Post-Transplant Management and Complications of Autoimmune Hepatitis, Primary Biliary Cholangitis, and Primary Sclerosing Cholangitis including Disease Recurrence

Autoimmune liver diseases have unique post-transplant considerations. These recipients are at increased risk of rejection, and recurrent disease may also develop, which can progress to graft loss and increase mortality. Monitoring for and managing these complications is therefore important, though data on associated risk factors and immunosuppression strategies has in most cases been mixed. There are also other disease-specific complications that require management and may impact these decisions, including inflammatory bowel disease in PSC. Further work to better understand the optimal management strategies for these patients post-transplant is needed.

Hypophosphatemia as a Predictor of Clinical Outcomes in Acute Pancreatitis: A Retrospective Study

OBJECTIVE

Phosphate is crucial for cellular repair after injury and may be important in recovery following acute pancreatitis (AP). This study aimed to evaluate the association between hypophosphatemia and severity of AP.

METHODS

Patients admitted with AP between 2014-2018 were identified and their records were retrospectively reviewed. Pancreatitis severity was defined using the modified Atlanta Criteria. Hypophosphatemia was defined as phosphate <2 mg/dL and was assessed at three time points: within one day, within two days, at any time during admission. The proportion of patients who developed severe AP was compared between patients with and without hypophosphatemia.

RESULTS

Of 312 patients, 30.1% (n = 94) developed severe AP. Hypophosphatemia occurred in 25.0% overall, within one day in 19.7%, and within two days in 20.0%. A higher proportion of patients with hypophosphatemia developed severe AP (overall: 47.4% vs. 24.4%, P < 0.001; one day: 47.4% vs. 23.9%, P = 0.004; two days: 42.9% vs. 24.5%, P = 0.01). Patients with hypophosphatemia within one day were also more likely to have ICU admission ( P < 0.001) and longer length of stay ( P < 0.001).

CONCLUSIONS

Early hypophosphatemia during an admission for AP was associated with increased AP severity, ICU admission, and longer length of stay.

Evaluation of the Potential Utility of an Artificial Intelligence Chatbot in Gastroesophageal Reflux Disease Management

INTRODUCTION

Artificial intelligence chatbots could serve as an information resource for patients and a tool for clinicians. Their ability to respond appropriately to questions regarding gastroesophageal reflux disease is unknown.

METHODS

Twenty-three prompts regarding gastroesophageal reflux disease management were submitted to ChatGPT, and responses were rated by 3 gastroenterologists and 8 patients.

RESULTS

ChatGPT provided largely appropriate responses (91.3%), although with some inappropriateness (8.7%) and inconsistency. Most responses (78.3%) contained at least some specific guidance. Patients considered this a useful tool (100%).

DISCUSSION

ChatGPT's performance demonstrates the potential for this technology in health care, although also its limitations in its current state.

Characterization of social determinants of health of a liver transplant referral population

Disparities exist in referral and access to the liver transplant (LT) waitlist, and social determinants of health (SDOH) are increasingly recognized as important factors driving health inequities, including in LT. The SDOH of potential transplant candidates is therefore important to characterize when designing targeted interventions to promote equity in access to LT. Yet, it is uncertain how a transplant center should approach this issue, characterize SDOH, identify disparities, and use these data to inform interventions. We performed a retrospective study of referrals for first-time, single-organ LT to our center from 2016 to 2020. Addresses were geoprocessed and mapped to the corresponding county, census tract, and census block group to assess their geospatial distribution, identify potential disparities in referrals, and characterize their communities across multiple domains of SDOH to identify potential barriers to evaluation and selection. We identified variability in referral patterns and areas with disproportionately low referrals, including counties in the highest quartile of liver disease mortality (9%) and neighborhoods in the highest quintile of socioeconomic deprivation (17%) and quartile of poverty (21%). Black individuals were also under-represented compared with expected state demographics (12% vs. 18%). Among the referral population, several potential barriers to evaluation and selection for LT were identified, including poverty, educational attainment, access to healthy food, and access to technology. This approach to the characterization of a transplant center's referral population by geographic location and associated SDOH demonstrates a model for identifying disparities in a referral population and potential barriers to evaluation that can be used to inform targeted interventions for disparities in LT access.

Rates of employment after liver transplant: A nationwide cohort study

BACKGROUND

Employment outcomes after liver transplant (LT) over the past decade have not been described.

METHODS

LT recipients ages 18-65 from 2010-2018 were identified in Organ Procurement and Transplantation Network data. Employment within two years post-transplant was assessed.

RESULTS

Of 35,340 LT recipients, 34.2% were employed post-LT, including 70.4% who were working pre-transplant, compared to only 18.2% not working preLT. Younger age, male sex, educational attainment, and functional status were associated with returning to employment.

CONCLUSION

Returning to employment is an important goal for many LT candidates and recipients, and these findings can be used to guide their expectations.

Performance of the Pooled Cohort Equations in non-alcoholic fatty liver disease: The Multi-Ethnic Study of Atherosclerosis

BACKGROUND AND AIMS

Non-alcoholic fatty liver disease (NAFLD) is associated with a high risk of cardiovascular disease. Whether risk scores developed in the general population accurately assess cardiovascular risk in the NAFLD population is unknown. This study aimed to evaluate the performance of the Pooled Cohort Equations (PCE) in NAFLD.

METHODS

Individuals in the Multi-Ethnic Study of Atherosclerosis with baseline non-contrast cardiac computed tomography scans with sufficient data to determine the presence of hepatic steatosis were identified and assessed for the development of incident 10-year atherosclerotic cardiovascular disease. The discrimination and calibration of the PCE were evaluated, and the observed and expected events by risk category (<5%, 5-<7.5%, 7.5-<20%, ≥20%) were determined. Risk reclassification with the addition of NAFLD to the PCE was assessed.

RESULTS

Of 4014 participants included, 698 (17.4%) with NAFLD were identified, including 247 (35.3%) with moderate-to-severe steatosis. Discrimination of the PCE was suboptimal in NAFLD (c-statistic 0.69), particularly moderate-to-severe steatosis (0.65), and calibration was overall poor. While risk was overestimated in non-NAFLD, it was underestimated in NAFLD in lower/intermediate risk categories, predominantly in women (5-<7.5% observed/expected ratio = 1.67). The addition of NAFLD to the PCE improved risk classification in women.

CONCLUSIONS

The PCE overall performed suboptimally in cardiovascular risk assessment in NAFLD, particularly in women and individuals with moderate-to-severe steatosis in clinically relevant risk categories. Primary prevention may need to be considered at a lower risk threshold in these groups, and further work is needed to improve risk stratification in this growing high-risk population.

Evaluation of an Abnormal Liver Panel After Liver Transplantation

Abnormal liver tests are common after liver transplantation. The differential diagnosis depends on the clinical context, particularly the time course, pattern and degree of elevation, and donor and recipient factors. The perioperative period has distinct causes compared with months and years after transplant, including ischemia-reperfusion injury, vascular thrombosis, and primary graft nonfunction. Etiologies seen beyond the perioperative period include biliary complications, rejection, infection, recurrent disease, and non-transplant-specific causes. The evaluation begins with a liver ultrasound with Doppler as well as appropriate laboratory testing and culminates in a liver biopsy if the imaging and laboratory testing is unrevealing.

Access to technology to support telehealth in areas without specialty care for liver disease

BACKGROUND AND AIMS

Telehealth may be a successful strategy to increase access to specialty care for liver disease, but whether the areas with low access to care and a high burden of liver-related mortality have the necessary technology access to support a video-based telehealth strategy to expand access to care is unknown.

APPROACH AND RESULTS

Access to liver disease specialty care was defined at the county level as <160.9 km (100 miles) from a liver transplant (LT) center or presence of local gastroenterology (GI). Liver-related mortality rates were compared by access to care, and access to technology was compared by degree of access to care and burden of liver-related mortality. Counties with low access to liver disease specialty care had higher rates of mortality from liver disease, and this was highest in areas both >160.9 km from an LT center and without local GI. These counties were more rural, had higher poverty, and had decreased access to devices and internet at broadband speeds. Technology access was lowest in areas with low access to care and the highest burden of liver-related mortality.

CONCLUSIONS

Areas with poor access to liver disease specialty care have a greater burden of liver-related mortality, and many of their residents lack access to technology. Therefore, a telehealth strategy based solely on patient device ownership and internet access will exclude a large proportion of individuals in the areas of highest need. Further work should be done at the local and state levels to design optimal strategies to reach their populations of need.

Social determinants of health data in solid organ transplantation: National data sources and future directions

Health equity research in transplantation has largely relied on national data sources, yet the availability of social determinants of health (SDOH) data varies widely among these sources. We sought to characterize the extent to which national data sources contain SDOH data applicable to end-stage organ disease (ESOD) and transplant patients. We reviewed 10 active national data sources based in the United States. For each data source, we examined patient inclusion criteria and explored strengths and limitations regarding SDOH data, using the National Institutes of Health PhenX toolkit of SDOH as a data collection instrument. Of the 28 SDOH variables reviewed, eight-core demographic variables were included in ≥80% of the data sources, and seven variables that described elements of social status ranged between 30 and 60% inclusion. Variables regarding identity, healthcare access, and social need were poorly represented (≤20%) across the data sources, and five of these variables were included in none of the data sources. The results of our review highlight the need for improved SDOH data collection systems in ESOD and transplant patients via: enhanced inter-registry collaboration, incorporation of standardized SDOH variables into existing data sources, and transplant center and consortium-based investigation and innovation.

Recent updates in preemptive transjugular intrahepatic portosystemic shunt for acute variceal bleeding

Content available: Author Interview and Audio Recording.

Trends in statin utilisation in US adults with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) has high morbidity and mortality related to cardiovascular disease (CVD), but statins have been historically underutilised in these patients due to concern for hepatotoxicity.

AIMS

To characterise trends in statin use among individuals with NAFLD and to determine predictors of statin utilisation in this population.

METHODS

Individuals with NAFLD were identified from 2005 to 2018 continuous National Health and Nutrition Examination Survey. Trends in statin use over time were assessed, and predictors of statin under-utilisation for primary prevention were identified. The roles of a known diagnosis of liver disease and disease severity were examined.

RESULTS

We included 14 113 individuals; 34.6% had NAFLD, of whom 5.4% reported a liver disease diagnosis. There was a significant increase in statin use for primary prevention between 2005 and 2018 (18.1%-25.0%; P = 0.03), but guideline-indicated use for this purpose was low (54.5% between 2005 and 2012; 48.6% between 2013 and 2018). A known NAFLD diagnosis was a negative predictor of statin use during the earlier time period but not more recently. Utilisation did not decrease with increasing liver disease severity.

CONCLUSIONS

In a nationally representative population with NAFLD, statin use for primary prevention has increased over time, but guideline-concordant use remains low. A known liver disease diagnosis was associated with lack of statin use in the earlier time period but not more recently, suggesting a changing perspective of underlying liver disease impacting statin utilisation. Further work to improve guideline-indicated statin use in this high-risk population is needed.

Risk of Cardiovascular Disease in Individuals With Nonobese Nonalcoholic Fatty Liver Disease

Nonalcoholic fatty liver disease (NAFLD) is independently associated with obesity and cardiovascular disease (CVD). CVD is the primary cause of mortality in the predominantly obese population of adults with NAFLD. NAFLD is increasingly seen in individuals who are lean and overweight (i.e., nonobese), but it is unclear whether their risk of CVD is comparable to those with NAFLD and obesity. Using a prospective cohort of patients with NAFLD, we compared the prevalence and incidence of CVD in individuals with and without obesity. NAFLD was diagnosed by biopsy or imaging after excluding other chronic liver disease etiologies. Logistic regression was used to compare the odds of baseline CVD by obesity status. Cox proportional hazards regression was used to evaluate obesity as a predictor of incident CVD and to identify predictors of CVD in subjects with and without obesity. At baseline, adults with obesity had a higher prevalence of CVD compared to those without obesity (12.0% vs. 5.0%, P = 0.02). During follow-up, however, obesity did not predict incident CVD (hazard ratio [HR], 1.24; 95% confidence interval [CI], 0.69-2.22) or other metabolic diseases. Findings were consistent when considering body mass index as a continuous variable and after excluding subjects who were overweight. Age (adjusted HR [aHR], 1.05; 95% CI, 1.03-1.08), smoking (aHR, 4.61; 95% CI, 1.89-11.22), and decreased low-density lipoprotein levels (aHR, 0.98; 95% CI, 0.96-1.00) independently predicted incident CVD in the entire cohort, in subjects with obesity, and in those without obesity, respectively. Conclusion: Individuals with overweight or lean NAFLD are not protected from incident CVD compared to those with NAFLD and obesity, although CVD predictors appear to vary between these groups. Patients without obesity also should undergo rigorous risk stratification and treatment.

Brief Report: Relationship Between Nonalcoholic Fatty Liver Disease and Cardiovascular Disease in Persons With HIV

BACKGROUND

Nonalcoholic fatty liver disease (NAFLD) and HIV are independently associated with cardiovascular disease (CVD). However, the factors associated with NAFLD in persons living with HIV (PWH) and whether CVD is more frequent in PWH with NAFLD are currently unknown.

METHODS

From the Partners HealthCare Research Patient Data Registry, we identified PWH with and without NAFLD between 2010 and 2017. NAFLD was defined using validated histological or radiographic criteria. CVD was defined by an ICD-9 diagnosis of coronary artery disease, myocardial infarction, coronary revascularization, peripheral vascular disease, heart failure, transient ischemic attack, or stroke and was confirmed by clinician review. Multivariable logistic regression was performed to examine the relationship between NAFLD and CVD.

RESULTS

Compared with PWH without NAFLD (n = 135), PWH with NAFLD (n = 97) had higher body mass index and more frequently had hypertension, obstructive sleep apnea, diabetes mellitus, dyslipidemia, coronary artery disease, and CVD (P < 0.01 for all). PWH with NAFLD were also more likely to have CD4 T-cell counts (CD4) <200 cells/mm. In multivariable models, the presence of NAFLD was significantly associated with CVD (adjusted odds ratio 3.08, 95% confidence interval: 1.37 to 6.94) and CD4 <200 cells/mm (adjusted odds ratio 4.49, 95% confidence interval: 1.74 to 11.55).

CONCLUSION

In PWH, CVD was independently associated with prevalent NAFLD after controlling for traditional CVD risk factors. NAFLD was also associated with CD4 <200 cells/mm, suggesting that immune dysfunction may be related to NAFLD. Both CVD and low CD4 count as risk factors for NAFLD require prospective evaluation.

Advanced fibrosis is associated with incident cardiovascular disease in patients with non-alcoholic fatty liver disease

BACKGROUND

Non-alcoholic fatty liver disease (NAFLD) is associated with an increased risk of cardiovascular disease. It is not well understood, however, which individuals with NAFLD are at highest risk for cardiovascular disease.

AIMS

To determine the factors associated with incident cardiovascular events in a prospective cohort of individuals with biopsy-proven NAFLD without pre-existing cardiovascular disease.

METHODS

From 2011 to 2018, adults with biopsy-proven NAFLD without cardiovascular disease were enrolled in a tissue repository and were followed prospectively to the first recorded date of incident cardiovascular disease, death or the end of follow-up (11/1/2018). Competing risks analysis was performed to identify predictors of incident cardiovascular disease.

RESULTS

After a median follow-up time of 5.2 years, 26/285 (9.1%) individuals experienced an incident cardiovascular event. Advanced fibrosis (stage 3-4) on biopsy was a significant predictor of incident cardiovascular disease, and this persisted on multivariable analysis (SHR 2.86, 95% CI 1.36-6.04) after considering relevant covariates, including cardiovascular risk scores, which were not independent predictors. Of the non-invasive indicators of fibrosis, the NAFLD fibrosis score was the only independent predictor of cardiovascular disease. Other histologic features, including steatohepatitis, were not associated with incident cardiovascular disease.

CONCLUSIONS

In adults with biopsy-proven NAFLD, advanced fibrosis on biopsy and higher NAFLD fibrosis score were significant and independent predictors of incident cardiovascular disease, even after considering traditional risk factors and cardiovascular risk scores. These findings should be considered when evaluating NAFLD patients for primary prevention of cardiovascular disease, and further evaluation into the link between advanced fibrosis and cardiovascular disease is needed.

The association of hepatitis C infection with the onset of CKD and progression into ESRD

Hepatitis C virus (HCV) infection is not only an important cause of chronic liver disease, but extrahepatic manifestations are common and include chronic kidney disease (CKD). HCV is classically associated with cryoglobulinemic glomerulonephritis in the context of mixed cryoglobulinemia syndrome, but other glomerular diseases also occur and may be significantly under-recognized. HCV may cause glomerular disease by immune complex deposition; however, other potential mechanisms by which HCV promotes CKD include a direct cytopathic effect of the virus on renal tissue, and by its association with accelerated atherosclerosis, insulin resistance, and chronic inflammation. Epidemiologic studies show HCV infection confers an increased risk of incident CKD and accelerates progression of CKD to end-stage renal disease (ESRD) in the general population, as well as subpopulations including diabetic patients, those coinfected with human immunodeficiency virus (HIV), and kidney transplant recipients. Patients with CKD and HCV infection experience inferior clinical outcomes, including poorer quality of life and an increased risk of mortality. Treatment with interferon-based regimens is associated with decreased risk of incident CKD and ESRD, though prior studies are limited by the small number of patients with HCV and CKD who underwent treatment. With the advent of new, well-tolerated direct-acting antiviral combinations that are not cleared by the kidneys, it is possible to treat all genotypes of HCV infection in patients with CKD and ESRD. More data on the effect of direct-acting antivirals on CKD incidence and progression are necessary. However, there is every expectation that with improved access to HCV treatment, the burden of CKD in patients with HCV could significantly decline.

The impact of human leukocyte antigen donor and recipient serotyping and matching on liver transplant graft failure in primary sclerosing cholangitis, autoimmune hepatitis, and primary biliary cholangitis

Human leukocyte antigen (HLA) serotyping is not considered to have significant impact on liver graft survival and does not factor into U.S. organ allocation. Immune-related liver diseases such as primary sclerosing cholangitis (PSC), autoimmune hepatitis (AIH), and primary biliary cholangitis (PBC) have been speculated to represent a disease subgroup that may have significantly different graft outcomes depending on HLA donor/recipient characterization. The aim of this study was to investigate whether HLA serotyping/matching influenced post-transplant graft failure for immune-related liver diseases using the United Network for Organ Sharing database. From 1994 to 2015, 5665 patients underwent first-time liver-only transplants for PSC, AIH, and PBC with complete graft survival and donor/recipient HLA data. Graft failure was noted in 38.6% (2188/5665), and all groups had comparable 5-year graft survival (75.1%-78.8%, P = 0.069). The overall degree of, and loci-specific mismatch level, did not influence outcomes. Multivariable Cox proportional hazards regression noted increased graft failure risk for recipient HLA-B7, HLA-B57, HLA-B75, HLA-DR13 and donor HLA-B55, HLA-B58, and HLA-DR8 for PSC patients, protective effects for recipient HLA-DR1 and HLA-DR3 for AIH patients, and increased risk for HLA-DR7 for AIH patients. These findings warrant further investigation to evaluate the impact of HLA serotyping on post-transplant outcomes.

Differences in Phenotypes and Liver Transplantation Outcomes by Age Group in Patients with Primary Sclerosing Cholangitis

BACKGROUND

There is increasing evidence for a heterogeneity of phenotypes in primary sclerosing cholangitis (PSC), but differences across the age spectrum in adults with PSC have not been well characterized.

AIMS

To characterize phenotypic variations and liver transplantation outcomes by age group in adults with PSC.

METHODS

The United Network for Organ Sharing database was used to identify waitlist registrations for primary liver transplantation in adults with PSC. Patients were split into three age groups: 18-39 (young), 40-59 (middle-aged), and ≥60 (older). Their clinical characteristics and outcomes on the waitlist and post-transplant were compared.

RESULTS

Overall, 8272 adults with PSC were listed for liver transplantation during the study period, of which 28.9% were young, 52.0% were middle-aged, and 19.1% were older. The young age group had the greatest male predominance (70.0 vs. 66.2 vs. 65.1%, p = 0.001), the highest proportion of black individuals (20.0 vs. 11.0 vs. 5.5%, p < 0.001), and the most patients listed with concomitant autoimmune hepatitis (2.2 vs. 1.0 vs. 0.8%, p < 0.001). Older patients experienced the greatest waitlist and post-transplant mortality. Graft survival was greatest in the middle-aged group. Young patients were most likely to experience acute rejection (31 vs. 22.8 vs. 18.0%, p < 0.001) and have graft failure due to chronic rejection or PSC recurrence (47.8 vs. 42.3 vs. 17.9%, p < 0.001).

CONCLUSIONS

Age-related differences exist among adults with PSC and are associated with outcomes pre- and post-transplant. Young patients may have a more robust immune-related phenotype that is associated with poorer graft survival. Future studies are needed to further investigate these findings.

Complementary and Alternative Medicine Use in United States Adults With Liver Disease

GOALS

To describe the complementary and alternative medicine (CAM) use in US adults with liver disease.

BACKGROUND

The prevalence and patterns of CAM use among US adults with liver disease have not been well characterized. The 2012 National Health Interview Survey is considered the most current and comprehensive source of information on CAM use in US adults.

STUDY

Using the results of the 2012 National Health Interview Survey, the prevalence of CAM use, most common modalities used, reasons for CAM use, perceived benefits, perceived helpfulness and importance, and disclosure of CAM to health care providers were compared between adults with and without liver disease.

RESULTS

Of the 647 adults with liver disease, 41% reported using CAM in the prior year, compared with 33% of adults without liver disease. The most common modality was herbs and supplements (23%), and 3% of respondents reported consumption of a potentially hepatotoxic substance in the previous 30 days. Only a small proportion of CAM therapies were used specifically for liver disease, with milk thistle being the most common. Among respondents with liver disease, CAM was used more commonly for anxiety or depression, fatigue, and substance use. The majority believed that these therapies improved health. Nearly one-third of therapies were not reported to health care providers, mostly due to failure of the provider to ask.

CONCLUSIONS

CAM use, particularly herbs and supplements, is prevalent among US adults with liver disease. Many do not disclose their CAM use to their providers, despite some using potentially hepatotoxic substances.

Outcomes of liver retransplantation in patients with primary sclerosing cholangitis

Liver retransplantation in patients with primary sclerosing cholangitis (PSC) has not been well studied. The aims of this study were to characterize patients with PSC listed for and undergoing retransplantation and to describe the outcomes in these patients. The United Network for Organ Sharing/Organ Procurement and Transplantation Network database was used to identify all primary liver transplantations and subsequent relistings and first retransplantations in adults with PSC between 1987 and 2015. A total of 5080 adults underwent primary transplantation for PSC during this period, and of the 1803 who experienced graft failure (GF), 762 were relisted, and 636 underwent retransplantation. Younger patients and patients with GF due to vascular thrombosis or biliary complications were more likely to be relisted, whereas those with Medicaid insurance or GF due to infection were less likely. Both 5-year graft and patient survival after retransplantation were inferior to primary transplantation (P < 0.001). Five-year survival after retransplantation for disease recurrence (REC), however, was similar to primary transplantation (graft survival, P = 0.45; patient survival, P = 0.09) and superior to other indications for retransplantation (graft and patient survival, P < 0.001). On multivariate analysis, mechanical ventilation, creatinine, bilirubin, albumin, advanced donor age, and a living donor were associated with poorer outcomes after retransplantation. In conclusion, although survival after liver retransplantation in patients with PSC was overall inferior to primary transplantation, outcomes after retransplantation for PSC REC were similar to primary transplantation at 5 years. Retransplantation may therefore represent a treatment option with the potential for excellent outcomes in patients with REC of PSC in the appropriate clinical circumstances. Liver Transplantation 23 769-780 2017 AASLD.

International research through networking: an old idea with new tools

The growth and refinement of electronic media capabilities, Internet, other electronic highways, fiber optics, microwaves, and satellites will have major impact on researchers and scholars, facilitating the timely sharing of information. The balance of time saved and money available may be the crucial issues in the rapidity of development. The dissemination of research results to a large audience through electronic journals, bulletin boards and data bases will become a dominant force in the formal publication of such results, with instant feedback from colleagues. The productivity of scientists and the quality of their research will be higher through better communications. Networking, however, is more than communications. It is shared interests and interaction, building on information received and provided and creating a relationship and a knowledge base to enhance international research.

A new high-performance liquid chromatographic procedure to quantitate hemoglobin A1c and other minor hemoglobins in blood of normal, diabetic, and alcoholic individuals

A new HPLC procedure is described for the separation and quantitation of minor human Hb variants. The cation exchanger, Synchropak CM 300, is a silica support with a bonded polymeric coating of carboxylic acid residues. The chromatogram is developed with 0.03M Bis-Tris-KCN buffers, pH 6.40, and a Na-acetate gradient increasing from 0 to 0.1125M. As many as 11 minor Hbs (including Hb A2) can be isolated. Some of these have been identified through rechromatography of the minor Hb zones obtained by Bio-Rex-70 chromatography. Quantitation of Hb A1c and Hb A2 is readily accomplished. Hb F0 and an unidentified minor Hb often observed in red cells of alcoholics co-chromatograph with Hb A1c. The method has been applied to blood samples of 10 normal adults, 13 diabetic patients, and nine alcoholic subjects. An excellent correlation exists between the Hb A1c percentages and the levels of Hb A1 determined by microcolumn chromatography. Some other minor Hbs, identified as components 9 and 10, which are (at least in part) Hb A0 with glucose attached to the alpha chains, are present in increased amounts in the blood of diabetic patients and others may be observed in patients who subject themselves to (severe) alcohol abuse. It is suggested that the new procedure is well-suited for detailed studies of the minor Hbs in patients with various abnormalities in carbohydrate metabolism.

Carboxymethyl-cellulose microchromatography for the quantitation of hemoglobin Bart's (gamma 4) and its use in the detection of the alpha-thalassemia conditions

A modification of an existing (micro) CM-cellulose chromatographic procedure is introduced for the quantitation of hemoglobin Bart's (or gamma 4) in blood samples of newborn babies. Normal newborn with four active alpha chain genes (alpha alpha/alpha alpha) have small amounts (average 0.55%) of this abnormal hemoglobin while increased percentages are present in newborn with an alpha-thalassemia-2 heterozygosity (alpha 0 alpha/alpha alpha; average 1.55%) or an alpha-thalassemia-2 homozygosity (alpha 0 alpha/alpha 0 alpha; average 4.65%). The identification of hemoglobin Bart's in normal newborn was made by high-performance liquid chromatography, and the absence of contaminating non-hemoglobin proteins was confirmed by electrophoresis and additional chromatographic experiments. This rapid procedure is useful for the detection and differentiation at time of birth of the different alpha chain deficiencies which are common among various populations in the world.

The connective tissue component of the caprine arthritis-encephalitis syndrome

The gross and microscopic connective tissue lesions in 12 goats with caprine arthritis-encephalitis (CAE) are described, including those from which a virus (CAEV) was isolated. Lesions were most often associated with synovial-lined structures including joints, tendon sheaths, and bursae, and were typified by synovial cell proliferations, subsynovial mononuclear cell infiltration, the presence of fibrin, fibrinous concretions, necrosis, and mineralization. Extrasynovial lesions were located in kidneys, vessels, and brain. The inflammatory infiltrates in these organs were predominantly mononuclear. Amyloid was also found in liver, spleen, and kidney. Microbiologic techniques failed to demonstrate any bacteria, mycoplasma, or chlamydia in the lesions.

Comparison of the lesions of Aleutian disease in mink and hypergammaglobulinemia in ferrets

Gross and microscopic lesions of Aleutian disease (AD) in mink and hypergammaglobulinemia in ferrets were compared. Both conditions were characterized by widespread proliferation of plasma cells, but proliferation was more prominent in mink infected with AD. Arteritis did not occur in hypergammaglobulinemic ferrets. Minimal or no glomerular alterations occurred in infected ferrets, but were severe in mink infected with AD. Bile duct proliferation was more prominent in diseased mink. Tissue alterations suggested that AD in Aleutian genotype mink is more rapidly progressive than is AD in ferrets, causing overt clinical disease and death. In contrast, hypergammaglobulinemia in ferrets appeared to progress more slowly, with little clinical evidence of disease. This is probably the result of a paucity of glomerular lesions in ferrets. Possible mechanisms to explain the differences in the development of lesions are discussed.

An outbreak of tularemia in mink

An outbreak of tularemia in farm raised mink is reported. Twenty-six of approximately 5000 mink succumbed within a 10 day period. Prodromal signs were minimal. Necropsy revealed necrotic nodules scattered in the parenchyma of the lungs, liver, spleen, and mesenteric lymph nodes. Francisella tularensis was isolated from spleens, livers and lungs.

Pathologic changes in ferrets exposed to pseudorabies virus

Ferrets experimentally infected by various routes with pseudorabies virus were examined for gross and microscopic lesions. Nonsuppurative meningoencephalomyelitis, as well as visceral lesions, occurred. The incubation period seemed related to the viral dose and to the distance between the inoculation site and the central nervous system. The distribution of the lesions in the central nervous system appeared to be closely related to the peripheral nerve pathways from the inoculation sites. Other findings indicated that the lymphohematogenous route could have a role in the dissemination of the virus in infected ferrets.

The influence of genotype on the development of glomerular lesions in mink with Aleutian disease virus

In an attempt to document progression rate differences in the development of glomerular lesions in mink infected with Aleutian disease virus (ADV), the glomeruli of Aleutian and non-Aleutian mink experimentally infected with ADV were evaluated by light, fluorescent, and electron microscopy. The animals were also examined for the presence of interstitial infiltrate, neutrophils, and arterial lesions. One hundred percent of the Aleutian mink had glomerular cell proliferation and interstitial infiltrate, while 95% of the Aleutian and 41% of the non-Aleutian mink had neutrophilic infiltrates and arteritis, respectively. Of the non-Aleutian mink, 91, 83, 42, and 12.5% had glomerular cell proliferations, glomerular neutrophils, interstitial infiltrate, and arterial lesions in, that order. All the Aleutian mink had glomerular depositions of gamma-globulin (IgG) and complement (C3), whereas 75% of non-Aleutian mink had deposits of IgG and C3. One hundred percent of both genotypes had glomerular deposits of immunoglobulin M (IgM). Ultrastructural glomerular changes consisting primarily of depositions of granular electron-dense material on basement membranes were observed in Aleutian mink 6 weeks after infection and 12 weeks after infection in non-Aleutian mink. These findings document progression rate differences in the development of glomerular lesions in Aleutian disease-affected Aleutian and non-Aleutian mink. Further, they emphasize the need for exploration of pathogenetic mechanisms involved in progression rate differences in lesion development.

Quantitation of immunoglobulin-bearing lymphocytes and lymphocyte response to mitogens in horses persistently infected by equine infectious anemia virus

A defect in lymphocyte function could be responsible for persistent infection by the equine infectious anemia virus. The number of lymphocytes bearing surface immunoglobulin, as detected by immunofluorescence, and lymphocyte response to mitogens were the same in uninfected and equine infectious anemia-infected animals. A defect in T or B lymphocyte numbers or ability to respond to stimuli was not detected in this chronic virus disease.

Persistent viral infections, immunologically mediated glomerulonephritis and arteritis, dysgammopathies. Aleutian disease of mink

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Study of the one-step growth curve of equine infectious anemia virus by immunofluorescence

Primary horse leukocyte cultures were inoculated with 2 or 10 50% tissue culture infective doses (TCID(50)) of equine infectious anemia (EIA) virus per cell, and the titer of cell-associated and fluid-phase virus was determined from 1 to 72 hr postinoculation (PI). Cover slips were collected from 4 to 72 hr PI and stained for EIA viral antigen by the indirect immunofluorescent (FA) technique. Viral replication was detected after a latent period of approximately 18 to 24 hr and reached peak titers of approximately 10(4.5) to 10(6) TCID(50)/0.5 ml from 48 to 72 hr PI. The fluid phase contained 10(1) to 10(2) TCID(50)/0.5 ml more virus than the cells. Viral antigen was first detected by FA from 18 to 24 hr PI. Approximately 75% of the cells contained antigen in their cytoplasm 72 hr PI. The FA technique is a sensitive method for detecting EIA virus in horse leukocyte cultures.

Aleutian disease of mink. Prevention of lesions by immunosuppression

Mink that were homozygous recessive for the Aleutian gene (aa) were inoculated with Aleutian disease virus (ADV) and simultaneously treated with cyclophosphamide (Cy). Control mink were inoculated with ADV. All mink were injected with bovine serum albumin (BSA) and their anti-BSA antibody response was measured to monitor the influence of drug therapy on the humoral antibody response. Formation of anti-BSA antibody was markedly suppressed and the hypergammaglobulinemia and development of AD lesions was inhibited in the Cy-treated mink. The non-Cy-treated control mink developed characteristic signs and lesions including glomerulonephritis and arteritis. The nontreated ADV-infected mink, but not the Cy-treated ADV-infected mink, had glomerular deposition of C3 and gamma globulin. Both groups had high titers of virus in their blood. These results indicate that the development of ADV lesions can be prevented by immunosuppressive treatment and further implicate host immune mechanisms in the pathogenesis of Aleutian disease.

Immunofluorescent localization of equine infectious anemia virus in tissue

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