Steven N. Lichtman

Features and Outcomes of 899 Patients With Drug-Induced Liver Injury: The DILIN Prospective Study

BACKGROUND & AIMS The Drug-Induced Liver Injury Network is conducting a prospective study of patients with DILI in the United States. We present characteristics and subgroup analyses from the first 1257 patients enrolled in the study. METHODS In an observational longitudinal study, we began collecting data on eligible individuals with suspected DILI in 2004, following them for 6 months or longer. Subjects were evaluated systematically for other etiologies, causes, and severity of DILI. RESULTS Among 1257 enrolled subjects with suspected DILI, the causality was assessed in 1091 patients, and 899 were considered to have definite, highly likely, or probable DILI. Ten percent of patients died or underwent liver transplantation, and 17% had chronic liver injury. In the 89 patients (10%) with pre-existing liver disease, DILI appeared to be more severe than in those without (difference not statistically significant; P = .09) and mortality was significantly higher (16% vs 5.2%; P < .001). Azithromycin was the implicated agent in a higher proportion of patients with pre-existing liver disease compared with those without liver disease (6.7% vs 1.5%; P = .006). Forty-one cases with latency ≤7 days were caused predominantly by antimicrobial agents (71%). Two most common causes for 60 DILI cases with latency >365 days were nitrofurantoin (25%) or minocycline (17%). There were no differences in outcomes of patients with short vs long latency of DILI. Compared with individuals younger than 65 years, individuals 65 years or older (n = 149) were more likely to have cholestatic injury, although mortality and rate of liver transplantation did not differ. Nine patients (1%) had concomitant severe skin reactions; implicated agents were lamotrigine, azithromycin, carbamazepine, moxifloxacin, cephalexin, diclofenac, and nitrofurantoin. Four of these patients died. CONCLUSIONS Mortality from DILI is significantly higher in individuals with pre-existing liver disease or concomitant severe skin reactions compared with patients without. Additional studies are needed to confirm the association between azithromycin and increased DILI in patients with chronic liver disease. Older age and short or long latencies are not associated with DILI mortality.

Hepatic inflammation in rats with experimental small intestinal bacterial overgrowth

Hepatobiliary inflammation and other extraintestinal manifestations accompany certain intestinal disorders, perhaps because of proliferation or enhanced transport of luminal bacteria or their phlogistic cell-wall components. Using jejunal self-filling blind loops to create small bowel bacterial overgrowth, we compared biochemical and histological evidence of hepatic inflammation in 3 rat strains chosen for their variable inflammatory responses to bacterial cell wall polymers. Lewis and Wistar rats developed weight loss, hepatomegaly, and hepatic inflammation 4 and 12 wk, respectively, after creation of SFBL. Plasma aspartate aminotransferase levels in Lewis rats 4 wk (578 +/- 77 U/L) and Wistar rats 12 wk (220 +/- 35 U/L) after self-filling blind loops were significantly greater than in rats with self-emptying blind loops (112 +/- 24 U/L, p less than 0.001; 104 +/- 22, p less than 0.05) or sham-operated Lewis (84 +/- 24, p less than 0.001) or Wistar (78 +/- 10, p less than 0.001) rats. Randomized comparison using a histology grading score showed abnormalities that paralleled aminotransferase values. Lewis and Wistar rats with self-filling blind loops had hepatic injury with bile duct proliferation, fibrosis and acute and chronic periportal and focal parenchymal inflammation. Lewis and Wistar rats with self-emptying blind loops developed occasional mild histologic lesions. 50% of Lewis rats with self-filling blind loops for 4 wk died compared with only 15% in other groups. However, Buffalo rats with self-filling blind loops developed no weight loss, hepatomegaly, or hepatic injury. Anaerobic cultures of blood, peritoneum and liver were negative in all strains. Diet-restricted, sham-operated Wistar rats with weights similar to the Wistar rats with self-filling blind loops did not develop histologic abnormalities or elevated aminotransferase levels (76 +/- 31 U/L). These results show that experimental small bowel bacterial overgrowth causes significant hepatic inflammation leading to fibrosis in susceptible rat strains. Caloric deprivation and hepatic bacterial invasion are not etiologically responsible. We suggest that bacterial cell wall polymers or other bacterial toxins from the blind loop cause hepatic lesions in genetically susceptible hosts.

Studies of Pediatric Liver Transplantation (SPLIT) : Year 2000 outcomes

Background. Initiated in 1995, the Studies of Pediatric Liver Transplantation (SPLIT) registry database is a cooperative research network of pediatric transplantation centers in the United States and Canada. The primary objectives are to characterize and follow trends in transplant indications, transplantation techniques, and outcomes (e.g., patient/graft survival, rejection, growth parameters, and immunosuppressive therapy.) Methods. As of June 15, 2000, 29 centers registered 1144 patients, 640 of whom received their first liver-only transplant while registered in SPLIT. Patients are followed every 6 months for 2 years and yearly thereafter. Data are submitted to a central coordinating center. Results. One/two-year patient survival and graft loss estimates are 0.85/0.82 and 0.77/0.72, respectively. Risk factors for death include: in ICU at transplant (relative risk (RR)=2.63, P <0.05) and height/weight deficits of two or more standard deviations (RR=1.67, P <0.05). Risk factors for graft loss include: in ICU at transplant (RR=1.77, P <0.05) and receiving a cadaveric split organ compared with a whole organ (RR=2.3, P <0.05). The percentage of patients diagnosed with hepatic a. and portal v. thrombosis were 9.7% and 7%, respectively; 15% had biliary complications within 30 days. At least one re-operation was required in 45%. One/two-year rejection probability estimates are 0.60/0.66. Tacrolimus, as primary therapy posttransplant, reduces first rejection risk (RR=0.70, P <0.05). Eighty-nine percent of school-aged children are in school full-time, 18 months posttransplant. Conclusions. This report provides one of the first descriptions of characteristics and clinical courses of a multicenter pediatric transplant population. Observations are subject to patient selection biases but are useful for generating hypothesis for future studies.

Hepatic Injury Associated With Small Bowel Bacterial Overgrowth in Rats Is Prevented by Metronidazole and Tetracycline

Susceptible rat strains develop hepatobiliary injury following the surgical creation of self-filling blind loops that cause small bowel bacterial overgrowth. Luminal bacteria or their cell wall polymers were implicated in the pathogenesis of the lesions because sham-operated rats and rats with self-emptying blind loops, having only slightly increased bacterial counts, did not develop hepatic injury. In this study, antibiotics with different spectra of activities were continuously administered starting 1 day or 22 days after surgery to determine which intestinal flora may be responsible for the development of hepatic injury in rats with small bowel bacterial overgrowth. Four weeks following surgery, Lewis rats with self-filling blind loops receiving no antibiotics had elevated liver histology scores (8.2 +/- 1.3 vs. 0.7 +/- 0.4) and plasma aspartate aminotransferase levels (269 +/- 171 vs. 84 +/- 24) compared with sham-operated rats, P less than 0.001. Oral gentamicin as well as oral and intraperitoneal polymyxin B, which binds endotoxin, did not prevent hepatic injury in rats with self-filling blind loops. However, oral metronidazole and tetracycline therapy continuously administered beginning 1 day after surgery diminished hepatic injury (histology score 3.0 +/- 1.8, 2.9 +/- 1.1; aspartate aminotransferase 87 +/- 25, 98 +/- 34; respectively P less than 0.001 compared with self-filling blind loops receiving no antibiotics). Metronidazole also protected Wistar rats that require 12 weeks to develop hepatic injury following experimentally induced small bowel bacterial overgrowth compared with rats with self-filling blind loops that received no antibiotic treatment (histology score 10.4 +/- 1.3 vs. 0.7 +/- 1.1, and aspartate aminotransferase 273 +/- 239 vs. 76 +/- 20, P less than 0.001). When rats started metronidazole therapy 22 days after self-filling blind loop surgery, elevated aspartate aminotransferase values decreased to normal during the next 77 days and final histology scores were normal. All rats with self-filling blind loops had negative peritoneal, liver, spleen, and blood cultures but approximately 75% of mesenteric lymph node cultures were positive irrespective of antibiotic treatment. Because Bacteroides species have been implicated in causing vitamin B12 and disaccharidase deficiencies in rats with self-filling blind loops, we documented the presence or absence of these organisms from blind loops using selective culture techniques. Metronidazole and tetracycline eliminated Bacteroides sp. from blind loops, but polymyxin B and gentamicin did not.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal migraine: Prophylactic treatment and follow-up

BACKGROUND Abdominal migraine is a syndrome characterized by recurrent stereotypic episodes of paroxysmal abdominal pain and nausea and/or vomiting with wellness between episodes. It is often associated with a positive family history of migraine and no other apparent underlying disease. The purpose of this study was to report in patients diagnosed with abdominal migraine the outcome, the effect of prophylactic treatment, and the duration of treatment. METHODS The records of 53 patients who underwent treatment after a diagnosis of abdominal migraine were retrospectively reviewed. Responses to treatment were graded as excellent (cessation of recurrent abdominal pain), fair (persistence of symptoms but milder and less frequent), or poor (no response). Follow-up data were available in 38 patients. Twenty-four patients were treated with propranolol and 12 with cyproheptadine. Four were not treated because of mild and infrequent symptoms. RESULTS Among the children treated with propranolol, 18 (75%) had an excellent response, 2 (8%) had a fair response, and 4 (17%) had no response. In those treated with cyproheptadine, 4 (33%) had an excellent response, 6 (50%) had a fair response, and 2 (17%) had no response. Patients were instructed to continue medication for 6 months or until cycles had stopped. However, 11 of 24 patients (46%) in the propranolol group took medication for less than 6 months and the remaining patients from 6 months to 3 years. Six patients in the cyproheptadine group (50%) took medication less than 10 months and the remaining patients for 10 months to 3 years. CONCLUSION Patients with abdominal migraine may benefit from prophylactic treatment with propranolol or cyproheptadine.

LPS receptor CD14 participates in release of TNF-α in RAW 264.7 and peritoneal cells but not in Kupffer cells

Lipopolysaccharide (LPS) is a bacterial polymer that stimulates macrophages to release tumor necrosis factor-α (TNF-α). In macrophages (RAW 264.7 and peritoneal cells), LPS binds to the CD14 surface receptor as the first step toward signaling. Liver macrophages, Kupffer cells, are the most numerous fixed-tissue macrophage in the body. The presence of CD14 on Kupffer cells and its role in LPS stimulation of TNF-α were examined. TNF-α release by Kupffer cells after LPS stimulation was the same in the presence and absence of serum. RAW 264.7 and peritoneal cells, which utilize the CD14 receptor, released significantly less TNF-α after LPS stimulation in the absence of serum because of the absence of LPS-binding protein. Phosphatidylinositol-phospholipase C treatment, which cleaves the CD14 receptor, decreased LPS-stimulated TNF-α release by RAW 264.7 cells but not by Kupffer cells. Deacylated LPS (dLPS) competes with LPS at the CD14 receptor when incubated in a ratio of 100:1 (dLPS/LPS). Such competition blocked LPS-stimulated TNF-α release from RAW 264.7 cells but not from Kupffer cells. Western and fluorescence-activated cell sorter analysis directly demonstrated the presence of CD14 on RAW 264.7 cells and murine peritoneal cells but showed only minimal amounts of CD14 in murine Kupffer cells. LPS stimulation did not increase the amount of CD14 detectable on mouse Kupffer cells. CD14 expression is very low in Kupffer cells, and LPS-stimulated TNF-α release is independent of CD14 in these cells.

Protection by Carolina rinse solution, acidotic pH, and glycine against lethal reperfusion injury to sinusoidal endothelial cells of rat livers stored for transplantation

The critical injury causing graft failure after prolonged liver storage involves reperfusion-induced killing of sinusoidal endothelial cells and activation of Kupffer cells. Treatment of stored livers with Carolina rinse solution (CRS) prevents endothelial cell killing, reduces Kupffer cell activation, and improves graft survival. Accordingly, our aim was to evaluate the components of CRS and other agents for protection against reperfusion injury to rat livers stored 24 hr in University of Wisconsin solution. CRS virtually abolished endothelial cell killing, prevented denudation of the sinusoidal lining, and decreased structural changes in Kupffer cells indicative of activation. The only component of CRS preventing endothelial cell killing was acidic pH of 6.5. However, when pH was subsequently increased to 7.4, antioxidants (allopurinol, deferoxamine mesylate, and glutathione), vasodilators (adenosine and nicardipine), and possibly energy substrates (fructose, glucose, and insulin) partially blocked pH-dependent cell killing (pH paradox). Na+/H+ exchange inhibition, protease inhibition, and Ca(2+)-free buffer did not decrease reperfusion injury, but the amino acid glycine protected strongly. Strychnine, which binds to glycine receptors in the central nervous system, protected equally well. Protection by glycine and CRS was synergistic, virtually.

Animal models of intestinal and joint inflammation

Recent rodent models have been exploited to explore mechanisms of intestinal and joint inflammation. HLA-B27 transgenic rats develop colitis, gastritis, and arthritis when raised in a conventional environment, but have no evidence of inflammation under germfree (sterile) conditions. Metronidazole treatment attenuates gastrointestinal inflammation, suggesting that anaerobic bacteria are important. Experimental bacterial over-growth of predominantly anaerobic bacteria reactivates arthritis in Lewis rats which have been previously injected intra-articularly with bacterial cell wall polymers. Reactivation arthritis is mediated by interleukin-1, tumour necrosis factor-alpha, and can be blocked by metronidazole. Intramural injection of the bacterial cell wall polymer, peptidoglycan-polysaccharide, leads to biphasic, chronic granulomatous enterocolitis and peripheral arthritis in Lewis rats, but only transient intestinal inflammation and no arthritis in Buffalo or MHC-matched Fischer rats. Chronic granulomatous inflammation is mediated by T lymphocytes and interleukin-1 and is dependent on persistent antigenic stimulation by poorly biodegradable bacterial polymers. Results in these models firmly incriminate resident normal enteric flora (especially anaerobes), bacterial products, and host genetic susceptibility in the pathogenesis of spondyloarthropathies. We suggest that increased uptake of luminal bacterial components across the inflamed mucosa leads to systemic distribution of these arthropathic products. The genetically susceptible host develops reactive arthritis due to defective downregulation of inflammation in response to immunologically active bacterial components.

Acute Valproic Acid Overdose: Clinical Course and Pharmacokinetic Disposition of Valproic Acid and Metabolites

SummaryAcute toxicity in the setting of valproic acid (valproate sodium) overdose is in most cases benign and readily reversible. However, serious toxicity has been reported. We present a case of accidental acute valproic acid overdose in a 26-month-old female, in whom serious neurological, metabolic, haematological and respiratory sequelae occurred. The major toxicity observed was delayed cerebral oedema. We also present data not previously reported, which describes the pharmacokinetic disposition of valproic acid and several of its metabolites during the course of this acute overdose. A comparison of an enzyme immunoassay and gas liquid chromatographic methodologies for measuring valproic acid in this setting is also presented. It appears that the 2-EN-valproic acid metabolite plays a role in the neurological toxicity.

A rat model of ileal pouch-rectal anastomosis.

Summary: After colectomy and ileal pouch‐rectal anastomosis, pouchitis may occur. Pouchitis is a poorly defined condition with unknown etiology. The aim of this study was to develop an animal model of pouchitis. Ileal pouch‐rectal anastomosis was created in Lewis and Sprague‐Dawley rats. Rats were studied 4 and 8 weeks after surgery, and pouchitis was assessed by stool output, histology, and tissue myeloperoxidase (MPO) levels. Some rats were treated with allopurinol or metronidazole beginning the day of surgery. Rats with pouches demonstrated inflammation with a monocytic infiltration, luminal exudate, mucosal ulcerations, and serosal inflammation. Rats with pouches had increased anaerobic bacterial flora compared with normal ileum. After creation of pouches, Lewis rats (histology score = 8.4 ± 1.6; MPO = 17.3 ± 3.6, mean ± SD) developed more severe inflammation than Sprague‐Dawley rats did (histology score = 4.3 ± 1.8; MPO = 5.5 ± 3.6) within 4 weeks, p < 0.001 and 8 weeks after surgery, p < 0.05. Stool output was also greater in Lewis (55 ± 7 g/kg/day) compared with Sprague‐Dawley rats with pouches (43 ± 5 g/kg/day), p < 0.05. Metronidazole treatment reduced histology score (6.0 ± 0.5) p < 0.05 and MPO (5.9 ± 1.6) p < 0.001 in rats with pouches compared with rats with pouches that had no treatment. Allopurinol treatment in rats with pouches reduced histology score (4.0 ± 1.7) and MPO (3.9 ± 1.6), p < 0.001, compared with rats with pouches that had no treatment. Ileal pouch‐rectal anastomosis in rats induced inflammation within 4 weeks, demonstrated differential host genetic susceptibility, and was associated with increased number of pouch bacteria. Anaerobes, especially bacteroides sp. and free radicals, may mediate inflammation. Ileal pouch‐rectal anastomosis surgery in rats may be a useful animal model for the study pouchitis.