Corrigendum: The paradigm of IL-23-independent production of IL-17F and IL-17A and their role in chronic inflammatory diseases

[This corrects the article DOI: 10.3389/fimmu.2023.1191782.].

The paradigm of IL-23-independent production of IL-17F and IL-17A and their role in chronic inflammatory diseases

Interleukin-17 family (IL-17s) comprises six structurally related members (IL-17A to IL-17F); sequence homology is highest between IL-17A and IL-17F, displaying certain overlapping functions. In general, IL-17A and IL-17F play important roles in chronic inflammation and autoimmunity, controlling bacterial and fungal infections, and signaling mainly through activation of the nuclear factor-kappa B (NF-κB) pathway. The role of IL-17A and IL-17F has been established in chronic immune-mediated inflammatory diseases (IMIDs), such as psoriasis (PsO), psoriatic arthritis (PsA), axial spondylarthritis (axSpA), hidradenitis suppurativa (HS), inflammatory bowel disease (IBD), multiple sclerosis (MS), and asthma. CD4+ helper T cells (Th17) activated by IL-23 are well-studied sources of IL-17A and IL-17F. However, other cellular subtypes can also produce IL-17A and IL-17F, including gamma delta (γδ) T cells, alpha beta (αβ) T cells, type 3 innate lymphoid cells (ILC3), natural killer T cells (NKT), or mucosal associated invariant T cells (MAIT). Interestingly, the production of IL-17A and IL-17F by innate and innate-like lymphocytes can take place in an IL-23 independent manner in addition to IL-23 classical pathway. This would explain the limitations of the inhibition of IL-23 in the treatment of patients with certain rheumatic immune-mediated conditions such as axSpA. Despite their coincident functions, IL-17A and IL-17F contribute independently to chronic tissue inflammation having somehow non-redundant roles. Although IL-17A has been more widely studied, both IL-17A and IL-17F are overexpressed in PsO, PsA, axSpA and HS. Therefore, dual inhibition of IL-17A and IL-17F could provide better outcomes than IL-23 or IL-17A blockade.

Disease activity indexes might not capture the same disease aspects in males and females with ankylosing spondylitis: A real-world nationwide analysis

Background

To evaluate gender differences in disease activity and health status (HS) in patients with radiographic axial spondyloarthritis (r-axSpA)/ankylosing spondylitis (AS).

Methods

Ancillary analysis of the MIDAS study, an observational, non-interventional, cross-sectional and retrospective multicenter nationwide study to assess disease activity and its relationship with HS in clinical practice. Adult patients with AS diagnosis, fulfilling ASAS and modified New York criteria, treated for ≥3 months upon study inclusion according to clinical practice were included. The primary outcome was "disease control" assessed by the percentage of patients in remission and low disease activity (BASDAI and ASDAS-CRP scores). HS was evaluated using the ASAS health index (ASAS-HI). Patients' responses and characteristics were analyzed by gender.

Results

We analyzed 313 patients with AS, 237 (75.7%) males and 76 (24.3%) females. A total of 202 (64.5%) patients had adequate disease control (BASDAI < 4); 69.2% of males [mean (SD) BASDAI 2.9 (2.1)] and 50.0% of females [mean (SD) BASDAI 3.8 (2.4); p = 0.01]. According to ASDAS-CRP, 57.5% of patients were adequately controlled (ASDAS-ID +ASDAS-LDA); 138 (58.2%) males and 42 (55.3%) females. The mean (SD) ASDAS-CRP was 1.9 (1.1); being 1.9 (1.0) in males and 2.0 (1.1) in females. Overall, the impact of AS on HS was low to moderate [mean (SD) ASAS-HI 5.8 (4.4)]; being 5.5 (4.4) for males and 6.8 (4.2) for females (p = 0.02).

Conclusion

This study showed a higher proportion of females with AS and active disease using the BASDAI definition. When using the ASDAS-CRP definition these differences by gender were less pronounced. The impact of disease activity on HS appears to be higher in females than males.

Validation of screening criteria for spondyloarthritis in patients with inflammatory bowel disease in routine clinical practice

BACKGROUND

Spondyloarthritis (SpA) is one of the most common extraintestinal manifestations of inflammatory bowel disease (IBD). Diagnostic delay must be avoided.

AIMS

We assessed the validity of SpA screening criteria (any of the following characteristics: chronic low back pain with onset before 45 years of age; inflammatory lower back pain or alternating buttock pain; arthritis; heel enthesitis; dacylitis; HLA-B27 positivity; sacroiliitis on imaging).

METHODS

This was a multicenter cross-sectional observational study in IBD patients aged ≥18 years. After evaluating the SpA screening criteria, the gastroenterologists referred the participants to the rheumatologists, who determined whether the patient fulfilled the screening criteria and carried out the necessary tests for SpA diagnosis.

RESULTS

35 (11.7%) out of 300 patients were diagnosed with SpA. The combination with the best balance between sensitivity and specificity (91.4% and 72.1%, respectively, when applied by the rheumatologists; 80% and 78.9%, when applied by the gastroenterologists) for SpA screening, was fulfillment of any of the following: chronic low back pain with onset before age 45 years, inflammatory low back pain or alternating buttock pain, arthritis, or dactylitis.

CONCLUSION

This is one of the first studies to validate SpA screening criteria in IBD patients in routine clinical practice.

Use of Generic Antiretroviral Drugs and Single-Tablet Regimen De-Simplification for the Treatment of HIV Infection in Spain

The present study sought to describe the use of generic drugs and single-tablet regimen (STR) de-simplification for the treatment of human immunodeficiency virus (HIV) infection among 41 hospitals from the cohort of the Spanish HIV/AIDS Research Network (CoRIS). In June 2018, we collected information on when generic antiretroviral drugs (ARVs) were introduced in the different hospitals, how the decisions to use them were made, and how the information was provided to the patients. Most of the nine available generic ARVs in Spain by June 2018 had been introduced in at least 85% of the participating hospitals, except for zidovudine (AZT)/lamivudine (3TC) and AZT. The time difference between the effective marketing date of each generic ARV and its first dispensing date in the hospitals was much shorter for the more recently approved generic ARV since the year 2017. However, only up to 20% of the hospitals de-simplified efavirenz (EFV)/tenofovir disoproxil (TDF)/emtricitabine (FTC), dolutegravir (DTG)/abacavir (ABC)/3TC, and rilpivirine (RPV)/TDF/FTC (to generic EFV+TDF/FTC, DTG+generic ABC/3TC, and RPV+generic TDF/FTC, respectively), whereas the generic STR EFV/TDF/FTC was introduced in 87.8% of the centers. The median times between the date of effective marketing of generic TDF/FTC and the date of de-simplification of EFV/TDF/FTC and RPV/TDF/FTC were 723 [interquartile range (IQR): 369-1,119] and 234 (IQR: 142-264) days, respectively; this time was 155 (IQR: 28-287) days for de-simplification of DTG/ABC/3TC. In conclusion, despite the widespread use of generic ARVs, STRs de-simplification was only undertaken in <20% of the hospitals. There was wide variability in the timing of the introduction of each generic ARV after they were available in the market.

Subcutaneous IL-6 Inhibitor Sarilumab vs. Standard Care in Hospitalized Patients With Moderate-To-Severe COVID-19: An Open Label Randomized Clinical Trial

Background

The use of IL-6 blockers in COVID-19 hospitalized patients has been associated with a reduction in mortality compared to standard care. However, many uncertainties remain pertaining to optimal intervention time, administration schedule, and predictors of response. To date, data on the use of subcutaneous sarilumab is limited and no randomized trial results are available.

Methods

Open label randomized controlled trial at a single center in Spain. We included adult patients admitted with microbiology documented COVID-19 infection, imaging confirmed pneumonia, fever and/or laboratory evidence of inflammatory phenotype, and no need for invasive ventilation. Participants were randomly assigned to receive sarilumab, a single 400 mg dose in two 200 mg subcutaneous injections, added to standard care or standard care, in a 2:1 proportion. Primary endpoints included 30-day mortality, mean change in clinical status at day 7 scored in a 7-category ordinal scale ranging from death (category 1) to discharge (category 7), and duration of hospitalization. The primary efficacy analysis was conducted on the intention-to-treat population.

Results

A total of 30 patients underwent randomization: 20 to sarilumab and 10 to standard care. Most patients were male (20/30, 67%) with a median (interquartile range) age of 61.5 years (56-72). At day 30, 2/20 (10%) patients died in the sarilumab arm vs. none (0/10) in standard care (Log HR 15.11, SE 22.64; p = 0.54). At day 7, no significant differences were observed in the median change in clinical status (2 [0-3]) vs. 3 [0-3], p = 0.32). Median time to discharge (days) was similar (7 [6-11] vs. 6 [4-12]; HR 0.65, SE 0.26; p = 0.27). No significant differences were detected in the rate of progression to invasive and noninvasive mechanical ventilation.

Conclusions and Relevance

Our pragmatic pilot study has failed to demonstrate the benefit of adding subcutaneous sarilumab to standard care for mortality by 30 days, functional status at day 7, or hospital stay. Findings herein do not exclude a potential effect of sarilumab in severe COVID-19 but adequately powered blinded randomized phase III trials are warranted to assess the impact of the subcutaneous route and a more selected target population.

Trial Registration

www.ClinicalTrials.gov, Identifier: NCT04357808.

Sustained low disease activity measured by ASDAS slow radiographic spinal progression in axial spondyloarthritis patients treated with TNF-inhibitors: data from REGISPONSERBIO

Background

To evaluate the influence of the disease activity on radiographic progression in axial spondyloarthritis (axSpA) patients treated with TNF inhibitors (TNFi).

Methods

The study included 101 axSpA patients from the Spanish Register of Biological Therapy in Spondyloarthritides (REGISPONSERBIO), which had clinical data and radiographic assessment available. Patients were classified into 2 groups based on the duration of TNFi treatment at baseline: (i) long-term treatment (≥4 years) and (ii) no long-term treatment (< 4 years). Radiographs were scored by two readers according to the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS) with known chronology. Disease activity differences between patients’ groups at each time point were assessed using a linear mixed-effect model.

Results

Radiographic progression was defined as an increase in ≥2 mSASSS units. At inclusion, approximately half of the patients (45.5%) were receiving long-term treatment with TNFi (≥4 years). In this group of subjects, a significant difference in averaged Ankylosing Spondylitis disease Activity Score (ASDAS) across follow-up was found between progressors and non-progressors (2.33 vs 1.76, p=0.027, respectively). In patients not under long-term TNFi treatment (54.5%) though, no significant ASDAS differences were observed between progressors and non-progressors until the third year of follow-up. Furthermore, no significant differences were found in progression status, when disease activity was measured by Bath Ankylosing spondylitis Disease Activity Index (BASDAI) and C reactive protein (CRP).

Conclusions

Patients on long-term TNFi treatment with a mean sustained low disease activity measures by ASDAS presented lower radiographic progression than those with active disease.

Role of diagnostic imaging in psoriatic arthritis: how, when, and why

Psoriasis is a common skin disease. Up to 30% of patients with psoriasis develop psoriatic arthritis (PsA) resulting, by far, the most prevalent coexisting condition. Heterogeneity of clinical and radiological presentation is a major challenge to diagnosis of PsA. Initial reports about PsA emphasized a benign course in most patients, but it is now recognized that psoriatic arthritis often leads to impaired function and a reduced quality of life. PsA is a progressive disease characterized by diverse clinical features, often resulting in diagnostic delay and treatment that are associated with poor clinical and structural outcomes. New effective treatments may halt PsA progression, and consequently, treatment goals have evolved from simple reduction of pain to achieving full remission or minimal disease activity. This emerging treat-to-target strategy paradigm emphasize a need for early diagnosis; sensitive imaging techniques may be of value in this process. While radiography and CT depict structural damage, US and MRI have emerged as helpful tools to evaluate magnitude and severity of active inflammatory lesions. This review aims to describe the role of imaging modalities in diagnosis, follow-up and prognosis of PsA.

Subcutaneous Sarilumab in hospitalised patients with moderate-severe COVID-19 infection compared to the standard of care (SARCOVID): a structured summary of a study protocol for a randomised controlled trial

Objectives

The main aim of the study is to evaluate the efficacy of a single dose of sarilumab, in subcutaneous administration, in hospitalised patients with moderate to early severe COVID-19 infection compared to the current standard of care, to prevent progression to systemic hyperinflammatory status. Our hypothesis is that use of subcutaneous sarilumab in early stages (window of opportunity) of COVID-19 moderate-severe pneumonia can prevent higher oxygenation requirements through non-invasive and invasive mechanical ventilation and decrease in-hospital stays, as well as death rate.

The secondary objectives of the study are to evaluate the safety of sarilumab through hospitalisation and up to day 14 after discharge, compared to the control arm as assessed by incidence of serious and non serious adverse events (SAEs).

In addition, as an exploratory objective, to compare the baseline clinical and biological parameters, including serum IL-6 levels, of the intervention population against controls of the same pandemic outbreak (using a propensity score) to search for markers that identify the best candidates for the treatment with subcutaneous IL-6R inhibitors and to attempt an approximation in the temporal frame of the “window of opportunity”

Trial design

SARCOVID is an investigator-initiated single center randomised proof of concept study.

Participants

Patients treated at the Hospital Universitario La Princesa, Madrid, Spain requiring hospitalisation will be consecutively recruited, meeting all inclusion criteria and none of the exclusion criteria

Inclusion criteria

a. Age >18, <80 years old

b. COVID-19 infection documented by a positive RT-PCR test or, in absence of a RT-PCR positive test, case definition of COVID 19 infection/pneumonia as per local protocol and the presence of a positive serologic test (IgM/IgA by ELISA)

c. Documented interstitial pneumonia requiring admission and at least two of the following parameters:

1) Fever ≥ 37.8°C (tympanic)

2) IL-6 in serum ≥ 25 pg/mL (in the absence of a previous dose of prednisone or equivalent> 1 mg / kg) or PCR> 5mg/dL

3) Lymphocytes <600 cells/mm³

4) Ferritin> 300 μg/L that doubles in 24 hours

5) Ferritin> 600 μg/L in the first determination and LDH> 250 U/L

6) D-dimer (> 1 mg/L)

d. Informed verbal consent or requested under urgent conditions, documented in the electronic medical record.

Exclusion criteria

a. Patients who require mechanical ventilation at the time of inclusion.

b. AST / ALT values > 5 folds the ULN.

c. Absolute neutrophil count below 500 cells/mm³

d. Absolute platelet count below 50,000 cells/mm³

e. Documented sepsis or high suspicion of superimposed infection by pathogens other than COVID-19.

f. Presence of comorbidities that can likely lead to an unfavourable result according to clinical judgment.

g. Complicated diverticulitis or intestinal perforation.

h. Current skin infection (eg, uncontrolled dermopiodermitis).

i. Immunosuppressive anti-rejection therapy.

j. Pregnancy or lactation.

k. Previous treatment with tocilizumab or sarilumab.

l. Patients participating in another clinical trial for SARS-CoV-2 infection.

m. Patients with known hypersensitivity or contraindication to sarilumab or excipients.

Intervention and comparator

The intervention group, sarilumab plus standard of care, will receive 400 mg single dose treatment with Sarilumab (Kevzara), 2 subcutaneous injections 200mg each in a pre-filled syringe. Treatment with drugs or procedures in routine clinical practice that the clinician responsible for the patient deems necessary is allowed.

The control group will receive drugs or procedures in routine clinical practice according to the best standard of care as per local protocol.

Main outcomes

Primary Outcome Measures

1. Mean change in clinical status assessment using the 7-point ordinal scale at day 7 after randomisation compared to baseline (Score ranges 1-7)

1. Death;

2. Hospitalised, requiring invasive mechanical ventilation or extracorporeal membrane oxygenation (ECMO);

3. Hospitalised, requiring non-invasive ventilation or high flow oxygen devices;

4. Hospitalised, requiring supplemental oxygen;

5. Hospitalised, not requiring supplemental oxygen - but in need of ongoing medical care (COVID-19 related or otherwise)

6. Hospitalised, not requiring supplemental oxygen - no longer requires ongoing medical care (independent)

7. Not hospitalised

2. Duration of hospitalisation: Days from the date of enrolment to the date of discharge

3. Number of deaths at the end of study

Randomisation

Randomisation to treatment arms sarilumab plus standard of care or standard of care in a 2:1 ratio will be performed by the Clinical Research and Clinical Trials Unit (CRCTU) at the Hospital using a table of random numbers, an internet-based randomisation tool. After checking that all inclusion criteria are met and none of the exclusion criteria, CRCTU will communicate the recruiting investigator the assigned treatment.

Blinding (masking)

This study is unblinded.

Numbers to be randomised (sample size)

30 patients treated by COVID-19 infection who require hospitalisation: 20 will receive sarilumab plus Standard of Care and 10 will receive Standard of Care.

Trial Status

The Protocol version number is 2, as of 6^th April 2020, with amendment 1, as of 7^th May 2020. The recruitment is ongoing. Recruitment started on April 13^th 2020 and is anticipated to be completed by November 2020.

Trial registration

This trial was first registered in the European Union Clinical Trials Register on 4 April 2020, EudraCT Number 2020-001634-36. Then, posted on ClinicalTrials.gov on 22 April 2020, Identifier: NCT04357808.

Full protocol

The full protocol is attached as an additional file, accessible from the Trials website (Additional file 1). In the interest in expediting dissemination of this material, the familiar formatting has been eliminated; this Letter serves as a summary of the key elements of the full protocol.

The study protocol has been reported in accordance with the International Council Harmonization guidelines:https://www.ich.org/page/efficacy-guidelines.

Recommendations for the prescription of physical exercise for patients with spondyloarthritis

OBJECTIVE

To develop expert-based recommendations on physical activity and exercise for patients with spondyloarthritis (SpA).

METHODS

Two discussion groups, one of physical therapists, rehabilitation physicians, and professionals of physical activity and sports, and another of rheumatologists interested in SpA, were held to discuss the results of a survey of rheumatologists on exercise and two focus groups with patients on barriers to exercise. Preliminary recommendations were drafted. These were submitted to the opinion of the experts in both groups according to a two round Delphi methodology.

RESULTS

Twenty one recommendations covering general aspects of exercise, adaptation to patient, how to deliver messages, pain management, and type of exercise and monitoring were issued. The level of agreement varied slightly between expert groups but it was high overall. Items with poor agreement were removed from the consensus.

CONCLUSIONS

We present recommendations on when and how to prescribe and monitor exercise in patients with SpA based on the opinion of experts in exercise and in SpA. We must now test whether these recommendations are useful for clinical practice and have an effect on patients with SpA seen by rheumatologists.

Sialodochitis fibrinosa (kussmaul disease) report of 3 cases and literature review

BACKGROUND

Sialodochitis fibrinosa is a rare disease which is characterized by recurring episodes of pain and swelling of the salivary glands due to the formation of mucofibrinous plugs. Analytic studies ascertain elevated levels of eosinophils and immunoglobulin E (IgE). Imaging studies such as magnetic resonance imaging (MRI) and sialography reveal dilation of the main salivary duct (duct ectasia). Treatment is initially supportive, consisting of compressive massages, and use of antihistamines and/or corticosteroids.

MATERIAL AND METHODS

In the following, 3 cases of sialodochitis fibrinosa are presented which were diagnosed in a third level hospital during the period of 2008 and 2016, as well as a literature review of all cases reported to our knowledge.

RESULTS

Of the 41 cases found, including the 3 of this article, 66% were women with an average age of 45 years old. However, 75% of reported cases were of Japanese heritage. Involvement of the parotid glands was more frequent than the submandibular glands. In more than half of all cases treatment with compressive massages, antihistamines and/or corticosteroids was effective.

CONCLUSION

Clinicians should consider sialodochitis fibrinosa as a diagnostic possibility when presented with cases of recurring parotid and submandibular gland tumescence.

Executive summary: Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015

Opportunistic infections continue to be a cause of morbidity and mortality in HIV-infected patients. They often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an opportunistic infection. The present article is an executive summary of the document that updates the previous recommendations on the prevention and treatment of opportunistic infections in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome. This document is intended for all professionals who work in clinical practice in the field of HIV infection.

Prevention and treatment of opportunistic infections and other coinfections in HIV-infected patients: May 2015

Despite the huge advance that antiretroviral therapy represents for the prognosis of infection by the human immunodeficiency virus (HIV), opportunistic infections (OIs) continue to be a cause of morbidity and mortality in HIV-infected patients. OIs often arise because of severe immunosuppression resulting from poor adherence to antiretroviral therapy, failure of antiretroviral therapy, or unawareness of HIV infection by patients whose first clinical manifestation of AIDS is an OI. The present article updates our previous guidelines on the prevention and treatment of various OIs in HIV-infected patients, namely, infections by parasites, fungi, viruses, mycobacteria, and bacteria, as well as imported infections. The article also addresses immune reconstitution inflammatory syndrome.

Executive summary of the consensus document on post-exposure prophylaxis against HIV, HBV and HCV in adults and children

Post-exposure prophylaxis (PEP) can be a secondary measure to prevent infection by human immunodeficiency virus (HIV) when primary prevention has failed. PEP is advised for people with sporadic and exceptional risk exposure to HIV. This consensus document about occupational and non-occupational PEP recommendations aims to be a technical document for healthcare professionals. Its main objective is to facilitate the appropriate use of PEP. To this end, some recommendations have been established to assess the risk of transmission in different types of exposure, situations where PEP should be recommended, special circumstances to take into account, antiretroviral (ARV) guidelines including start and end of the treatment, early monitoring of tolerance and adherence to the treatment, subsequent monitoring of people exposed, independently of having received PEP or not, and need of psychological support. This document is intended for all professionals who work in clinical practice in the field of HIV infection.

Executive summary of the consensus document on metabolic disorders and cardiovascular risk in patients with HIV infection

The importance of the metabolic disorders and their impact on patients with HIV infection requires an individualized study and continuous updating. HIV patients have the same cardiovascular risk factors as the general population. The HIV infection per se increases the cardiovascular risk, and metabolic disorders caused by some antiretroviral drugs are added risk factors. For this reason, the choice of drugs with a good metabolic profile is essential. The most common metabolic disorders of HIV infected-patients (insulin resistance, diabetes, hyperlipidemia or osteopenia), as well as other factors of cardiovascular risk, such as hypertension, should also be dealt with according to guidelines similar to the general population, as well as insisting on steps to healthier lifestyles. The aim of this document is to provide a query tool for all professionals who treat HIV-patients and who may present or display any metabolic disorders listed in this document.

[Role of MRI in the diagnosis and progression of spondyloarthritis]

The introduction of magnetic resonance imaging in spondyloarthritis constitutes the main improvement in imaging over the past two decades. X-rays remains the cornerstone of diagnosis, although magnetic resonance imaging is more sensitive in early stages of the disease. The primary advantage of magnetic resonance imaging is its ability to visualize soft tissue inflammation and inflammatory lesions within bone in three dimensions. Studies continue to appear describing its diagnostic utility, its sensitivity in early disease, its reliability, its predictive value for the detection of damage progression and its value in the assessment of certain complications. In this paper we review the characteristics of this imaging technique and the advantages and limitations of magnetic resonance imaging in spondyloarthritis.

[Conventional Radiology: Total BASRI and SASSS]

Conventional radiology is a very important tool used to evaluate patients with spondyloarthropathies. It is necessary not only to evaluate the efficacy of the different treatments but also to reflect the history of the disease, maintaining a registry of the progression of the destructive process, evaluating the affection and quantifying the damage. We have at our disposal three methods specifically designed for the evaluation of structural damage in SA: the BSARI (Bath Ankylosing Spondylitis Radiology Index), the SASSS (Stoke Ankylosing Spondylitis Spine Score) and a modification of the latter. This review intends to perform a detailed description of each one of these methods and expose the advantages and disadvantages of their use.

[Infliximab in ankylosing spondylitis associated with chronic hepatitis B infection. Role of Lamivudine therapy]

Anti-tumor necrosis factor-a (TNF) therapy has been associated with reactivation of hepatitis B virus infection. Case reports have suggested the concomitant need of lamivudine treatment in patients with HBV infection treated with antiTNFa agents. We describe a case of ankylosing spondylitis with positive HBV surface antigen (HBsAg) treated with infliximab and lamivudine. Clinical response was excellent but when lamivudine therapy was stopped, reactivation of replication viral occurred. After the reintroduction of lamivudine, viral replication was controlled and liver function tests were normalized. Preventive long-term lamivudine therapy is mandatory when anti-TNFa therapy is maintained in patients with chronic HBV infection.

Background radiation in low-pressure flashlamps from ablation phenomena

Radiation emitted from flashlamps operating in a wall ablation regime consists mainly of background radiation, the observed line radiation from wall elements being only an indicator of the transition to the ablative regime. We analyze the origin of that background radiation. It does not come from a rise in temperature, but from an increase in electron concentration caused by the ionization of ablation elements. In LTE conditions (N(e) = 3 x 10(23)m(-3),T = 2 x 10(4) K), we determine temperatures and concentrations in the tube axis and in the discharge border. Ablation products concentrate mainly near the walls where the temperature is lower.