Post-cardiac surgery outcomes following COVID-19 infection in unvaccinated patients.

The provision of cardiac surgery services nationwide has been affected by the COVID-19 pandemic. We noticed a high COVID-19 mortality rate in unvaccinated patients who were diagnosed with COVID-19 after recent cardiac surgery. All the patients were tested negative for COVID-19 before surgery. We conducted a review of our hospital data and reported our findings. We identified 15 patients and reported 7 deaths (46.7%). All the patients died from COVID-19 or its complications. We recommend that cardiac centres actively promote vaccination before cardiac surgery and also enhance infection control measures to prevent nosocomial infections.

Early outcome of cardiac surgery in dialysis-dependent end-stage renal failure patients.

INTRODUCTION: Preoperative dialysis-dependent renal failure is a strong independent risk factor for in-hospital mortality and morbidity after open heart surgery. This retrospective study analyses the early outcome in dialysis-dependent renal failure patients who underwent elective open-heart surgery in the Institut Jantung Negara (IJN). METHODS: We retrospectively analyse a series of 228 consecutive postoperative patients with dialysis-dependent (end stage renal failure (ESRF)) admitted to the adult cardiothoracic ICU in IJN between January 2012 and December 2016. RESULTS: The overall early mortality rate included 34 patients (15.8%). Patients with ESRF underwent combined procedure recorded a very high mortality rate at 56.3%. Twenty-four patients (11.2%) needed resternotomy for postoperative bleeding or cardiac temponade. Postoperative mediastinitis rate was high, involving 13 patients (6%). The neurological and gastrointestinal complications rate were recorded at 2.3% (5 patients) and 6% (13 patients) respectively. In the group of patients (n=199) with sinus rhythm during the preoperative period, 100 patients (50.3%) developed postoperative AF. 77 patients (35.8%) stayed in hospital for more than 14 days. CONCLUSIONS: dialysis-dependent patients undergoing cardiac surgery poses higher perioperative risk of mortality and morbidity of 3-4 times higher compared to those patients with normal renal function. IJN shows acceptable perioperative risk of mortality and morbidity which is comparable to other centres.

Right vertebral artery injury as a result of misplaced internal jugular vein catheter withdrawal.

Central venous cannulation is a common procedure done for various medical indications. The use of the central venous cannula is associated with various immediate complications such as pneumothorax, vascular injury, and arrhythmia. The following is an unusual case of delayed presentation of a right vertebral artery injury due to central venous cannulation which resulted in a posterior circulation stroke. This is a condition that can be difficult to diagnose and has a significant impact on patient's quality of life. Clinicians and radiologists should be alert to this possibility to prevent further morbidity resulting from the iatrogenic injury.

Alternative algorithms for human immunodeficiency virus infection diagnosis using tests that are licensed in the United States.

Serodiagnosis of human immunodeficiency virus (HIV) infection in the United States has traditionally relied on a sequential two-test algorithm: an initial screen with an enzyme immunoassay (EIA) and reflex testing of EIA-reactive specimens with a more specific supplemental test such as Western blotting or immunofluorescence. The supplemental tests are tedious, subjective, and expensive. In addition, there have been major improvements in the performance and accuracy of the EIA tests as well as the introduction of rapid serologic tests (RT) and HIV nucleic acid amplification tests (NAAT). Related to these improvements is the possibility that alternative algorithms using combinations of currently approved HIV tests may function as well as if not better than the current algorithm, with more flexibility, improved accuracy, and lower cost. To this end, we evaluated the performance of 12 currently licensed tests and 1 in-house HIV test (6 EIA, 4 RT, and 3 NAAT) on panels of plasma samples from HIV-infected (n = 621 HIV type 1 [HIV-1] and 34 HIV-2) and uninfected (n = 513) people and of sequential specimens from people early in seroconversion (183 specimens from 15 patients). Test combinations were analyzed in two dual-test (sensitivity-optimized and specificity-optimized) algorithms and in a three-test (tie-breaking) algorithm, and performance was compared to the conventional algorithm. The results indicate that alternative algorithm strategies with currently licensed tests compare favorably with the conventional algorithm in detecting and confirming established HIV infection. Furthermore, there was a lower frequency of discordant or indeterminate results that require follow-up testing, and there was improved detection of early infection.

New multiple antigenic peptide-based enzyme immunoassay for detection of simian immunodeficiency virus infection in nonhuman primates and humans.

Infections with human immunodeficiency virus types 1 and 2 (HIV-1 and HIV-2, respectively) are zoonotic infections. In Africa, the potential exists for additional cross-species transmissions from at least 33 different species of simian immunodeficiency virus (SIV)-infected nonhuman primates (NHPs) through hunting and butchering of these animals for food. Here we describe a highly sensitive and specific enzyme immunoassay (EIA) with chemically modified, multiple antigenic peptides (MAPs) developed for the detection and discrimination of antibodies to SIV genetic lineages. The SIV EIA was developed by using a comprehensive array of MAPs covering two envelope gene regions from all of the SIV lineages for which env sequences were available. Assay sensitivity was evaluated by using 63 plasma or serum samples obtained from primates naturally or experimentally infected with SIVs from 10 genetic lineages. Assay specificity was determined by using 97 known SIV-negative plasma specimens from these same species. Also used in the evaluations were 369 human samples: 198 HIV seronegative, 170 HIV-1 and/or HIV-2 seropositive, and 1 from a human SIVsm infection. Overall assay sensitivity and specificity were 100% with both immunodominant region (IDR) and V3 region MAPs. Although SIV env sequences from talapoin monkeys were not available for specific MAP inclusion, 5 (100%) of 5 SIVtal-infected samples were detected through cross-reactivity with other SIV IDR MAPs used in the assay. The one human SIVsm infection was identified. In conclusion, our SIV MAP EIA proved to be highly sensitive and specific for detecting SIV infections in NHPs and humans. As shown with SIV-infected talapoin monkeys, this assay has the potential to detect previously unidentified SIV strains and should be suitable for sentinel surveillance for potential new cross-species transmissions of SIVs to humans.

Comparing tandem repeats and multiple antigenic peptides as the antigens to detect antibodies by enzyme immunoassay.

Short synthetic peptides are useful alternatives to whole lysate or recombinant proteins as the antigens used for serodiagnosis of bacterial or viral infections. However, certain known antigenic peptides displayed low seroreactivities in direct enzyme immunoassay. This was believed to be due to the low coating efficiency, a constrained orientation, or loss of flexibility required for optimal antibody binding. Using a model peptide system derived from the V3-loop of HIV-1 gp120, we demonstrated that low antigenicity could be overcome by using either tandem repeats (TR) or multiple antigenic peptides (MAPs) which contained the same amino acid sequence as the monomeric peptide. In our model system, a four-branch MAP was a better choice compared to the tandem repeats because of the MAP's slightly higher sensitivity and lower cost of production.

Assessment of antibody assays for identifying and distinguishing recent from long-term HIV type 1 infection.

We evaluated 16 antibody assays for their performance in discriminating recent from established HIV-1 infection. These approaches were based on antigen specificity, quantity, conformation dependence, and avidity/affinity of HIV-specific antibodies. A panel of 41 sera from subjects who had seroconverted in the previous 2-6 months (n = 20) and from subjects with established infection (>1 year, n = 21) were run in each assay. Compared with anti-Gag and anti-Pol responses, quantitative anti-Env antibody levels were initially lower and ultimately higher, resulting in the greatest spread and least overlap between incident and established infection. Quantitative measurement included end-point titer in Western blot, end-point titer or response at a given dilution in solid-phase enzyme immunoassays (EIAs) with recombinant proteins or synthetic peptides, and IgG capture assays that reflect the relative proportion of IgG that is anti-HIV antibody. Focusing on the anti-env response, we measured specific responses to the V3 region of gp120, to the CD4-binding site of gp120, to a peptide corresponding to the immunodominant region of gp41, and to conformation-dependent epitopes of gp120. We also measured antibody affinity for gp41 peptide and the relative avidity for gp120 or gp41 peptide by thermal or urea-elution assays. These assays also discriminated recent from established infection but were not necessarily superior to the quantitative anti-Env assays. Appropriate approaches, based on distinct principles or combination of principles, can be used to develop simple assays for identifying individuals recently infected with HIV-1.

Comparison of serologic assays and PCR for diagnosis of human herpesvirus 8 infection.

A variety of assays for the diagnosis human herpesvirus 8 (HHV-8) infection have been reported. We compared several such assays with a panel of 88 specimens from human immunodeficiency virus (HIV)-infected patients with Kaposi's sarcoma (KS) (current-KS patients; n = 30), HIV-infected patients who later developed KS (later-KS patients; n = 13), HIV-infected patients without KS (no-KS patients; n = 25), and healthy blood donors (n = 20). PCR assays were also performed with purified peripheral blood mononuclear cells (PBMCs) to confirm positive serologic test results. The order of sensitivity of the serologic assays (most to least) in detecting HHV-8 infection in current-KS patients was the mouse monoclonal antibody-enhanced immunofluorescence assay (MIFA) for lytic antigen (97%), the orfK8.1 peptide enzyme immunoassay (EIA) (87%), the orf65 peptide EIA (87%), MIFA for latent antigen (83%), the Advanced Biotechnologies, Inc., EIA (80%), and the orf65 immunoblot assay (80%). Combination of the results of the two peptide EIAs (combined peptide EIAs) increased the sensitivity to 93%. For detection of infection in later-KS patients, the MIFA for lytic antigen (100%), the orfK8.1 peptide EIA (85%), and combined peptide EIAs (92%) were the most sensitive. Smaller percentages of no-KS patients were found to be positive (16 to 56%). Most positive specimens from the current-KS and later-KS groups were positive by multiple assays, while positive specimens from the no-KS group tended to be positive only by a single assay. PCR with PBMCs for portions of the HHV-8 orf65 and gB genes were positive for less than half of current-KS and later-KS patients and even fewer of the no-KS patients. The concordance between serologic assays was high. We propose screening by the combined peptide EIAs. For specimens that test weakly positive, we recommend that MIFA for lytic antigen be done. A positive result with a titer of >/=1:40 would be called HHV-8 positive. A negative or low titer would be called HHV-8 negative. If a population has a high percentage of persons who test positive by the combined peptide EIAs, then a MIFA could be performed with the negative specimens to determine if any positive specimens are being missed. Alternatively, if a population has a low percentage that test positive, then a MIFA could be performed with a subset of the negative specimens for the same reason. As described above, only a titer of >/=1:40 would be considered HHV-8 positive.

New immunofluorescence assays for detection of Human herpesvirus 8-specific antibodies.

Several assays have been developed for detection of immunoglobulin G antibodies to Human herpesvirus 8 (HHV-8), including immunofluorescence assays (IFAs) and enzyme-linked immunosorbent assays (ELISAs). However, the specificity and sensitivity of these assays are not completely defined due to the lack of a "gold standard." Although IFAs based on primary effusion lymphoma (PEL) cell lines are used widely, the assays can be confounded by nonspecific reactions against cellular components and potential cross-reaction with antibodies against other herpesviruses. To provide more reliable IFAs, we established recombinant Semliki Forest viruses (rSFVs) expressing the HHV-8-specific proteins ORF73 and K8.1 and used BHK-21 cells infected with these rSFVs for IFA (ORF73-IFA and K8.1-IFA). Expression of the HHV-8-specific proteins at very high levels by the rSFV system allowed easy scoring for IFA and thereby increased specificity. The rSFV system also allowed detection of antibodies against glycosylation-dependent epitopes of K8.1. Titers measured by rSFV-based IFAs and PEL-based IFAs correlated well (correlation coefficients of >0.9), and concordances of seroreactivities between rSFV-based and PEL-based IFAs were >97% (kappa > 0.93). K8.1-IFA was more sensitive than either ORF73-IFA or peptide ELISAs. Using PEL-based lytic IFA as a reference assay, the sensitivity and specificity of K8.1-IFA were estimated to be 94 and 100%, respectively. HHV-8 prevalences determined by K8.1-IFA among the human immunodeficiency virus (HIV)-positive (HIV(+)) Kaposi's sarcoma (KS) patients, HIV(+) KS(-) patients, and healthy controls were 100, 65, and 6.7%, respectively, which were consistent with prior reports. Therefore, our rSFV-based IFAs may provide a specific and sensitive method for use in epidemiology studies. In addition, they will provide a basis for further development of diagnostic tests for HHV-8 infection.

Glycoprotein B of human herpesvirus 8 is a component of the virion in a cleaved form composed of amino- and carboxyl-terminal fragments.

Human herpesvirus 8 (HHV-8) or Kaposi's sarcoma-associated herpesvirus (KSHV) is the only known human member of the Rhadinovirus genus of the gammaherpesvirus subfamily. Antibodies against peptides representing portions of the amino- and carboxyl-termini of HHV-8 gB were produced and used to detect gB expression in Vero cells transfected with the gB gene, in the HHV-8-harboring cell line, BCBL-1, and in purified virions. Expression of gB was detected in approximately 3% of uninduced BCBL-1 cells, while up to 30% of the cells expressed gB after 12-O-tetradecanoylphorbol-13-acetate (TPA) induction of virus replication. Indirect immunofluorescence assays and confocal microscopy showed that gB was distributed throughout the cytoplasm of BCBL-1 cells and transfected Vero cells. Immunoblot analyses of virion preparations revealed the presence of full-length as well as two smaller than full-length gB-derived species corresponding to the amino- and carboxy-terminal portions of gB, respectively. Biochemical analysis of the gB carbohydrate moieties using glycosylation inhibitors revealed that gB contained N-linked oligosaccharides of the high-mannose type, characteristic of precursor carbohydrate chains added in the endoplasmic reticulum.

Mapping and serodiagnostic application of a dominant epitope within the human herpesvirus 8 ORF 65-encoded protein.

A dominant epitope within the human herpesvirus 8 (HHV8) ORF 65-encoded protein was mapped to an 8-amino-acid (aa) sequence (RKPPSGKK [aa 162 to 169]) by an amino acid replacement method. Using a 14-aa peptide (P4) encompassing this epitope as the antigen, we developed an enzyme immunoassay for HHV8 antibodies. The presence of P4 antibodies in a panel of 61 human serum specimens was highly correlated with biopsy-confirmed Kaposi's sarcoma. The homologous Epstein-Barr virus peptide derived from BFBR3-encoded protein did not interfere with the assay, suggesting that P4 is specific for HHV8.

Genetic variability of HIV type 1 in Honduras.

PIP: While Honduras is home to only 15% of Central America's population, it has 60% of the region's AIDS cases. There have been 4973 reported cases of full-blown AIDS in the country and the Health Ministry reports that more than 8000 Hondurans have been infected with HIV since the first Honduran case was diagnosed in 1985. 995 people with AIDS have since died. The authors conducted an investigation to determine which HIV-1 subtype is present in Honduras and the degree of genetic variation among HIV-1 strains by analyzing viral nucleotide sequences from the envelope region of HIV-1 isolates obtained from the two most affected regions of the country. They determined the predominant HIV-1 subtype among 27 HIV-1-infected patients attending sexually transmitted disease clinics in San Pedro Sula and Tegucigalpa by sequencing and analyzing the C2V3 regions of the envelope glycoprotein gp 120. Genomic DNA was isolated from patients' peripheral blood mononuclear cells. Phylogenetic analysis determined that all 27 Honduran sequences clustered with known subtype B sequences.^ieng

Frequency of human immunodeficiency virus (HIV) infection among contemporary anti-HIV-1 and anti-HIV-1/2 supplemental test-indeterminate blood donors. The Retrovirus Epidemiology Donor Study.

BACKGROUND: Follow-up studies from the mid-1980s showed that 1 to 5 percent of blood donors testing reactive in anti-human immunodeficiency virus type 1 (HIV-1) enzyme immunoassay (EIA) and testing indeterminate in Western blot were infected with HIV-1 and were in the process of seroconverting. The present study was conducted to establish the rate of HIV infection among contemporary anti-HIV-1/HIV type 2 (HIV-2) EIA-reactive, Western blot-indeterminate donors. STUDY DESIGN AND METHODS: Donations (n = 607) with indeterminate HIV supplemental test results were identified by screening 3,021,342 donations given from November 1990 through August 1993 at five participating blood centers. Consenting donors were enrolled and samples taken 4 to 8 weeks after donation. Follow-up sera were tested by EIA and Western blot for anti-HIV-1 seroconversion and by type-specific peptide assays for antibodies to HIV-2 and HIV-1 subtype O. Peripheral blood mononuclear cells and/or plasma from the follow-up samples were tested for HIV-1 DNA and/or RNA by polymerase chain reaction. The rate of HIV-1 infection among Western blot-indeterminate donors was also estimated by multiplying the incidence rate of HIV-1 seroconversion in this donor population by the estimated duration of the EIA-reactive and Western blot-indeterminate window during seroconversion (8.5 days). RESULTS: Supplemental test-indeterminate donors (n = 355) enrolled a median of 38 days after donation; 265 (75%) of these donors were identified as indeterminate after an anti-HIV-1/2 EIA-reactive donation. Enrolled and non-enrolled donors had similar distributions of demographic characteristics and band patterns. Follow-up samples from all 355 donors tested negative for HIV-1 in polymerase chain reaction. Follow-up sera tested Western blot-negative in 54 cases (15%) and Western blot-indeterminate in 299 (84%). Two follow-up sera (0.6%) were interpreted, according to manufacturer's package insert criteria, as Western blot positive with p24 and gp41 bands and/or gp120/160 bands; however, paired testing of index and follow-up sera from these two cases showed identical Western blot and EIA reactivity, and polymerase chain reaction was negative for HIV RNA and DNA, which ruled out HIV infection. The absence of HIV infection in 355 Western blot-indeterminate donors was consistent with our incidence-based model analysis, which yielded an estimate of one HIV-1 infection for every 215 Western blot-indeterminate donations (95% CI, 1/39-1/8333). CONCLUSION: Contemporary blood donors classified as indeterminate in supplemental HIV testing are infrequently infected with HIV. Donors whose follow-up samples test negative in anti-HIV-1/2 EIAs and negative or persistently indeterminate in Western blots should be considered eligible for reinstatement.

Human immunodeficiency virus (HIV) antigens: structure and serology of multivalent human mucin MUC1-HIV V3 chimeric proteins.

Molecular modeling and two-dimensional NMR techniques enable us to identify structural features in the third variable region (V3) loop of the human immunodeficiency virus (HIV) surface glycoprotein gp120, in particular the principal neutralizing determinant (PND), that remain conserved despite the sequence variation. The conserved structure of the PND is a solvent-accessible protruding motif or a knob, structurally isomorphous with the immunodominant knobs in the tandem repeat protein of human mucin 1 (MUC1) (a tumor antigen for breast, pancreatic, and ovarian cancer). We have replaced the mucin antigenic knobs by the PND knobs of the HIV MN isolate in a set of chimeric human MUC1/HIV V3 antigens. This produced multivalent HIV antigens in which PNDs are located at regular intervals and separated by extended mucin spacers. In this article we show by two-dimensional NMR spectroscopy that the multivalent antigens preserve the PNDs in their native structure. We also demonstrate by ELISA that the antigens correctly present the PNDs for binding to monoclonal antibodies or polyclonal antisera from HIV-infected patients.

Sensitivity of United States HIV antibody tests for detection of HIV-1 group O infections.

Infections by highly divergent strains of HIV-1, first detected in central Africa and grouped provisionally as group O, have not been reliably detected by certain European HIV screening tests. Serum specimens from eight probable group O infections from Cameroon were tested by ten HIV assays licensed by the US Food and Drug Administration. All assays based on synthetic peptides or recombinant antigens failed to detect at least one of the infections; assays based on whole-virus lysates performed better. Divergent HIV strains may be undetected by current HIV tests. Thus active surveillance for and characterisation of HIV variants to evaluate and, when necessary, modify current tests is urgently needed.

Antigenic variation and serotyping of HIV type 1 from four World Health Organization-sponsored HIV vaccine sites. WHO Network for HIV Isolation and Characterization.

Serologic reactivities of serum or plasma from 55 HIV-1 subjects in four countries--Brazil, Rwanda, Thailand, and Uganda--were examined by V3 peptide immunoassay. Forty-seven (85.5%) of the 55 specimens tested positive to the homologous peptide. A strong correlation between serotype (i.e., pattern of serologic reactivity with a panel of peptides) and genotype was not found. However, the V3 peptide immunoassays may be useful for epidemiologic studies to trace the distinctive HIV-1 strains from different geographic regions of the world. The serology data obtained may be useful for the development of effective V3-based vaccines.

Highly specific V3 peptide enzyme immunoassay for serotyping HIV-1 specimens from Thailand.

OBJECTIVE: To develop and evaluate a simple V3 peptide-based enzyme immunoassay (EIA) for large-scale serotyping of HIV-1 specimens from Thailand. DESIGN: Serologic reactivities with synthetic peptides derived from the V3 loop of gp120 were used for typing HIV-1 specimens. METHODS: Synthetic peptides PND-A and PND-B, derived from the consensus amino-acid sequences of the V3 loop of gp120 from two major genomic variants of HIV-1 in Thailand (A and B), were evaluated in an EIA on 61 Thai HIV-1 sera for which genotypes had been determined by polymerase chain reaction. The peptide EIA was then applied to sera from 188 HIV-1-infected patients, selected in non-random, convenience samples of known risk groups from four geographic regions of Thailand. RESULTS: The sensitivities and specificities of PND-A and PND-B were 86% (30 out of 35) and 96% (25 out of 26) and 92% (24 out of 26) and 94% (33 out of 35), respectively, with 100% predictive values of a monoreactive positive test for both peptides. The assay classified 101 specimens as serotype A, 39 as serotype B, eight as serotype AB (dually reactive), and 40 as untypable (non-reactive). Excluding dual reactors and non-reactors, 92% (77 out of 84) of specimens from patients probably infected by sexual contact were serotype A; conversely, 76% (28 out of 37) of injecting drug users were serotype B. CONCLUSION: The serologic results corroborated previous findings, in a smaller subset of samples, of an apparent segregation of viral subtypes by mode of transmission, suggesting two separate HIV-1 epidemics in Thailand. This peptide EIA could be a valuable epidemiologic tool in determining the dynamics of the rapid spread of HIV-1 in Thailand.

PIP: A simple synthetic enzyme immunoassay (EIA) for serotyping HIV-1 specimens from Thailand, based on gp120 V3 loop peptide, was developed and tested on 188 sera from 4 regions of the country. There are 2 major known gene variants of HIV-1 in Thailand designated genotype A and B. The peptide EIA was tested on 61 sera that had been characterized by polymerase chain reaction and DNA sequencing. The EIA was then tested on 188 sera from high risk groups collected in the northern, northeastern, central and southern regions in mid-1991. The PND-A assay was 86% sensitive and 96% specific; the PND-B assay was 96% sensitive and 92% specific. The EIAs showed 100% predictive values when sera known to be reactive to only HIV A or B were tested. In the series there were also 8 sera reactive to both A and B and 40 not reactive to either variant. Excluding dual and non-reactors, 92% of patients with sexual high risk factors had HIV-1 type A and 76% of those with IV drug use history had type B. The results suggest that 2 HIV-1 epidemics have occurred in Thailand, an initial wave in 1988 among IV drug users and a later wave centered among prostitutes and their clients.

Evaluation of testing algorithms following the use of combination HIV-1/HIV-2 EIA for screening purposes.

The licensure of combination human immunodeficiency virus type 1 and type 2 (HIV-1/HIV-2) enzyme immunoassays (EIAs) by the Food and Drug Administration has been accompanied by a recommendation that U.S. blood banks begin testing the nation's blood supply for HIV-2 by June 1, 1992. The performance of a recently licensed combination HIV-1/HIV-2 EIA (Genetic Systems) was evaluated using 3100 sera collected in the United States. A total of 2,049 sera were obtained from populations with low risk for HIV infections, and 1,051 sera from populations with high-risk behaviors. The combination EIA, in comparison with monospecific EIA, was found to be 100% sensitive for HIV-1 for both populations. The high-risk population had an HIV-1 seroprevalence rate of 17.4%, with a positive predictive value (PPV) of 97.3%. The low-risk population had an HIV-1 seroprevalence of 0.05% with a PPV of 8%. The incorporation of the combination EIA in various testing algorithms was also evaluated, and recommendations are given with consideration for the type of screening and populations involved.