Prognostic genomic alterations in patients undergoing liver resection for hepatocellular carcinoma.

INTRODUCTION: Genetic mutations and amplifications found in hepatocellular carcinoma (HCC) have a potentially prognostic impact. The aim of this study was to investigate the prognostic value of mutations and amplifications in HCC from patients that were liver resected. METHODS: Patients liver resected for HCC at Copenhagen University Hospital Rigshospitalet between May 2014 and January 2018 were included. DNA from freshly frozen tumour tissue was investigated with TruSight Oncology 500. Mutations and amplifications were correlated with disease-free survival and overall survival using multivariate Cox regression to assess the effect on prognosis. RESULTS: Of the 51 patients included, 88% were male and the median age was 69 years. Most patients had a single tumour (84%) with no vascular invasion (67%) in a non-cirrhotic liver (76% with fibrosis, 24% with cirrhosis). The median follow-up was 37 months. Patients with a MYC amplification (8%) were significantly younger than the remaining patients. Furthermore, they had a significantly shorter overall survival (15 months (95% CI: 0.0-31.6) vs. 59 months (95% CI: 34.4-83.6), p = < 0.001) and disease-free survival (8 months (95% CI: 4.6-11.4) vs. 19 months (95% CI: 12.3-25.7), p = 0.03). However, only overall survival remained statistically significant in the adjusted analysis. Furthermore, all patients with an ARID1A mutation (6%) had microvascular invasion and significantly larger tumours than the patients without ARID1A mutation. CONCLUSION: MYC amplifications had a prognostic influence on survival, whereas ARID1A gene mutations were correlated with microvascular invasion. These may serve as prognostic biomarkers and should be validated in large, independent cohort.

Anti-CD20 antibody therapy and risk of infection in patients with demyelinating diseases.

BACKGROUND: Anti-CD20 antibody therapy may be associated with an increased risk of infections. We therefore investigated risk factors for infection in patients with demyelinating diseases treated with anti-CD20 antibody therapy. METHODS: In this retrospective uncontrolled study, patients ever treated with anti-CD20 antibodies at an academic clinic were identified through the Danish Multiple Sclerosis Registry (DMSR). Data were collected from medical charts and the DMSR. We assessed occurrence of severe infections (requiring hospitalization), varicella zoster virus (VZV), major comorbidities and routine laboratory values for lymphocytes, IgG and IgM. RESULTS: A total of 447 patients ever treated with anti-CD20 antibody therapy were identified; of these 416 with 649 patient years of follow-up were still under therapy. In this group, seven patients had VZV infections, and 16 patients had been hospitalized with infections during up to three years of follow-up on anti-CD20 therapy. Comorbidity was recorded in 80 patients. The risk of severe infection was associated with comorbidities, higher age, longer duration of treatment, and higher Expanded Disability Status Scale (EDSS) scores. In multivariable analyses treatment duration, EDSS scores and presence of comorbidity were independently associated with risk of severe infections. Serum concentrations of IgG and IgM decreased with increasing duration of therapy but were not associated with risk of severe infections. Patients with VZV infection had lower lymphocyte counts and lower serum concentrations of IgM. In multivariable analyses only lymphocyte counts were independently associated with risk of VZV infection. CONCLUSIONS: In this retrospective study of patients treated with anti-CD20 antibodies, the risk of infections requiring hospitalization was independently associated with comorbidities, duration of treatment, and higher EDSS scores. Risk of VZV infection was independently associated with lymphopenia. Future studies investigating strategies for mitigating risk of infection in patients treated with anti-CD20 antibodies are warranted, especially for older patients, patients with higher levels of disability and for patients with a longer duration of treatment.

Cardiac chamber volumes and left ventricular mass in people living with HIV and matched uninfected controls.

OBJECTIVES: People living with HIV (PLWH) have increased risk of cardiovascular diseases compared with uninfected populations. We assessed structural cardiac abnormalities and their associated risk factors in well-treated PLWH and uninfected controls using multidetector computed tomography (MDCT). METHODS: People living with HIV and age- and sex-matched uninfected controls underwent MDCT to determine left atrial volume (LAV), left ventricular diastolic volume (LVDV), right ventricular diastolic volume (RVDV) and left ventricular mass (LVM). All outcomes were indexed to body surface area (BSA) (LAVi, LVDVi, RVDVi and LVMi). RESULTS: A total of 592 PLWH and 1184 uninfected controls were included in the study. PLWH had smaller mean (SD) LAVi [40 (8) vs. 41 (9) mL/m2 ; P = 0.002] and LVDVi [61 (13) vs. 65 (14) mL/m2 ; P < 0.001] but larger RVDVi [89 (18) vs. 86 (17) mL/m2 ; P < 0.001] than uninfected controls. HIV was independently associated with 7 mL (95% CI: -10 to -3) smaller LVDV, and with 12 mL (95% CI: 8-16) larger RVDV, and 4 g (95% CI: 1-6) larger LVM after adjustment for cardiovascular risk factors and BSA. Large RVDV in PLWH was not associated with obstructive lung function. CONCLUSIONS: HIV was independently associated with smaller LVDV and larger RVDV and LVM. Alterations in cardiac chamber volumes in PLWH were mainly minor. The clinical impact of these findings is uncertain, but it seems unlikely that alterations in cardiac chamber volumes explain the increased burden of cardiovascular disease previously observed in PLWH.

Prevalence of impaired renal function in virologically suppressed people living with HIV compared with controls: the Copenhagen Comorbidity in HIV Infection (COCOMO) study.

OBJECTIVES: While renal impairment is reported more frequently in people living with HIV (PLWH) than in the general population, the PLWH samples in previous studies have generally been dominated by those at high renal risk. METHODS: Caucasian PLWH who were virologically suppressed on antiretroviral treatment and did not have injecting drug use or hepatitis C were recruited from the Copenhagen Comorbidity in HIV Infection (COCOMO) study. Sex- and age-matched controls were recruited 1:4 from the Copenhagen General Population Study up to November 2016. We defined renal impairment as one measurement of estimated glomerular filtration rate ≤ 60 mL/min/1.73 m2 , and assessed associated factors using adjusted logistic regression models. The impact of HIV-related factors was explored in a subanalysis. RESULTS: Among 598 PLWH and 2598 controls, the prevalence of renal impairment was 3.7% [95% confidence interval (CI) 2.3-5.5%] and 1.7% (95% CI 1.2-2.2%; P = 0.0014), respectively. After adjustment, HIV status was independently associated with renal impairment [odds ratio (OR) 3.4; 95% CI 1.8-6.3]. In addition, older age [OR 5.4 (95% CI 3.9-7.5) per 10 years], female sex [OR 5.0 (95% CI 2.6-9.8)] and diabetes [OR 2.9 (95% CI 1.3-6.7)] were strongly associated with renal impairment. The association between HIV status and renal impairment became stronger with older age (P = 0.02 for interaction). Current and nadir CD4 counts, duration of HIV infection and previous AIDS-defining diagnosis were not associated with renal impairment among virologically suppressed PLWH. CONCLUSIONS: The prevalence of renal impairment is low among low-risk virologically suppressed Caucasian PLWH, but remains significantly higher than in controls. Renal impairment therefore remains a concern in all PLWH and requires ongoing attention.

Diagnostic performance of clinical characteristics to detect airflow limitation in people living with HIV and in uninfected controls.

OBJECTIVES: Chronic obstructive pulmonary disease (COPD) is underdiagnosed in the general population and possibly also in people living with HIV (PLWH). We evaluated the diagnostic performance of symptoms and risk factors for assessment of airflow limitation in PLWH and in uninfected controls. METHODS: Spirometry was performed in the Copenhagen Comorbidity in HIV Infection (COCOMO) study and Copenhagen General Population Study (CGPS), and airflow limitation was defined by forced expiratory volume in 1 s/forced vital capacity < lower limit of normal. We calculated the sensitivity, specificity, predictive values and area under the curve (AUC) of symptoms and risk factors for assessment of airflow limitation in PLWH and uninfected controls. RESULTS: A total of 1083 PLWH and 12 074 uninfected controls were included in the study. The sensitivity for sputum, chronic cough, breathlessness, wheezing, current and cumulative smoking and self-reported COPD was higher, but the specificity lower, in PLWH than in uninfected controls. The negative and positive predictive values were largely similar between the groups. The AUCs were similar or slightly higher in PLWH and highest for > 20 pack-years smoked [0.65; 95% confidence interval (CI) 0.58-0.72] and wheezing (0.64; 95% CI 0.57-0.71). A summed score for five variables was associated with slightly higher AUC in PLWH compared with uninfected controls [0.71 (95% CI 0.63-0.79) versus 0.65 (95% CI 0.63-0.68), respectively; P = 0.06]. CONCLUSIONS: Clinical variables were relatively poor discriminators of airflow limitation in PLWH and uninfected controls. Active COPD case finding by screening for symptoms and relevant exposures, as recommended in the general population, is likely to yield similar diagnostic power in PLWH.

HIV infection is independently associated with a higher concentration of alpha-1 antitrypsin.

OBJECTIVES: Alpha-1 antitrypsin (AAT) deficiency is associated with an increased risk of chronic obstructive pulmonary disease and has been related to CD4 T-cell count decline in people living with HIV (PLWH). We determined whether HIV status is associated with AAT concentrations and assessed associations between AAT concentration, pulmonary function and immunological status. METHODS: Alpha-1 antitrypsin was measured and spirometry performed in 1011 PLWH from the Copenhagen Comorbidity in HIV Infection (COCOMO) study and in 11 962 age- and sex-matched uninfected controls. We studied associations between AAT concentration, HIV status, pulmonary function, and current and nadir CD4 T-cell counts using multivariate linear regression analyses. RESULTS: The mean age of PLWH was 50.7 [standard deviation (SD) 11.3] years and 98.6% were receiving combination antiretroviral therapy (cART). The mean current CD4 T-cell count was 718 (SD 284) cells/µL. PLWH had a higher median AAT concentration than uninfected controls [1.4 (interquartile range (IQR) 1.3-1.6) versus 1.3 (IQR 1.2-1.4) g/L; P < 0.0001] and HIV infection was independently associated with higher AAT concentration [adjusted ß = 0.10 g/L; 95% confidence interval (CI) 0.08; 0.11 g/L; P < 0.001]. Low AAT concentration (< 1.0 g/L) was not more common in PLWH with airflow limitation (defined as forced expiratory volume in 1 second/forced vital capacity (FEV1 /FVC) < 0.7 with FEV1 -predicted < 80%) compared with uninfected controls with airflow limitation, and the effect of AAT on FEV1 %-predicted was comparable to that in uninfected controls (P-interaction = 0.66). AAT concentration was not associated with current or nadir CD4 T-cell count. CONCLUSIONS: HIV infection was independently associated with a higher concentration of AAT through unknown mechanisms. However, AAT does not seem to contribute to lower pulmonary function or to low CD4 T-cell counts in PLWH.

Bacillus Calmette-Guérin vaccination at birth and in vitro cytokine responses to non-specific stimulation. A randomized clinical trial.

Several studies have shown increased in vitro cytokine responses to non-related pathogens after Bacillus Calmette-Guérin (BCG) vaccination. A total of 158 infants (80 BCG administered within 7 days of birth; 78 controls) were bled 4 days post-randomization, and at age 3 and 13 months. Geometric mean concentrations of IL-1ß, TNF-α, IL-6 (24 h stimulation) and IFN-γ, IL-10, IL-17, IL-22 (96 h stimulation) in response to in vitro stimulation with RPMI, LPS, PHA, Escherichia coli, Streptococcus pneumoniae, Candida albicans and BCG were compared among BCG vaccinated children and controls. BCG vaccination did not affect in vitro cytokine production, except IFN-γ and IL-22 response to BCG. Stratifying for 'age at randomization' we found a potentiating effect of BCG on cytokine production (TNF-α, IL-6, IL-10) in the 4 days post randomization stimulations, among children who were vaccinated at age 2-7 days versus age 0-1 days. BCG vaccination did not potentiate cytokine production to non-BCG antigens. At 4 days post randomization, BCG was associated with higher cytokine production in the later randomized children.

Ageing with neurogenic bowel dysfunction.

STUDY DESIGN: Longitudinal study with postal survey. OBJECTIVES: To describe changes in the patterns of neurogenic bowel dysfunction and bowel management in a population of people with spinal cord injury (SCI) followed for two decades. SETTING: Members of the Danish SCI Association. METHODS: In 1996, a validated questionnaire on bowel function was sent to the members of the Danish SCI Association (n=589). The same questionnaire was sent to all the surviving members in 2006 (n=284) and in 2015 (n=178). A total of 109 responded to both the 1996 and 2015 questionnaires. RESULTS: Comparing data from 2015 with those from the exact same participants in 1996, the proportion of respondents needing more than 30 min for each defaecation increased from 21 to 39% (P<0.01), the use of laxatives increased (P<0.05) and the proportion considering themselves very constipated increased from 19 to 31% (P<0.01). In contrast, the proportion suffering from faecal incontinence remained stable at 18% in 1996 and 19% in 2015. During the 19-year period, there had been no significant change in the methods for bowel care, but 22 (20%) had undergone surgery for bowel dysfunction, including 11 (10%) who had some form of stoma. CONCLUSION: Self-assessed severity of constipation increased but quality of life remained stable in a cohort of people with SCI followed prospectively for 19 years. Methods for bowel care remained surprisingly stable but a large proportion had undergone stoma surgery.

Comparative study of HbA1c and fasting plasma glucose vs the oral glucose tolerance test for diagnosis of diabetes in people with tuberculosis.

AIM: To compare HbA1c and fasting plasma glucose assessment, with the 2-h oral glucose tolerance test as reference, in screening for diabetes in people with turberculosis. METHODS: Individuals (N=268) with newly diagnosed smear-positive tuberculosis were screened for diabetes at a tertiary hospital in Lahore, Pakistan. Diabetes diagnosis was based on WHO criteria: thresholds were ≥48 mmol/mol (≥6.5%) for HbA1c and ≥7.0mmol/l for fasting plasma glucose. RESULTS: The proportion of participants diagnosed with diabetes was 4.9% (n =13) by oral glucose tolerance test, while 11.9% (n =32) and 14.6% (n =39) were diagnosed with diabetes using HbA1c and fasting plasma glucose criteria, respectively. The area under the receiver-operating characteristic curve was 0.79 (95% CI 0.64 to 0.94) for HbA1c and 0.61 (95% CI 0.50 to 0.73) for fasting plasma glucose, with a borderline significant difference between the two tests (P=0.07). CONCLUSIONS: HbA1c and fasting plasma glucose performed equally in terms of diagnosing new diabetes cases in individuals with tuberculosis, but the proportion of participants falsely classified as positive was higher for fasting plasma glucose. This may be explained by acute blood glucose fluctuations when using fasting plasma glucose. HbA1c may be a more reliable test in individuals with transient hyperglycaemia.

Chronic abdominal pain in long-term spinal cord injury: a follow-up study.

STUDY DESIGN: A longitudinal postal survey. OBJECTIVES: To evaluate the prevalence and characteristics of abdominal pain in long-term spinal cord injury (SCI). SETTING: Members of the Danish SCI Association. METHODS: In 2006, a questionnaire on chronic abdominal pain and discomfort was sent to the 284 members of the Danish SCI association who had been members for at least 10 years; 203 of them responded. An almost identical questionnaire including questions on intensity and interference of pain within the past 7 days, as well as descriptors and treatment, was sent to the 178 surviving members in 2015. RESULTS: Of 130 (73%) responders, 125 answered the question on chronic abdominal pain. The mean time since injury was 30.5 (9.8) years. Chronic abdominal pain or discomfort was reported by 32.8% (41/125), and 23% (29/125) of responders had been at least moderately bothered by this in the past week. Abdominal pain or discomfort was more common in women and in those with self-reported constipation. The median intensity (numeric rating scale) was 6.0 (range 3-10) and it was often associated with autonomic symptoms. Nine (8%) of the 115 individuals who responded in both 2006 and 2015 had developed new abdominal pain or discomfort, 30 (26%) no longer reported it, and 28 (24%) reported it at both time points with a similar intensity. CONCLUSIONS: Chronic abdominal pain or discomfort is common and bothersome in long-term SCI. It has a late onset, but the prevalence and severity do not seem to further increase between 20 and 30 years following SCI.

The lectin pathway of complement: advantage or disadvantage in HIV pathogenesis?

The pattern recognition molecules of the lectin complement pathway are important components of the innate immune system with known functions in host-virus interactions. This paper summarizes current knowledge of how these intriguing molecules, including mannose-binding lectin (MBL), Ficolin-1, -2 and -3, and collectin-11 (CL-11) may influence HIV-pathogenesis. It has been demonstrated that MBL is capable of binding and neutralizing HIV and may affect host susceptibility to HIV infection and disease progression. In addition, MBL may cause variations in the host immune response against HIV. Ficolin-1, -2 and -3 and CL-11 could have similar functions in HIV infection as the ficolins have been shown to play a role in other viral infections, and CL-11 resembles MBL and the ficolins in structure and binding capacity.

Progressive disseminated histoplasmosis in the HIV population in Europe in the HAART era. Case report and literature review.

INTRODUCTION: In highly endemic areas, up to 20 % of human immunodeficiency virus (HIV)-infected persons will develop progressive disseminated histoplasmosis (PDH). Europe is not endemic to histoplasmosis, and the disease is mainly found in immigrants often co-infected with HIV. METHODS: We present a case of a patient with HIV and PDH highlighting the possible diagnostic difficulties that may arise in a non-endemic area and review the literature of histoplasmosis in the context of HIV infection with special focus on Europe. DISCUSSION: When cellular immunity wanes (usually at CD4 T-lymphocyte counts <150 cells/µL) histoplasma infection, acquired earlier, can reactivate and disseminate. PDH is an acquired immune deficiency syndrome(AIDS)-defining disease and a life-threatening infection, with a clinical spectrum ranging from an acute, fatal course with lung infiltrates and respiratory failure, shock, coagulopathy and multi-organ failure, to a more subacute disease with focal organ involvement, pancytopenia and hepatosplenomegaly. Mortality rates remain high for untreated patients, but early diagnosis, proper antifungal treatment and early initiation of antiretroviral therapy have improved the prognosis. CONCLUSION: European infectious diseases physicians, microbiologists and pathologists must be aware of histoplasmosis, particularly when facing HIV-infected immigrants from endemic areas. This is increasingly important due to migration and travel activities from these areas.

Impaired thymic output in patients with chronic hepatitis C virus infection.

Altered T cell homeostasis in chronic hepatitis C virus (HCV) infection has been demonstrated. However, it is unknown whether fibrosis is associated with more perturbed T cell homeostasis in chronic HCV infection. The aim of this study was to examine and compare T cell subsets including recent thymic emigrants (RTE), naive, memory, senescent, apoptotic and IL-7 receptor α (CD127) expressing CD4⁺ and CD8⁺ T cells as well as telomere length and interferon-γ production in HCV-infected patients with (n = 25) and without (n = 26) fibrosis as well as in healthy controls (n = 24). Decreased proportions of CD4⁺ and CD8⁺ RTE were found in HCV-infected patients, especially in HCV-infected patients with fibrosis (14.3% (9.7-23.0) and 28.8% (16.1-40.5), respectively) compared with healthy controls (24.2% (16.3-32.1), P = 0.004 and 39.1% (31.6-55.0), P = 0.010, respectively). Furthermore, HCV-infected patients with fibrosis presented with a higher proportion of CD4⁺ T cells expressing CD127 compared with HCV-infected patients without fibrosis [88.4% (84.5-91.0) versus 83.8% (79.9-86.8), P = 0.016]. Thus, impaired thymic output in HCV infection was found, and high proportion of CD127⁺ T cells may illustrate a compensatory mechanism to preserve T cell counts.

Markers of microbial translocation predict hypertension in HIV-infected individuals.

OBJECTIVES: The aim of the study was to test the hypothesis that microbial translocation, quantified by levels of lipopolysaccharide (LPS) and subsequent monocyte activation [soluble (sCD14)], is associated with hypertension in HIV-infected individuals. METHODS: In this exploratory substudy, 42 patients were recruited from a larger, longitudinal HIV-infected cohort study on blood pressure. LPS and sCD14 levels were measured retrospectively at the time of nadir CD4 cell count, selecting untreated HIV-infected patients with both advanced immunodeficiency and preserved immunocompetence at the time of nadir. Patients with later sustained hypertension (n = 16) or normotension (n = 26) throughout the study were identified. LPS was analysed using the Limulus Amebocyte Lysate colorimetric assay (Lonza, Walkersville, MD) and sCD14 using an enzyme-linked immunosorbent assay (ELISA). Nonparametric statistical tests were applied. RESULTS: In the HIV-infected patients [median (interquartile range) age 42 (32-46) years; 79% male and 81% Caucasian], LPS and sCD14 levels were both negatively correlated with nadir CD4 cell count. Plasma levels of LPS (P < 0.001) and sCD14 (P = 0.024) were elevated in patients with later hypertension compared with patients with normotension. There was a stepwise increase in the number of patients with hypertension across tertiles of LPS (P = 0.001) and sCD14 (P = 0.007). Both LPS and sCD14 were independent predictors of elevated blood pressure after adjustment for age and gender. For each 10-unit increase in LPS (range 66-272 pg/ml), the increment in mean blood pressure in the first period of blood pressure recording was 0.86 (95% confidence interval 0.31-1.41) mmHg (P = 0.003). CONCLUSIONS: As LPS and sCD14 were both independently associated with elevated blood pressure, microbial translocation may be linked to the development of hypertension.

CD4⁺ and CD8⁺ regulatory T cells (Tregs) are elevated and display an active phenotype in patients with chronic HCV mono-infection and HIV/HCV co-infection.

The aim of this study was to examine regulatory T cells (Tregs) in peripheral blood and liver tissue in patients with chronic hepatitis C virus (HCV) mono-infection and in patients with HIV/HCV co-infection. In a cross-sectional study were included 51 patients with chronic HCV infection, 24 patients with HIV/HCV co-infection and 24 healthy individuals. CD4⁺ and CD8⁺ Tregs were determined using flow cytometry. Fibrosis was examined by transient elastography. Inflammation, fibrosis and Tregs were determined in liver biopsies from 12 patients. Increased frequency of CD4⁺ and CD8⁺ Tregs was found in HIV/HCV co-infected patients [median: 6.4% (IQR: 5.7-6.9) and 1.0% (0.7-1.2), respectively] compared to HCV mono-infected patients [5.6% (4.2-6.3), P = 0.01 and 0.5% (0.3-0.7), P < 0.001, respectively]. Furthermore, HCV mono-infected patients had increased frequencies of Tregs compared with healthy controls (P < 0.05). However, no associations between the frequency of Tregs and fibrosis were found. Furthermore, characterization of CD4⁺ Tregs using CD45RA demonstrated a higher frequency of activated Tregs in both HCV mono-infected and HIV/HCV co-infected patients compared with healthy controls. Finally, number of intrahepatic Tregs was associated with both peripheral CD8⁺ Tregs and intrahepatic inflammation. In conclusion, HCV mono-infected patients and particularly HIV/HCV co-infected patients have increased the frequency of CD4⁺ and CD8⁺ Tregs compared with healthy controls. Furthermore, CD4⁺ Tregs in infected patients displayed an active phenotype. Tregs were not associated with fibrosis, but a positive correlation between intrahepatic Tregs and inflammation was found. Taken together, these results suggest a role for Tregs in the pathogenesis of chronic HCV infection.

Low thymic size in preterm infants in the neonatal intensive care unit, a possible marker of infection? A prospective study from birth to 1 year of age.

AIM: To study the growth of the thymus in preterm infants. METHODS: Ultrasonographic thymic size (Ti) was studied in 80 preterm infants (gestational age 24-36 weeks) from birth to discharge from the neonatal intensive care unit (NICU). Thirty-three of these infants were followed to 1 year of age. RESULTS: At birth, the median Ti was 5.2 compared with 11.8 in term infants. At discharge, the median Ti was 10.0 and not significantly different from Ti in term infants at birth (p = 0.22). The size of the thymus was significantly associated with postmenstrual age and weight (both p < 0.01). Infections during admission were negatively associated with the size of the thymus (p < 0.01). During the first 3 months after discharge, preterm infants had a significantly higher frequency of infections than did term infants (p = 0.002); hereafter, the preterm infants had significantly fewer infections than term infants (p = 0.002). The median Ti in preterm infants and term infants at 1 year of age was 21.1 and 17.3, respectively. This difference was not statistically significant (p = 0.41). CONCLUSIONS: Growth of thymus was not compromised by preterm birth. Ti is negatively associated with the frequency of infections in preterm neonates submitted to NICU.

HIV-infected patients with a large thymus maintain higher CD4 counts in a 5-year follow-up study of patients treated with highly active antiretroviral therapy.

CD4 recovery in HIV-infected patients treated with highly active antiretroviral therapy (HAART) is in part believed to be dependent on the degree of preserved thymic function. We investigated whether the thymus has a prolonged effect on CD4 recovery. Total and naïve CD4 counts as well as thymic output determined as the number of CD4 + cells containing T-cell receptor-rearrangement excision DNA circles were measured prospectively in 25 HIV-infected patients with known thymic size during 5 years of HAART. Patients with larger thymic size had at all time points of follow-up significantly higher CD4 counts than patients with minimal thymic size (P = 0.0036). The CD4 increase from time of initiation of HAART until 6 months of follow-up differed significantly between the two thymic groups (P = 0.045), but did not at later time points. Thymic output remained significantly higher in patients with larger thymic size at follow-up. However, no difference in the increase in thymic output was seen between thymic groups. In conclusion, the importance of the thymus to the rate of cellular restoration seems primarily to lie within the first two years of HAART. However, patients with larger thymic size are able to maintain higher CD4 counts even after 5 years of HAART.

Limited impact of the thymus on immunological recovery during and after chemotherapy in patients with diffuse large B-cell lymphoma.

To investigate the impact of thymus on immunological recovery after dose-dense chemotherapy a prospective study of 17 patients diagnosed with diffuse large B-cell lymphoma (DLBCL) was conducted. Patients were monitored before, during and until 3 months after chemotherapy. The thymus was visualized using computer tomographic scans. Patients were divided into two groups according to thymic size, one group comprising of patients without detectable thymus and one group of patients with detectable thymus. Naïve CD4 and CD8 counts were measured by flow cytometry, and to measure thymic output determination of CD4+ cells containing T-cell receptor excision circles (TREC) was done. During chemotherapy, the naïve CD4 count decreased significantly as did the CD4-TREC%. Significant difference in recovery of naïve CD4 counts between patients with detectable and undetectable thymic tissue during treatment with chemotherapy was not found. CD4-TREC% was associated with lower age. It was not possible to demonstrate an association between thymic size and recovery of the naïve CD4+ cells. The study terminated 3 months after the last cycle of chemotherapy, and at that time point the naïve CD4 counts and the CD4-TREC% had not returned to pretreatment levels. However, patients with detectable thymic tissue had higher naïve CD4 counts after the first cycles of chemotherapy, suggesting that these patients may be less susceptible to infectious complications related to chemotherapy.

Increased levels of regulatory T cells (Tregs) in human immunodeficiency virus-infected patients after 5 years of highly active anti-retroviral therapy may be due to increased thymic production of naive Tregs.

This study determines levels of regulatory T cells (T(regs)), naive T(regs), immune activation and cytokine patterns in 15 adult human immunodeficiency virus (HIV)-infected patients receiving prolonged highly active anti-retroviral therapy (HAART) who have known thymic output, and explores if naive T(regs) may represent recent thymic emigrant T(regs). HIV-infected patients treated with HAART with a median of 1 and 5 years were compared with healthy controls. Percentages of T(regs) (CD3(+)CD4(+)CD25(+)CD127(low)), naive T(regs) (CD3(+)CD4(+)CD25(+)CD45RA(+)) and activation markers (CD38(+)human leucocyte antigen D-related) were determined by flow cytometry. Forkhead box P3 mRNA expression and T cell receptor excision circles (T(REC)) content in CD4(+) cells were determined by polymerase chain reaction and cytokines analysed with Luminex technology. Levels of T(regs) were significantly higher in HIV-infected patients compared with controls, both after 1 and 5 years of HAART (P<0.001), despite fully suppressed HIV-RNA and normalization of both CD4 counts, immune activation and cytokine patterns. Furthermore, levels of naive T(regs) were elevated significantly in HIV-infected patients (P<0.001) and were associated with thymic output measured as the T(REC) frequency in CD4(+) cells (P=0.038). In summary, T(reg) levels in HIV-infected patients are elevated even after 5 years of HAART. Increased thymic production of naive T(regs) may contribute to higher T(reg) levels in HIV-infection.

Regulatory T cells in human immunodeficiency virus-infected patients are elevated and independent of immunological and virological status, as well as initiation of highly active anti-retroviral therapy.

Infection with human immunodeficiency virus (HIV) causes a dysregulation of the immune system. This is caused by HIV-specific as well as non-specific mechanisms and has not been explained fully. In particular, knowledge is lacking about the potential role of host-mediated immunosuppressive mechanisms. During recent years it has become evident that a subpopulation of T cells [T regulatory (T(regs))] play a major role in sustaining tolerance to self-antigens. To investigate the influence of initiation of highly active anti-retroviral therapy (HAART) on the T(reg) level in HIV-infected patients we have conducted a prospective study enrolling treatment-naive HIV-infected patients just prior to starting treatment with HAART, measuring levels of T(regs) by flow cytometry and mRNA expression of forkhead box P3 (FoxP3) at weeks 0, 4, 12 and 24 of treatment. In this prospective study neither the percentage of CD4(+)CD25(high+) nor the expression of FoxP3 changed significantly during 24 weeks of HAART. Furthermore, HIV patients have higher T(regs) measured as percentages of CD4(+)CD25(high+) cells paralleled by higher levels of FoxP3 compared with healthy controls. The elevated level of T(regs) was found to be independent of both immunological and virological status, indicating that initiation of HAART has minor effects on the T(reg) level in HIV-infected patients.