Ulf Hammar

Fibrosis stage but not NASH predicts mortality and time to development of severe liver disease in biopsy-proven NAFLD

BACKGROUND & AIMS Non-alcoholic fatty liver disease (NAFLD) is very common in the general population, but identifying patients with increased risk of mortality and liver-specific morbidity remains a challenge. Non-alcoholic steatohepatitis (NASH) is thought to enhance this risk; therefore, resolution of NASH is a major endpoint in current pharmacologic studies. Herein, we aim to investigate the long-term prognosis of a large cohort of NAFLD patients, and to study the specific effect of NASH and fibrosis stage on prognosis. METHODS We conducted a retrospective cohort study of 646 biopsy-proven NAFLD patients. Each case was matched for age, sex and municipality to ten controls. Outcomes on mortality and severe liver disease, defined as cirrhosis, liver decompensation/failure or hepatocellular carcinoma, were evaluated using population-based registers. Cox regression models adjusted for age, sex and type 2 diabetes were used to examine the long-term risk according to fibrosis stage. Likelihood ratio tests were used to assess whether adding NASH to these models increased the predictive capacity. Laplace regression was used to estimate the time to severe liver disease according to stage of fibrosis. RESULTS During a follow-up of mean 20years (range 0-40) equivalent to 139,163 person-years, 12% of NAFLD patients and 2.2% of controls developed severe liver disease (p<0.001). Compared to controls, the risk of severe liver disease increased per stage of fibrosis (hazard ratio ranging from 1.9 in F0 to 104.9 in F4). Accounting for the presence of NASH did not change these estimates significantly (likelihood ratio test >0.05 for all stages of fibrosis). Similar results were seen for overall mortality. The lower end of the 95% confidence interval for the 10th percentile of time to development of severe liver disease was 22-26years in F0-1, 9.3years in F2, 2.3years in F3, and 0.9years to liver decompensation in F4. CONCLUSIONS In this, the largest ever study of biopsy-proven NAFLD, the presence of NASH did not increase the risk of liver-specific morbidity or overall mortality. Knowledge of time to development of severe liver disease according to fibrosis stage can be used in individual patient counselling and for public health decisions. LAY SUMMARY Non-alcoholic fatty liver disease (NAFLD) is very common in the general population, but reaching an accurate prognosis remains challenging. We investigate the long-term prognosis of a large cohort of NAFLD patients. In this, the largest ever study of biopsy-proven NAFLD, the presence of NASH did not increase the risk of liver-specific morbidity or overall mortality. Knowledge of time to development of severe liver disease according to fibrosis stage can be used in individual patient counselling and for public health decisions.

Incidence of human papillomavirus positive tonsillar and base of tongue carcinoma: A stabilisation of an epidemic of viral induced carcinoma?

AIM To investigate whether the rise during the past decades in the incidence of tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC) and the proportion of human papillomavirus (HPV) positive cancer has continued in Stockholm. PATIENTS AND METHODS Pre-treatment biopsies (n=252) available from 280 patients diagnosed with TSCC and BOTSCC during 2008-2012 in the County of Stockholm were tested for HPV DNA by a multiplex bead-based assay. Incidence records were acquired from the Swedish Cancer Registry. The data obtained were evaluated together with previous figures from 1970 to 2007. RESULTS HPV DNA was present in 186/252 (74%) of TSCC and BOTSCC biopsies obtained during 2008-2012 in Stockholm. In this region the age-standardised incidence, including the prevalence of HPV-positive and HPV-negative TSCC stabilised 2007-2012 compared to 2000-2006, while for BOTSCC throughout 1998-2012 the same parameters increased moderately (p<0.05, for all). In parallel, from 2000 to 2006 through 2007-2012 in Sweden, the age-standardised incidence of both TSCC and BOTSCC continued to rise (p=0.012 and p=0.001 respectively). CONCLUSION During 2000-2012 the age-standardised incidence and the proportion of HPV-positive TSCC have stabilised at a high level, while the proportion of HPV-negative cancer has remained at a low level in Stockholm, whereas for BOTSCC all parameters are increasing moderately. In contrast, in Sweden the incidence of both TSCC and BOTSCC is still increasing. We hypothesise that the HPV epidemic could be stabilising, first for TSCC, but so far not for BOTSCC, in e.g. some urban areas, while previous trends for both tumours persist at other geographic locations.

Increased YKL-40 and Chitotriosidase in Asthma and Chronic Obstructive Pulmonary Disease

RATIONALE Serum chitinases may be novel biomarkers of airway inflammation and remodeling, but less is known about factors regulating their levels. OBJECTIVES To examine serum chitotriosidase activity and YKL-40 levels in patients with asthma and chronic obstructive pulmonary disease (COPD) and evaluate clinically relevant factors that may affect chitinase levels, including genetic variability, corticosteroid treatment, disease exacerbations, and allergen exposure. METHODS Serum chitotriosidase (CHIT1) activity and YKL-40 (CHI3L1) levels, as well as the CHIT1 rs3831317 and CHI3L1 rs4950928 genotypes, were examined in subsets of patients with mild to moderate asthma (n = 76), severe asthma (n = 93), and COPD (n = 64) taking part in the European multicenter BIOAIR (Longitudinal Assessment of Clinical Course and Biomarkers in Severe Chronic Airway Disease) study. Blood was obtained at baseline, before and after a 2-week oral steroid intervention, up to six times during a 1-year period, and during exacerbations. Baseline chitinase levels were also measured in 72 healthy control subjects. The effect of allergen inhalation on blood and sputum YKL-40 levels was measured in two separate groups of patients with mild atopic asthma; one group underwent repeated low-dose allergen challenge (n = 15), and the other underwent high-dose allergen challenge (n = 16). MEASUREMENTS AND MAIN RESULTS Serum chitotriosidase and YKL-40 were significantly elevated in patients with asthma and those with COPD compared with healthy control subjects. Genotype and age strongly affected both YKL-40 and chitotriosidase activity, but associations with disease remained following adjustment for these factors. Correlations were observed with lung function but not with other biomarkers, including exhaled nitric oxide, blood eosinophils, periostin, and IgE. Generally, acute exacerbations, allergen-induced airway obstruction, and corticosteroid treatment did not affect circulating chitinase levels. CONCLUSIONS YKL-40 and chitotriosidase are increased in asthma and more so in COPD. The data in the present study support these substances as being relatively steroid-insensitive, non-T-helper cell type 2-type biomarkers distinctly related to chronic inflammatory disease processes.

Asymptomatic Multiclonal Plasmodium falciparum Infections Carried Through the Dry Season Predict Protection Against Subsequent Clinical Malaria

BACKGROUND Immunity to the antigenically diverse parasite Plasmodium falciparum is acquired gradually after repeated exposure. Studies in areas of high malaria transmission have shown that asymptomatic individuals infected with multiclonal infections are at reduced risk of febrile malaria during follow-up. METHODS We assessed the relationship between the genetic diversity of clones in P. falciparum infections that persist through the dry season and the subsequent risk of febrile malaria in 225 individuals aged 2-25 years in Mali, where the 6-month malaria and dry seasons are sharply demarcated. Polymerase chain reaction-based genotyping of the highly polymorphic merozoite surface protein 2 gene was performed on blood samples collected at 5 cross-sectional surveys. RESULTS In an age-adjusted analysis, individuals with multiclonal P. falciparum infections before the rainy season were at reduced risk of febrile malaria, compared with individuals who were uninfected (hazard ratio [HR], 0.28; 95% confidence interval [CI], .11-.69). In contrast, there was no significant association between risk of malaria and having 1 clone at baseline (HR, 0.71; 95% CI, .36-1.40). CONCLUSIONS The results suggest that persistent multiclonal infections carried through the dry season contribute to protection against subsequent febrile malaria, possibly by maintaining protective immune responses that depend on ongoing parasite infection.

A model for predicting clinical outcome in patients with human papillomavirus-positive tonsillar and base of tongue cancer.

AIM To combine clinical and molecular markers into an algorithm for predicting outcome for individual patients with human papillomavirus (HPV) DNA/p16(INK4a) positive tonsillar and base of tongue squamous cell carcinoma (TSCC and BOTSCC). BACKGROUND Head-neck cancer treatment has become more intensified, comprising not only surgery and radiotherapy, but also induction/concomitant chemotherapy and targeted therapy. With less treatment, 3-year disease free survival (DFS) is 80% for HPV-positive TSCC and BOTSCC. An 85-100% 3-year DFS is observed for HPV(+) TSCC and BOTSCC with absence of HLA class I, or CD44 expression, or high CD8(+) tumour-infiltrating lymphocyte (TIL) counts suggesting that therapy could be tapered for many if patients could be identified individually. PATIENTS AND METHODS Patients treated curatively, with HPV DNA/p16(INK4a) positive tumours examined for HLA class I and II, CD44 and CD8(+)TILs, were included. An L1-regularised logistic regression was used to evaluate the effect of the biomarker data, age, stage, diagnosis, smoking and treatment on 3-year risk of death or relapse on a training cohort of 197 patients diagnosed 2000-2007 and validated on a cohort of 118 patients diagnosed 2008-2011. RESULTS The variables finally included in the model were HLA class I, CD8(+) TILs, age, stage and diagnosis (TSCC or BOTSCC). The model showed acceptable discrimination and calibration. The discriminative ability of the model did not diminish after validation (AUC=0.77). CONCLUSION To our knowledge, this is the first model to utilise information from several markers to predict an individual probability of clinical outcome for patients with HPV DNA/p16(INK4a) positive tumours.

Risk for development of severe liver disease in lean patients with nonalcoholic fatty liver disease: A long-term follow-up study

Most patients with nonalcoholic fatty liver disease (NAFLD) are overweight or obese. However, a significant proportion of patients have a normal body mass index (BMI), denoted as lean NAFLD. The long‐term prognosis of lean NAFLD is unclear. We conducted a cohort study of 646 patients with biopsy‐proven NAFLD. Patients were defined as lean (BMI < 25.0), overweight (BMI 25.0‐29.9), or obese (BMI ≥ 30.0) at the time of biopsy. Each case was matched for age, sex, and municipality to 10 controls. Overall mortality and development of severe liver disease were evaluated using population‐based registers. Cox regression models adjusted for age, sex, type 2 diabetes, and fibrosis stage were used to examine the long‐term risk of mortality and liver‐related events in lean and nonlean NAFLD. Lean NAFLD was seen in 19% of patients, while 52% were overweight and 29% were obese. Patients with lean NAFLD were older, had lower transaminases, lower stages of fibrosis, and lower prevalence of nonalcoholic steatohepatitis at baseline compared to patients with a higher BMI. During a mean follow‐up of 19.9 years (range 0.4‐40 years) representing 12,631 person years and compared to patients who were overweight, patients with lean NAFLD had no increased risk for overall mortality (hazard ratio 1.06; P =  0.73) while an increased risk for development of severe liver disease was found (hazard ratio 2.69; P =  0.007). Conclusion: Although patients with lean NAFLD have lower stages of fibrosis, they are at higher risk for development of severe liver disease compared to patients with NAFLD and a higher BMI, independent of available confounders. (Hepatology Communications 2018;2:48–57)

A register-based study: adverse events in colonoscopies performed in Sweden 2001–2013

Abstract Objectives: The rates for colonoscopy-associated adverse events vary considerably worldwide. In Sweden, the figures are known to a limited extent. We assessed the frequency of severe colonoscopy-related adverse events and the impacts of different risk factors, including the use of general anaesthesia. Material and methods: This is a retrospective population-based cohort study of the colonoscopies performed during the years 2001–2013 on adults identified in the Swedish health registers. The rates for bleeding, perforation, splenic injury and 30-day mortality were calculated. Covariates for risks were assessed in a multivariate Poisson regression model. Results: There were 593,315 colonoscopies performed on the 426,560 individuals included in the study. The rates for colonoscopy-related bleeding and perforation were 0.17% and 0.11%, respectively. When polypectomy was performed, the rates were 0.53% for bleeding and 0.25% for perforation. There were 31 splenic injuries (1:20,000 colonoscopies) reported. The crude 30-day death rate for colonoscopy was 0.68%. Of those diagnosed with bleeding or perforation, 5.6% and 6.1% were dead within 30 days, respectively. The multivariate RR for perforation when general anaesthesia was employed was 2.65 (p < .001; 95%CI 1.71–4.12). Conclusions: The perforation rate seemed to be relatively high in an international perspective. General anaesthesia was associated with a significantly higher risk for perforation. Splenic injuries were more frequent than expected.

Cohort study of growth patterns by gestational age in preterm infants developing morbidity

Objectives To examine differences in growth patterns in preterm infants developing major morbidities including retinopathy of prematurity (ROP), bronchopulmonary dysplasia (BPD), necrotising enterocolitis (NEC) and intraventricular haemorrhage (IVH). Study design Cohort study of 2521 infants born at a gestational age (GA) of 23–30 weeks from 11 level III neonatal intensive care units in USA and Canada, and 3 Swedish population-based cohorts. Outcomes Birth weight and postnatal weight gain were examined relative to birth GA and ROP, BPD, NEC and IVH development. Results Among infants with a birth GA of 25–30 weeks, birth weight SD score and postnatal weight were lower in those developing ROP and BPD. Infants developing ROP showed lower growth rates during postnatal weeks 7–9 in the 23–24 weeks GA group, during weeks 4–6 in the 25–26 weeks GA group and during weeks 1–5 in the 27–30 weeks GA group. Infants with BPD born at 27–30 weeks GA showed lower growth rates during postnatal weeks 3–5. Infants with NEC had lower growth rates after postnatal week 6 in all GA groups, with no significant differences in birth weight SD score. IVH was not associated with prenatal or postnatal growth. Conclusions In this cohort study of extremely preterm infants, we found that the postnatal growth pattern was associated with morbidities such as ROP, BPD and NEC as well as with gestational age at birth.

Cellular aging dynamics after acute malaria infection: A 12‐month longitudinal study

Accelerated cellular aging and reduced lifespan have recently been shown in birds chronically infected with malaria parasites. Whether malaria infection also affects cellular aging in humans has not been reported. Here, we assessed the effect of a single acute Plasmodium falciparum malaria infection on cellular aging dynamics in travelers prospectively followed over one year in Sweden. DNA and RNA were extracted from venous blood collected at the time of admission and repeatedly up to one year. Telomere length was measured using real‐time quantitative PCR, while telomerase activity and CDKN2A expression were measured by reverse transcriptase (RT)–qPCR. Our results show that acute malaria infection affects cellular aging as reflected by elevated levels of CDKN2A expression, lower telomerase activity, and substantial telomere shortening during the first three months postinfection. After that CDKN2A expression declined, telomerase activity increased and telomere length was gradually restored over one year, reflecting that cellular aging was reversed. These findings demonstrate that malaria infection affects cellular aging and the underlying cellular mechanism by which pathogens can affect host cellular aging and longevity need to be elucidated. Our results urge the need to investigate whether repeated malaria infections have more pronounced and long‐lasting effects on cellular aging and lifespan (similarly to what was observed in birds) in populations living in malaria endemic areas.

Obesity and Diabetes as Risk Factors for Severe Plasmodium falciparum Malaria: Results From a Swedish Nationwide Study

Summary In this nationwide observational study of 937 adults diagnosed with Plasmodium falciparum malaria in Sweden, Charlson comorbidity score ≥1 as well as diabetes and obesity were significantly associated with severe malaria in both nonimmune travelers and immigrants from endemic countries.