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Two fatal cases of acute liver failure due to HSV-1 infection in COVID-19 patients following immunomodulatory therapies

Abstract We reported two fatal cases of acute liver failure secondary to Herpes Simplex Virus 1 infection in COVID-19 patients, following tocilizumab and corticosteroid therapy.Screening for and prompt recognition of Herpes Simplex Virus 1 reactivation in these patients, undergoing immunomodulatory treatment, may have potentiallyrelevant clinical consequences.

M a n u s c r i p t

ABSTRACT:
We reported two fatal cases of acute liver failure secondary to Herpes Simplex Virus 1 infection in COVID-19 patients, following tocilizumab and corticosteroid therapy.
Screening for and prompt recognition of Herpes Simplex Virus 1 reactivation in these patients, undergoing immunomodulatory treatment, may have potentially relevant clinical consequences.
A c c e p t e d M a n u s c r i p t BACKGROUND In patients with SARS-CoV-2 infection, high levels of pro-inflammatory cytokines and chemokines seem to be related to severe pneumonia and poor outcome [1]. The use of immunomodulating therapies to counteract the "cytokine storm" has been proposed [2] and widely prescribed on a compassionate basis in Italy since the beginning of the SARS-CoV-2 epidemic, despite the lack of an evidence-based benefit or data regarding serious side effects.
During SARS-CoV-2 infection, liver damage may occur [3] as a result of a variety of mechanisms [4]. Although liver impairment is fairly frequent during SARS-CoV-2 infection, acute liver failure has never been reported so far.
We describe the cases of two COVID-19 patients who developed acute liver failure (ALF) secondary to herpes simplex virus 1 (HSV-1) infection, out of 107 consecutive COVID-19 patients admitted to intensive care unit (ICU) from February 25 th to April 25 th , 2020. Our hospital is a liver transplant centre and local reference centre for the treatment of acute liver failure.
PATIENT 1: a 66-year-old man, with a history of hypertension, hypercholesterolemia and depression presented to our hospital with interstitial bilateral pneumonia.
PaO2/FiO2 ratio at admission was 188, C-reactive protein (CRP) 4.2 mg/dL and lactate dehydrogenase (LDH) 2156 U/L. A nasopharyngeal swab for SARS-CoV-2 tested positive. The patient was treated according to the Emilia-Romagna Regional guidelines [5] with hydroxychloroquine (400 mg/two times a day for 3 days, then tapered to 200 mg/twice a day for the following 4 days) and azithromycin (500 mg/day for 5 days). On day 2, due to respiratory failure requiring noninvasive A c c e p t e d M a n u s c r i p t ventilation, tocilizumab was administered subcutaneously, 162 mg in two different sites. On day 4, laboratory exams documented the persistence of high levels of LDH 1997 U/L, ferritin 1028 ng/mL and D-dimer >40,000 ng/mL together with total lymphocytes count (TLC) 580 cells/mm 3 , so methyl-prednisolone 80 mg was added and then tapered to 40 mg/day for 3 days and 20 mg/day for 1 day. In the following days, the patient progressively restored respiratory function and biochemistry, but  On day 2, the patient started treatment with hydroxychloroquine (same regimen as above) [5]. On day 6, due to a worsening of dyspnea and PaO2/FiO2 ratio of 108 that was poorly responsive to oxygen therapy, the patient was admitted to ICU to undergo invasive mechanical ventilation. On day 13, considering the persistent respiratory failure and the radiological worsening of parenchymal thickening, two doses of tocilizumab 800 mg were intravenously administered 12 hours apart, while TLC was 320 cell/mm 3 . On day 25, the patient developed delirium with panic attacks and extreme agitation treated with dexmedetomidine and antipsychotics. On day 29, during weaning from mechanical ventilation, the patient developed a fever and laboratory data showed in the subsequent days a progressive increase in ALT = 6080 U/L and AST = 6906 U/L, with total bilirubin 0.7 mg/dL. A CT scan did not evidence ongoing veno-occlusive liver disease and screening for hepatotropic viruses was negative. On day 33, the patient was admitted to our ICU with the diagnosis of ALF of unknown origin. Once admitted to our ICU, we obtained the report of more than 14,375,000 HSV-1 copies/mL on cell-free plasma by real-time PCR assay, so acyclovir 800 mg (10 mg/kg of ideal body weight)/3 times a day was started.  expose the patient to secondary viral, bacterial and fungal infections [6]. Both of our patients underwent therapy with tocilizumab, a selective interleukin-6 receptor antagonist [7] widely used in treating the Covid-19 associated "cytokine storm" in Italy. The risk of serious infections related to tocilizumab was not considered greater than that of patients receiving placebo [8]. However, suppressed T cell immune response and decreased T cells in COVID-19 patients are related to down-regulated gene expression involved in T cell activation and differentiation [9] and the inhibition of IL-6/IL-6R complex formation may trigger the dysfunction of antigen-specific CD8positive T cells. For instance, IL-6 knockout mice were reported to be more susceptible to infection by herpes simplex virus [10].
HSV-1 reactivation may frequently occur in critically ill patients admitted to ICU [11], however, fulminant HSV-1 hepatitis is a rare disease [12]. In addition, it seems unlikely that the cumulative dosage of short-term steroids administered in patient 1 (220 mg of methylprednisolone in 5 days) could have contributed significantly to HSV-1 liver failure, but this cannot be entirely ruled out [13].
A c c e p t e d M a n u s c r i p t Beyond ALF, patient 2 probably also developed HSV-1 encephalitis, as suggested by the CSF positivity for HSV-1, but it was not formally proven by brain autopsy examination due to biohazard precautions in our dissection room. Some considerations arise from our experience. Careful screening and monitoring of HSV-1 should be considered in patients with severe SARS-CoV-2 pneumonia presenting clinical manifestations suspected for an infectious aetiology, particularly when immunomodulatory therapies are used. Antiviral prophylactic or pre-emptive strategies may be advisable in COVID-19 patients with specific risk factors as preexisting immune suppression, ICU admission and use of specific immunomodulatory agents.
In conclusion, our cases described a novel infectious risk associated with the    A c c e p t e d M a n u s c r i p t