Albinism in phylogenetically and geographically distinct populations of Astyanax cavefish arises through the same loss-of-function Oca2 allele

The Mexican tetra, Astyanax mexicanus, comprises 29 populations of cave-adapted fish distributed across a vast karst region in northeastern Mexico. These populations have a complex evolutionary history, having descended from 'old' and 'young' ancestral surface-dwelling stocks that invaded the region ∼6.7 and ∼2.8 MYa, respectively. This study investigates a set of captive, pigmented Astyanax cavefish collected from the Micos cave locality in 1970, in which albinism appeared over the past two decades. We combined novel coloration analyses, coding sequence comparisons and mRNA expression level studies to investigate the origin of albinism in captive-bred Micos cavefish. We discovered that albino Micos cavefish harbor two copies of a loss-of-function ocular and cutaneous albinism type II (Oca2) allele previously identified in the geographically distant Pachón cave population. This result suggests that phylogenetically young Micos cavefish and phylogenetically old Pachón cave fish inherited this Oca2 allele from the ancestral surface-dwelling taxon. This likely resulted from the presence of the loss-of-function Oca2 haplotype in the 'young' ancestral surface-dwelling stock that colonized the Micos cave and also introgressed into the ancient Pachón cave population. The appearance of albinism in captive Micos cavefish, caused by the same loss-of-function allele present in Pachón cavefish, implies that geographically and phylogenetically distinct cave populations can evolve the same troglomorphic phenotype from standing genetic variation present in the ancestral taxon.

Non-responders to previous treatment for hepatitis C

The main principle in treating chronic hepatitis C is the prevention of serious liver complications. Because curing hepatitis C virus infection has been demonstrated to prevent progression of liver disease and even promote regression of fibrosis, it remains the primary goal of treatment. However, nearly half of patients are not cured with our best treatment. Patients who failed older therapies should be treated with peginterferon and ribavirin, but those with advanced fibrosis or African heritage will have very low rates of response. Non-responders to peginterferon and ribavirin present a special challenge. If there were problems related to dosing, adherence, or access during treatment, then one can consider re-treating with the same regimen if the problems can be corrected. Otherwise, non-responders with early-stage fibrosis can observe without further treatment until newer drugs are available. Those with advanced fibrosis should consider low-dose peginterferon maintenance treatment or participation in an experimental trial. Experimental approaches include intensification of existing therapies, combination of new agents with existing drugs, long-term virus suppression, inhibition of liver fibrogenesis, and inhibition of hepatitis C RNA or hepatitis C viral enzymes.

Herpes esophagitis: clinical syndrome, endoscopic appearance, and diagnosis in 23 patients

The unexpected diagnosis of herpetic esophagitis in a patient with nausea led us to review our experience with this disease. Review of our records from 1979 to 1989 produced 23 cases proven by endoscopic culture or microscopic examination (Cowdry-type A inclusions), the largest such series reported to date. Twenty-two of the 23 patients were immunocompromised. Odynophagia and chest pain were each present in half of the cases, but 26% of patients had neither. Gastrointestinal bleeding was attributable to herpetic esophagitis in 30%. Thirty percent of patients had disseminated herpes simplex infection and 70% had simultaneous infections with other organisms. Endoscopic findings included nonspecific inflammation, discrete ulcers, coalescent ulcers, and pseudomembranous esophagitis. Herpes virus was not suspected endoscopically as the cause of esophagitis in 30% of cases. Culture was slightly more sensitive than microscopic examination for diagnosis (89% vs. 76%), but both methods should be employed in any immunocompromised patient with esophagitis.

Outcome of hospital care of liver disease associated with hepatitis C in the United States

We describe mortality and resource utilization for inpatient care of hepatitis C (HCV) in comparison to alcohol-induced liver disease (ALD) in the United States and identify factors that affect outcomes. The Healthcare Cost and Utilization Project database, a national inpatient sample was used to identify hospitalization records with diagnoses related to liver disease from HCV and ALD. Outcome of hospitalizations was analyzed in terms of in-hospital deaths and health care resource utilization. For 1995, we estimate that there were 26,700 hospitalizations and 2,600 deaths in acute, nonfederal hospitals in the United States for liver diseases caused by HCV. Total charges for these hospitalizations were $514 million. In comparison, ALD was associated with 101,200 hospitalizations, 13,400 deaths, and $1.8 billion in charges. Simultaneous HCV and alcohol abuse was associated with younger ages at the time of hospitalization and death compared with HCV or ALD alone. In a logistic regression analysis, alcohol abuse (odds ratio [OR], 1.4; 95% confidence interval [CI], 1.2-1.5) and human immunodeficiency virus (HIV) infection (OR, 4.5; 95% CI, 4.0-4.9) were associated with an increased risk of death among those with HCV. Liver transplantation and patient death were associated with the largest increase in hospitalization charges. Major complications of cirrhosis, such as variceal bleeding, encephalopathy, and hepatorenal syndrome, and sociodemographic factors, such as race and health insurance, were also significantly associated with the risk of death and hospitalization charges, which were similar in HCV and ALD. This study provides new estimates regarding the public health impact of HCV, for use in health policy decisions and cost-effectiveness analyses of preventive and therapeutic interventions.

Human leukocyte antigen DR markers as predictors of progression to liver transplantation in patients with chronic hepatitis C

OBJECTIVE

Because many patients with chronic viral hepatitis do not progress to end-stage liver disease, it is possible that host factors such as human leukocyte antigen (HLA) differences are important. Our aims were to determine HLA marker-specific rates of progression to liver transplantation among patients with chronic hepatitis C; and to determine if polymerase chain reaction (PCR)-based HLA DRB1 typing can be performed on stored serum samples.

METHODS

Forty-two hepatitis C virus RNA-positive liver transplant patients and 87 untransplanted patients were included in a Cox proportional hazards model to test whether the occurrence of certain HLA DRB1 markers were associated with progression to liver transplantation. HLA DRB1 typing was performed on stored serum samples using a PCR method.

RESULTS

There were no differences among the HLA DRB1 markers with regard to the HLA marker-specific rate of progression to transplantation among patients with chronic hepatitis C.

CONCLUSIONS

HLA DRB1 markers do not appear to be associated with progression of disease in chronic viral hepatitis C. It is possible to perform PCR-based HLA DRB1 typing on stored frozen serum samples.

Multiport epidural catheters: does the air test work?

BACKGROUND

Multiport epidural catheters are popular; however, the reliability of the air test has not been evaluated with this catheter design. The authors determined the effectiveness of aspirating for blood and the air test in detecting intravascular multiorifice epidural catheters.

METHODS

Three hundred women in labor underwent placement of a blunt-tip, three-hole, 20-gauge, lumbar epidural catheter. If there were no signs of spinal anesthesia, 3 ml lidocaine or bupivacaine was injected and the patient was observed for signs of spinal anesthesia. If there were no signs of spinal anesthesia, the authors injected 1 ml air through the epidural catheter while listening to the maternal precordium using a Doppler fetal heart rate monitor. Catheters through which blood was aspirated were air-tested and replaced. Patients with air-test-positive, blood-aspiration-negative catheters received 100 mg lidocaine through the catheter and were questioned about toxicity symptoms. The authors injected bupivacaine-fentanyl through aspiration-negative,air-test-negative catheters and recorded the sensory analgesic level 20 min later.

RESULTS

The authors aspirated cerebrospinal fluid through one catheter and documented intravascular placement in 11 catheters. Results of the air test and blood aspiration were positive for eight catheters. Blood could not be aspirated from one air-test-positive catheter; perioral numbness developed in the patient after lidocaine injection. Blood was freely aspirated from two air-test-negative catheters. In the remaining 288 catheters, bupivacaine-fentanyl injection produced epidural analgesia in 279 patients and no effect in 9 patients.

CONCLUSIONS

The authors obtained false-negative results with both catheter aspiration and the air test. Fractionating the local anesthetic dose is important when using multiorifice epidural catheters.

Hepatitis A antibodies in liver transplant recipients: evidence for loss of immunity posttransplantation

Liver transplant recipients frequently have chronic liver diseases and should be considered for vaccination against hepatitis A virus (HAV). However, persistence of protective antibodies after orthotopic liver transplantation (OLT) has not been shown in this population, which may have implications for future vaccine recommendations. We evaluated the prevalence and epidemiological significance of immunoglobulin G (IgG) antibody to HAV (anti-HAV) in a nonvaccinated population before OLT (immunity from previous exposure) and determined the persistence of IgG anti-HAV at 1 and 2 years after OLT. One hundred consecutive patients were identified who underwent OLT and had at least 2 years of follow-up post-OLT. They were not vaccinated against HAV infection at any time. Clinical data were summarized from medical records, and stored sera were tested for IgG anti-HAV before OLT and at 1 and 2 years after OLT by a commercially available enzyme immunoassay. Of 100 patients, 24 had IgG anti-HAV before OLT. No epidemiological differences were noted between those with or without detectable IgG anti-HAV before OLT. Among patients with detectable IgG anti-HAV before OLT, 4 of 22 patients (18%) and 7 of 24 patients (29%) became negative for IgG anti-HAV at 1 and 2 years post-OLT, respectively. None of the patients with undetectable IgG anti-HAV before OLT became positive at any time. Most of our patients with end-stage liver disease had no serological evidence for immunity against HAV. A significant proportion of patients with detectable protective antibodies before OLT lost their antibodies at 2 years after OLT.

The pharmacodynamic effect of a remifentanil bolus on ventilatory control

BACKGROUND

In doses typically administered during conscious sedation, remifentanil may be associated with ventilatory depression. However, the time course of ventilatory depression after an initial dose of remifentanil has not been determined previously.

METHODS

In eight healthy volunteers, the authors determined the time course of the ventilatory response to carbon dioxide using the dual isohypercapnic technique. Subjects breathed via mask from a to-and-fro circuit with variable carbon dioxide absorption, allowing the authors to maintain end-tidal pressure of carbon dioxide (PET(CO2)) at approximately 46 or 56 mm Hg (alternate subjects). After 6 min of equilibration, subjects received 0.5 microg/kg remifentanil over 5 s, and minute ventilation (V(E)) was recorded during the next 20 min. Two hours later, the study was repeated using the other carbon dioxide tension (56 or 46 mm Hg). The V(E) data were used to construct two-point carbon dioxide response curves at 30-s intervals after remifentanil administration. Using published pharmacokinetic values for remifentanil and the method of collapsing hysteresis loops, the authors estimated the effect-site equilibration rate constant (k(eo)), the effect-site concentration producing 50% respiratory depression (EC50), and the shape parameter of the concentration-response curve (gamma).

RESULTS

The slope of the carbon dioxide response decreased from 0.99 [95% confidence limits 0.72 to 1.26] to a nadir of 0.27 l x min(-1) x mm Hg(-1) [-0.12 to 0.66] 2 min after remifentanil (P<0.001); within 5 min, it recovered to approximately 0.6 l x min(-1) x mm Hg(-1), and within 15 min of injection, slope returned to baseline. The computed ventilation at PET = 50 mm Hg (VE50) decreased from 12.9 [9.8 to 15.9] to 6.1 l/min [4.8 to 7.4] 2.5 min after remifentanil injection (P<0.001). This was caused primarily by a decrease in tidal volume rather than in respiratory rate. Estimated pharmacodynamic parameters based on computed mean values of VE50 included k(eo) = 0.24 min(-1) (T1/2 = 2.9 min), EC50 = 1.12 ng/ml, and gamma = 1.74.

CONCLUSIONS

After administration of 0.5 microg/kg remifentanil, there was a decrease in slope and downward shift of the carbon dioxide ventilatory response curve. This reached its nadir approximately 2.5 min after injection, consistent with the computed onset half-time of 2.9 min. The onset of respiratory depression appears to be somewhat slower than previously reported for the onset of remifentanil-induced electroencephalographic slowing. Recovery of ventilatory drive after a small dose essentially was complete within 15 min.

Unrecognized bulimia nervosa: a potential cause of perioperative cardiac dysrhythmias

PURPOSE

To report serious cardiac dysrhythmias in two patients whose bulimia nervosa was not revealed during preoperative screening.

CLINICAL REPORT

Case #1: A 25-yr-old woman with preoperative hypokalemia (K+ = 3.1 mEq x l(-1)) required anesthesia for removal of a wrist ganglion. She claimed the hypokalemia was of unknown etiology, and denied other medical problems. Shortly after induction of anesthesia with thiopental and isoflurane, the ECG revealed two runs of torsades de pointes. This was successfully treated by decreasing pulmonary ventilation, allowing P(ET)CO2 to increase from 32 to 45 mm Hg. Case #2: A 39-yr-old woman who denied any medical problems received propofol, rocuronium sevoflurane and N2O during general anesthesia for breast augmentation. In the PACU, the patient complained of light-headedness, and the ECG revealed a heart rate of 44 bpm with P-R interval of 0.42 sec. Following 0.5 mg atropine, the heart rate increased but the P-R interval remained prolonged (0.36 sec) and the corrected Q-T interval was 0.51 sec. Treatment with 2.5 g MgSO4, 20 mEq KCl, and 9.4 mEq calcium gluconate i.v. normalized the Q-T interval, and decreased the P-R interval to 0.22 sec. Upon specific questioning, she admitted to a remote history of bulimia, but denied any bulimic behavior for the last 16 yr.

CONCLUSION

Two patients with histories of eating disorders failed to disclose this information during preoperative evaluation. Perioperative cardiac dysrhythmias developed in these patients, even though they claimed that eating behavior had returned to normal.

Clinical significance of TT virus infection in patients with chronic hepatitis C

OBJECTIVE

The TT virus (TTV) is a novel DNA virus that has recently been identified. The clinical significance of TTV infection in patients with chronic hepatitis C has not been determined. The aim of this study was to determine the prevalence and possible role of TTV in a well characterized population with chronic hepatitis C infection.

METHODS

Ninety patients with chronic HCV and known time of HCV acquisition were selected from approximately 250 patients followed at our institution. Characteristics including age, sex, histology, and length of disease were recorded. Direct sequencing of the NS5 region was used for HCV genotyping. TTV DNA detection was based on PCR.

RESULTS

TTV infection was present in 24 of 90 (27%) HCV patients. Patients were divided into four groups based on stage of disease; chronic hepatitis (CH, 29 patients), compensated cirrhosis (CC, 17 patients), decompensated cirrhosis (DC, 28 patients), and hepatocellular carcinoma (HCC, 16 patients). TTV was present in 2/29 (7%), 2/17 (12%), 11/28 (39%), and 9/16 (56%) in those with CAH, CC, DC, and HCC respectively. TTV was significantly more prevalent among those with advanced disease (DC and HCC) compared to those with stable disease (CH and CC; p = 0.001). Mean age, sex, and the time from exposure to HCV to development of complications were similar in TTV-positive and -negative patients. TTV infection was more common in patients infected with HCV genotype 1b. Univariate analysis showed that length of HCV infection, HCV genotype 1b, and TTV infection were important in predicting the stage of liver disease in HCV patients. However, after adjusting for length of HCV infection, TTV but not HCV genotype was important in predicting the stage of liver disease.

CONCLUSIONS

We conclude that 1) TTV infection is common in patients with chronic HCV; 2) TTV infection is more prevalent among patients with advanced HCV-associated liver disease (DC and HCC) than in those with stable disease (CH and CC); and 3) TTV infection is more common in patients with HCV genotype 1b but is independent from genotype in predicting the stage of HCV-associated liver disease.

A comparison of midazolam and diazepam for conscious sedation during colonoscopy in a prospective double-blind study

BACKGROUND

Midazolam and diazepam are commonly used for conscious sedation, but their comparative respiratory depressive effects have not been accurately studied. We used a novel real-time, on-line, computerized data acquisition system to compare the two agents in a randomized double-blind study.

METHODS

One hundred patients undergoing colonoscopy were studied. The maximum end-tidal carbon dioxide tension (PetCO2) and the minimum oxygen saturation by pulse oximetry (SpO 2) were recorded by computer every minute. Patients received meperidine (25 to 50 mg) and incremental doses of either midazolam or diazepam to an identical end point of slurred speech and/or ptosis. Sedation was scored from 1 (unarousable) to 5 (wide awake).

RESULTS

Sedation scores were 3.6 +/- 0.1 (mean +/- standard error) after each agent. The doses of midazolam and diazepam were 0. 031 +/- 0.002 and 0.106 +/- 0.009 mg/kg, respectively. In the first 45 minutes (PetCO2) was significantly higher with midazolam than with diazepam (p < 0.05). SpO2 was significantly depressed for 80 minutes after each agent, and the number of minutes when the minimum Sp O2 was less than 90% did not differ between the two agents.

CONCLUSIONS

Midazolam was 3.4 times more potent than diazepam. The duration of oxygen desaturation emphasizes the importance of monitoring SpO2 until ventilation and oxygenation have recovered. Although the degree of hypoxemia was comparable, midazolam led to higher end-tidal carbon dioxide tensions.

The clinical significance of simultaneous infection with hepatitis G virus in patients with chronic hepatitis C

OBJECTIVES

Hepatitis G virus (HGV) is a recently discovered member of the flavivirus family that has been associated with acute and chronic hepatitis. HGV infection has been reported to coexist in 10-20% of patients with chronic hepatitis C. The significance of simultaneous infection with HGV and hepatitis C virus (HCV) remains to be clarified, as do the effects on HGV of therapeutic interventions such as interferon treatment or liver transplantation.

THE AIMS OF OUR STUDY WERE

1) to examine the frequency of HGV infection in the settings of liver transplantation and interferon therapy for hepatitis C; and 2) to compare HGV RNA levels before and after liver transplantation or interferon treatment.

METHODS

Pre-treatment sera were available in 65 patients with chronic hepatitis C treated with interferon; pretransplant sera were available in 49 patients transplanted for end stage liver disease associated with chronic hepatitis C. Information collected included age, sex, risk factors for hepatitis, concurrent liver disease, patient and allograft survival, biochemical response to interferon, histological activity index, and degree of fibrosis/cirrhosis. HCV genotyping was performed by sequencing the NS-5 region. HGV quantitation was performed using a research-based branched DNA (bDNA) assay with a set of probes directed at the 5' untranslated region.

RESULTS

HGV was detected in 10 of 49 patients (20%) before transplant and in 13 of 65 patients (20%) treated with interferon. There was a female predominance among HGV-positive compared with HGV-negative transplant patients (80% vs 20%; p < 0.01), but such a difference was not observed in the interferon-treated group. Hepatic iron concentration was lower in hepatic explants from patients who were HGV-positive than in those who were HGV-negative (318 +/- 145 microg/g dry weight vs 1497 +/- 2202 microg/g dry weight; p = 0.02). HCV exposure after 1980 was more common in the HGV-positive patients than in those who were HGV-negative for the entire study population (10 of 20 [50%] vs 16 of 66 [24%]; p = 0.03), as well as for the nontransplant subgroup (8 of 12 [67%] vs 12 of 39 [31%]; p = 0.03). HGV RNA levels declined at 1 yr after transplant in seven of eight patients. Among nine patients tested during or after interferon treatment, HGV RNA levels declined from pretreatment levels in all and disappeared in three.

CONCLUSIONS

Among patients with chronic hepatitis C treated with either interferon or liver transplantation, the frequency of coinfection with HGV is about 20%. HGV may be a more recent virus in the US than HCV. Coinfection with HGV does not appear to affect the likelihood of response to interferon in patients with hepatitis C. Finally, HGV RNA levels appear to decline after both liver transplantation and interferon therapy, suggesting possible suppression by increased HCV replication in the former case, and a possible drug treatment effect in the latter.

Diphenylhydramine increases ventilatory drive during alfentanil infusion

BACKGROUND

Diphenhydramine is used as an antipruritic and antiemetic in patients receiving opioids. Whether it might exacerbate opioid-induced ventilatory depression has not been determined.

METHODS

The ventilatory response to carbon dioxide during hyperoxia and the ventilatory response to hypoxia during hypercapnia (end-tidal pressure of carbon dioxide [PETCO2] is approximately equal to 54 mmHg) were determined in eight healthy volunteers. Ventilatory responses to carbon dioxide and hypoxia were calculated at baseline and during an alfentanil infusion (estimated blood levels approximately equal to 10 ng/ml) before and after diphenhydramine 0.7 mg/kg.

RESULTS

The slope of the ventilatory response to carbon dioxide decreased from 1.08+/-0.38 to 0.79+/-0.36 l x min(-1) x mmHg(-1) (x +/- SD, P < 0.05) during alfentanil infusion; after diphenhydramine, the slope increased to 1.17+/-0.28 l x min(-1) x mmHg(-1) (P < 0.05). The minute ventilation (VE) at PETCO2 approximately equal to 46 mmHg (VE46) decreased from 12.1+/-3.7 to 9.7+/-3.6 l/min (P < 0.05) and the VE at 54 mmHg (VE54) decreased from 21.3+/-4.8 to 16.6+/-4.7 l/min during alfentanil (P < 0.05). After diphenhydramine, (VE46 did not change significantly, remaining lower than baseline at 9.9+/-2.9 l/min (P < 0.05), whereas VE54 increased significantly to 20.5+/-3.0 l/min. During hypoxia, VE at SpO2 = 90% (VE90) decreased from 30.5+/-9.7 to 23.1+/-6.9 l/min during alfentanil (P < 0.05). After diphenhydramine, the increase in VE90 to 27.2+/-9.2 l/min was not significant (P = 0.06).

CONCLUSIONS

Diphenhydramine counteracts the alfentanil-induced decrease in the slope of the ventilatory response to carbon dioxide. However, at PETCO2 = 46 mmHg, it does not significantly alter the alfentanil-induced shift in the carbon dioxide response curve. In addition, diphenhydramine does not exacerbate the opioid-induced depression of the hypoxic ventilatory response during moderate hypercarbia.

Clinician's guide to hepatitis C

Hepatitis C virus infection is common, often silent, and almost always chronic and can lead to cirrhosis and hepatocellular cancer. Deaths related to chronic hepatitis C are expected to increase dramatically in the future. Many cases of infection are asymptomatic and are undiagnosed because of a lack of recognition by patients and physicians. All patients currently or previously at risk of infection should undergo screening, including those who received blood transfusions before 1992. Interferon is the only effective therapy, but disappearance of virus is sustained in only 10 to 15% of patients. The combination of interferon and oral ribavirin therapy may increase the sustained response rate to about 40%. New agents such as hepatitis C virus-specific protease inhibitors may be available in the next 5 to 10 years, and treatment is evolving toward multiple-drug regimens analogous to those used for human immunodeficiency virus (HIV) infection. In contrast to public funding for drug development in HIV, such funding for hepatitis C has been limited.

Treatment of chronic hepatitis C with interferon with or without ursodeoxycholic acid: a randomized prospective trial

The only effective and approved therapy for chronic hepatitis C is interferon-alpha. Because sustained response rates with interferon alone are disappointingly low, multidrug treatment regimens are currently being investigated. Ursodeoxycholic acid has been used in other chronic liver diseases and can limit hepatocyte injury. To evaluate the potential benefit of ursodeoxycholic acid in combination with interferon-alpha for the treatment of chronic hepatitis C, we conducted a prospective, double-blinded, randomized, placebo-controlled trial comparing the combination therapy of interferon-alpha 2b and ursodeoxycholic acid with interferon alone. Thirty-one patients with chronic hepatitis C were randomized to receive 3 million units of interferon-alpha 2b subcutaneously three times per week and either 13 to 15 mg/kg/day ursodeoxycholic acid or placebo orally for 6 months. The 6-month treatment period was followed by 6 months of observation. Biochemical normalization at the end of treatment occurred in 5 of 14 (36%) patients receiving monotherapy versus 8 of 15 (53%) patients (p = 0.34) receiving combination therapy. No patient treated with interferon alone had a sustained biochemical response 6 months after therapy; however, 3 of 12 patients (25%) treated with combination interferon and ursodeoxycholic acid maintained biochemical normalization at 6 months after therapy (p = 0.08). No difference in liver histology or clearance of hepatitis C viral RNA was noted 6 months after treatment. We conclude that combination therapy with ursodeoxycholic acid and interferon-alpha 2b was no more effective than interferon monotherapy in inducing a biochemical response in previously untreated patients with chronic hepatitis C. Ursodeoxycholic acid, however, may be useful in prolonging the biochemical response to interferon therapy.

Hepatitis G virus infection in patients transplanted for cryptogenic cirrhosis: red flag or red herring?

BACKGROUND

The significance of hepatitis G (HGV) infection in liver transplant recipients is not known. We set out to determine the pre-orthotopic liver transplantation (OLT) prevalence, the pre- and postoperative viral titers of HGV, and the allograft histology in patients infected with HGV who underwent OLT for cryptogenic cirrhosis.

METHODS

HGV RNA was measured using a research-based branched DNA assay. The assay used a target-specific probe set that was based on the 5'-untranslated region of the HGV genome. Allograft histology was assessed with protocol liver biopsies in all patients who survived longer than 6 months.

RESULTS

The preoperative prevalence of HGV infection in recipients transplanted for cryptogenic cirrhosis was 26%. Thirty-seven percent (12 of 33) of recipients who had serum available in the first postoperative month had HGV infection. Mean HGV RNA levels were 9.8 (+/-4.2) (viral molecular equivalents/ml x 10[6]) before OLT and 37.5 (+/-10.7) at 1 year after OLT. In 4 of the 11 cryptogenic recipients in whom HGV RNA was detectable in the first postoperative month, HGV RNA fell to undetectable levels at the most recent follow-up (mean 70 months). Of the five cryptogenic recipients who continue to have measurable HGV RNA, three have unexplained hepatitis histologically.

CONCLUSIONS

These findings suggest the following: 1) The prevalence of HGV infection in patients undergoing OLT for cryptogenic cirrhosis is about 25%. 2) In recipients persistently infected with HGV, mean HGV RNA titers increase after OLT. 3) HGV RNA becomes undetectable in about one third of recipients who had detectable HGV RNA in the first month after OLT. 4) Hepatitis of uncertain etiology occurs in 60% (3 of 5) of persistently HGV-infected cryptogenic recipients.

Cost-effectiveness of 6 and 12 months of interferon-alpha therapy for chronic hepatitis C

BACKGROUND

Interferon-alpha is effective in only a small number of patients with chronic hepatitis C, although prolonged treatment may increase the response rate. There is concern that the expense of interferon-alpha therapy may not be justified by the low response rates and uncertain long-term benefit.

OBJECTIVE

To compare clinical and economic outcomes after 6 months and 12 months of interferon-alpha therapy for chronic hepatitis C.

DESIGN

A Markov model depicting the natural progression of chronic hepatitis C. On the basis of this model, a simulated trial compared no therapy with 6 and 12 months of interferon-alpha therapy at standard doses (3 million U three times weekly).

PATIENTS

Four age-specific cohorts (30, 40, 50, and 60 years of age) with chronic hepatitis C.

MEASUREMENTS

Number of deaths from liver disease, total costs, and cumulative quality-adjusted life-years (QALYs).

RESULTS

Six and 12 months of interferon-alpha treatment gained 0.25 QALYs at an incremental cost of $1000 and 0.37 QALYs at an incremental cost of $1900, respectively. Thus, although 6 months of interferon-alpha therapy was less efficacious than 12 months of therapy, it was more cost-effective ($4000 per QALY gained compared with $5000 per QALY gained). Nonetheless, in patients younger than 60 years of age, both 6 and 12 months of therapy compared favorably with other established medical interventions, such as screening mammography and cholesterol reduction programs. Important variables affecting the cost-effectiveness of interferon-alpha treatment included the cost and efficacy of interferon-alpha, the cost of treatment for decompensated cirrhosis, and quality of life in patients with chronic hepatitis C.

CONCLUSION

From the standpoint of cost-effectiveness, interferon-alpha therapy for 6 or 12 months may be justified in patients with chronic hepatitis C. The possible exception is patients older than 60 years of age.