A rare presentation of acute myocarditis as a manifestation of adult-onset Still's disease: a case report

Background

Adult-onset Still's disease (AOSD) is a rare systemic autoinflammatory condition characterized by a classical triad of symptoms that include prolonged fever, polyarthritis, and a characteristic salmon-pink skin rash. It can affect a variety of organ systems resulting in many different clinical presentations and is usually a diagnosis of exclusion. Myocarditis complicated by cardiogenic shock is a rare and life-threatening manifestation of AOSD, typically affecting younger patients. There is a limited experience and evidence in how best to manage this challenging patient cohort.

Case summary

A previously fit and well 22-year-old male presented with fever, arthralgia, and general malaise. On clinical examination, he was pyrexial and hypotensive, requiring vasopressor support for presumed septic shock. Subsequent transthoracic echocardiography and cardiac MRI findings were in keeping with fulminant myocarditis. Further septic and auto-immune screens were negative although he responded well to high-dose intravenous corticosteroids. Attempts to wean immunosuppression were unsuccessful, and his ferritin was markedly elevated (20 233 μg/L). A diagnosis of AOSD was suspected after exclusion of other possible causes. The successful addition of tocilizumab (an interleukin-6 receptor antagonist) therapy allowed for gradual de-escalation of steroid therapy and disease remission, with on-going remission at 18 months on maintenance therapy.

Discussion

This case highlights the importance of considering AOSD as a rare cause for myocarditis, especially when fever is present, or disease is severe. Failure to improve with first-line therapy involving high-dose corticosteroids, or inability to wean that therapy, should prompt consideration for escalation of therapy, with tocilizumab seemingly an effective treatment option.

Hyperferritinaemia: An Iron Sword of Autoimmunity

BACKGROUND

Ferritin is a molecule that plays many roles being the storage for iron, signalling molecule, and modulator of the immune response.

METHODS

Different electronic databases were searched in a non-systematic way to find out the literature of interest.

RESULTS

The level of ferritin rises in many inflammatory conditions including autoimmune disorders. However, in four inflammatory diseases (i.e., adult-onset Still's diseases, macrophage activation syndrome, catastrophic antiphospholipid syndrome, and sepsis), high levels of ferritin are observed suggesting it as a remarkable biomarker and pathological involvement in these diseases. Acting as an acute phase reactant, ferritin is also involved in the cytokine-associated modulator of the immune response as well as a regulator of cytokine synthesis and release which are responsible for the inflammatory storm.

CONCLUSION

This review article presents updated information on the role of ferritin in inflammatory and autoimmune diseases with an emphasis on hyperferritinaemic syndrome.

Elevation of serum ferritin levels for predicting a poor outcome in hospitalized patients with influenza infection

OBJECTIVES

There is increasing evidence that ferritin is a key marker of macrophage activation, but its potential role in influenza infection remains unexplored. Our aim was to assess whether hyperferritinaemia (ferritin ≥500 ng/mL) could be a marker of poor prognosis in hospitalized patients with confirmed influenza A infection.

METHODS

We prospectively recruited all hospitalized adult patients who tested positive for the influenza A rRT-PCR assay performed on respiratory samples in two consecutive influenza periods (2016-17 and 2017-18). Poor outcome was defined as the presence of at least one of the following: respiratory failure, admission to the intensive care unit, or in-hospital mortality.

RESULTS

Among 494 patients, 68 (14%) developed poor outcomes; 112 patients (23%) had hyperferritinaemia (39/68, 57% in the poor-outcome group versus 73/426, 17% in the remaining patients, p < 0.0001). Median serum ferritin levels were significantly higher in the subgroup of patients with poor outcomes (609 ng/mL, range 231-967 versus 217 ng/mL, range 140-394, p < 0.0001). In multivariate analysis, hyperferritinaemia was associated with a five-fold increase in the odds ratio of developing poor outcome. After adjusting for classic influenza risk factors, ferritin remained as a significant predictive factor in all exploratory models. Ferritin levels had a good discriminative capacity with an area under the ROC curve of 0.72 (95% confidence interval (CI) 0.65-0.8, p < 0.001) and an overall diagnostic accuracy for predicting poor outcome of 79.3% (95%CI 75.4-82.7%).

CONCLUSIONS

Serum ferritin may discriminate a subgroup of patients with influenza infection who have a higher risk of developing a poor outcome.

Iron: how much is too much?

Gross iron overload has long been known to result in diabetes mellitus. However, it is now thought that milder levels of iron overload, possibly within the normal range, also increase the risk of diabetes mellitus. The article by Rawal et al in this issue (Diabetologia doi: 10.1007/s00125-016-4149-3 ) provides further support for the relationship between mild degrees of iron overload and the risk of gestational diabetes. The purpose of this commentary is to briefly discuss the background of this relationship and the implications it may have for routine pregnancy care.

How should hyperferritinaemia be investigated and managed?

Hyperferritinaemia is commonly found in clinical practice. In assessing the cause of hyperferritinaemia, it is important to identify if there is true iron overload or not as hyperferritinaemia may be seen in other conditions such as excess alcohol intake, inflammation and non-alcoholic fatty liver disease. Assessment of whether the serum ferritin level is elevated or not should take into account body mass index, gender and age. This review article provides an overview of the different causes of hyperferritinaemia, differentiating those due to iron overload from those not due to iron overload, and provides an algorithm for clinicians to use in clinical practice to carry out appropriate investigations and management.