A 2-month-old male infant was admitted to our hospital with a 1 month history of persistent white stools.
The meconium of the child was dark green. Three days later, his stool turned yellow. After that, the stool color gradually became white stool over the next month. The test results of the infant's liver function were: albumin 16.5 g/L, total bilirubin (TB) 35.2 mumol/l, direct bilirubin (DB) 27.7 mumol/l, and total bile acid (TBA) 63.0 mumol/l. The child had taken probiotics and the symptoms did not improve.
The patient had no significant past medical history. And the mother's pregnancy was uneventful.
At the time of admission, the infant's body weight was 3400 g (<3rd percentile) and his height was 60 cm (50-70th percentile). The physical examination revealed hepatomegaly (4 cm below the ribs with soft texture) and pitting edema of both lower limbs. No abnormality was revealed for the consciousness, cardiopulmonary examination, and nervous system examination.
Routine laboratory testing upon admission showed hemoglobin was 63 g/L, packed cell volume 19.9%, normal mean-cell volume, mean cell hemoglobin concentration was at the lower end of normal, and platelets 304 x 109/L. The patient was tested negative for hepatitis A, B, and, C, syphilis, HIV, TORCH, EBV-IgM antibody, and EBV DNA; his thyroid function and blood coagulation function were within the normal range. The patient's blood glucose during admission was normal and blood and urine tandem mass spectrometry showed that the amino acid and acylcarnitine spectrum analysis were normal. Cytomegalovirus IgM test was positive. Liver function tests revealed slightly elevated levels of TB, DB, and gamma-glutamyltransferase (gamma-GT) (shown in Table 1).
The cardiac ultrasound showed no abnormalities. The chest radiograph was normal. Abdominal ultrasound showed hepatosplenomegaly, liver parenchyma echoes, but the gallbladder and pancreas were normal.
In order to differentially diagnose whether there is biliary atresia (BA), we perfected the examination of liver, gallbladder, spleen color Doppler ultrasound, and gallbladder contraction. In order to differentially diagnose cardiogenic edema, we perfected the cardiac color Doppler ultrasound. The infant's parents refused to permit cholangiography and a liver biopsy. Due to the unclear diagnosis, we performed a genetic test. The infant's genetic analysis showed a CFTR hemizygous mutation site (c.223C>T) in exon 3 and exon 2-3 heterozygous deletion mutation. A genetic verification of the infant's parents was also performed; the father had a point mutation and the mother had a CFTR gene exon 2-3 heterozygous deletion mutation (shown in Figure 1). To further verify whether the child had pancreatic exocrine insufficiency, we tested fecal pancreas elastase 1 and the result was 0.6 mug/g, significantly lower than the normal value of 200 mug/g. Stool testing showed fat globules of 70-80/HP. These findings, combined with the manifestations of cholestasis, supported the diagnosis of CF. Because our hospitals and other testing institutions cannot perform a sweat chloride test, we did not perform it.
After hospital admission, the infant was placed on a lactose-free fortified medium-chain fatty acid milk powder feeding, oral ursodeoxycholic acid (UDCA) 30 mg/(kg.d), and supplemented with fat-soluble vitamins A, D, E, and K. The stool color remained unchanged. Fecal pancreas elastase 1 suggested that the child had insufficient pancreatic exocrine function, so aspergillus oryzae pancreatic enzymes tablets (half a tablet once, three times per day) were added 2 weeks after diagnosis. Two weeks after the oral pancreatic enzyme tablets were administered, the color of the infant's stool changed to yellow and his weight increased (shown in Figure 2).