An unusual course of COVID-19 infection with late increase in C-reactive protein (clinical case reports) 10.18093/0869-0189-2020-30-5-709-714 Нетипичное течение новой коронавирусной инфекции COVID-19 с по здним повышением уровня (клинические

Russia Abstract Clinical signs of COVID-19 infection are non-specific and diagnosis is typically based on comprehensive evaluation of the patient’s history, clinical status, radiological and laboratory findings. A common finding in COVID-19 patients is increased C-reactive protein (CRP), though in some patients, CRP remains within normal range notwithstanding the presence of other criteria of severe disease. We describe two clinical cases of COVID-19 with severe bilateral pneumonia and late increase in CRP. Similar cases re quite challenging for making the diagnosis and indicating the antiinflammatory Key infection. interests. The declare the absence of

lenged while assessing the disease severity and choosing the therapy for such patients. We describe two clinical cases of COVID-19 with late CRP increase.

Case 1
32-year old male who lived in Moscow was admitted to a hospital on the 4 th of May, 2020, with fever for past 5 days, diarrhea and vomiting for past 3 days. At home, the patient took paracetamol and aspirin. Previously, he had a history of gastroesophageal reflux disease, pollinosis (allergic rhinitis and allergic conjunctivitis during birch pollution) and angioedema after eating nuts. The patient is a current smoker of hookan quite daily during past 3 or 4 years; he was not exposed to other hazards. He did not have the history of drug intolerance. The patient did not have a close contact to anyone infected by SARS-CoV-2 virus during the previous two weeks.
At presentation, he was febrile to 38.3 °C. Vital signs at the time of presentation revealed normal respiratory rate (RR, 18/min), mild tachycardia (heart rate, 90/min), normal blood pressure (BP, 130/80 mm Hg), normal oxygen saturation (SpO 2 , 95%) at the room air; no peripheral oedema, no cyanosis. Lung auscultation was not performed.
The initial therapy included mefloquine (7 days, the standard regimen), oral azithromycin 500 mg daily, oral lopinavir/ritonavir 400/100 mg daily, paracetamol, fraxiparine 0.4 mg daily. The fever remained at 38.5 °С. On day 3 of admission, the diarrhoea worsened and a sharp increase in hepatic transaminases (AST, 233 U/L; ALT, 234 U/L; gamma-glutamyl transpeptidase (GGT), 112 U/L) and lactate dehydrogenase (LDH) (up to 1,069 U/L) was revealed. By this reason, azithromycin, mefloquine, and ritonavir/lopinavir were withdrawn. From day 5 of ad-mission (day 10 from disease onset), the temperature decreased to 37.5 °C, but hypoxia occurred with the decrease in SpO 2 to 94 -91% at room air. Supplemental oxygen therapy was initiated via nasal prongs followed by a face mask because the oxygen flow gradually increased to 8 -10 L/min. Dexamethasone 24 mg/ day i.v. was added. Repeated chest CT (day 10 after disease onset) showed further extension of ground glass opacities and the appearance of consolidation areas in both lungs. The total lung involvement increased to 50 -75% for each lung ( Figure 1В).
CRP remained low during first 12 days of the disease (1.9 -5.27 mg/L) and increased to 42.7 mg/L by day 13. Serum ferritin remained normal as well (127 -166 μg/L; normal value is > 200 μg/L). IL-6 was measured on day 13 and was 2.5 times higher than normal (15.4 pg/mL; normal value is > 6 pg/mL).
On day 13 of admission, the low-grade fever remains; the patient had mild respiratory failure (SpO 2 80 -84% at room air with the increase to 96% when using supplemental oxygen 6 L/min via a face mask).
Considering the respiratory failure, slow but progressive increase in CRP level and the liver damage with unsuccessful treatment with previous drugs including systemic steroids, sarilumab (human anti-IL-6R monoclonal IgG1 antibody) 200 mg was administered. This was followed by a rapid decrease in CRP to 10 -16 mg/L and in the body temperature to 36.4 °С. SpO 2 improved until after the physical rehabilitation was started. To day 21 of the disease, SpO 2 reached 92% at room air and the supplemental oxygen flow was reduced to 3 L/min via nasal prongs. The changes in key markers of systemic inflammation, such as CRP, fibrinogen, IL-6, and lymphocytes, were shown in Figure 2. AST, ALT, GGT and LDH reduced gradually, but were still increased at the patient's discharge from the hospital.
The patient was discharged on day 20 of hospitalisation (day 25 from disease onset) with normal body temperature and SpO 2 of 95% at room air. Chest CT follow-up in a month after the discharge showed mild ground glass opacities and no consolidation ( Figure 1С).

Case 2
39-year old male who lived in Moscow was admitted to a hospital on the 30 th of April, 2020, on day 6 of disease onset with fever (39 °С), diarrhea, and sore throat. The initial treatment before admission with hydroxychloroquine 200 mg b.i.d. and azithro- mycin 500 mg q.d. was unsuccessful. The patient did not have previous chronic diseases or hazardous exposure. No history of allergic reactions or drug intolerance. At admission, the patient was febrile to 38.7 °C. He was overweight with body mass index of 30.9 kg/m 2 . Vital signs at the time of admission revealed normal RR (19/min), moderate tachycardia (heart rate, 101 beats/min) and slightly decreased BP (108/66 mm Hg). SpO 2 was 96% at room air at rest. No peripheral oedema and no cyanosis were found. Lung auscultation was not performed.
Therapy with lopinavir/ritonavir 800/200 mg/day, interferon-β-1b, and enoxaparin was started at admission. Hydroxychloroquine 400 mg/day was continued. On day 4 after admission, the patient was still febrile with the body temperature of 39 °С and SpO 2 fell to 92% at room air. CRP grew from 32 to 48 mg/L. Supplemental oxygen 6 L/min was initiated via nasal prongs resulting in the SpO 2 improvement to 96%.
On day 5 of hospitalisation (day 11 of disease), the fever became low-grade, but dyspnea worsened. SpO 2 reduced to 87 -88% at room air. This required to increase the oxygen flow up to 10 L/min with improvement in SpO 2 to 91 -92%. CRP continued growing to 82 -113 mg/L. Leukopenia and lymphopenia worsened to 2.9 × 10 9 /L and 0.34 × 10 9 /L, respectively. There was an increase in LDH to 1,253 U/L, AST to 244 U/L, ALT to 552 U/L, total bilirubin to 21.8 μmol/L, and fibrinogen to 5.73 g/L (the normal value is < 4.00 g/L). Chest CT demonstrated further extension of ground glass opacities to 50 -75% in each lung corresponding to CT-3.
Given the growing CRP, progressive respiratory failure and liver damage, tocilizumab 480 mg was administered i.v.; the dose of enoxaparin was increased to 0.8 mL b.i.d.; lopinavir/ritonavir and hydroxychloroquine were withdrawn.
The temperature dropped to 37.4 °C several hours after tocilizumab infusion and became normal a day later. CRP reduced to 47 mg/L in the next day after tocilizumab infusion with further decrease to 8 -5 -2 mg/L. NIV allowed to keep SpO 2 at 95 -96%. Liver transaminases also reduced, but had not reached the normal level to the time of the patient's discharge from the hospital (Figure 2).
On day 8 of hospitalisation, the patient was weaned from NIV to supplemental oxygen 10 L/min via a face mask and was transferred from ICU to a general ward. The patient was discharged on day 19 of hospitalisation after clinical and laboratory stability was achieved. Chest CT at the end of hospitalisation showed linear and patchy consolidation; the overall right lung involvement reduced to 25% and the overall left lung involvement reduced to 25 -50% compared to the baseline; this corresponded to CT-2 [9].

Discussion
Clinical cases of COVID-19 with severe bilateral pneumonia were described in this article. A particular feature of these cases was late increase in CRP. The respiratory failure worsened together with CRP growth. Development of "cytokine storm" requires administration of monoclonal antibodies against ILs or IL receptors. Clinically, these drugs should be used in patients with significant lung injury (50 -75%) and at least two of the following signs: low SpO 2 , CRP as high as > 60 mg/L or 3-fold growth in CRP on days 8 -14 of disease; fever of > 38 °С during 5 days, WBC < 3.0 × 10 9 /L, blood lymphocyte count < 1 × 10 9 /L and/or < 15% [9]. However, physicians are often guided by CRP level and underestimate these clinical criteria.  Both patients described were febrile and had low blood lymphocyte count. The patient 2 had also low WBC count. However, the lung involvement in both patients was not extensive enough to suspect the "cytokine storm". When the lung involvement enlarged, the fever, another important clinical sign of "cytokine storm", surprisingly reduced to low-grade level.
In patient 1, CRP has not reached the threshold of 60 mg/L during all the course of the disease and 3-fold growth was found on day 13 only (from 5.27 to 42.7 mg/L). Dexamethasone did not impact significantly on the clinical presentation. In patient 2, CRP exceeded 60 mg/L to day 11 of disease only and 3-fold increase in CRP level occurred much more later (Figure 3). Therefore, "cytokine storm" is not always associated with contemporary CRP growth to high values in real clinical practice. The measurement of another marker of "cytokine storm", IL-6, is not available everywhere.
Of note, both patients had significantly increased liver transaminases. A rise of liver transaminases could be seen in 20 -35% of COVID-19 patients; this could reflect acute liver injury associated with COVID-19 [10][11][12]. Liver damage can be caused by SARS-CoV-2 virus itself that binds to angiotension-converting enzyme (ACE II) receptor in order to enter an epithelial cell. ACE II receptors are expressed on epithelial cells of bile ducts in hepatic tissue and, to a lesser extent, on hepatocytes [10,11]. An increase in liver transaminases was demonstrated to correlate directly with COVID-19 severity [10,12]. On the other hand the majority of drugs used to treat the novel coronavirus infection COVID-19, such as ritonavir/ lopinavir and hydroxychloroquine, can damage the liver. Both patients received aminoquinolines (mefloquine or hydroxychloroquine) and lopinavir/ritonavir from day 1 of admission. Therefore, it is hard to say whether the increase in transaminases level was associated with COVID-19 severity (in this case, high AST and ALT, similarly to CRP, are features of disease severity) or with drug-induced liver injury. The former thesis is supported by the fact that the liver transaminases begun rising three days after the thera-py was started and remained at a high level for 2 -3 weeks after drugs had been withdrawn.
CRP is produced in the liver [1], therefore, It could be assumed that virus-induced liver damage could dysregulate synthetic liver function followed by lowering CRP level. However, some authors report that an increase in liver transaminases was associated with more severe systemic inflammation in COVID-19 [13,14]. Q. Cai et al. found that hospitalized COVID-19 patients are at higher risk of drug-induced liver injury, primarily due to use of lopinavir/ritonavir which increases this risk in 4 times [15]. Many authors describe a direct association between the increase in liver transaminases and the severity of COVID-19 [13,15,16].

Сonclusion
In conclusion, COVID-19 patients with higher liver transaminase level should be considered as patients with potentially severe course of COVID-19, even if CRP is normal or slightly increased. We suppose that increased liver transaminases in a patient with chest CT typical for COVID-19 and long-lasting fever should be considered as an indication for administration of anti-IL monoclonal antibodies.