NOSAs) was detected in five patients. One patient (genotype1a) diagnosed with a single ventricle and Fontan surgery developed persistent anti-LKM (titers 1:160–1:620) and the rheumatoid factor throughout the evolution of the disease. Liver biopsy could not be obtained in this patient. Another male patient (genotype 1b) had positive ANA for 2 years, which subsequently normalized. This patient had increased ALT, and the liver biopsy showed minimal necrosis with inflammatory changes (HAI: 2) and no fibrosis. A third patient (genotype 1b) had persistent PGCA during her follow-up period (10 years), with slightly elevated ALT levels, mild necrosis with inflammatory changes (HAI: 4) and minimal fibrosis (stage 1). A fourth patient (genotype1b) with AST levels greater than fourfold the upper normal level presented SMA during the last 2 years of her follow-up (HAI: 6). The patient diagnosed with Turner syndrome and IgA deficiency (genotype 1b) developed throughout the years a seronegative poli-articular rheumatoid arthritis, psoriasis and celiac disease. She had intermittently positive ANA. The levels of T4 and TSH were normal in all patients, and no patient developed antithyroid antibodies. Abdominal ultrasounds did not show significant abnormalities. Only the patient who presented cirrhosis had changes associated to portal hypertension. 2 Table 2 Histopathological features of patients positive for HCV-RNA Liver biopsy n Necroinflammatory activity    1–2 6   3–4 7   5–6 4   6–18 0 Fibrosis    F0 8   F1 6   F2 2   F3 0   F4 (Cirrhosis) 1 Steatosis 0 A second hepatic biopsy was performed in three patients after 5, 12 and 14 years, respectively. The minimal necroinflammatory activity observed in the first biopsy specimens of these three children remained unchanged in the second biopsy. One of the patients progressed from F0 to F1 fibrosis. A second patient never presented with fibrosis, and both samples of the third patient had minimal fibrosis (F1). During the follow-up period, 2/27 patients became persistently HCV-RNA-negative (for 9 and 10 years, respectively). Both patients showed minimal necrosis and inflammatory activity with minimal fibrosis (F1) in the biopsy performed before HCV-RNA clearance. One patient of Group 1 was HIV-positive, while one patient of Group 1 and six patients of Group 2 were HGV-positive. 1 Discussion In this study, chronic hepatitis C infection was silent in most of the children, and there was little biochemical evidence of liver disease in these patients. Only one girl with portal hypertension and liver failure developed symptoms related to the infection. Consequently, our data suggest that HCV infection may be currently underdiagnosed in children and, moreover, that young patients could become a potential source of infection. We therefore strongly recommend that children falling in risk groups be screened for HCV infection. 7 13 22 16 16 4 13 22 18 2 9 6 8 9 23 3 15 17 3 19 Table 3 Hepatic fibrosis in biopsies from children with HCV infection   23 9 8 6 This report Number of patients 17 38 112 a 17 Mean duration of the HCV infection (year) 21.2 ± 4.6 n n 8.04 ± 5.3 Non-determined 11.2 ± 5,6 Fibrosis       No/low grade b 23 15 25/81 20/4 7/9 Severe/cirrhosis c 0 0 5/1 d e a b c d e 10 24 14 Conclusion Most children chronically infected with HCV are asymptomatic and present only mild biochemical evidence of hepatic injury. Spontaneous clearing of the virus occurs occasionally. Autoantibodies are common in HCV patients. The natural history of chronic hepatitis C in children differs from that in adults since HCV infection is relatively benign, induces mild changes in the liver with a low level of fibrosis and a low rate of progression and is rarely associated with severe or decompensate liver disease.