Serum beta 2-microglobulin and C reactive protein concentrations in viral infections

Serum beta2-microglobulin and peripheral blood eosinophils for the assessment of severity and prognosis with omicron variant COVID-19 infection

Background

The Omicron variant's high transmissibility has made it the most widespread novel coronavirus variant. Elevated serum β2-MG levels from viral infections and EOS' role in viral clearance have garnered attention. However, their predictive value for Omicron's severity and prognosis needs further exploration.

Methods

This retrospective study included 424 patients with confirmed COVID-19 Omicron variant admitted to the Second Hospital of Jilin University in Changchun, China, of whom 128 experienced in-hospital mortality. Patients were divided into high and low groups according to β2-MG and EOS levels; the relationship between disease severity and patient prognosis was analyzed.

Results

Our findings showed that severe-to-critical Omicron patients had higher β2-MG levels than mild-normal patients. Conversely, EOS levels were higher in mild-moderate cases. Both β2-MG and EOS levels normalized when Omicron patients tested negative for nucleic acid. Deceased Omicron patients had significantly lower pre-mortem EOS levels. Elevated β2-MG and lower EOS levels correlated with reduced overall survival. Multivariate COX regression analysis indicated that elevated β2-MG was an independent adverse prognostic factor for Omicron patients.

Conclusion

High serum β2-MG levels and low eosinophil levels upon admission correlate with omicron variant severity and prognosis. β2-MG is an independent risk factor for poor outcomes in omicron patients.

Transcriptome analysis revealed the new mechanism of the intra-myocardial injectable alginate-hydrogel in the treatment of ventricular function degradation

Background

Myocardial infarction (MI) is one of the most lethal cardiovascular diseases. The loss of cardiomyocytes and the degradation of the extracellular matrix leads to high ventricular wall stress, which further drives the pathological thinning of the ventricular wall during MI. Injecting biomaterials to thicken the infarct ventricular wall provides mechanical support, thereby inhibiting the continued expansion of the heart. As an injectable biomaterial, alginate hydrogel has achieved exciting results in clinical trials, but further research needs to be conducted to determine whether it can improve cardiac function in addition to providing mechanical support. This study sought to explore these mechanisms in an animal model of MI.

Methods

A MI model was established in male C57BL/6J mice by ligation of the proximal left anterior descending (LAD) coronary artery. Intramyocardial injections (hydrogel or saline group) were performed in the proximal wall regions bordering the infarct area (with one 20-µL injection). Four weeks after MI, RNA sequencing revealed that 342 messenger RNAs (mRNAs) from the infarcted hearts were differentially expressed between the saline group and hydrogel group. We subsequently conducted a Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis to analyze the RNA sequencing data. In addition, we employed both western blotting and quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) techniques to verify a number of genes that were differentially expressed and could potentially affect cardiac function after MI. Subsequently, we confirmed these findings through in vitro experiments.

Results

We found that compared with hydrogel treatment group, 250 mRNAs were upregulated and 92 mRNAs were downregulated in saline group (P<0.05). And by exploring the GO and KEGG signaling pathways as well as the protein-protein interaction (PPI) network, we found that administration of alginate hydrogel modulated cardiomyocyte inflammation-associated proteins as well as chemokine-related proteins during the inflammatory response phase after MI. In addition, our analysis at both the protein and RNA level revealed that B2M was effective in improving cardiac function after MI in the hydrogel treatment group, which was consistent in the myocardium oxygen and glucose deprivation (OGD) injury model.

Conclusions

We explored the transcriptome changes of infarcted hearts after alginate-hydrogel injection during the inflammatory response period. Our findings suggest that the injectable hydrogel directly alters the inflammatory response and the chemokine-mediated signaling pathway of cardiomyocytes, ultimately improving cardiac function.

Early cellular and molecular signatures correlate with severity of West Nile virus infection

Infection with West Nile virus (WNV) drives a wide range of responses, from asymptomatic to flu-like symptoms/fever or severe cases of encephalitis and death. To identify cellular and molecular signatures distinguishing WNV severity, we employed systems profiling of peripheral blood from asymptomatic and severely ill individuals infected with WNV. We interrogated immune responses longitudinally from acute infection through convalescence employing single-cell protein and transcriptional profiling complemented with matched serum proteomics and metabolomics as well as multi-omics analysis. At the acute time point, we detected both elevation of pro-inflammatory markers in innate immune cell types and reduction of regulatory T cell activity in participants with severe infection, whereas asymptomatic donors had higher expression of genes associated with anti-inflammatory CD16+ monocytes. Therefore, we demonstrated the potential of systems immunology using multiple cell-type and cell-state-specific analyses to identify correlates of infection severity and host cellular activity contributing to an effective anti-viral response.

Elevated serum beta-2 microglobulin level predicts short-term poor prognosis of patients with de novo acute omicron variant COVID-19 infection

Background

The devastating coronavirus disease of 2019 (COVID-2019) epidemic has been declared a public health emergency, resulting in a worldwide pandemic. The omicron variety is the most common epidemic mutant strain in the globe. Serum beta-2 microglobulin (β2-MG) is associated with endothelial cell injury and has value in monitoring the progression of inflammation in infected individuals. Nonetheless, the potential functions of β2-MG in omicron remain elusive.

Methods

To investigate the prognostic value of serum β2-MG levels at diagnosis, we retrospectively analyzed a cohort of 240 people with omicron. Over the course of 65 days, all patients were monitored, and death was the primary outcome. Patients were allocated to two groups: those with high and low β2-MG levels. The Kaplan-Meier method was used to examine OS, and the log-rank test was used to compare them. Univariate and multivariate Cox hazard models were used to determine the prognostic significance.

Results

Our results revealed that β2-MG was significantly elevated in omicron. β2-MG levels in severe patients were higher than in mild-to-moderate patients, and the difference was statistically significant. Timely, interleukin-6 (IL-6) and interleukin-10 (IL-10) were observed to be significantly increased in individuals exhibiting elevated levels of β2-MG. In addition, patients exhibiting elevated levels of β2-MG demonstrated a statistically significant decrease in overall survival (OS, P < 0.0001). An elevated β2-MG level (≥4.72 mg/l) was found to be an independent, adverse prognostic factor for OS in omicron patients, according to multivariate Cox proportional hazards regression analysis (P = 0.001).

Conclusion

Serum β2-MG level at initial diagnosis was significantly correlated with omicron severity and prognosis. Thus, we propose that β2-MG may be an independent poor additional prognostic factor in patients with omicron.

Association of beta-2-microglobulin with cardiovascular and all-cause mortality in the general and non-CKD population

β-2 microglobulin, a light chain in the major histocompatibility complex Class 1 molecule, is associated with mortality in dialysis or uremic patients. Current evidence on the relationship between beta-2-microglobulin (B2M) and mortality in the general and non-chronic kidney disease (CKD) population are limited and controversial. Data from the nutrition and health examination survey database and the nutrition and health examination survey linked mortality file were used. In total, 10,388 adults who had complete data for B2M were included. Weighted multivariable Cox proportional hazards regression models and regression splines were employed to evaluate the relationship between B2M with mortality. Moreover, subgroup and sensitivity analyses were performed. During a median follow up of 17.9 years (interquartile range 15.2-18.7), 2780 people died, 902 (32%) from cardiovascular disease. Restricted cubic splines showed that B2M is J-shaped nonlinear positively associated with all-cause mortality and cardiovascular disease mortality in the non-CKD and general population. Based on the multivariable adjustment model, the adjusted hazard ratios comparing the highest versus lowest quartile of the distribution of B2M were 2.50 (95% confidence interval: 1.90, 3.28) for all-cause mortality in the general population, 2.58 (95% confidence interval: 1.52, 4.37) for cardiovascular disease mortality in the general population, 2.58 (1.91, 3.49) for all-cause mortality in the non-CKD population and 2.62 (1.52, 4.53) for cardiovascular disease mortality in the non-CKD population. The positive associations between B2M and outcomes remained broadly significant across subgroups and sensitivity analyses. Higher B2M levels were associated with cardiovascular and all-cause mortality in the general and non-CKD population.

Association of Beta-2 Microglobulin with Stroke and All-Cause Mortality in Adults Aged ≥40 in U.S.: NHANES III

Background

Stroke is the predominant cause of death worldwide. We aimed to investigate the association of serum beta-2 microglobulin ( β 2M) concentrations with risk of stroke and all-cause mortalities in a cohort study.

Methods

Overall, 4914 U.S. adults (mean age = 63.0 years, 44.3% male) were recruited from the National Health and Nutrition Examination Survey (NHANES Ⅲ). During a median follow-up of 19.4 years, 254 stroke deaths and 3415 all-cause deaths were identified by the National Center for Health Statistics. The associations of β 2M with stroke and all-cause mortalities were investigated by using weighted Cox proportional hazard regression models.

Results

β 2M was positively associated with stroke and all-cause mortality in unadjusted models and multivariable-adjusted models. The multivariable HR (95% CI) for stroke mortality in Q5 VS Q1 of serum β 2M concentrations was 3.45 (1.33-8.91; p for trend = 0.001) and that for all-cause mortality was 3.95 (3.05-5.12; p for trend < 0.001). In subgroup analyses, the association of β 2M and stroke mortality did not vary by different levels of sociodemographic and general stroke risk factors (p interaction > 0.05). In addition, the magnitude of positive association between β 2M with all-cause mortality did vary by age, ratio of family income to poverty, smoking status, and history of hypertensive (p interaction < 0.05).

Conclusions

Our findings suggest that support that β 2M may be a marker of stroke and all-cause mortality, which provides a new perspective for the study of cerebrovascular health and long-term survival in the future.

Longitudinal serum proteomics analyses identify unique and overlapping host response pathways in Lyme disease and West Nile virus infection

Advancement in proteomics methods for interrogating biological samples has helped identify disease biomarkers for early diagnostics and unravel underlying molecular mechanisms of disease. Herein, we examined the serum proteomes of 23 study participants presenting with one of two common arthropod-borne infections: Lyme disease (LD), an extracellular bacterial infection or West Nile virus infection (WNV), an intracellular viral infection. The LC/MS based serum proteomes of samples collected at the time of diagnosis and during convalescence were assessed using a depletion-based high-throughput shotgun proteomics (dHSP) pipeline as well as a non-depleting blotting-based low-throughput platform (MStern). The LC/MS integrated analyses identified host proteome responses in the acute and recovery phases shared by LD and WNV infections, as well as differentially abundant proteins that were unique to each infection. Notably, we also detected proteins that distinguished localized from disseminated LD and asymptomatic from symptomatic WNV infection. The proteins detected in both diseases with the dHSP pipeline identified unique and overlapping proteins detected with the non-depleting MStern platform, supporting the utility of both detection methods. Machine learning confirmed the use of the serum proteome to distinguish the infection from healthy control sera but could not develop discriminatory models between LD and WNV at current sample numbers. Our study is the first to compare the serum proteomes in two arthropod-borne infections and highlights the similarities in host responses even though the pathogens and the vectors themselves are different.

Longitudinal Analysis of Biologic Correlates of COVID-19 Resolution: Case Report

While the biomarkers of COVID-19 severity have been thoroughly investigated, the key biological dynamics associated with COVID-19 resolution are still insufficiently understood. We report a case of full resolution of severe COVID-19 due to convalescent plasma transfusion. Following transfusion, the patient showed fever remission, improved respiratory status, and rapidly decreased viral burden in respiratory fluids and SARS-CoV-2 RNAemia. Longitudinal unbiased proteomic analysis of plasma and single-cell transcriptomics of peripheral blood cells conducted prior to and at multiple times after convalescent plasma transfusion identified the key biological processes associated with the transition from severe disease to disease-free state. These included (i) temporally ordered upward and downward changes in plasma proteins reestablishing homeostasis and (ii) post-transfusion disappearance of a subset of monocytes characterized by hyperactivated Interferon responses and decreased TNF-α signaling. Monitoring specific dysfunctional myeloid cell subsets in peripheral blood may provide prognostic keys in COVID-19.

Association of Beta-2-Microglobulin With Coronary Heart Disease and All-Cause Mortality in the United States General Population

Few prospective studies explored the association of beta-2-microglobulin (B2M) with coronary heart disease (CHD) mortality. The primary objective of this study was to examine the association of serum B2M with CHD and all-cause mortality. This is a prospective cohort study of a nationally representative sample of 4,885 adults, aged 40–85 years, who participated in the National Health and Nutrition Examination Survey (NHANES III) from 1988 to 1994. The relationships between B2M and CHD and all-cause mortality were estimated using Cox proportional hazards regression models. During a median follow-up of 15.5 years, 845 CHD and 3,388 all-cause deaths occurred among 4,885 participants [2,568 women (55.7%); mean (S.D.) age, 66.4 (12.5) years], respectively. In the unadjusted model, B2M concentration was strongly linearly associated with CHD and all-cause mortality (p-trend < 0.001). After adjusting multivariable factors, a positive linear association between B2M and all-cause mortality was still observed (H.R. for Q4 vs. Q1 5.90; 95% CI: 5.31–6.57; p-trend < 0.001). In the multivariable adjustment model, B2M was significantly associated with an increased risk of CHD mortality (H.R. for Q4 vs. Q1 2.72; 95% CI: 2.07–3.57; p-trend < 0.001). In the stratified analyses, the associations of B2M with CHD and all-cause mortality varied by risk factors, such as age, smoking status, and history of hypertension. The findings suggest a significant relationship between the higher serum B2M concentration and increased risk for CHD and all-cause mortality. Further large-scale follow-up studies are also needed to validate this association.

Differential Diagnosis of Histiocytic Necrotizing Lymphadenitis and Malignant Lymphoma with Simple Clinical Findings

It is desirable that noninvasive differential diagnosis takes place without lymph node biopsy for histiocytic necrotizing lymphadenitis (HNL) or malignant lymphoma (ML). In this study, we propose a novel scoring model for the differential diagnosis of these diseases using clinical information and clinical findings. We retrospectively analyzed the data from 15 HNL and 13 ML pediatric patients. First, a univariate analysis identified 14 clinical factors with significant differences. Second, a subsequent analysis using receiver operating characteristic (ROC) curve analysis identified three factors among them with area under the ROC curve values of >0.95: body temperature (°C), maximum lymph node size (cm), and serum β₂-microglobulin level (mg/L). Finally, the cut-off values of each of these three factors were determined and examined for the 28 cases. All 15 HNL cases were within 2–3 of the cut-off values among the three factors, no ML case was within two or more cut-off values. Thus, the diagnostic sensitivity and specificity of this novel scoring system were both 100%, indicating that clinical scoring with body temperature, maximum lymph node size, and β₂-microglobulin are useful for distinguishing between HNL and ML.

Biologic correlates of beneficial convalescent plasma therapy in a COVID-19 patient reveal disease resolution mechanisms

BACKGROUND

While the biomarkers of COVID-19 severity have been thoroughly investigated, the key biological dynamics associated with COVID-19 resolution are still insufficiently understood.

MAIN BODY

We report a case of full resolution of severe COVID-19 due to convalescent plasma transfusion in a patient with underlying multiple autoimmune syndrome. Following transfusion, the patient showed fever remission, improved respiratory status, and rapidly decreased viral burden in respiratory fluids and SARS-CoV-2 RNAemia. Longitudinal unbiased proteomic analysis of plasma and single-cell transcriptomics of peripheral blood cells conducted prior to and at multiple times after convalescent plasma transfusion identified the key biological processes associated with the transition from severe disease to disease-free state. These included (i) temporally ordered upward and downward changes in plasma proteins reestablishing homeostasis and (ii) post-transfusion disappearance of a particular subset of dysfunctional monocytes characterized by hyperactivated Interferon responses and decreased TNF-α signaling.

CONCLUSIONS

Monitoring specific subsets of innate immune cells in peripheral blood may provide prognostic keys in severe COVID-19. Moreover, understanding disease resolution at the molecular and cellular level should contribute to identify targets of therapeutic interventions against severe COVID-19.

Alveolar-like Macrophages Attenuate Respiratory Syncytial Virus Infection

Respiratory Syncytial Virus (RSV) is the leading cause of acute lower respiratory infections in young children and infection has been linked to the development of persistent lung disease in the form of wheezing and asthma. Despite substantial research efforts, there are no RSV vaccines currently available and an effective monoclonal antibody targeting the RSV fusion protein (palivizumab) is of limited general use given the associated expense. Therefore, the development of novel approaches to prevent RSV infection is highly desirable to improve pediatric health globally. We have developed a method to generate alveolar-like macrophages (ALMs) from pluripotent stem cells. These ALMs have shown potential to promote airway innate immunity and tissue repair and so we hypothesized that ALMs could be used as a strategy to prevent RSV infection. Here, we demonstrate that ALMs are not productively infected by RSV and prevent the infection of epithelial cells. Prevention of epithelial infection was mediated by two different mechanisms: phagocytosis of RSV particles and release of an antiviral soluble factor different from type I interferon. Furthermore, intratracheal administration of ALMs protected mice from subsequent virus-induced weight loss and decreased lung viral titres and inflammation, indicating that ALMs can impair the pathogenesis of RSV infection. Our results support a prophylactic role for ALMs in the setting of RSV infection and warrant further studies on stem cell-derived ALMs as a novel cell-based therapy for pulmonary viral infections.

Serum β2-microglobulin levels in Coronavirus disease 2019 (Covid-19): Another prognosticator of disease severity?

β2-microglobulin (β2-m), a 11.8 kDa protein, pairs non-covalently with the α3 domain of the major histocompatibility class (MHC) I α-chain and is essential for the conformation of the MHC class I protein complex. Shed β2-m is measurable in circulation, and various disorders are accompanied by increases in β2-m levels, including several viral infections. Therefore, we explored whether β2-m levels could also be elevated in Coronavirus disease 2019 (Covid-19) and whether they predict disease severity. Serum β2-m levels were measured in a cohort of 34 patients infected with SARS-CoV-2 on admission to a tertiary care hospital in Riyadh, Saudi Arabia, as well as in an approximately age-sex matched group of 34 uninfected controls. Mean β2-m level was 3.25±1.68 mg/l (reference range 0.8-2.2 mg/l) in patients (mean age 48.2±21.6) and 1.98±0.61 mg/l in controls (mean age 48.2±21.6). 17 patients (mean age 36.9± 18.0) with mean β2-m levels of 2.27±0.64 mg/l had mild disease by WHO severity categorization, 12 patients (mean age 53.3±18.1) with mean β2-m levels of 3.57±1.39 mg/l had moderate disease, and five patients (of whom 2 died; mean age 74.4±13.8) with mean β2-m levels of 5.85±1.85 mg/l had severe disease (P < = 0.001, by ANOVA test for linear trend). In multivariate ordinal regression β2-m levels were the only significant predictor of disease severity. Our findings suggest that higher β2-m levels could be an early indicator of severity of disease and predict outcome of Covid-19. As the main limitations of the study are a single-center study, sample size and ethnicity, these results need confirmation in larger cohorts outside the Arabian Peninsula in order to delineate the value of β2-m measurements. The role of β2-m in the etiology and pathogenesis of severe Covid-19 remains to be elucidated.

Association of beta-2-microglobulin and cardiovascular events and mortality: A systematic review and meta-analysis

Background and aims

Beta-2-microglobulin (B2M) has been suggested as an emerging biomarker for cardiovascular diseases (CVD), including coronary heart disease (CHD) and stroke, and mortality.

Methods

Three databases were searched from inception to January 2, 2020, supplemented by scanning reference lists of identified studies. We identified studies that reported associations of baseline serum or plasma B2M and CVD incidence, CVD mortality, or CHD and stroke separately, in either general populations or patients with renal disease. Relative risks (RR) were extracted and harmonized to a comparison of the highest versus lowest third of the distribution of B2M, and the results were aggregated.

Results

Sixteen studies (5 in general populations, and 11 in renal disease populations) were included, involving 30,988 participants and 5391 CVD events. Based on random-effects meta-analysis, the pooled adjusted RRs comparing the highest versus lowest third of the distribution of B2M were 1.71 (95%CI: 1.37–2.13) for CVD, 2.29 (1.51–3.49) for CVD mortality, 1.64 (1.14–2.34) for CHD, and 1.51 (1.28–1.78) for stroke, with little to high heterogeneity between studies (0.0% ≤ I² ≤ 80.0%). The positive associations between B2M and risks of CVD outcomes remained broadly significant across subgroup analyses. Moreover, the pooled adjusted RRs were 2.51 (1.94–3.26; I² = 83.7%) for all-cause mortality and 2.64 (1.34–5.23; I² = 83.1%) for infectious mortality.

Conclusions

Available observational data show that there are moderate positive associations between B2M levels and CVD events and mortality, although few studies have been conducted in general populations.

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Available epidemiological evidence shows that circulating B2M levels are moderately associated with CVD events and mortality.

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Future large-scale general population-based prospective studies and genetic studies are needed to assess the causality.

Characterization of a novel STAT 2 knock-out hamster model of Crimean-Congo hemorrhagic fever virus pathogenesis

Crimean-Congo hemorrhagic fever virus (CCHFV) is a tick-borne pathogen causing a febrile illness in humans, which can progress to hemorrhagic manifestations, multi-organ failure, and death. Current mouse models of CCHFV infection reliably succumb to virus challenge but vary in their ability to reflect signs of disease similar to humans. In this study, we established a signal transducer and activator of transcription 2 (STAT2) knockout hamster model to expand the repertoire of animal models of CCHFV pathogenesis that can be used for therapeutic development. These hamsters demonstrated a systemic and lethal disease in response to infection. Hallmarks of human disease were observed including petechial rash, blood coagulation dysfunction, and various biochemistry and blood cell count abnormalities. Furthermore, we also demonstrated the utility of this model for anti-CCHFV therapeutic evaluation. The STAT2 knock-out hamster model of CCHFV infection may provide some further insights into clinical disease, viral pathogenesis, and pave the way for testing of potential drug and vaccine candidates.

β 2-Microglobulin and Neutrophil Gelatinase-Associated Lipocalin, Potential Novel Urine Biomarkers in Periodontitis: A Cross-Sectional Study in Japanese

Objectives

Several serum biomarkers have been reported to increase in periodontitis patients as possible mediators linking periodontal inflammation to systemic diseases. However, the relationship between periodontitis and urine biomarkers is still unclear. The aim of this cross-sectional study was to investigate potential urine biomarkers of periodontitis in a Japanese population.

Materials and Methods

This study included 108 male subjects, and microbiological and clinical parameters were evaluated as a periodontitis marker. The correlation between nine urine biomarkers (typically used to diagnose kidney disease) and periodontal parameters was analyzed. Based on the findings, β₂-microglobulin (β₂-MG) and neutrophil gelatinase-associated lipocalin (NGAL) were selected for comparison and multivariate regression analysis, and the Kruskal–Wallis test followed by Bonferroni correction was used to identify differences in their concentrations between the three periodontitis groups (severe, moderate, and no/mild periodontitis).

Results

β₂-MG and NGAL exhibited a significant correlation with clinical parameters of periodontitis. The prevalence of clinical parameters such as bleeding on probing and number of sites with probing depth (PD) ≥ 6 mm were greater in the β₂-MG high group (≥300 μg/g creatinine) than in the normal group (P=0.017 and 0.019, respectively). Multivariate regression analysis indicated that the number of sites with PD ≥ 6 mm was independently associated with urine β₂-MG. Moreover, the number of sites with the clinical attachment level (CAL) ≥ 6 mm was greater in the NGAL high group (highest quartile) (P=0.041). Multivariate regression analysis showed that the number of sites with CAL ≥ 6 mm was associated independently with urine NGAL. Finally, β₂-MG was significantly higher in the severe periodontitis subjects compared to the no/mild periodontitis subjects.

Conclusion

The significant association between urine β₂-MG or NGAL and periodontitis was revealed. These biomarkers can potentially be used to screen for or diagnose periodontitis. This trial is registered with the UMIN Clinical Trials Registry UMIN000013485.

HIV-1-Associated Neurocognitive Disorders: Is HLA-C Binding Stability to β2-Microglobulin a Missing Piece of the Pathogenetic Puzzle?

AIDS dementia complex (ADC) and HIV-associated neurocognitive disorders (HAND) are complications of HIV-1 infection. Viral infections are risk factors for the development of neurodegenerative disorders. Aging is associated with low-grade inflammation in the brain, i.e., the inflammaging. The molecular mechanisms linking immunosenescence, inflammaging and the pathogenesis of neurodegenerative disorders, such as Alzheimer's disease (AD) and Parkinson's disease, are largely unknown. ADC and HAND share some pathological features with AD and may offer some hints on the relationship between viral infections, neuroinflammation, and neurodegeneration. β2-microglobulin (β2m) is an important pro-aging factor that interferes with neurogenesis and worsens cognitive functions. Several studies published in the 80-90s reported high levels of β2m in the cerebrospinal fluid of patients with ADC. High levels of β2m have also been detected in AD. Inflammatory diseases in elderly people are associated with polymorphisms of the MHC-I locus encoding HLA molecules that, by associating with β2m, contribute to cellular immunity. We recently reported that HLA-C, no longer associated with β2m, is incorporated into HIV-1 virions, determining an increase in viral infectivity. We also documented the presence of HLA-C variants more or less stably linked to β2m. These observations led us to hypothesize that some variants of HLA-C, in the presence of viral infections, could determine a greater release and accumulation of β2m, which in turn, may be involved in triggering and/or sustaining neuroinflammation. ADC is the most severe form of HAND. To explore the role of HLA-C in ADC pathogenesis, we analyzed the frequency of HLA-C variants with unstable binding to β2m in a group of patients with ADC. We found a higher frequency of unstable HLA-C alleles in ADC patients, and none of them was harboring stable HLA-C alleles in homozygosis. Our data suggest that the role of HLA-C variants in ADC/HAND pathogenesis deserves further studies. If confirmed in a larger number of samples, this finding may have practical implication for a personalized medicine approach and for developing new therapies to prevent HAND. The exploration of HLA-C variants as risk factors for AD and other neurodegenerative disorders may be a promising field of study.

Prospective association between β2-microglobulin levels and ischemic stroke risk among women

OBJECTIVE

To determine whether elevated β₂-microglobulin (B2M) levels were associated with an increased risk of incident ischemic stroke events among women.

METHODS

We performed a nested case-control study among women enrolled in the Nurses' Health Study who provided blood samples between 1989 and 1990 and were free of prior stroke and cancer. We measured B2M levels in 473 ischemic strokes cases confirmed by medical record review and in 473 controls matched 1:1 to the cases on age, race, date of blood collection, menopausal status, postmenopausal hormone use, and smoking status. We analyzed the association between B2M and ischemic stroke using multivariable conditional logistic regression to adjust for traditional stroke risk factors.

RESULTS

Median levels of B2M were higher among cases (1.86 mg/L) than controls (1.80 mg/L, p = 0.009, Wilcoxon rank-sum test). Women in the highest B2M quartile had a multivariable-adjusted increased risk of ischemic stroke compared to those in the lowest quartile (odds ratio [OR] 1.56, 95% confidence interval [CI] 1.02-2.39). Results were similar when restricted to those without evidence of chronic kidney disease (estimated glomerular filtration rate ≥60 mL·min^-1·1.73 m^-2) (OR 1.49, 95% CI 1.08-2.06). In an exploratory analysis, the association between B2M and thrombotic stroke was similar to the overall ischemic stroke results, but no association was observed for embolic stroke risk.

CONCLUSION

High levels of B2M were associated with an increased risk of ischemic stroke among women.

Extranodal induction of therapeutic immunity in the tumor microenvironment after intratumoral delivery of Tbet gene-modified dendritic cells

Murine dendritic cells (DC) transduced to express the Type-1 transactivator T-bet (i.e. mDC.Tbet) and delivered intratumorally as a therapy are superior to control wild-type DC in slowing the growth of established subcutaneous MCA205 sarcomas in vivo. Optimal antitumor efficacy of mDC.Tbet-based gene therapy was dependent on host natural killer (NK) cells and CD8(+) T cells, and required mDC.Tbet expression of major histocompatibility complex class I molecules, but was independent of the capacity of the injected mDC.Tbet to produce proinflammatory cytokines (interleukin-12 family members or interferon-γ) or to migrate to tumor-draining lymph nodes based on CCR7 ligand chemokine recruitment. Conditional (CD11c-DTR) or genetic (BATF3(-/-)) deficiency in host antigen-crosspresenting DC did not diminish the therapeutic action of intratumorally delivered wild-type mDC.Tbet. Interestingly, we observed that intratumoral delivery of mDC.Tbet (versus control mDC.Null) promoted the acute infiltration of NK cells and naive CD45RB(+) T cells into the tumor microenvironment (TME) in association with elevated expression of NK- and T-cell-recruiting chemokines by mDC.Tbet. When taken together, our data support a paradigm for extranodal (cross)priming of therapeutic Type-1 immunity in the TME after intratumoral delivery of mDC.Tbet-based gene therapy.

Evaluation of salivary beta-2 microglobulin as HBV proliferation marker in HBS Ag(+), HBV DNA PCR(+) and HBV DNA PCR(-) subjects

AIM

The aim of this study was to determine the concentration of salivary B2M as a marker of viral proliferation in HBS Ag(+), HBV DNA PCR(+) and Hbs Ag(+) and HBV DNA PCR(-) subjects.

BACKGROUND

Beta-2 microglobulin (B2M) is responsible for transmission of viral antigens such as Hepatitis B (HBV) on the surface of liver cells as part of an HLA complex.

PATIENTS AND METHODS

In this case control study, 25 PCR(+) and 2 PCR(-) patients were included. 5 mL of the saliva sample was obtained from all patients and salivary B2M level was measured using nephelometer. The data was evaluated by the descriptive, chi square and t tests.

RESULTS

72% of the PCR(+) patients received medications and in contrast, 85.7% of the patients with PCR(-) did not take any medication (P < 0.001). The average salivary concentration ofBeta-2 microglobulin in the PCR(+) group (5.28 ± 5.45 mg/deciliter) was more than PCR(-) group (1.51±0.77) and this difference was statistically significant (P = 0.003).

CONCLUSION

The salivary B2Mlevel can be used as a marker of viral proliferation in patients with hepatitis B.

Vulnerability, distress, and immune response to vaccination in older adults

Psychological distress and biobehavioral vulnerability (e.g., arising from being older or sedentary) have independently predicted immune responses to influenza vaccination in older adults. Recent research examining basal inflammatory markers suggests that, rather than having additive effects, distress and vulnerability interact with each other. The present study tested the interactions between distress and age, sex, education, BMI, sleep quality, and physical activity over up to 8 years in older adults (N=134; M age=74 years) who received annual influenza vaccinations. Measured vaccination responses were changes from baseline in antibody to the three vaccine components, interleukin (IL)-6, and β2-microglobulin. As predicted, the most robust effects were interactions between distress and vulnerability. BMI interacted with stable individual differences in distress to predict antibody response (t(132)=3.09, p<0.003), such that only the combination of low BMI and low distress was associated with a more robust antibody response. Likewise, changes in physical activity over time interacted with changes in distress (t(156)=2.96, p<0.004), such that only the combination of increased physical activity and decreased distress was associated with a more robust antibody response. Finally, there was a smaller tendency for age to interact with stable individual differences in distress (t(130)=2.46, p<0.015), such that distress was more strongly associated with post-vaccination IL-6 at older ages. The synergistic effects of distress and other forms of vulnerability are an important direction for future research and a target for interventions to improve immunological health in older adults.

Beta 2 microglobulin and the risk for cardiovascular events in patients with asymptomatic carotid atherosclerosis

BACKGROUND AND PURPOSE

Atherosclerosis is a chronic inflammatory disease. Ongoing inflammation is associated with elevated levels of beta 2 microglobulin (B2M). We investigated B2M levels in a large cohort of patients with carotid atherosclerosis for the occurrence of major adverse cardiovascular events.

METHODS

One thousand five of 1286 consecutive, neurologically asymptomatic patients with carotid atherosclerosis were followed for a median of 3 years (interquartile range, 2.5 to 3.5) for the occurrence of major adverse cardiovascular events, a composite of myocardial infarction, percutaneous coronary intervention, coronary bypass graft, stroke, and death.

RESULTS

We recorded 359 major cardiovascular events in 271 (27%) patients. B2M was significantly associated with the occurrence of major adverse cardiovascular events. With increasing quartiles of B2M, the adjusted hazard ratios were 1.19 (95% CI, 0.81 to 1.73), 1.51 (95% CI, 1.05 to 2.18), and 1.88 (95% CI, 1.26 to 2.79) compared with the lowest quartile, respectively (P<0.001). Adjusted hazard ratios for the occurrence of death, myocardial infarction, and stroke for increasing quartiles of B2M were 1.25 (95% CI, 0.92 to 1.70), 1.52 (95% CI, 1.12 to 2.06), and 1.62 (95% CI, 1.16 to 2.67) compared with the lowest quartile, respectively (P<0.001). Through statistical estimation of improvement in risk stratification, addition of B2M to baseline risk factors improved the risk stratification for major cardiovascular events, at least as much as high-sensitivity C-reactive protein or even better.

CONCLUSIONS

B2M was independently and significantly associated with adverse cardiovascular outcome in patients with prevalent asymptomatic carotid atherosclerosis.

Residual viraemia in HIV-1-infected patients with plasma viral load <or=20 copies/ml is associated with increased blood levels of soluble immune activation markers

Despite undetectable viral load in conventional assays, probably all human immunodeficiency virus (HIV)-1 infected patients have residual viraemia (RV) detectable by ultra-sensitive assays. To study this issue, this study investigated virologic and immunologic consequences of RV in highly active antiretroviral therapy (HAART)-treated HIV-1-infected patients with plasma HIV-1 RNA <or=20 copies/ml. The study included 32 HAART-treated HIV-1-infected patients with HIV-1 RNA <or=20 copies/ml followed prospectively 6-monthly for 24 months. RV was detected by transcription-mediated amplification (TMA-RV) technique (Procleix HIV-1 Discriminatory Assay; Chiron) and by PCR (PCR-RV, Amplicor HIV-1 Monitor Assay; Roche Diagnostics). The association between RV and proviral-HIV-1-DNA, CD4-count, CD8-count, soluble [soluble tumour necrosis factor receptor (TNFr)-II, beta(2)-microglobulin, immunoglobulins] and cellular (HLA-DR, CD38, CD45RO, CD45RA, CD62L) T-cell markers of immune activation was investigated. In the 24-months study-period, 23 patients had >or=1 episode with TMA-RV whereas 9 patients had undetectable TMA-RV throughout the study-period. Time-points with TMA-RV and PCR-RV were associated with higher circulating sTNFrII (+0.234 ng/ml, P = 0.030) and beta(2)-microglobulin (+22 nmol/l, P = 0.016) and time-points with PCR-RV were also associated with higher IgA (+0.82 micromol/l, P = 0.035) and CD8-count (+1.18-fold, P = 0.001). Patients with TMA-RV in the study-period had higher HIV-1 RNA pre-HAART (P = 0.032). RV was not associated with proviral-HIV-1-DNA, CD4-count, CD4+HLA-DR+, CD8+HLA-DR+CD38+, CD4+CD45RA-CD45RO+, CD8+CD45RA-CD45RO+, CD4+CD45RA+CD62L+, CD8+CD45RA+CD62L+ T cells, IgG or IgM. In conclusion, RV was associated with increased blood levels of soluble immune activation markers in HAART-treated HIV-1-infected patients. The finding that RV was associated with higher pre-HAART plasma viral load suggests that RV is linked to pre-HAART disease progression.

Fetal serum β2-microglobulin as a marker for fetal infectious diseases

OBJECTIVES

To evaluate whether fetal serum beta2-microglobulin could be used as a marker of fetal cytomegalovirus (CMV) or toxoplasmosis infection.

METHODS

beta2-microglobulin was retrospectively assayed in fetal serum collected from 64 patients with maternal infectious seroconversion (toxoplasmosis in 49 cases, CMV in 15). Using a beta2-microglobulin cutoff of 5 mg/L, infection and control groups were compared.

RESULTS

Fetal serum beta2-microglobulin was >5 mg/L (5.2-13.5 mg/L) in 12 of the 13 cases with proved fetal toxoplasmosis infection, indicating 90% sensitivity. In the 39 pregnancies with maternal seroconversion but no laboratory signs of fetal infection, fetal serum beta2-microglobulin was <5 mg/L, indicating 100% specificity. Fetal serum was >5 mg/L (6.3-32 mg/L) in 14 of the 15 cases with proved fetal CMV infection, indicating 93.3% sensitivity. Specificity cannot be evaluated because maternal serum is not routinely screened for CMV during pregnancy.

CONCLUSIONS

Fetal serum beta2-microglobulin is a reliable marker of fetal CMV or toxoplasmosis infection, which can be used in ambiguous situations. Because this increase is not specific, fetal serum beta2-microglobulin would potentially be raised in other fetal infections.

Serum beta2-microglobulin values among healthy Brazilians using a DPC IMMULITE assay

PURPOSE

The present study was designed to determine the normal range of serum beta 2-microglobulin (Sb2M) levels among healthy volunteers in Brazil. Levels of Sb2M are elevated in human immunodeficiency virus (HIV)-infected patients and have been shown to be the best predictor of HIV infection status and of some malignant disorders, especially multiple myeloma. In order to achieve its optimal use in Brazilian clinical diagnosis, an adequate reference interval study was performed for Sb2M IMMULITE assay, based on the fact that its reference range limits were evaluated among European populations.

METHODS

Ninety-six healthy blood donors were evaluated, and Sb2M levels were measured by chemiluminescent enzyme immunoassay using the IMMULITE automated analyzer.

RESULTS

A normal range of Sb2M values, established by a nonparametric statistical method, was 1.05 to 3.9 mg/mL, with the upper limit being higher than that reported elsewhere.

CONCLUSIONS

This study presented new data indicating that there is a significant difference between the current reference limits for Sb2M IMMULITE assay and those found in Brazil, providing evidence that significant differences in range of normal values may occur among different populations, and that these new values should be considered for Brazilian individuals.

Relationship of .BETA.2-Microglobulin to Arterial Stiffness in Japanese Subjects

Beta2-Microglobulin (beta2m) is related to inflammatory diseases, but there have been few reports of a relationship between beta2m and atherosclerosis. We have examined the influence of beta2m on brachial-ankle pulse wave velocity (baPWV) to clarify whether it is related to arterial stiffness. baPWV, beta2m, C-reactive protein (CRP), and conventional risk factors were measured in 614 males and 158 females. The adjusted means of baPWV were compared with the quartiles of beta2m, and significant differences in baPWV were observed across the quartiles of beta2m (p = 0.037). After being adjusted for potential confounders, quartile 4 of beta2m, quartile 4 of CRP, and the combination of high beta2m plus high CRP were significantly associated with a high value of PWV (quartile 4 of beta2m: odds ratio [OR] 2.53, 95% confidence interval [CI], 1.31-4.89; quartile 4 of CRP: OR 2.27, 95% CI, 1.18-4.34; high beta2m plus high CRP: OR 5.60, 95% CI, 2.38-13.2). These results suggest that beta2m is associated with an increase of arterial stiffness. Further studies are needed to clarify whether beta2m is related to atherosclerotic diseases, and whether the combination of beta2m and CRP measurement is a useful predictor for the development of atherosclerosis.

Serum and urine beta-2-microglobulin in hemophagocytic syndrome

BACKGROUND

Previous reports suggesting a correlation between lymphoproliferative disease and serum levels of beta-2-microglobulin (beta-2M) and in vitro data indicating a role of cytokines in the production of beta-2M prompted a study of serum and urine beta-2M concentration in patients with hemophagocytic syndrome (HPS), because no data were previously available for HPS, a pathologic state associated with excessive cytokines secreted from activated reactive/malignant lymphocytes and histiocytes.

METHODS

Serum and urine beta-2M levels were measured in six children with HPS during active and convalescent phase and in other diseases.

RESULTS

Serum and urine beta-2M levels during active phase HPS were significantly high not only in serum (median, 7.5 mg/l; range, 2.3-16.0 mg/l; P < 0.01), but also in urine (median, > 31,650 micrograms/gram Creatinine (gCr); range, 8179-236,333 micrograms/gCr; P < 0.01), compared with levels during convalescent phase HPS (median, 2.0 mg/l; range, 0.9-2.5 mg/l in serum and median, 338 micrograms/gCr; range, 223-585 micrograms/gCr in urine) and in control subjects with diseases such as acute lymphocytic leukemia (median, 2.3 mg/l; range, 1.0-2.8 mg/l in serum and median, 327 micrograms/gCr; range, 48-2684 micrograms/gCr in urine), infectious mononucleosis (median, 2.9 mg/l; range, 2.5-5.5 mg/l in serum and median, 348 micrograms/gCr; range, 80-1325 micrograms/gCr in urine), and Kawasaki disease (median, 2.8 mg/l; range, 1.5-3.3 mg/l in serum and median, 1016 micrograms/gCr; range, 214-4500 micrograms/gCr in urine). Noteworthy was the observation that urine beta-2M levels correlated closely with HPS disease activity.

CONCLUSIONS

Urine beta-2M appears to be a useful marker for assessing disease activity in patients with HPS.

HIV type 1-specific cytotoxic T lymphocytes stimulate HLA class I and intercellular adhesion molecule type 1 expression and increase beta 2-microglobulin levels in vitro

Besides acting in a direct manner, cytolytic HIV-1-specific CTLs release a variety of cytokines. To assess the potential role of cytokines released by these CTLs we tested the ability of soluble products secreted by HIV-1-specific CTLs to induce HLA class I and ICAM-1 expression and to raise beta 2-microglobulin (beta 2M) concentrations in cell culture. To this end, supernatants were derived from HIV-1-specific CTLs incubated with autologous B lymphoblasts presenting either the cognate HIV-1 epitope or a control peptide. Cell lines and peripheral blood mononuclear cells (PBMCs) were incubated with these supernatants for 24-48 hr. Similarly, cells were cocultured with CTLs and their targets. This study demonstrates that in parallel with lysis of their cognate target, HIV-1-specific CTLs secreted products that stimulated HLA class I and ICAM-1 expression on cell lines and PBMCs. As few as 1000 CTLs significantly induced the expression of these molecules. In addition, secreted products of HIV-specific CTLs enhanced beta 2M release by PBMCs and Jurkat cells. These effects were mediated primarily by IFN-gamma and suggest that HIV-specific CTLs may contribute to increased HLA class I expression in infected tissue and elevated ICAM-1 and beta 2M concentrations in serum and cerebrospinal fluid of infected individuals.

Do high levels of C-reactive protein in Tanzanian children indicate malaria morbidity

Children under 6 years of age living in an area of Tanzania highly endemic for malaria were tested for C-reactive protein (CRP) in order to determine how the acute-phase response is related to malaria in children of different ages and to investigate whether serum CRP concentrations might be useful in the qualification of morbidity in such children. The median CRP level in the 629 finger-prick blood samples measured, 6.0 mg/liter, was much higher than that reported in the blood of children in Europe. The CRP concentration was correlated with recent illness reported by the parents. High CRP levels were most strongly associated with Plasmodium falciparum parasitemia in children under 1 year of age. In older children, lower levels of CRP were associated with parasitemia, and fewer children had increased CRP levels attributable to parasitemia. The levels of malaria-attributable CRP appear to track the acquisition of parasitological and clinical tolerance in this area with very high levels of P. falciparum transmission. Determination of CRP levels should be useful in the rapid assessment of the overall burden of morbidity, especially in infants. In areas where malaria is endemic, CRP associated with increased parasite densities provides an objective measure of malaria-specific morbidity. This would be an efficient approach to estimating malaria morbidity risks from small-scale serological surveys.

Beta-2 microglobulin as a predictor of prognosis in HIV-infected men with haemophilia: a proposed strategy for use in clinical care

Whilst the prognostic value of serum beta-2 microglobulin (s-beta 2m) is well documented, the lack of a simple strategy for its use means that it is rarely ever measured in clinical practice. The prognosis associated with s-beta 2m at two different points in HIV infection, as defined by the CD4 count, was studied in a cohort of 111 men with haemophilia registered at the Royal Free Hospital School of Medicine, London. At CD4 counts of 0.5 and 0.2 x 10(9)/l, a raised s-beta 2m level was significantly associated with an increased risk of developing AIDS (P = 0.002 and 0.022 respectively, adjusted for the patient's age). Kaplan-Meier progression rates to AIDS by 4.5 years after a CD4 count of 0.5 x 10(9)/l were 57% (95% CI 32-82%) in those with s-beta 2m levels of 3 mg/l or more, but 20% (95% CI 4-36%) in those with s-beta 2m levels of less than 3 mg/l. By 3.5 years after a CD4 count of 0.2 x 10(9)/l, Kaplan-Meier progression rates to AIDS were 75% (95% CI 52-98%) in those with s-beta 2m levels of 3.8 mg/l or more, and 47% (95% CI 29-66%) in those with s-beta 2m levels of less than 3.8 mg/l. In the absence of acute viral infections, a raised s-beta 2m indicates those who will tend to progress to AIDS more rapidly than those with lower s-beta 2m levels and the same CD4 count. S-beta 2m levels in general are likely to be higher in haemophilia patients than in other, non-haemophilic risk groups. Whilst care should be taken, therefore, when applying our chosen cut-off values to non-haemophilic patients, our findings support the introduction of prophylaxis and antiviral therapies at a higher CD4 count in those with raised s-beta 2m levels relative to other patients in the same risk group whilst delaying treatment in those with lower CD4 counts, but relatively normal s-beta 2m levels.

Surrogate markers for assessing treatment response in HIV disease

OBJECTIVE

To provide an awareness of the issues surrounding the selection and utility of surrogate markers to evaluate treatment response for new antiretroviral therapies for HIV infection.

DATA SOURCES

A MEDLINE search of applicable articles published between 1987 to the present, including clinical trials, commentaries, and editorials, was performed.

DATA SYNTHESIS

Surrogate markers are proximal indicators that are predictive of rare or distant outcomes and can be used in clinical trials to decrease sample size and study duration. Characteristics of potential surrogate endpoints include relevance to disease state, face validity, ability to be detected in the majority of patients, and correlation between treatment-induced changes and terminal endpoints. Potential surrogate markers for assessing treatment response in HIV infection can be categorized as either virologic (p24 antigen, plasma viremia, proviral DNA) or immunologic (CD4+ lymphocytes, neopterin, beta 2-microglobulin, soluble interleukin-2 receptors, immunoglobulin A [IgA]). The CD4+ lymphocyte count and the p24 antigen have been evaluated in most of the clinical trials examining antiretroviral agents and have the greatest documentation supporting their use. Neopterin and beta 2-microglobulin are nonspecific markers, but may improve the predictive value of the CD4+ count when used in combination. Other markers (i.e., soluble interleukin-2 receptors, IgA) remain relatively unstudied at this point.

CONCLUSIONS

There is no current consensus regarding the selection of surrogate markers for HIV disease. On the basis of the present literature, the CD4+ lymphocyte count has the greatest endorsement: however, combination with several surrogate markers may prove to be useful in clinical trials. Studies are needed to verify the reliability of surrogate markers used alone and in combination to predict therapeutic response from antiretroviral therapy.

Serum protein concentrations in Plasmodium falciparum malaria

In patients with uncomplicated Plasmodium falciparum infection cytokine-mediated serum protein levels of C-reactive protein (CRP), coeruloplasmin (COE), beta 2-microglobulin (B2M), alpha 1-acid glycoprotein (AAG), alpha 1-antitrypsin (AAT), haptoglobin (HPT), prealbumin (PRE), retinol binding protein (RBP), albumin (ALB) and transferrin (TRF) were measured in an endemic area of the Amazonian rain forest. Semi-immune (SI) and nonimmune (NI) patients were investigated. In both patient groups the serum concentrations of CRP, COE and B2M were elevated on admission. In addition AAG and AAT concentrations were increased in NI patients compared to control subjects. Significantly lower serum concentrations of HPT, PRE, RBP, ALB and TRF were seen in both patient groups during the acute phase of the disease, and were more pronounced in NI patients. After a 28-day follow-up, AAT and B2M were normal in SI patients but HPT, AAT and B2M were still significantly altered in NI patients.

Expression of beta-2-microglobulin by nasopharyngeal carcinoma

Serum beta-2-microglobulin (beta 2M) levels of 274 Chinese patients with different stages of nasopharyngeal carcinoma at presentation and that of 35 patients who developed distant metastases post-treatment were assayed. beta 2M level was found to increase with advancing stage of disease, with statistically significant differences among early-stage, advanced-stage, and metastatic disease. Elevated pre-treatment beta 2M levels were expressed more frequently by tumours with lower degree of histological differentiation. The sensitivity of serum beta 2M for diagnosis of nasopharyngeal carcinoma, however, is low.

Serum beta-2 microglobulin and C-reactive protein levels in acute adenovirus conjunctivitis

Serum beta-2 microglobulin and C-reactive protein levels were measured in 52 patients with acute adenovirus conjunctivitis and 58 healthy subjects, by ELISA technique. Serum beta-2 microglobulin levels were found to be significantly increased while there was no change in C-reactive protein levels. Serum beta-2 microglobulin levels closely paralleled the severity of the disease. The increased beta-2 microglobulin level in serum showed a significant fall to normal level on clinical improvement. There was no difference in the serum beta-2 microglobulin levels in virus-isolation positive and negative patients.

Increased serum beta 2-microglobulin concentrations in hyperthyroid states

Serum beta 2-microglobulin concentrations were determined in 21 untreated hyperthyroid patients (12 with Graves' disease, and nine with toxic nodular adenoma) and in 20 healthy controls. All subjects had normal serum creatinine concentrations and urine analysis. Both total and free thyroid hormones were significantly higher in the hyperthyroid groups than in controls. Beta 2-microglobulin concentrations were significantly increased in both groups of hyperthyroid patients compared with controls. No difference was found in the thyroid hormone and beta 2-microglobulin concentrations between both sets of patients. The beta 2-microglobulin and thyroid hormone concentrations were not correlated. These data show that hyperthyroidism is another cause of increased beta 2-microglobulin production along with viral infections, immunologically mediated diseases, and malignant neoplasms. The increased serum beta 2-microglobulin concentration in thyroid hyperfunction is probably related to metabolic rate, even if autoimmunity might contribute to its overproduction.

beta 2-Microglobulin and antiviral therapy for chronic hepatitis type B

During a randomized controlled trial of interferon and descyclovir therapy, the beta 2-microglobulin and SGOT serum levels in 36 patients with chronic HBe-positive hepatitis B were studied in order to determine whether beta 2-microglobulin has prognostic value for HBe seroconversion. Pretreatment levels of beta 2-microglobulin were elevated in 39% of patients. Significant differences in mean beta 2-microglobulin activity and mean SGOT between treated patients and untreated controls were observed after 4 and 8 weeks of treatment (P less than 0.05). Levels in control patients remained stable. Prior to and during therapy, the mean elevation of beta 2-microglobulin and SGOT levels was similar in responders (N =7) and non-responders (N = 11). The outcome of antiviral therapy in our patients was not dependent on beta 2-microglobulin levels measured before or during interferon therapy.

Fluctuations of plasma beta 2-microglobulin, soluble interleukin 2 receptor and interferon-gamma concentrations after adoptive immunotherapy with high-dose interleukin 2 and lymphokine-activated killer cells

We report the serum levels of soluble interleukin 2 receptor (sIL2R), beta 2-microglobulin (beta 2-M) and interferon-gamma (IFN-gamma) in patients undergoing adoptive immunotherapy with rIL2 and lymphocyte-activated killer (LAK) cells. Our results indicate that rIL2 induced a marked increase of the serum concentration of these markers, although this increase varied considerably for different individuals. Parallel studies with the same patients also showed a marked rise in the number of IL2R+ lymphocytes: the IL2Rs expressed on these cells were mainly of the "low affinity" type. We suggest that evaluation of these markers may allow the monitoring of immune system activation induced by rIL2 in patients undergoing adoptive rIL2 and LAK cell immunotherapy.

Acute phase response in cerebral infarction

The serum concentrations of the acute phase proteins, C-reactive protein, serum amyloid A protein, and alpha-1-antichymotrypsin were determined in 50 young and middle aged patients with cerebral infarction and in sex and age matched community controls. Of 46 case control pairs, 11 cases but only one control had raised acute phase protein concentrations simultaneously (p less than 0.01); four case control pairs were excluded because of an infectious complication following infarction and an acute phase response. Seven of the 11 patients (64%) with raised acute phase protein concentrations had a history of bacterial infection in the preceding month but of the remaining 35 patients without raised concentrations only four (11%) had such a history (p less than 0.01). In general, the acute phase response was less pronounced and occurred less often than has been reported in patients after acute myocardial infarction. The results suggest that a positive acute phase response is associated with a preceding bacterial infection or with an infectious complication after cerebral infarction. Measurement of acute phase proteins, therefore, could be used to evaluate the possible role of preceding bacterial infection in the development of cerebral infarction and also in the management of these patients as an early indicator of possible infectious complications.

A longitudinal study of serum beta 2-microglobulin levels in haemophilia

Serum beta 2-microglobulin (beta 2-m) levels were measured in 75 adults with haemophilia A. Beta 2-microglobulin was found to be significantly elevated in haemophiliacs compared with the non-haemophiliac population. There was a greater rise in beta 2-m in HIV antibody-positive haemophiliacs. No further significant increase occurred in the subgroup with HIV-related disease but all these patients had beta 2-m levels greater than or equal to 3 mg/l. Over the study period of 18 months no significant increase in beta 2-m was documented in either HIV antibody-negative or -positive groups. Beta 2-microglobulin was elevated in HIV antibody-negative subjects with raised transaminase levels. No correlation was found between beta 2-m and the amount of factor VIII concentrate infused, T-cell subsets, thrombocytopenia or age. It is concluded that probable reasons for elevated beta 2-m levels in haemophiliacs include infection with HIV and other viruses, chronic liver disease, and repeated antigenic challenge from multiple infusions of factor VIII. The role of serial measurement of beta 2-m in haemophiliacs with a view to predicting the onset of HIV-related disease warrants further study.

Alpha- and gamma-interferon (IFN alpha, IFN gamma) but not interleukin-1 (IL-1) modulate synthesis and secretion of beta 2-microglobulin by hepatocytes

Soluble serum beta 2-microglobulin has been thought to result from membrane shedding by activated T-lymphocytes. This hypothesis could explain the increase of beta 2-microglobulin serum levels during virally induced mononucleosis, but not elevated levels as observed in other virally induced and in malignant diseases. In this paper we demonstrate that beta 2-microglobulin is a true secretory protein, and that its synthesis in hepatocytes is modulated by IFNs but not by IL-1. While the 45,000 MW HLA antigen can be found only in cell lysates, beta 2-microglobulin is shown to be secreted also into the culture medium like other secretory proteins (e.g. albumin-factor B-complement C3). Furthermore, interferon alpha (IFN alpha) as well as interferon gamma (IFN gamma) directly stimulate, in a dose- and time-dependent manner, beta 2-microglobulin synthesis by human hepatoma cells (Mz-Hep-1 and PLC/PRF5) and murine hepatocyte primary cultures. The increase of beta 2-microglobulin production induced by interferons is demonstrated at both the protein and the RNA level, indicating that interferon acts at a pretranslational level. The interferon effect on beta 2-microglobulin synthesis is specific since synthesis of secretory proteins like complement C3 or albumin, and of a structural protein like actin, remains unchanged. In contrast to IFN, IL-1, the main mediator of acute phase response, does not change beta 2-M biosynthesis rate. These data indicate that (i) beta 2-microglobulin is a secretory protein, (ii) IFNs but not IL-1 can mediate increased beta 2-M serum levels, and (iii) the liver may be its primary source.