A262 NEONATAL ACUTE LIVER FAILURE DUE TO PRESUMED GESTATIONAL ALLOIMMUNE LIVER DISEASE - A CASE REPORT

Background

Neonatal acute liver failure (NALF) is a rare disease that is distinct from acute liver failure seen in older children and adults. Gestational alloimmune liver disease (GALD) is the most frequent cause, is initiated in utero by sensitization of the maternal immune system to a fetal hepatocyte antigen and subsequent production of maternal immunoglobulin G antibodies that cross the placenta. Maternal IgG binds to a fetal hepatocyte antigen and initiates an innate immune response involving the terminal complement cascade and membrane attach complex. The understanding of the alloimmune origin has led to the use of intravenous immunoglobulin (IVIG) treatment and exchange transfusion, significantly increasing survival. However, approximately 25% of patients may not respond and require salvage liver transplantation. In spite of an increased rate of comorbidities, concern for technical difficulties and limited graft availability, young infants eligible for transplant have been shown to have similar overall patient and graft survival rates compared to older children with other indications for liver transplant.

Purpose

The primary aim of our study is to report a case of NALF with successful liver transplant.

Method

We present the case of a preterm girl with NALF due to GALD refractory to medical management, requiring liver transplantation.

Result(s)

This is a 35-week preterm girl, with scant pre-natal care, birth weight of 1.825 kg and Apgar 9/9. She is the seventh child of non-consanguineous parents, with healthy siblings. On day-of-life (DOL) 1 she presented with acute kidney injury, progressive worsening metabolic acidosis and hyperammonemia and was found to be profoundly coagulopathic (INR 6), with normal liver enzymes and liver failure was diagnosed. Initial investigation ruled out congenital infections, sepsis, neonatal hemophagocytic lymphohistiocytosis and metabolic diseases. Magnetic resonance imaging of the body demonstrated findings in keeping with iron deposition in the thyroid, liver and pancreas, suggestive of GALD. Completed double volume exchange transfusion and IVIG on DOL 9 and repeat IVIG on DOL 13 and 15, with partial improvement in INR. Due to persistent ascites, conjugated hyperbilirubinemia and hyperammonemia she was transferred for urgent liver transplant assessment. Persistent liver dysfunction in the form of hyperammonemia, hypoglycemia and progressive coagulopathy led to transplant listing on DOL 30. ABO incompatible deceased donor liver transplant was completed on DOL 62 (4.075 kg, estimated dry weight 3.5 kg). The procedure was uncomplicated, liver enzymes normalized, coagulopathy and hypoglycemia resolved. She was transferred to the ward on post-operative day (POD) 6. and weaned off sedatives and transitioned to oral feeds within 2 weeks of transplant, with complex abdominal wound closure on POD 29.

Conclusion(s)

Successful liver transplantation is possible in neonates with acute liver failure due to GALD refractory to medical management and weighing 4kg or less.

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Disclosure of Interest

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MICROBIOME & MICROBIAL THERAPY

A218 A CASE REPORT OF PSEUDOHYPONATREMIA IN CHOLESTATIC LIVER DISEASE

Background

True hyponatremia in the setting of cholestatic liver disease may signify cirrhosis with fluid overload, and is therefore an ominous sign of deteriorating liver function. In pediatric liver transplant candidates, it is associated with increased waitlist mortality. Pseudohyponatremia however, is a falsely low measurement of plasma sodium when measured by indirect potentiometry. Pseudohyponatremia secondary to hypercholesterolemia is a phenomenon that occurs due to a reduced aqueous fraction of the plasma when levels of cholesterol or triglycerides are greatly elevated. Severe hypercholesterolemia due to Lipoprotein X accumulation may be the cause of pseudohyponatremia in biliary obstruction or cholestasis.

Aims

To describe a case of pseudohyponatremia secondary to hypercholesterolemia in an infant with Alagille syndrome (ALGS) and cholestatic liver disease.

Methods

This 7 month-old male with ALGS (confirmed JAGGED1 mutation) and severe cholestasis, failure to thrive, and pruritus, developed new-onset progressive hyponatremia as low as 121 mmol/L at an outside institution. He was therefore transferred to our center for liver transplant assessment due to concerns of progressive liver dysfunction and for management of the hyponatremia.

Results

Upon admission, the patient was jaundiced but euvolemic, with no evidence of ascites or peripheral edema. Laboratory work drawn at our institution showed conjugated bilirubin of 180 mmol/L, ALT 300 U/L, AST 250 U/L, and GGT 1200 U/L. INR was 1.1 and albumin of 35 g/L. The cholesterol was elevated above 16.8 mmol/L, with high triglycerides 2.68 mmol/L, and the serum appeared visibly lipemic. The sodium level was 138 mmol/L as measured by direct potentiometry due to the visible lipemia. The osmolality of 288 mmol/kg was normal with a normal osmolar gap. Urine osmolality and sodium were also normal. He underwent routine evaluation and was listed for a liver transplant due to the profound cholestasis and growth failure.

Conclusions

Pseudohyponatremia is an important entity to recognize when caring for patients with cholestatic liver disease and hyponatremia. Both direct potentiometry and indirect potentiometry are currently used for sodium testing in blood in biochemistry laboratories. These measurement techniques show good agreement as long as protein and lipid concentrations in blood are normal, however, hyperlipidemia is a well-recognized cause for error in sodium estimation. It is therefore imperative to evaluate apparent hyponatremia correctly, especially when the patient appears euvolemic clinically and by normal serum osmolality. In this clinical setting, pseudohyponatremia is the likely cause and a workup should be carried out to identify possible underlying etiologies, the most probable being hypercholesterolemia. Failure to recognize this phenomenon may lead to unnecessary and potentially harmful treatments and interventions.

Funding Agencies

None

Basiliximab with delayed introduction of calcineurin inhibitors as a renal-sparing protocol following liver transplantation in children with renal impairment

Renal impairment is frequently compromised in patients with end-stage liver disease and is associated with increased long-term mortality post-LT. In contrast to CNI, basiliximab is an immunosuppressive agent with minimal nephrotoxic potential. This study reviews the experience of a single pediatric liver transplant center's renal-sparing approach with the use of basiliximab and MMF to compensate for delayed entry of CNI in children with renal impairment at the time of organ availability. There were no differences in renal function between pediatric patients with and without pre-LT renal impairment within the first year (cGFR: 135 mL/min/1.73 m2 vs. 144 mL/min/1.73 m2 ; p = 0.56) or at 5-8 yr following LT, (129 mL/min/1.73 m2 vs. 130 mL/min/1.73 m2 ; p = 0.97). In addition, there was no difference in ACR rates (50% vs. 43%, p = 0.62) between patients in the basiliximab group and those patients receiving standard CNI and steroid strategies. The utilization of a renal-sparing approach with basiliximab alongside delayed entry and lower early target trough levels of CNI in children with renal impairment at the time of LT is safe and maintains excellent long-term kidney function.

Intra-operative parathyroid hormone monitoring in secondary hyperparathyroidism: is it useful?

OBJECTIVES

To assess the use of intra-operative parathyroid hormone (PTH) level monitoring as a predictor of persistent hypoparathyroidism after total parathyroidectomy in renal hyperparathyroidism.

SETTING

University Teaching Hospital Otorhinolaryngology and Head and Neck Surgery Unit.

PARTICIPANTS

All patients with renal hyperparathyroidism undergoing parathyroidectomy between January 2004 and July 2005. Twenty-nine patients were identified.

MAIN OUTCOME MEASURES

Comparison is made between pre- and intra-operative PTH levels (ioPTH) in patients who at 3 months postoperatively maintained hypoparathyroidism and patients who did not. Results were analysed to see whether ioPTH predicts maintenance of the hypoparathyroid state.

RESULTS

The mean preoperative PTH level was 932 pg/L (range: 58-1808). The mean postoperative PTH level was 147 pg/L (range: 16-498). The mean 3-month PTH level was 47 pg/L (range: <1-515). The mean postoperative PTH level for patients with a persistently high PTH level at 3 months was 286 pg/L (range: 272-299), compared with 63 pg/mL (16-160) in patients remaining normparathyroid, and 159 pg/L (range: 39-498) for patients with persistent hypoparathyroidism. If the normoparathyroid state is strictly considered to be failure following total parathyroidectomy, ioPTH is not predictive of hypoparathyroidism. However, ioPTH is indicative of biochemical resolution of the hyperparathyroid state (normo- or hypoparathyroidism).

CONCLUSION

We conclude that the use of ioPTH monitoring in the surgical management of secondary hyperparathyroidism fails to predict persistent hypoparathyroidism following total parathyroidectomy, but does predict biochemical resolution of hyperparathyroidism.

Accelerated solvent extraction and gas chromatography/mass spectrometry for determination of polycyclic aromatic hydrocarbons in smoked food samples

Accelerated solvent extraction (ASE) is a new sample extraction method offering a number of advantages such as low pe -extraction cost, reduced solvent and time consumption, and simplified extraction protocols. In this study, the ASE method was applied to the extraction of polycyclic aromatic hydrocarbons (PAHs) from biological samples. For recovery studies, fish tissues and ground pork were used as sample matrices. Sample aliquots fortified with 16 PAHs were extracted by ASE, and the extracts were treated with sulfuric acid and Florisil, followed by gas chromatography-mass spectrometry analysis. The PAH recoveries by the ASE method were found to be comparable with or better than those by Soxhlet extraction. The extraction and quantitation method was then applied to the determination of PAHs in several smoked meat samples obtained from a local market. Up to 12 PAHs were found to be present at concentrations ranging from 3 to 52 ng/g wet sample.

A high performance liquid radiochromatographic assay for the simultaneous analysis of iloprost and misoprostol

A high-performance liquid chromatographic (HPLC) method utilizing ultraviolet absorbance coupled with radioisotove detection was developed for the precise and simultaneous determination of iloprost and misoprostol. This assay allows complete resolution of iloprost diastereoisomers and has a total run time of approximately twenty minutes. Samples were prepared for chromatographic analysis by extracting a mixture of tritiated drugs from rat plasma with acetonitrile. The resulting solutions were chromatographed on a reversed phase Zorbax Rx-C8 column using 0.02M potassium phosphate (pH 3.0), acetonitrile, and methanol (46:30:24, v/v) at a flow rate of 1.7 mL/min. 2-Naphthoic acid was employed as an internal standard. The correlation coefficient for varying concentrations of tritiated iloprost (12.7 Ci/mmol specific activity) from 2.18 ng/mL to 21.8 ng/mL was 0.995, and the correlation coefficient for concentrations of tritiated misoprostol (50 Ci/mmol specific activity) from 0.617 ng/mL to 6.17 ng/mL was 0.993. The high selectivity and sensitivity of this assay make it useful for the simultaneous quantitation of iloprost and misoprostol.

How we do it: use of a venous cannulation needle for endoscopic Teflon injection to the vocal folds

Since its introduction in the 1960's the injection of Teflon into a paralysed vocal fold has become a standard treatment in laryngology. Although in recent years alternative treatments have been suggested, such as the injection of collagen or autogenous fat (Mikaelian et al., 1991), re-innervation procedures and thyroplasty (Crumley, 1990), the use of Teflon is still widespread (Rontal and Rontal, 1991; Dedo, 1992). Various instruments have been developed for the application of Teflon paste and these take the form of a gun-like syringe with a ratchet mechanism. For a number of years we have injected Teflon using a needle marketed for internal jugular vein cannulation along with a plastic 1 ml syringe thus making substantial savings to our department in terms of both time and cost.

Anaesthesia, movement and emesis

One hundred and eighty-two women undergoing dilatation and curettage were allocated randomly to receive premedication comprising temazepam, papaveretum-hyoscine or placebo. The temazepam recipients reported significantly fewer episodes of postoperative nausea. Movement was blamed by 66% of patients who identified a cause for nausea. These patients had higher scores on a motion sickness susceptibility questionnaire and were more likely to have been treated previously for nausea or vomiting. It may be possible to identify susceptible patients before surgery.

Mediastinal emphysema simulating acute pericarditis

A case of extensive subcutaneous emphysema, retropneumoperitoneum and mediastinal emphysema is described. The mediastinal emphysema was associated with signs and symptoms of pericardial tamponade, and previously undocumented ECG changes, consistent with acute pericarditis, were noted.

Automated analysis of chlorthalidone

Chlorthalidone inhibition of the enzymatic hydrolysis rate of p-nitrophenyl acetate by bovine erythrocyte carbonic anhydrase was used as a basis for chlorthalidone determination in plasma and urine. For urinary samples, a completely automated, continuous flow system was developed to extract the samples and perform the enzymatic reaction. Over 100 samples per day could be assayed by one person. The assay had a sensitivity of 0.5 micrograms/ml and thus could determine urinary concentrations after a therapeutic chlorthalidone dose. To determine plasma concentrations after a therapeutic dose, a manual extraction procedure was used in combination with a second continuous flow system for the enzymatic reaction. This system was optimized to detect the lowest chlorthalidone concentration allowed by the enzymatic inhibition constant and could detect 25 ng/ml.