Neutralization of SARS-CoV-2 Omicron XBB.1.5 and JN.1 variants after COVID-19 booster-vaccination and infection.

SARS-CoV-2 Omicron lineages continue to emerge and evolve into new sublineages, causing infection waves throughout 2022 and 2023, which has been attributed to immune escape. We examined neutralizing antibody responses to the recently emerged SARS-CoV-2 JN.1 variant in comparison to ancestral D614G and Omicron BA.1, BA.2, BA.5, and XBB.1.5 variants. We tested 79 human sera from cohorts with different combinations of vaccinations and infections, including 23 individuals who had been repeatedly exposed to Omicron. Individuals with a monovalent XBB.1.5 vaccine booster or XBB.1.5 breakthrough infection had robust antibody levels against all variants tested; however, JN.1 evaded antibodies in individuals after single Omicron BA.1, BA.2 or BA.5 breakthrough infections. Moreover, in the non-vaccinated cohort, serum antibodies demonstrated almost no cross-neutralization activities against D614G, XBB.1.5 and JN.1. after infections with earlier Omicron variants. These findings show that SARS-CoV-2-immunity is heterogeneous, depending on different combinations of vaccinations and infections, and emphasize the importance of considering different immune-backgrounds when evaluating novel variants.

Comparison of anti-nucleocapsid antibody assays for the detection of SARS-CoV-2 Omicron vaccine breakthroughs after various intervals since the infection.

Antibody assays with the nucleocapsid (NC) protein as the target antigen can identify severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections when polymerase chain reaction (PCR) analyses are unavailable. Regarding the kinetics of NC-specific antibodies, vaccine breakthroughs with Omicron subvariants may differ from infections with the ancestral wild-type virus. Therefore, we evaluated which assays have the highest sensitivity for detecting NC-specific antibodies after various intervals since breakthrough infections with an Omicron subvariant. The study included 279 samples from vaccinated subjects who experienced PCR-confirmed Omicron breakthrough infections between 21 and 266 days before sampling. The samples were comparatively assessed with the Elecsys® Anti-SARS-CoV-2 N (Roche), the Anti-SARS-CoV-2-NCP-ELISA (Euroimmun), the recomLine SARS-CoV-2 IgG (Mikrogen), and the SARS-CoV-2 ViraChip IgG assays (Viramed). In the whole cohort, the Elecsys® Anti-SARS-CoV-2 N assay displayed the highest sensitivity (93%, p < 0.0001), followed by the recomLine SARS-CoV-2 IgG assay (70%), the SARS-CoV-2 ViraChip IgG assay (41%) and the Anti-SARS-CoV-2-NCP-ELISA (35%). Although measured antibody levels and time-dependent sensitivities differed, the extent of the antibody decrease was similar among all assays. As demonstrated by this study, manufacturer-dependent differences in the sensitivities of NC-specific antibody assays should be considered when serology is applied to link previous SARS-CoV-2 infections with potential post-COVID sequelae.

Limited role of children in transmission of SARS-CoV-2 virus in households-Immunological analysis of 26 familial clusters.

BACKGROUND: The impact of children on the transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) remains uncertain. This study provides an insight into distinct patterns of SARS-CoV-2 household transmission in case of pediatric and adult index cases as well as age-dependent susceptibility to SARS-CoV-2 infection. METHODS: Immune analysis, medical interviewing, and contact tracing of 26 families with confirmed SARS-CoV-2 infection cases have been conducted. Blood samples were analyzed serologically with the use of a SARS-CoV-2-specific IgG assay and virus neutralization test (VNT). Uni- and multivariable linear regression and mixed effect logistic regression models were used to describe potential risk factors for higher contagiousness and susceptibility to SARS-CoV-2 infection. RESULTS: SARS-CoV-2 infection could be confirmed in 67 of 124 family members. Fourteen children and 11 adults could be defined as index cases in their households. Forty of 82 exposed family members were defined as secondarily infected. The mean secondary attack rate in households was 0.48 and was significantly higher in households with adult than with pediatric index cases (0.85 vs 0.19; p < 0.0001). The age (grouped into child and adult) of index case, severity of disease, and occurrence of lower respiratory symptoms in index cases were significantly associated with secondary transmission rates in households. Children seem to be equally susceptible to acquire a SARS-CoV-2 infection as adults, but they suffer milder courses of the disease or remain asymptomatic. CONCLUSION: SARS-CoV-2 transmission from infected children to other household members occurred rarely in the first wave of the pandemic, despite close physical contact and the lack of hygienic measures.

Viral infections in pediatric brain tumor patients treated with targeted therapies.

BACKGROUND: Brain tumors are the most common solid malignancies and the leading cause of cancer-related mortality in children. While numerous studies report on viral infections in children with hematologic malignancies and solid organ transplantation, epidemiologic data on the incidence and outcome of viral infections in pediatric patients with brain tumors treated with targeted therapies are still lacking. OBJECTIVES/STUDY DESIGN: We retrospectively reviewed all children with brain tumors receiving targeted therapies in a primary or recurrent setting at the Medical University of Vienna from 2006 to 2021. Demographic variables, quantitative and qualitative parameters of possible infections, and treatment outcomes were recorded. RESULTS: In our cohort (n = 117), 36% of the patients developed at least one PCR-proven viral infection. Respiratory and gastrointestinal tract infections were most common, with 31% and 25%, respectively. Central nervous system (CNS) infections occurred in approximately 10%, with an almost equal distribution of varicella-zoster virus, John Cunningham virus (JCV), and enterovirus. Two patients tested PCR-positive for SARS-CoV-2 infection, with one virus-related death caused by a SARS-CoV-2-related acute respiratory distress syndrome. Patients receiving bevacizumab or mTOR inhibitors seem to have a greater susceptibility to viral infections. CONCLUSION: Pediatric patients with brain tumors receiving targeted therapies have a higher risk of viral infections when compared to children receiving conventional chemotherapy or the general population, and life-threatening infections can occur. Fast detection and upfront treatment are paramount to prevent life-threatening infections in immunocompromised children suffering from brain tumors receiving targeted therapies.

Three rounds of a national external quality assessment reveal a link between disharmonic anti-SARS-CoV-2 antibody quantifications and the infection stage.

OBJECTIVES: The WHO's standardized measuring unit, "binding antibody units per milliliter (BAU/mL)," should allow the harmonization of quantitative results by different commercial Anti-SARS-CoV-2 immunoassays. However, multiple studies demonstrate inter-assay discrepancies. The antigenic changes of the Omicron variant affect the performance of Spike-specific immunoassays. This study evaluated the variation of quantitative Anti-SARS-CoV-2-Spike antibody measurements among 46, 50, and 44 laboratories in three rounds of a national external quality assessment (EQA) prior to and after the emergence of the Omicron variant in a diagnostic near-to-real-life setting. METHODS: We analyzed results reported by the EQA participant laboratories from single and sequential samples from SARS-CoV-2 convalescent, acutely infected, and vaccinated individuals, including samples obtained after primary and breakthrough infections with the Omicron variant. RESULTS: The three immunoassays most commonly used by the participants displayed a low intra-assay and inter-laboratory variation with excellent reproducibility using identical samples sent to the participants in duplicates. In contrast, the inter-assay variation was very high with all samples. Notably, the ratios of BAU/mL levels quantified by different immunoassays were not equal among all samples but differed between vaccination, past, and acute infection, including primary infection with the Omicron variant. The antibody kinetics measured in vaccinated individuals strongly depended on the applied immunoassay. CONCLUSIONS: Measured BAU/mL levels are only inter-changeable among different laboratories when the same assay was used for their assessment. Highly variable ratios of BAU/mL quantifications among different immunoassays and infection stages argue against the usage of universal inter-assay conversion factors.

Characterization of the antibody response to SARS-CoV-2 in a mildly affected pediatric population.

BACKGROUND: While children usually experience a mild course of COVID-19, and a severe disease is more common in adults, the features, specificities, and functionality of the SARS-CoV-2-specific antibody response in the pediatric population are of interest. METHODS: We performed a detailed analysis of IgG antibodies specific for SARS-CoV-2-derived antigens S and RBD by ELISA in 26 SARS-CoV-2 seropositive schoolchildren with mild or asymptomatic disease course, and in an equally sized, age- and gender-matched control group. Furthermore, a detailed mapping of IgG reactivity to a panel of microarrayed SARS-CoV-2 proteins and S-derived peptides was performed by microarray technology. The capacity of the antibody response to block RBD-ACE2 binding and virus neutralization were assessed. Results were compared with those obtained in an adult COVID-19 convalescent population. RESULTS: After mild COVID-19, anti-S and RBD-specific IgG antibodies were developed by 100% and 84.6% of pediatric subjects, respectively. No difference was observed in regards to symptoms and gender. Mounted antibodies recognized conformational epitopes of the spike protein and were capable to neutralize the virus up to a titer of ≥80 and to inhibit the ACE2-RBD interaction by up to 65%. SARS-CoV-2-specific IgG responses in children were comparable to mildly affected adult patients. CONCLUSION: SARS-CoV-2 asymptomatic and mildly affected pediatric patients develop a SARS-CoV-2-specific antibody response, which is comparable regarding antigen, epitope recognition, and the ability to inhibit the RBD-ACE2 interaction to that observed in adult patients after mild COVID-19.

Levels of donor-derived cell-free DNA and chemokines in BK polyomavirus-associated nephropathy.

BACKGROUND: BK polyomavirus-associated nephropathy (BKPyVAN) carries a risk of irreversible allograft injury. While detection of BK viremia and biopsy assessment are the current diagnostic gold standard, the diagnostic value of biomarkers reflecting tissue injury (donor-derived cell-free DNA [dd-cfDNA]) or immune activation (C-X-C motif chemokine ligand [CXCL]9 and CXCL10) remains poorly defined. METHODS: For this retrospective study, 19 cases of BKPyVAN were selected from the Vienna transplant cohort (biopsies performed between 2012 and 2019). Eight patients with T cell-mediated rejection (TCMR), 17 with antibody-mediated rejection (ABMR) and 10 patients without polyomavirus nephropathy or rejection served as controls. Fractions of dd-cfDNA were quantified using next-generation sequencing and CXCL9 and CXCL10 were detected using multiplex immunoassays. RESULTS: BKPyVAN was associated with a slight increase in dd-cfDNA (median; interquartile range: .38% [.27%-1.2%] vs. .21% [.12%-.34%] in non-rejecting control patients; p = .005). Levels were far lower than in ABMR (1.2% [.82%-2.5%]; p = .004]), but not different from TCMR (.54% [.26%-3.56%]; p = .52). Within the BKPyVAN cohort, we found no relationship between dd-cfDNA levels and the extent of tubulo-interstitial infiltrates, BKPyVAN class and BK viremia/viruria, respectively. In some contrast to dd-cfDNA, concentrations of urinary CXCL9 and CXCL10 exceeded those detected in ABMR, but similar increases were also found in TCMR. CONCLUSION: BKPyVAN can induce moderate increases in dd-cfDNA and concomitant high urinary excretion of chemokines, but this pattern may be indistinguishable from that of TCMR. Our results argue against a significant value of these biomarkers to reliably distinguish BKPyVAN from rejection.

Performance of Four IgM Antibody Assays in the Diagnosis of Measles Virus Primary Infection and Cases with a Serological Profile Indicating Reinfection.

The object of this study was to determine the diagnostic performance of four commercially available IgM tests in the diagnosis of measles virus (MeV) primary infection and cases with a serological profile indicating reinfection. Sera from 187 patients with MeV primary infection, 30 patients with suspected reinfection (after vaccine failure), and 153 patients with rash-like symptoms after exclusion of MeV infection were retested with four IgM tests. MeV infection was verified by reverse transcriptase PCR (RT-PCR), and primary and suspected reinfections were differentiated by IgG avidity and neutralization assays. All IgM assays displayed significant agreement (Cohen's κ, ≥0.604; all P < 0.001) and a higher diagnostic accuracy in primary infection than in suspected reinfection (indicated by high IgG avidity and significantly higher anti-MeV-IgG and neutralizing titers). In the overall cohort, the areas under the curve (AUC) were comparable among all tests, ranging from 0.875 to 0.931, with ranges increasing to 0.911 to 0.930 in the primary infection and decreasing to 0.765 to 0.940 in the setting of high anti-MeV-IgG avidity, and all tests displayed high specificity (81.1 to 92.2%). Of note, IgM tests with the highest diagnostic accuracy had discriminatory abilities not significantly different than PCR from serum. Although reinfections pose a challenge for IgM testing, IgM assays remain a cornerstone in the diagnosis of MeV infections. Especially in samples with a serological profile indicating reinfections, IgM tests displayed an equal or even superior diagnostic ability compared to PCR from serum.

Assessment of S1-, S2-, and NCP-Specific IgM, IgA, and IgG Antibody Kinetics in Acute SARS-CoV-2 Infection by a Microarray and Twelve Other Immunoassays.

In this study, we comprehensively analyzed multispecific antibody kinetics of different immunoglobulins in hospitalized patients with acute severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Three hundred fifty-four blood samples longitudinally obtained from 81 IgG-seroconverting progressed coronavirus disease 2019 (CoVID-19) patients were quantified for spike 1 (S1), S2, and nucleocapsid protein (NCP)-specific IgM, IgA, IgG, and total Ig antibodies using a microarray, 11 different enzyme-linked immunosorbent assays (ELISAs)/chemiluminescence immunoassays (CLIAs), and 1 rapid test by seven manufacturers. The assays' specificity was assessed in 130 non-CoVID-19 pneumonia patients. Using the microarray, NCP-specific IgA and IgG antibodies continuously displayed higher detection rates during acute CoVID-19 than S1- and S2-specific ones. S1-specific IgG antibodies, however, reached higher peak values. Until the 26th day post-symptom onset, all patients developed IgG responses against S1, S2, and NCP. Although detection rates by ELISAs/CLIAs generally resembled those of the microarray, corresponding to the target antigen, sensitivities and specificities varied among all tests. Notably, patients with more severe CoVID-19 displayed higher IgG and IgA levels, but this difference was mainly observed with S1-specific immunoassays. In patients with high SARS-CoV-2 levels in the lower respiratory tract, we observed high detection rates of IgG and total Ig immunoassays with a particular rise of S1-specific IgG antibodies when viral concentrations in the tracheal aspirate subsequently declined over time. In summary, our study demonstrates that differences in sensitivity among commercial immunoassays during acute SARS-CoV-2 infection are only partly related to the target antigen. Importantly, our data indicate that NCP-specific IgA and IgG antibodies are detected earlier, while higher S1-specific IgA antibody levels occur in severely ill patients.

Characterization of 100 sequential SARS-CoV-2 convalescent plasma donations.

BACKGROUND: Transfusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) convalescent plasma is a promising treatment for severe coronavirus disease 2019 (COVID-19) cases, with success of the intervention based on neutralizing antibody content. Measurement by serologic correlates without biocontainment needs as well as an understanding of donor characteristics that may allow for targeting of more potent donors would greatly facilitate effective collection. STUDY DESIGN AND METHODS: One hundred convalescent plasma units were characterized for functionally active SARS-CoV-2 neutralizing antibodies, as well as for SARS-CoV-2 binding antibodies, with the intention to establish a correlation between the functionally more relevant neutralization assay and the more accessible enzyme-linked immunosorbent assay (ELISA). Donor demographics such as COVID-19 severity, age, and sex were correlated with antibody titers. RESULTS: A mean neutralization titer 50% of 230 (range, <8-1765) was seen for the 100 convalescent plasma units, with highly significant (P < .0001) yet quantitatively limited (R2 = 0.2830) correlation with results of the ELISA. Exclusion of units with particularly high titers (>500) from analysis improved correlation (R2 = 0.5386). A tendency of higher-titer plasma units from donors with increased disease severity, of advanced age, and of male sex was seen, yet the functional relevance of this difference is questionable. CONCLUSION: The ELISA-based correlation to neutralization titer enabled a threshold proposal that could be used to eliminate lower-titer units from the clinical supply for COVID-19 treatment. Disease severity may be associated with the development of higher titers of neutralizing antibodies, although larger case numbers will be needed for additional confirmation.

Lessons from low seroprevalence of SARS-CoV-2 antibodies in schoolchildren: A cross-sectional study.

BACKGROUND: Children are discussed as hidden SARS-CoV-2 virus reservoir because of predominantly mild or even asymptomatic course of disease. The objective of this cross-sectional study in May-July 2020 was to assess the prevalence of SARS-CoV-2 antibodies and virus RNA in schoolchildren, consistent with previous infection by contact tracing. METHODS: School authorities approached parents for voluntary participation. Interested families were contacted by the study team. A nasal and oropharyngeal swab, a blood sample, and a questionnaire were employed. Primary endpoint was the frequency of SARS-CoV-2 real-time PCR (RT-PCR) and antibody-positive children. Antibody positivity was assessed by a highly sensitive first-line ELISA, and a neutralization assay and two other immunoassays as confirmatory assays. RESULTS: Of 2069 children (median age 13 years, IQR 10-15), 2 cases (0.1%) tested positive for SARS-CoV-2 RNA and 26 cases (1.3%) tested positive for specific antibodies. SARS-CoV-2-specific antibodies exhibited detectable virus-neutralizing activity in 92% (24 of 26 samples). Seropositivity was associated with a history of mild clinical symptoms in 14 children (53.8%), while 12 children (46.2%) remained asymptomatic. Among 13 seropositive children being tested concomitantly with their siblings, only one pair of siblings was seropositive. Contact tracing revealed adult family members and school teachers as potential index cases. CONCLUSION: In schoolchildren, the infection rate with SARS-CoV-2 is low and associated with a mild or asymptomatic course of disease. Virus spreading seemed to occur more likely in intergenerational contacts than among siblings in the same household. The presence of neutralizing SARS-CoV-2 antibodies in children may reflect protective adaptive immunity.

Diagnosis of COVID-19 using multiple antibody assays in two cases with negative PCR results from nasopharyngeal swabs.

We report of two cases of progressed COVID-19 with negative PCR tests from nasopharyngeal swabs, in whom diagnosis was made by different antibody assays, including a lateral flow rapid test and multiple commercial ELISAs, finally confirmed by comprehensive serological assays. These cases highlight that commercial ELISAs and even rapid tests might significantly aid the diagnosis of COVID-19, particularly, if a combination of serological assays is used with a specific clinical question, in severely ill patients after seroconversion and when comprehensive serological methods are used for confirmation.

Elevated CXCL10 Serum Levels in Measles Virus Primary Infection and Reinfection Correlate With the Serological Stage and Hospitalization Status.

We quantified serum concentrations of chemokine CXCL10 in 288 patients with measles virus (MeV) primary infection and 16 patients with reinfection (vaccine failure). CXCL10 peaked with emergence of IgM antibodies and was elevated in hospitalized patients (3233 vs 1930 pg/mL, P < .0001). CXCL10 differed between primary and reinfection (1958 vs 932 pg/mL, P = .0402). In comparison to other viral infections with rash-like symptoms, CXCL10 was highly elevated in MeV infection (area under the curve = 0.935; 95% confidence interval, .905-.965; P < .0001). CXCL10 is a potential marker for diagnosis, stage, and severity of MeV infection.

Performance of Severe Acute Respiratory Syndrome Coronavirus 2 Antibody Assays in Different Stages of Infection: Comparison of Commercial Enzyme-Linked Immunosorbent Assays and Rapid Tests.

We comparatively assessed sensitivities and specificities of 4 commercial enzyme-linked immunosorbent assays (ELISAs) and 2 rapid tests in 77 patients with polymerase chain reaction-confirmed severe acute respiratory syndrome coronavirus 2 infection, grouped by interval since symptom onset. Although test sensitivities were low (<40%) within the first 5 days after disease onset, immunoglobulin (Ig) M, IgA, and total antibody ELISAs increased in sensitivity to >80% between days 6 and 10 after symptom onset. The evaluated tests (including IgG and rapid tests) provided positive results in all patients at or after the 11th day after onset of disease. The specificities of the ELISAs were 83% (IgA), 98% (IgG), and 97% (IgM and total antibody).

Longitudinal assessment of the CXCL10 blood and urine concentration in kidney transplant recipients with BK polyomavirus replication-a retrospective study.

In kidney transplant recipients (KTRs), BK polyomavirus (BKPyV) replication may progress to polyomavirus-associated nephropathy (PVAN). In this retrospective study, we assessed the chemokine CXCL10 in urine and blood samples consecutively acquired from 85 KTRs who displayed different stages of BKPyV replication and eventually developed PVAN. In parallel to progression toward PVAN, CXCL10 gradually increased in blood and urine, from baseline (prior to virus replication) to BKPyV DNAuria (median increase in blood: 42.15 pg/ml, P = 0.0156), from mere DNAuria to low- and high-level BKPyV DNAemia (median increase: 52.60 and 87.26 pg/ml, P = 0.0010 and P = 0.0002, respectively) and peaked with histologically confirmed PVAN (median increase: 145.00 pg/ml, P < 0.0001). CXCL10 blood and urine levels significantly differed among KTRs with respect to simultaneous presence of human cytomegalovirus (P < 0.001) as well as in relation to the clinical severity of respective BKPyV DNAemia episodes (P = 0.0195). CXCL-10 concentrations were particularly lower in KTRs in whom BKPyV DNAemia remained without clinical evidence for PVAN, as compared to individuals who displayed high decoy cell levels, decreased renal function and/or biopsy-proven PVAN (median blood concentration: 266.97 vs. 426.42 pg/ml, P = 0.0282). In conclusion, in KTRs CXCL10 rises in parallel to BKPyV replication and correlates with the gradual development of PVAN.

The Chemokine CXCL-10 Is a Marker of Infection Stage in Individuals With DNAemia Due to Parvovirus B19.

Background: Accurate diagnosis of parvovirus B19 (B19V) infection requires the differentiation between acute and past infection, which is especially important when DNAemia due to B19V (hereafter, "B19V DNAemia") is detected in pregnancy. Here, we explored whether the level of the chemokine CXCL-10, in combination with findings of molecular and serological assays, can discriminate between acute and past B19V infection. Methods: B19V DNA-positive serum samples from 222 immunocompetent individuals were analyzed for (1) viral DNA loads, (2) anti-B19V immunoglobulin M (IgM) and immunoglobulin G (IgG), (3) anti-VP1 IgG avidity, (4) anti-VP-2 epitope type specificity (ETS), and (5) CXCL-10 serum levels. Results: Anti-B19V IgM and IgG, avidity, and ETS assays were used to categorize individuals with B19V DNAemia as having acute or past B19V infection. Acute B19V infection caused a significant increase in the serum concentration of CXCL-10, compared with the concentration at baseline, before infection. Higher CXCL-10 serum levels were furthermore detected in acute B19V infection as compared to past infection. As a marker, CXCL-10 serum levels could discriminate between acute and past B19V infection, with an excellent discriminatory capacity when CXCL-10 and B19V DNA levels were used as combined parameters. Conclusion: Acute B19V infection is associated with increased CXCL-10 production, and measurement of CXCL-10 serum levels thus allows for the staging of B19V infection in individuals with B19V DNAemia.

Micro RNAs mir-106a, mir-122 and mir-197 are increased in severe acute viral hepatitis with coagulopathy.

BACKGROUND & AIMS: The severity of acute viral hepatitis, which may be caused by several distinct viruses, varies among individual patients. In rare cases, severe hepatic injury with sudden loss of liver function may occur, which is clinically indicated by the occurrence of coagulopathy or encephalopathy. As the molecular mechanisms of this liver injury are largely unknown, we investigated extracellular micro RNA (miRNA) profiles in 54 patients acutely infected with one of four different hepatotropic viruses, in order to identify those miRNAs which indicate severe viral hepatitis associated with coagulopathy. METHODS: First, the profile of miRNAs was extensively analysed using a microarray-based approach in highly characterized 24 patients, matched in terms of sex, age and level of liver enzymes, as well as in three healthy controls. The cohort included samples from 18 patients with moderate and six individuals with severe hepatitis, indicated by abnormal prothrombin time and higher alanine aminotransferase and bilirubin levels. miRNAs found to be upregulated in severe hepatitis were then quantified by real-time PCR in the expanded cohort of 54 patients. RESULTS: Comprehensive microarray-based miRNA profiling identified upregulation of mir-106a, mir-122 and mir-197 in patients with severe acute viral hepatitis with coagulopathy, as compared to patients who did not develop coagulopathy. mir-106a, mir-122 and mir-197 were then proven to be significantly upregulated in patients with severe acute viral hepatitis by quantitative real-time PCR (P < 0.01, Mann-Whitney U-test). CONCLUSIONS: mir-106a, mir-122 and mir-197 could be potential markers for severe acute viral hepatitis associated with coagulopathy.