Diagnosis and investigation of suspected haemophagocytic lymphohistiocytosis in adults: 2023 Hyperinflammation and HLH Across Speciality Collaboration (HiHASC) consensus guideline.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome characterised by persistently activated cytotoxic lymphocytes and macrophages, which, if untreated, leads to multiorgan dysfunction and death. HLH should be considered in any acutely unwell patient not responding to treatment as expected, with prompt assessment to look for what we term the three Fs-fever, falling blood counts, and raised ferritin. Worldwide, awareness of HLH and access to expert management remain inequitable. Terminology is not standardised, classification criteria are validated in specific patient groups only, and some guidelines rely on specialised and somewhat inaccessible tests. The consensus guideline described in this Health Policy was produced by a self-nominated working group from the UK network Hyperinflammation and HLH Across Speciality Collaboration (HiHASC), a multidisciplinary group of clinicians experienced in managing people with HLH. Combining literature review and experience gained from looking after patients with HLH, it provides a practical, structured approach for all health-care teams managing adult (>16 years) patients with possible HLH. The focus is on early recognition and diagnosis of HLH and parallel identification of the underlying cause. To ensure wide applicability, the use of inexpensive, readily available tests is prioritised, but the role of specialist investigations and their interpretation is also addressed.

Translation of cytoplasmic UBA1 contributes to VEXAS syndrome pathogenesis.

Somatic mutations in UBA1 cause vacuoles, E1 ubiquitin-activating enzyme, X-linked, autoinflammatory somatic (VEXAS) syndrome, an adult-onset inflammatory disease with an overlap of hematologic manifestations. VEXAS syndrome is characterized by a high mortality rate and significant clinical heterogeneity. We sought to determine independent predictors of survival in VEXAS and to understand the mechanistic basis for these factors. We analyzed 83 patients with somatic pathogenic variants in UBA1 at p.Met41 (p.Met41Leu/Thr/Val), the start codon for translation of the cytoplasmic isoform of UBA1 (UBA1b). Patients with the p.Met41Val genotype were most likely to have an undifferentiated inflammatory syndrome. Multivariate analysis showed ear chondritis was associated with increased survival, whereas transfusion dependence and the p.Met41Val variant were independently associated with decreased survival. Using in vitro models and patient-derived cells, we demonstrate that p.Met41Val variant supports less UBA1b translation than either p.Met41Leu or p.Met41Thr, providing a molecular rationale for decreased survival. In addition, we show that these 3 canonical VEXAS variants produce more UBA1b than any of the 6 other possible single-nucleotide variants within this codon. Finally, we report a patient, clinically diagnosed with VEXAS syndrome, with 2 novel mutations in UBA1 occurring in cis on the same allele. One mutation (c.121 A>T; p.Met41Leu) caused severely reduced translation of UBA1b in a reporter assay, but coexpression with the second mutation (c.119 G>C; p.Gly40Ala) rescued UBA1b levels to those of canonical mutations. We conclude that regulation of residual UBA1b translation is fundamental to the pathogenesis of VEXAS syndrome and contributes to disease prognosis.

Understanding the diagnosis and management of multisystem inflammatory syndrome in adults (MIS-A) in the UK: results of a national Delphi process.

Infection with SARS-CoV-2 may trigger a delayed hyper-inflammatory illness in children called paediatric multisystem inflammatory syndrome temporally associated with COVID-19 (PIMS-TS). A similar syndrome is increasingly recognised in adults termed multisystem inflammatory syndrome in adults (MIS-A) and may present acutely to medical or surgical specialties with severe symptoms, such as acute abdominal pain or cardiogenic shock. No national guidelines exist in the UK for the management of MIS-A and there is limited evidence to guide treatment plans. We undertook a national Delphi process to elicit opinions from experts in hyperinflammation about the diagnosis and management of MIS-A with the dual aim of improving recognition and producing a management guideline. Colleagues in paediatrics successfully initiated a national consensus management document that facilitated regional multidisciplinary referral and follow-up pathways for children with PIMS-TS, and we propose a similar system be developed for adult patients across the UK. This would facilitate better recognition and treatment of MIS-A across the multiple specialties to which it may present as well as enable follow-up with specialty services post-discharge.

Incidence and survival of haemophagocytic lymphohistiocytosis: A population-based cohort study from England.

BACKGROUND: Haemophagocytic lymphohistiocytosis (HLH) is a rare hyper-inflammatory condition with poor outcomes. OBJECTIVES: Few population-based estimates of the incidence and survival in adults exist. We aimed to provide these data for England. METHODS: We used population-based linked data from primary care, secondary care, cancer registries and mortality databases in England to identify people diagnosed with HLH between 1 January 2000 and 31 December 2016. We calculated annual incidence rates by age and sex, modelled change in incidence over time with Poisson regression, calculated overall 1-year survival using Kaplan-Meier methods and estimated adjusted hazard ratios (HRs) of death using a Cox proportional hazards model. RESULTS: We identified 214 patients with HLH. The reported age and sex-adjusted incidence increased twofold over the period, from around one to around two per million. Incidence was highest in those below 1 year (14.6 per million) and ≥75 years (2.2 per million), and lowest in those aged 15-44 years (0.8 per million). One-year survival varied by age and sex from 77% (95% confidence interval [CI] 63%-86%) in those <15 years to 30% (95% CI 14%-49%) in those ≥75. In patients with haematological cancer, the adjusted HR for death was 2.60 (95% CI 1.45-4.66) compared to patients with no malignant or rheumatological disease. CONCLUSION: The incidence of HLH diagnosis in England has increased between 2000 and 2016 and occurs in all ages with varying underlying diseases. One-year survival varies substantially, being particularly poor in those aged over 75 years and those with haematological malignancy.

Multisystem inflammatory syndrome in adults following COVID-19 infection: A case report presenting with colitis.

BACKGROUND: Multisystem Inflammatory Syndrome in Adults (MIS-A) is a recently emerging condition that occurs as a delayed complication of COVID-19 infection. It involves inflammation of multiple extra-pulmonary organ systems. Diagnostic criteria and treatment recommendations have yet to be clearly defined. We present a case of a young adult with suspected MIS-A who initially displayed symptoms and radiological findings of colitis.Case: A 22-year-old male with no past medical history suffered a minor respiratory illness for a few days and tested positive on SARS-CoV-2 RT-PCR. Approximately 6 weeks later, he presents after 3 days of right-sided abdominal pain, diarrhoea and fever. He is initially admitted with a working diagnosis of gastroenteritis. Sustained fever and escalating blood markers of illness led to abdominal CT; showing inflammation of ascending colon as well as some loops of small bowel. Hypotension becomes increasingly pronounced and on the fourth day of admission he developed type 1 respiratory failure with evidence of fluid overload. He was transferred to critical care for vasopressor and respiratory support. All microbiological and autoimmune screens performed return negative results but inflammatory markers were significantly elevated, he was diagnosed as MIS-A. IVIg was added to the antibiotics on day 4. His clinical condition dramatically improved and he was discharged home after 10 days in hospital. His blood tests have returned to normal and he has no lasting complications from his illness. DISCUSSION: This case displays the potential for MIS-A to present in various ways, with this example a primarily gastroenterological illness. It therefore highlights the importance of physicians in different fields having an awareness of the condition, in order to identify when MDT input is required to guide treatment. We review the current literature on various presentations and treatments of MIS-A, and discuss the need for clear case definition.

A validation study of the identification of haemophagocytic lymphohistiocytosis in England using population-based health data.

We assessed the validity of coded healthcare data to identify cases of haemophagocytic lymphohistiocytosis (HLH). Hospital Episode Statistics (HES) identified 127 cases within five hospital Trusts 2013-2018 using ICD-10 codes D76.1, D76.2 and D76.3. Hospital records were reviewed to validate diagnoses. Out of 74 patients, 73 were coded D76.1 or D76.2 (positive predictive value 89·0% [95% Confidence Interval {CI} 80·2-94·9%]) with confirmed/probable HLH. For cases considered not HLH, 44/53 were coded D76.3 (negative predictive value 97·8% [95% CI 88·2-99·9%]). D76.1 or D76.2 had 68% sensitivity in detecting HLH compared to an established active case-finding HLH register in Sheffield. Office for National Statistics (ONS) mortality data (2003-2018) identified 698 patients coded D76.1, D76.2 and D76.3 on death certificates. Five hundred and forty-one were coded D76.1 or D76.2 of whom 524 (96·9%) had HLH in the free-text cause of death. Of 157 coded D76.3, 66 (42·0%) had HLH in free text. D76.1 and D76.2 codes reliably identify HLH cases, and provide a lower bound on incidence. Non-concordance between D76.3 and HLH excludes D76.3 as an ascertainment source from HES. Our results suggest electronic healthcare data in England can enable population-wide registration and analysis of HLH for future research.

Systematic Review of Factors Affecting Transition Readiness Skills in Patients with Inflammatory Bowel Disease.

BACKGROUND AND AIMS: The incidence of inflammatory bowel disease [IBD] diagnosed before adulthood is increasing worldwide. Transition from paediatric to adult health care requires certain skills. The aim of this study was to identify factors affecting these skills. METHODS: This review was registered on the PROSPERO database [CRD42019152272]. Inclusion criteria were: 1] studies of factors affecting transition readiness skills in patients with IBD; 2] written in English; 3] published since 1999. MEDLINE, CINAHL, and PsychINFO databases were searched between 1999 and 2019. Quality was assessed using the Joanna Briggs Institute critical appraisal tools. RESULTS: Searches identified 822 papers. Sixteen papers were included. Age was positively associated with skills including disease knowledge and performing self-management behaviours [14 studies]. Improvement often occurs at 18; however, skill deficiency may still remain. Increased self-efficacy [confidence] was associated with greater disease knowledge and performing self-management behaviours [three studies]. Self-efficacy was positively correlated with transition duration [two studies] and health-related quality of life [r = 0.57, p <0.001] [one study], negatively correlated with depression [r = -0.57, p <0.001] and anxiety [r = -0.23, p = 0.03] [one study], and was associated with higher education level [two studies] and a family history of IBD [one study]. Females had higher self-management scores [three studies], and greater health care satisfaction was significantly associated with higher knowledge [one study]. Greater transition communication improved knowledge, self-management, and overall transition readiness [two studies]. CONCLUSIONS: Potentially modifiable factors have been identified that could be supported in the transitioning IBD population, to improve transition readiness. Identification of those with non-modifiable characteristics associated with poor readiness may aid targeted support.

COVID-19-associated hyperinflammation and escalation of patient care: a retrospective longitudinal cohort study.

BACKGROUND: A subset of patients with severe COVID-19 develop a hyperinflammatory syndrome, which might contribute to morbidity and mortality. This study explores a specific phenotype of COVID-19-associated hyperinflammation (COV-HI), and its associations with escalation of respiratory support and survival. METHODS: In this retrospective cohort study, we enrolled consecutive inpatients (aged ≥18 years) admitted to University College London Hospitals and Newcastle upon Tyne Hospitals in the UK with PCR-confirmed COVID-19 during the first wave of community-acquired infection. Demographic data, laboratory tests, and clinical status were recorded from the day of admission until death or discharge, with a minimum follow-up time of 28 days. We defined COV-HI as a C-reactive protein concentration greater than 150 mg/L or doubling within 24 h from greater than 50 mg/L, or a ferritin concentration greater than 1500 µg/L. Respiratory support was categorised as oxygen only, non-invasive ventilation, and intubation. Initial and repeated measures of hyperinflammation were evaluated in relation to the next-day risk of death or need for escalation of respiratory support (as a combined endpoint), using a multi-level logistic regression model. FINDINGS: We included 269 patients admitted to one of the study hospitals between March 1 and March 31, 2020, among whom 178 (66%) were eligible for escalation of respiratory support and 91 (34%) patients were not eligible. Of the whole cohort, 90 (33%) patients met the COV-HI criteria at admission. Despite having a younger median age and lower median Charlson Comorbidity Index scores, a higher proportion of patients with COV-HI on admission died during follow-up (36 [40%] of 90 patients) compared with the patients without COV-HI on admission (46 [26%] of 179). Among the 178 patients who were eligible for full respiratory support, 65 (37%) met the definition for COV-HI at admission, and 67 (74%) of the 90 patients whose respiratory care was escalated met the criteria by the day of escalation. Meeting the COV-HI criteria was significantly associated with the risk of next-day escalation of respiratory support or death (hazard ratio 2·24 [95% CI 1·62-2·87]) after adjustment for age, sex, and comorbidity. INTERPRETATION: Associations between elevated inflammatory markers, escalation of respiratory support, and survival in people with COVID-19 indicate the existence of a high-risk inflammatory phenotype. COV-HI might be useful to stratify patient groups in trial design. FUNDING: None.

Anakinra in the treatment of protracted paradoxical inflammatory reactions in HIV-associated tuberculosis in the United Kingdom: a report of two cases.

Paradoxical reactions, including immune reconstitution inflammatory syndrome (IRIS), are common in patients co-infected with human immunodeficiency virus (HIV) and tuberculosis (TB). Paradoxical reactions may confer substantial morbidity and mortality, especially in cases of central nervous system (CNS) TB, or through protracted usage of corticosteroids. No high-quality evidence is available to guide management in this scenario. Interleukin-1-mediated inflammation has been implicated in the pathophysiology of TB-IRIS. We describe two cases where anakinra (human recombinant interleukin-1 receptor antagonist) was used as steroid-sparing therapy for life-threatening protracted paradoxical inflammation in HIV-associated TB. In the first case of disseminated TB with lymphadenitis, protracted TB-IRIS led to amyloid A amyloidosis and nephrotic syndrome. In the second case of disseminated TB with cerebral tuberculomata, paradoxical inflammation caused unstable tuberculomata leading to profound neuro-disability. In both cases, paradoxical inflammation persisted for over a year. Protracted high-dose corticosteroid use led to adverse events yet failed to control inflammatory pathology. In both patients, anakinra successfully controlled paradoxical inflammation and facilitated withdrawal of corticosteroid therapy. Following anakinra therapy, nephrotic syndrome and neuro-disability resolved, respectively. Anakinra therapy for protracted paradoxical inflammation in HIV-associated TB may be a viable therapeutic option and warrants further research.

Silencing the cytokine storm: the use of intravenous anakinra in haemophagocytic lymphohistiocytosis or macrophage activation syndrome.

The term cytokine storm syndromes describes conditions characterised by a life-threatening, fulminant hypercytokinaemia with high mortality. Cytokine storm syndromes can be genetic or a secondary complication of autoimmune or autoinflammatory disorders, infections, and haematological malignancies. These syndromes represent a key area of interface between rheumatology and general medicine. Rheumatologists often lead in management, in view of their experience using intensive immunosuppressive regimens and managing cytokine storm syndromes in the context of rheumatic disorders or infection (known as secondary haemophagocytic lymphohistiocytosis or macrophage activation syndrome [sHLH/MAS]). Interleukin (IL)-1 is pivotal in hyperinflammation. Anakinra, a recombinant humanised IL-1 receptor antagonist, is licenced at a dose of 100 mg once daily by subcutaneous injection for rheumatoid arthritis, systemic juvenile idiopathic arthritis, adult-onset Still's disease, and cryopyrin-associated periodic syndromes. In cytokine storm syndromes, the subcutaneous route is often problematic, as absorption can be unreliable in patients with critical illness, and multiple injections are needed to achieve the high doses required. As a result, intravenous anakinra is used in clinical practice for sHLH/MAS, despite this being an off-licence indication and route of administration. Among 46 patients admitted to our three international, tertiary centres for sHLH/MAS and treated with anakinra over 12 months, the intravenous route of delivery was used in 18 (39%) patients. In this Viewpoint, we describe current challenges in the management of cytokine storm syndromes and review the pharmacokinetic and safety profile of intravenous anakinra. There is accumulating evidence to support the rationale for, and safety of, intravenous anakinra as a first-line treatment in patients with sHLH/MAS. Intravenous anakinra has important clinical relevance when high doses of drug are required or if patients have subcutaneous oedema, severe thrombocytopenia, or neurological involvement. Cross-speciality management and collaboration, with the generation of international, multi-centre registries and biobanks, are needed to better understand the aetiopathogenesis and improve the poor prognosis of cytokine storm syndromes.

Haemophagocytic lymphohisticytosis-an underrecognized hyperinflammatory syndrome.

Haemophagocytic lymphohisticytosis (HLH) is a syndrome of uncontrolled, severe systemic inflammation (hyperinflammation) arising either from a genetic immune system defect [primary (pHLH)] or triggered as a complication of malignancy, infection, or rheumatologic disease [secondary (sHLH)]. Patients with HLH often have non-specific symptoms and become progressively and critically unwell, with fever, cytopenia and multi-organ failure. Untreated, HLH is almost universally fatal, but even when treated, mortality is high, particularly when HLH complicates malignancy. HLH is managed with immunosuppression, and this can seem difficult to justify in such unwell patients. This review aims to examine the diagnostic and treatment challenges posed by sHLH and to improve recognition among rheumatologists who, being expert in the management of multisystem diseases and in the use of immunosuppression, are ideally placed to deliver care and build an evidence base for better disease characterization and treatment.

Macrophage activation syndrome in adults: recent advances in pathophysiology, diagnosis and treatment.

Haemophagocytic lymphohistiocytosis (HLH) is a hyperinflammatory syndrome, which if not promptly treated, can lead rapidly to critical illness and death. HLH is termed macrophage activation syndrome (MAS) when associated with rheumatic disease (where it is best characterized in systemic JIA) and secondary HLH (sHLH) when associated with other triggers including malignancy and infection. MAS/sHLH is rare and coupled with its mimicry of other conditions, is underrecognized. These inherent challenges can lead to diagnostic and management challenges in multiple medical specialties including haematology, infectious diseases, critical care and rheumatology. In this review we highlight the pathogenesis of MAS/sHLH including its underlying triggers, key clinical features and diagnostic challenges, prognostic factors and current treatments in adults.