Pericardial Cytokine "Storm" in a COVID-19 Patient: the Confirmation of a Hypothesis

Novel Coronavirus Disease in most cases produces mild symptoms which resolve after a few days. Some authors hypothesized that SARS-CoV-2 infection could trigger excessive cytokine production leading to a severe multi-organ disease requiring intensive care admission. Respiratory and neurological symptoms are the most frequently reported manifestation of the disease. Indeed, cardiac involvement is reported mostly as a part of a systemic disease. Few isolated cardiac manifestations of COVID-19 infection have been described. We report herein a case of SARS-CoV-2 related severe isolated pericardial involvement requiring ICU admission due to cardiac tamponade needing urgent drainage. Analysis of pericardial fluid from drainage demonstrated a higher cytokine concentration than blood values. Other causes of pericardial disease, such as autoimmunity, bacterial or other than COVID-19 infection, neoplasms or acute myocardial infarction were also evaluated, but all tests confirmed negative results. The suspicion of isolated involvement of the pericardium was therefore demonstrated by the analysis of cytokines which strongly support our hypothesis.

Pericarditis after SARS-CoV-2 Infection: Another Pebble in the Mosaic of Long COVID?

With the emerging success of the COVID-19 vaccination programs, the incidence of acute COVID-19 will decrease. However, given the high number of people who contracted SARS-CoV-2 infection and recovered, we will be faced with a significant number of patients with persistent symptoms even months after their COVID-19 infection. In this setting, long COVID and its cardiovascular manifestations, including pericarditis, need to become a top priority for healthcare systems as a new chronic disease process. Concerning the relationship between COVID-19 and pericardial diseases, pericarditis appears to be common in the acute infection but rare in the postacute period, while small pericardial effusions may be relatively common in the postacute period of COVID-19. Here, we reported a series of 7 patients developing pericarditis after a median of 20 days from clinical and virological recovery from SARS-CoV-2 infection. We excluded specific identifiable causes of pericarditis, hence we speculate that these cases can be contextualized within the clinical spectrum of long COVID. All our patients were treated with a combination of colchicine and either ASA or NSAIDs, but four of them did not achieve a clinical response. When switched to glucocorticoids, these four patients recovered with no recurrence during drug tapering. Based on this observation and on the latency of pericarditis occurrence (a median of 20 days after a negative nasopharyngeal swab), could be suggested that post-COVID pericarditis may be linked to ongoing inflammation sustained by the persistence of viral nucleic acid without virus replication in the pericardium. Therefore, glucocorticoids may be a suitable treatment option in patients not responding or intolerant to conventional therapy and who require to counteract the pericardial inflammatory component rather than direct an acute viral injury to the pericardial tissue.

Airborne Transmission of a Serotype 4 Fowl Adenovirus in Chickens

Serotype 4 fowl adenovirus (FAdV-4) is the main pathogen for hydropericardium syndrome (HPS) in chickens. It has caused major economic losses in the global poultry industry. Currently, FAdV-4's transmission routes in chickens remain unclear. Here we investigate the airborne transmission routes of FAdV-4 in chickens. A total of 45 ten-day-old chickens were equally divided into three groups (infected group/isolator A, airborne group/isolator B, and control group/isolator C). Of note, isolators A and B were connected by a leak-free pipe. The results showed that the virus could form a viral aerosol, detected in isolators two days post infection (dpi). The viral aerosol reached a peak at 4 dpi in the infected group. Healthy chickens in the airborne group were infected by the virus at 8 dpi. The chickens of the airborne group demonstrated subclinical symptoms capable of shedding the virus for some time. This finding suggests that FAdV-4 can be efficiently transmitted among chickens by aerosol transmission. These findings have significant implications for developing strategies to control this infectious disease epidemic.

Antiviral and myocyte protective effects of murine interferon-β and -α2in coxsackievirus B3-induced myocarditis and epicarditis in Balb/c mice

The present study tested the hypothesis that murine (m)IFN-β or mIFN-α2can eliminate cardiac viral load and protect cardiomyocytes from injury in animals infected with coxsackievirus B3 (CVB3). CVB3-inoculated male Balb/c mice exhibited signs of illness, including lethargy, progressive weight loss, and death (10% on day 3 and 100% on day 8). Cardiac viral load was high [4,277 ± 1,009 plaque-forming units and 25 ± 5 copies CVB3/hypoxanthine guanine phosphoribosyl transferase 1 mRNA] on day 4. The cardiac tissue exhibited severe inflammatory infiltration and myocyte damage with an average myocarditis integrated pathology score of 2.1 ± 0.2 on day 7. Most of the mice infected with CVB3 also developed epicarditis, and 55% had intraventricular thrombi present. Treatment with mIFN-β [2.5 to 10 million international units (MIU)/kg] dose-dependently improved the general health status in CVB3-inoculated mice, as evidenced by reduction in weight loss, prevention of death, elimination of cardiac viral load, protection of myocytes from injury, decrease in inflammatory cell infiltration, and attenuation of intraventricular thrombus formation. Treatment with 10 MIU/kg mIFN-α2resulted in a similar level of efficacy as that induced by 5 MIU/kg mIFN-β, with the exception that mIFN-α2did not reduce cardiac CVB3 mRNA. However, mIFN-α2, but not any dose group of mIFN-β, significantly attenuated CVB3-induced epicarditis. These data demonstrate antiviral effects for both mIFN-β and mIFN-α2, which lead to protection of the mice from CVB3-induced myocarditis. However, the potential mechanisms leading to a differential host response for the two isoforms of mIFN remain to be elucidated.

Relation of subepicardial adipose tissue to carotid intima-media thickness in patients with human immunodeficiency virus

Patients infected with human immunodeficiency virus (HIV) are at increased risk for subclinical atherosclerosis. Whether increased cardiac adiposity may be related to HIV subclinical atherosclerosis is still unexplored. The objective of this study was to evaluate whether echocardiographically determined subepicardial adipose tissue, an index of cardiac adiposity, is related to carotid intima-media thickness (IMT), an index of subclinical atherosclerosis, in HIV-infected patients receiving highly active antiretroviral therapy. Echocardiographic epicardial fat thickness and ultrasonographic IMT were measured in 103 consecutive HIV-infected Caucasian subjects receiving highly active antiretroviral therapy. Echocardiographic subepicardial adipose tissue showed an excellent correlation with IMT (r = 0.92, p <0.01). Multiple regression analysis showed that IMT was best predicted by epicardial fat thickness (r(2) = 0.81, p <0.01). In conclusion, this study suggests, for the first time, that epicardial adipose tissue, an index of cardiac adiposity, may be significantly related to subclinical atherosclerosis in HIV-infected patients.

The role of histopathology in establishing the diagnosis of tuberculous pericardial effusions in the presence of HIV

AIMS

To establish the influence of human immunodeficiency virus (HIV) infection on the histopathological features of patients presenting with tuberculous pericarditis.

METHODS AND RESULTS

A prospective study was carried out at Tygerberg Academic Hospital, South Africa; 36 patients with large pericardial effusions had open pericardial biopsies under general anaesthesia and were included in the study. Patients underwent pericardiocentesis, followed by daily intermittent catheter drainage; a comprehensive diagnostic work-up (including histopathology of the pericardial tissue) was also performed. Histological tuberculous pericarditis was diagnosed according to predetermined criteria. Tuberculous pericarditis was identified in 25 patients, five of whom were HIV+. The presence of granulomatous inflammation (with or without necrosis) and/or Ziehl-Neelsen positivity yielded the best test results (sensitivity 64%, specificity 100% and diagnostic efficiency 75%).

CONCLUSIONS

Co-infection with HIV impacts on the histopathological features of pericardial tuberculosis and leads to a decrease in the sensitivity of the test. In areas which have a high prevalence of tuberculosis, the combination of a sensitive test such as adenosine deaminase, chest X-ray and clinical features has a higher diagnostic efficiency than pericardial biopsy in diagnosing tuberculous pericarditis.

The hydropericardium syndrome in poultry--a current scenario

Inclusion-body hepatitis hydropericardium syndrome (IBH-HPS) is an important, recently emerged, disease of poultry, particularly of 3- to 6-week-old broiler chicks, characterized by its sudden onset, with high mortality ranging from 20% to 70%, typical hydropericardium and enlarged mottled and friable livers, with intranuclear inclusion bodies in the hepatocytes. The causative agent is a non-enveloped icosahedral fowl adenovirus (FAV) serotype 4, belonging to the Adenovirus genus of the family Adenoviridae, which can be propagated or cultivated in chicken embryo liver and kidney primary cell cultures. The transmission of disease occurs vertically and laterally by the oral-faecal route. The liver of infected birds shows necrotic foci and basophilic intranuclear inclusion bodies in the hepatocytes. The disease can be diagnosed from its gross and histopathological changes in the liver and by various serological tests, such as agar gel immunodiffusion, counterimmunoelectrophoresis, indirect haemagglutination, the fluorescent antibody technique, enzyme-linked immunosorbent assay and the polymerase chain reaction. The disease has been brought under control by the use of formalin-inactivated vaccines, prepared from infected liver homogenate, and of inactivated cell culture vaccines. The vaccines are effective in the face of natural outbreaks or experimental challenge and significantly reduce the mortality.

Studies on structural and immunogenic polypeptides of hydropericardium syndrome virus by SDS-PAGE and western blotting

The polypeptide pattern of a local isolate of a virus causing hydropericardium syndrome was analyzed by sodium dodecyl sulphate-polyacrylamide gel electrophoresis. A total of 12 polypeptides ranging in molecular weight between 13.8 and 110.0 kDa were observed. Western blot analysis of structural polypeptides revealed seven immunogenic polypeptides ranging in molecular weight between 15.8 and 110.0 kDa.

Isolation of etiological agent of hydropericardium syndrome in chicken embryo liver cell culture and its serological characterization

The virus causing hydropericardium syndrome was isolated in chicken embryo liver (CEL) cell culture from livers obtained from naturally infected broilers. The cytopathic effects characterized by rounding and degeneration of cells were visible 36 hr post infection in first passage. At 4th passage level, the infectivity titre was 5.24 log10 TCID50/ml. In May-Grunwald and Giemsa stained cells, basophilic intranuclear inclusions ('bird eye' inclusion), typical of aviadenovirus infection, were observed. The specificity of inclusion was confirmed by indirect immunofluorescence. Various serological tests, such as agar gel precipitation test, counter immuno electrophoresis, micro serum neutralization test and enzyme linked immunosorbent assay were also standardized to confirm the isolation of etiological agent of hydropericardium syndrome in CEL cell culture and to diagnose the disease in poultry.

Prevention of inclusion body hepatitis/hydropericardium syndrome in progeny chickens by vaccination of breeders with fowl adenovirus and chicken anemia virus

The hypothesis that an effective protection of progeny chickens against inclusion body hepatitis/hydropericardium syndrome (IBH/HP) can be achieved by dual vaccination of breeders with fowl adenovirus (FAV) serotype 4 and chicken anemia virus (CAV) was tested. Thus, 17-wk-old brown leghorn pullet groups were vaccinated by different schemes including single FAV (inactivated), single CAV (attenuated), FAV and CAV dually, or were not vaccinated (controls). Subsequent progenies of these breeders were challenged with the virulent strains FAV-341 and CAV-10343 following three strategies: 1) FAV-341 intramuscularly (i.m.) at day 10 of age (only FAV-vaccinated and control progenies); 2) FAV + CAV i.m. simultaneously at day 10 of age (all progenies); 3) CAV i.m. at day 1 and FAV orally at day 10 of age (all progenies). The induction of IBH/HP in these progenies was evaluated throughout a 10-day period. Both breeder groups vaccinated against FAV and those vaccinated against CAV increased virus neutralizing specific antibodies. Challenge strategy 1 showed 26.6% mortality in control progeny chickens and 13.3% in the progeny of FAV-vaccinated breeders. Presence of lesions in the liver of these groups showed no significant differences (P > 0.05), suggesting a discreet protective effect of the vaccine. Challenge strategy 2 showed 29.4% mortality in controls and 94% of chickens showed hepatic inclusion bodies (HIB). Single CAV vaccination of breeders did not demonstrate a beneficial effect, with both mortality and liver lesions resembling the nonvaccinated controls. FAV vaccination of breeders significantly reduced both mortality (7.4%) and liver lesions (26% HIB) (P < 0.05), providing protection against this challenge strategy. Dual vaccination of breeders with FAV and CAV proved to be necessary to achieve maximum protection of the progeny (no mortality and 7% HIB). Challenge strategy 3 produced no mortality but consistent liver damage in controls (96% HIB). In this case, both CAV and FAV + CAV-vaccinated breeders showed best protection results in terms of liver histopathology (8% and 0% HIB, respectively). FAV vaccination alone produced 24% HIB, similar to challenge strategy 2, demonstrating a lower protective effect.

Nucleotide sequence of L1 and part of P1 of hexon gene of fowl adenovirus associated with hydropericardium hepatitis syndrome differs with the corresponding region of other fowl adenoviruses

In order to study the serotypic variations in hydropericardium hepatitis syndrome (HHS) causing virus, the DNA was extracted from the purified virus, a 0.7 kb variable region of hexon gene encoding L1 and part of P1 amplified and sequenced. Both nucleotide and derived amino acid sequences, corresponding to the variable region, were compared with the published fowl adenovirus sequences (FAV serotypes 10, 1 and 8). As expected the 0.7 kb sequence showed single open reading frame (ORF). There was a nucleotide sequence variation of 8.2, 28.1 and 40.3%, respectively, with FAV serotypes 10, 1 and 8. The dendrogram constructed with the nucleotide sequences showed that HHS virus and FAV10 are closer to each other and are away to FAV1 and FAV8. However, the derived amino acid sequence showed variations as high as 28.8, 38 and 45.1% with FAV serotypes 10, 1 and 8, respectively. Such high degree variation has been found due to the shift in the reading frame caused by deletions indicating that the FAV4 associated with HHS is unique and different from FAV10. To the best of our knowledge this is the first report on nucleotide sequence analysis of hexon gene fragment of FAV4 associated with HHS.

Postpericardiotomy syndrome: no evidence for a viral etiology

BACKGROUND

Postpericardiotomy syndrome has been considered a disorder induced by viral infection. This conclusion is based on serologic criterions, but these may be unreliable following either cardiopulmonary bypass or transfusion therapy. Previous studies have not verified the proposed etiology either by isolation of viruses, or by detection of their genome. We sought, therefore, to clarify the role, if any, of viruses in this syndrome.

METHODS AND RESULTS

We studied prospectively 149 children aged from 6 months to 16 years who were undergoing open heart surgery. Blood samples were collected from all prior to operation, and again 7 to 10 days post-operatively, and 47 were sampled at the time of development of symptoms of pericardial involvement. Serums were analyzed for the presence of IgM and IgG antibodies to cytomegalovirus, herpes simplex virus, and Epstein-Barr virus. The polymerase chain reaction was used for amplification when assessing the genome of the enteroviruses. Cultures for viruses were established on samples of stool, urine, and throat swabs collected 7 days post-operatively, and at the time of postpericardial symptoms. Pericardial fluid obtained from 5 patients with the syndrome was cultured for viruses, and tested for enterovirus genome. On the basis of clinical and echocardiographic findings, 34 children were determined to have definite evidence of the syndrome, 13 were considered to have possible evidence, and the results from these patients were compared to those from patients with no pericardial symptoms, the latter being matched for age and transfusion status. We isolated viruses from one or more sites in five patients with definite evidence (16%), from one (9%) of those with possible evidence, and from seven (19%) of the controls. All serums and pericardial samples were negative for enterovirus genome. IgM antibodies were found in only 5 patients, three with symptoms of pericardial involvement and two without. Rates of seroconversion to IgG for the viruses were lower in the patients with symptoms of pericardial involvement compared to controls, but were strongly influenced by transfusion status.

CONCLUSION

Our study has provided no evidence to support a viral etiology for the postpericardiotomy syndrome.

Vertical induction of the inclusion body hepatitis/hydropericardium syndrome with fowl adenovirus and chicken anemia virus

The hypothesis that fowl adenovirus (FAV) and chicken anemia virus (CAV), transmitted vertically and simultaneously, induce the inclusion body hepatitis (IBH)/hydropericardium (HP) syndrome in progeny chickens was tested. Thus, 35-wk-old light brown layer breeders, showing absence of antibodies against FAV and variable titers against CAV, were intramuscularly singly infected with the FAV serotype 4 isolate 341 or dually infected with CAV (isolate 10343) and FAV. All hens (groups A [FAV alone], B [FAV + CAV], and C [noninfected]) were clinically healthy throughout the experimental period. Both infectious viruses FAV and CAV were isolated from progenies obtained as early as 5 days after infection of their breeders. Hematocrit, serum proteins, and aspartate-aminotransferase values showed a few statistical differences between the progeny groups. Most of these differences were detected in the progeny chickens of group B. However, almost all values met reference values for the species. The pathologic findings showed that progeny chickens obtained from both singly and dually infected breeders developed macroscopic and histopathologic changes of IBH/HP. The pathologic findings shown by progeny chickens of group A (FAV) were not expected because neither synergism nor prior immunodepression by CAV was concurrent. Chickens of group B (CAV + FAV) also developed IBH/HP. Although not many differences in the evaluated parameters between groups A and B were statistically significant, most pathologic findings of group B indicated a more severe manifestation of the disease. However, because FAV alone did reproduce the syndrome, the results shown by group B would not allow a definitive confirmation of the hypothesis that the association of FAV and CAV is necessary for the successful induction of the IBH/HP syndrome in chickens when transmitted vertically.

Chicken anemia virus and fowl adenoviruses: association to induce the inclusion body hepatitis/ hydropericardium syndrome

The effects of a simultaneous and/or a subsequent coinfection with chicken anemia virus (CAV) isolate 10343 and fowl adenovirus (FAV) isolate 341 in specific-pathogen-free light chickens were evaluated. The simultaneous coinfection was conducted by the intramuscular route, whereas the subsequent coinfection trial considered FAVs administered orally. In trial 1, 20-day-old chickens simultaneously coinfected with CAV (10343) and FAV (341) intramuscularly (i.m.) showed 55% mortality and characteristic signs and lesions of inclusion body hepatitis/hydropericardium (IBH/HPS). In contrast, birds singly infected with FAV i.m. showed 10% mortality due to IBH/HPS. Trial 2 showed that birds receiving FAV 341 orally at day 7 post-CAV intramuscular infection (group A) developed a mild form of IBH/HPS with presence of inclusion bodies (INIBs) in 60% of the group and virus-neutralizing antibodies against FAV 341. Group B (FAV orally 14 days after CAV) showed significant decreased weight gain, nonspecific microscopic lesions in the liver, spleen, bursa, and thymus, and an antibody response against FAV 341. However, no INIBs could be detected in the hepatocytes of these chickens. Group C (FAV orally 35 days after CAV) showed nonspecific histopathologic changes in the liver and no antibody response to FAV. The oral single infection with FAV isolate 341 induced neither mortality nor macroscopic lesions of IBH/HPS in the birds. The present results corroborate previous reports on pathogenicity of Chilean FAV isolates, which suggest that synergism with other viruses or prior immunosuppression is necessary to produce IBH/HPS in chickens. These results also suggest that the susceptibility of chickens to FAV oral infection resulting in IBH/HPS varies throughout the course of CAV infection.

Adenoviral-mediated gene transfer induces sustained pericardial VEGF expression in dogs: effect on myocardial angiogenesis

OBJECTIVE

Angiogenic peptides like VEGF (vascular endothelial growth factor) and bFGF (basic fibroblast growth factor) have entered clinical trials for coronary artery disease. Attempts are being made to devise clinically relevant means of delivery and to effect site-specific delivery of these peptides to the cardiac tissue, in order to limit systemic side-effects. We characterized the response of the pericardium to delivery of a replication-deficient adenovirus carrying the cDNA for AdCMV.VEGF165, and assessed the effect of pericardial VEGF165 on myocardial collateral development in a canine model of progressive coronary occlusion.

METHODS

Ameroid constrictors were placed on the proximal left circumflex coronary artery of mongrel dogs. Ten days later, 6 x 10(9) pfu AdCMV.VEGF165 (n = 9). AdRSV.beta-gal (n = 9), or saline (n = 7) were injected through an indwelling pericardial catheter. Transfection efficiency was assessed by X-gal staining. Pericardial and serum VEGF levels were measured serially by ELISA. Maximal myocardial collateral perfusion was quantified with radiolabeled or fluorescent microspheres 28 days after treatment.

RESULTS

In AdRSV.beta-gal-treated dogs, there was extensive beta-gal staining in the pericardium and epicardium, with minimal beta-gal staining in the mid-myocardium and endocardium. Pericardial delivery of AdCMV.VEGF165 resulted in sustained (8-14 day) pericardial transgene expression, with VEGF levels peaking 3 days after infection (> 200 ng/ml) and decreasing thereafter. There was no detectable increase in serum VEGF levels. Maximal collateral perfusion, a principal correlate of collateral development and angiogenesis, was equivalent in all groups.

CONCLUSION

Adenoviral-mediated gene transfer is capable of inducing sustained VEGF165 expression in the pericardium; however, locally targeted pericardial VEGF delivery failed to improve myocardial collateral perfusion in this model.