Clinical and Para Clinical Findings in Children with Progressive Familial Intrahepatic Cholestasis in Iran; A Referral Center Report

Background Progressive Familial Intrahepatic Cholestasis (PFIC) is a heterogeneous group of disorders with various clinical and para-clinical manifestations. We report clinical and para-clinical ndings in children with progressive familial intrahepatic cholestasis in Southern Iran. among a large series of patients with PFIC.


Introduction
Cholestasis is an alternative response to malfunctions of the liver and biliary system which may be caused by extrahepatic or intrahepatic obstruction to the bile ow (1). Cholestasis may be due to genetic, metabolic, infectious, mechanical obstruction of bile ow or functional impairment of the hepatic biliary function and bile secretion (2).
Progressive familial intrahepatic cholestasis (PFIC) is an important but relatively rare hereditary cause of cholestasis among pediatrics. PFIC was rst described in an Amish kindred, then reported in families in Europe, the United States, Japan, Iran and the other parts of the world (3)(4)(5)(6)(7). PFIC is an inherited disorder in children with cholestasis of hepatocellular origin which presents in early infancy and childhood, progresses to cirrhosis within the rst decade of life, and leads to death due to liver failure at ages ranging from infancy to childhood (3). The combined considerations of clinical, para-clinical, radiological and histological approaches, as well as speci c tests for excluding other causes of childhood cholestasis aid in the diagnosis of PFIC. Diagnosis of PFIC is based on clinical and para-clinical manifestations, liver ultrasonography, liver histopathology, as well as molecular investigations (8). Medical therapy, biliary diversion and liver transplantation (LT) are three major curative modalities for treatment of the disease (5). It has been mentioned that surgical methods for treatment of PFIC such as partial external biliary diversion (PEBD) and LT are better treatment choices compared to medical therapy (9).
Multiple studies have evaluated different aspects of PFIC, however to the best of the authors' knowledge, no study with a large sample size has evaluated clinical and para-clinical features of PFIC among children. The aim of this study is to evaluate clinical and para-clinical ndings of children with PFIC as well as treatment choices in southern Iran.

Study settings and patient selection
All children ≤ 18 years with signs of liver disease who referred to Namazi Hospital, a liated to Shiraz University of Medical Sciences, since March 2008 till February 2012, were initially assessed and cases that were diagnosed with PFIC were included in the current report. Namazi Hospital is the main referral center for southern and central Iran and patients from all neighboring provinces are referred to this medical center.
Patients with recurrent episodes of cholestatic jaundice, clay colored stool, dark colored urine and pruritus were initially considered for inclusion in this study.

Variables
All medical records of children with PFIC were evaluated. Data on rst clinical presentation (patients' complaint), clinical ndings, sonography ndings, biopsy ndings as well as para-clinical data were obtained. Pediatric end-stage liver disease (PELD) score, model for end-stage liver disease score (MELD), and 3-month mortality rate were also calculated.
Through evaluation any case with anatomical and metabolic disorders of the liver other than PFIC and inborn errors of metabolism were excluded from the study.

Ethical consideration
Data on patient health identi cation (PHI) and any other personal data were kept safe. Research protocol was approved by the ethics committee of Shiraz University of Medical Sciences, Shiraz, Iran.

Statistical analysis
Disease manifestations including clinical ndings, sonography ndings and, biopsy ndings were presented as frequencies (%) and parametric variables were presented as mean ± standard deviation. The data were analyzed through SPSS version 21.0. The graphs were extracted using Minitab 16.0.
Mean and median age of the children was 48.82 ± 48.79 SD and 30 (10, 84) IQR months. The youngest patient with PFIC was 2 months.
The most frequent complaint of patients was isolated jaundice seen among 53 (51.96%) patients, followed by pruritus and jaundice in 15 (14.70%), jaundice and elevated liver enzymes in 11 (10.78%), isolated elevated liver enzymes in 9 (8.82%), and pruritus in 9 (8.82%) cases. Overall, jaundice, pruritus and elevated liver enzymes were observed in 75, 29 and 24 cases, respectively. Most patients had more than one clinical presentation at referral.

Discussion
PFIC diseases include a group of autosomal recessive hereditary diseases, which usually present in infancy or childhood that have cholestasis of hepatocellular origin (10). PFIC is an indications for liver transplantation in 10-15% of children (3,10). In 1965, Clayton et al. rst described this disease as Byler disease (11). The true incidence of PFIC is not precisely known, but it is considered a rare disease, with an estimated incidence of 1/50,000 to 1/100,000 among all births (12,13).
In a referral and educational hospital such as that in our study, diseases are diagnosed by expert specialists based on patients' history, clinical and para-clinical manifestations of the disease. Cholestasis which is characterized by jaundice and pruritus, is the hallmark presentation of PFIC (3). Similarly, in our study jaundice was the most frequent clinical complaint of patients followed by pruritus and elevated liver enzymes. PFIC usually appears in the rst months of patients' life and is characterized by recurrent episodes of jaundice, becoming permanent later. Age distribution of the disease in our subjects showed that the disease is mostly presented and diagnosed in early periods of children's life.
Extrahepatic manifestations of PFIC includes persistent poor growth, short stature, sensorineural deafness, watery diarrhea, pancreatitis, elevated sweat electrolyte concentration, liver steatosis, gastrointestinal bleeding and cirrhosis (14). In our cases, the most frequent clinical signs were ascites, pruritus, fever, encephalopathy, diarrhea, gastrointestinal bleeding, clay stool, poor feeding and, palmar erythema. Vomiting, spontaneous bacterial peritonitis (SBP), ecchymosis and tea color urine were other clinical ndings in children with PFIC.
Gastrointestinal bleeding can occur in older children or young adults due to cirrhosis and portal hypertension (15). Sun et al. (16) mentioned that diagnosis of PFIC should be suspected in patients with a clinical history of cholestasis of unknown origin after exclusion of other common cause of cholestasis (20). Both genders are usually equally affected (8). Affected children have a poor quality of life secondary to growth retardation, intractable pruritus and severe rickets (3,10,17).
Biochemical analysis of PFIC patients shows alteration in liver function test. Para-clinical and biochemical analysis of children with PFIC showed elevated levels of liver enzymes such as ALT, AST and alkaline phosphatase. Prolonged international normalized ratio (INR) is common and correctable with injectable vitamin K in early stages of the disease (15). In our study, INR was prolonged compared with normal ranges of healthy children.
There is various ultrasound nding in children with PFIC such as hepatomegaly, splenomegaly and increased echogenicity of the liver (18, 19). Abdominal sonography ndings of our subjects showed liver inhomogeneous echo, splenomegaly (enlarged spleen), hepatomegaly (enlarged liver), cirrhosis, ascites, increased liver echogenicity and, and a small sized liver (in cirrhotic patients). Normal ultrasound ndings were also considerable in our study.
Histopathological ndings in liver specimen biopsies of PFIC patients were also in favor of cirrhosis, brosis, cholestasis, and in ammation of liver tissue, destruction of lobular and vascular architecture which was similar with the results of studies reported by Morotti et al. and (2), Alonso et al. (20) .
Different treatment modalities are considered in treatment of PFIC including liver transplantation, medical therapy and biliary diversion (6). Medical treatment with ursodeoxycholic acid may improve the pruritus and the biochemical tests in 10-50% of the patients (21). Indications for liver transplantation in PFIC patients are severe intractable pruritus, not responding to medical treatment, growth failure despite adequate nutritional support and severe rickets unresponsive to treatment (22,23). In our study, liver transplantation was performed for 67% of patients, medical therapy in 13% and biliary diversion in 11% of the cases. Twelve patients died during the study period. Hereditary liver diseases such as PFIC can cause mortality in infants and children (24). In one study, 1-year mortality after liver transplantation for PFIC was reported ranging from 5-15% (25). In our study, 13.1% of the children with PFIC died during the study period.
Antenatal diagnosis may be proposed for affected families in which a mutation has been identi ed. As well as Ursodeoxycholic acid (UDCA) therapy, biliary diversion may also be effective. However, most PFIC patients are ultimately candidates for liver transplantation.
The study did have some limitations. One of the limitations of the study was lack of molecular investigation data for determination of PFIC type. So, we didn't have any information with regard to PFIC type. As this was a referral center based study we were not able to have an estimate on prevalence of the disease and this would require population based national registries to be established. On the other hand the heterogeneity of our patients makes this study a good representative of the Iranian population.
Moreover, we evaluated different aspects of PFIC patients including clinical and para-clinical variables as well as sonography and liver biopsy analysis in a considerable sample size of patients.
More detailed studies with molecular investigations with longer follow-ups are suggested.

Consent for publication
No individual person's data are present in this manuscript.

Competing interests
There is no Competing interests for this study.

Funding
The study was performed as a PhD thesis with a grant No. of 93-7346.
Authors' contributions MZ, and SMD had designed the study. MZ, FE, MRF, and RK collected data. MZ, SMBT, and AD performed data analysis. MF and MZ wrote the draft manuscript. All authors contributed in revisions.