Increased Levels of Tumor Necrosis Factor α Are Associated with an Increased Risk of Cytomegalovirus Infection after Allogeneic Hematopoietic Stem Cell Transplantation

Circulating cytokine and chemokine patterns associated with cytomegalovirus reactivation after stem cell transplantation

Objectives

Human cytomegalovirus (HCMV) reactivation is the leading viral complication after allogeneic haematopoietic stem cell transplantation (allo-HSCT). Understanding of circulating cytokine/chemokine patterns which accompany HCMV reactivation and correlate with HCMV DNAemia magnitude is limited. We aimed to characterise plasma cytokine/chemokine profiles in 36 allo-HSCT patients (21 with HCMV reactivation and 15 without HCMV reactivation) at four time-points in the first 100-day post-transplant.

Methods

The concentrations of 31 cytokines/chemokines in plasma samples were analysed using a multiplex bead-based immunoassay. Cytokine/chemokine concentrations were compared in patients with high-level HCMV DNAemia, low-level HCMV DNAemia or no HCMV reactivation, and correlated with immune cell frequencies measured using mass cytometry.

Results

Increased plasma levels of T helper 1-type cytokines/chemokines (TNF, IL-18, IP-10, MIG) were detected in patients with HCMV reactivation at the peak of HCMV DNAemia, relative to non-reactivators. Stem cell factor (SCF) levels were significantly higher before the detection of HCMV reactivation in patients who went on to develop high-level HCMV DNAemia (810-52 740 copies/mL) vs. low-level HCMV DNAemia (< 250 copies/mL). High-level HCMV reactivators, but not low-level reactivators, developed an elevated inflammatory cytokine/chemokine profile (MIP-1α, MIP-1β, TNF, LT-α, IL-13, IL-9, SCF, HGF) at the peak of reactivation. Plasma cytokine concentrations displayed unique correlations with circulating immune cell frequencies in patients with HCMV reactivation.

Conclusion

This study identifies distinct circulating cytokine/chemokine signatures associated with the magnitude of HCMV DNAemia and the progression of HCMV reactivation after allo-HSCT, providing important insight into immune recovery patterns associated with HCMV reactivation and viral control.

Protective and pathological roles of regulatory immune cells in human cytomegalovirus infection following hematopoietic stem cell transplantation

Human cytomegalovirus (HCMV) is ubiquitously prevalent. Immune system in healthy individuals is capable of controlling HCMV infection; however, HCMV can be life-threatening for immunocompromised individuals, such as transplant recipients. Both innate and adaptive immune systems are critically involved in the HCMV infection. Recent studies have indicated that regulatory immune cells which play essential roles in maintaining a healthy immune environment are closely related to immune response in HCMV infection. However, the exact role of regulatory immune cells in immune regulation and homoeostasis during the battle between HCMV and host still requires further research. In this review, we highlight the protective and pathological roles of regulatory immune cells in HCMV infection following hematopoietic stem cell transplantation (HSCT).

Expression of a Tagless Single-Chain Variable Fragment (scFv) of Anti-TNF-α by a Salt Inducible System and its Purification and Characterization

BACKGROUND

Anti-TNF-α scFv is gaining acceptance as an effective drug for various diseases, such as rheumatoid arthritis and Crohn's disease that involve elevated levels of TNF-α. The single-chain variable fragment (scFv) consists of variable regions of heavy and light chains of monoclonal antibodies (mAb). Due to its smaller size, it curbs the mAb's auto-antibody effects and their limitation of penetration into the tissues during the neutralization of TNF-α.

OBJECTIVE

In this work, a cDNA coding for anti-TNF-α scFv was successfully cloned into a pRSET-B vector and efficiently expressed in an E. coli strain GJ1158, a salt inducible system that uses sodium chloride instead of IPTG as an inducer.

METHODS

The protein was expressed in the form of inclusion bodies (IB), solubilized using urea, and refolded by pulse dilution. Further, the amino acid sequence coverage of scFv was confirmed by ESI-Q-TOF MS/MS and MALDI-TOF. Further studies on scaling up the production of scFv and its application of scFv are being carried out.

RESULTS

The soluble fraction of anti-TNF-α scFv was then purified in a single chromatographic step using CM-Sephadex chromatography, a weak cation exchanger with a yield of 10.3 mg/L. The molecular weight of the scFv was found to be ~ 28 kDa by SDS PAGE, and its presence was confirmed by western blot analysis and mass spectrometry.

CONCLUSION

Anti-TNF-α scFv has been successfully purified in a salt inducible system GJ1158. As per the best of our knowledge, this is the first report of purification of Anti-TNF-α scFv in a salt inducible system from soluble fractions as well as inclusion bodies.

Cytomegalovirus Hepatitis in Immunocompetent and Immunocompromised Hosts

Human cytomegalovirus (HCMV) infection is common and affects between 40-100% of the worldwide population. However, the majority of cases are asymptomatic and when severe disease occurs, it is usually restricted to immunocompromised patients. Liver involvement by HCMV differs significantly, accordingly to the immune status of the host. In immunocompromised patients, particularly liver transplant patients, it often causes clinically significant hepatitis. On the other hand, in immunocompetent patients, HCMV hepatitis requiring hospitalization is extremely rare. This review aims to appraise studies regarding the pathophysiology of HCMV hepatitis, including mechanisms of latency and reactivation and its contribution to disease development, clinical presentation, diagnostic modalities and treatment, with a focus on comparing different aspects between immunocompromised and immunocompetent hosts.

Risk Factors Analysis for Human Cytomegalovirus Viremia in Donor+/Recipient+ Hematopoietic Stem Cell Transplantation

OBJECTIVE

To assess the rate of, and risk factors for, human cytomegalovirus viremia (HCMV) in donor+/recipient+ (HCMV serostatus matched) hematopoietic stem-cell transplantation (HSCT) recipients.

METHODS

HCMV DNA from 144 donor+/recipient+ HSCT recipients was examined by quantitative polymerase chain reaction (qPCR).

RESULTS

The cumulative incidence of HCMV viremia was 69.4% (100/144) during the 48 weeks after HSCT. In a multivariate analysis, acute graft-versus-host disease (aGVHD) was discovered to be a risk factor for the occurrence of HCMV viremia (P = .006). The cumulative incidence of HCMV viremia and increasing DNA loads were significantly associated with aGVHD occurrence (P = .001 for each). The occurrence of late-term HCMV viremia was associated with aGVHD (P = .001) and a higher DNA load during the first 12 weeks after HSCT (P = .04).

CONCLUSIONS

aGVHD is a risk factor for HCMV viremia. Recipients with aGVHD who have a high HCMV DNA load should be strictly monitored to prevent HCMV activation.

Risk factors for cytomegalovirus DNAemia following haploidentical stem cell transplantation and its association with host hepatitis B virus serostatus

BACKGROUND

The risk factors associated with CMV DNAemia are not well known after haploidentical stem cell transplantation (SCT).

OBJECTIVES

This study investigated the risk factors and prognosis for CMV DNAemia among CMV seromatched donors and recipients (D+/R+).

STUDY DESIGN

A retrospective study of patients undergoing haploidentical stem cell transplantation (SCT) between January 2010 and January 2012 was conducted. Cox regression analysis was performed to identify the risk factors for CMV DNAemia. These possible factors included recipient/donor age, recipient/donor gender, gender disparity, recipient HBsAg serostatus, diagnosis, risk stratification, anti-thymocyte globulin (ATG) dose (6mg/kg,10mg/kg), early neutrophil engraftment (≤12 days, >12 days), absolute lymphocyte count on day 30 (ALC30) and the occurrence of acute GVHD before CMV DNAemia.

RESULTS

The total number of patients was 248 with median age of 31 years (range, 14-56). The cumulative incidence of CMV DNAemia (146/248) was 59.5%. CMV DNAemia was first detected after a median of +35 days (range,12-82). Seventeen patients (17/146, 11.6%) developed CMV disease. Multivariate analysis identified HBsAg seropositivity (P=0.002, hazard ratio (HR)=1.833; 95%CI=1.257-2.673) and the occurrence of acute GVHD before CMV DNAemia (P=0.014; HR=1.520; 95%CI=1.088-2.124) as risk factors for CMV DNAemia. CMV DNAemia was associated with subsequent II-IV acute graft-versus-host disease (GVHD) (P=0.014), III-IV aGVHD (P=0.013) and chronic GVHD (P=0.008). Totally, CMV DNAemia was found to be a poor prognostic factor in terms of non-relapse mortality (NRM) (P=0.003, HR=2.730; 95%CI=1.406-5.197), and overall survival (OS) (P=0.045, HR=1.654; 95%CI=1.012-2.701).

CONCLUSIONS

Our data showed HBsAg seropositivity was associated with an increased risk of cytomegalovirus DNAemia. Detection of CMV DNAemia proved to be a poor prognostic factor for haploidentical patients.

Granulocyte-macrophage colony-stimulating factor increases the proportion of circulating dendritic cells after autologous but not after allogeneic hematopoietic stem cell transplantation

BACKGROUND AIMS

Granulocyte-macrophage (GM) colony-stimulating factor (CSF) has been used as an adjuvant in cancer immunotherapy. We tested the hypothesis that GM-CSF (Leukine(®); sargramostim) improves immune reconstitution after hematopoietic stem cell transplantation (HSCT) based on our prior in vitro work that demonstrated the pro-inflammatory effects of GM-CSF on dendritic cells (DC).

METHODS

GM-CSF was administered to donors, along with standard granulocyte (G) CSF, during stem cell mobilization, and to recipients from the day prior to transplant until engraftment. Eighteen patients consented to the GM-CSF(+) protocol and were compared with 17 matched controls undergoing HSCT during the same time period (GM-CSF(-)).

RESULTS

Numbers of white blood cells (WBC) and CD34(+) stem cells in the graft were comparable to controls. Surprisingly, contrary to our hypothesis, the allogeneic donor graft had significantly decreased numbers of CD3(+) T cells and their subsets (CD4(+), CD4(+) CD45RA(+), CD4(+) CD45RO(+), CD8(+) and CD8(+) CD45RO(+)), DC (both myeloid and plasmacytoid) and natural killer (NK) cells (CD16(+) CD56(+)). In the GM-CSF arm, following allogeneic transplantation, the levels of DC, T cells and NK cells did not increase with treatment. Conversely, autologous transplant patients receiving GM-CSF had a higher proportion of DC at the time of engraftment.

CONCLUSIONS

These findings demonstrate that administration of GM-CSF improves DC reconstitution after autologous rather than allogeneic HSCT.

Blood stream infection (BSI) and acute GVHD after hematopoietic SCT (HSCT) are associated

BSI and acute GVHD (aGVHD) are serious complications of HSCT. We hypothesized that the two events were not independent of one another. We studied (1) associations between BSI and aGVHD; (2) the impact of BSI and/or aGVHD on death within 100 days after HSCT, employing a retrospective cohort analysis. Risk factor analysis was performed using multivariable Cox proportional hazards analyses. Of 211 subjects undergoing allogeneic HSCT from 1/00–12/05 (58% of whom underwent reduced intensity transplantation), 82 (39%) developed BSI. In 49 patients (23%), grades (gr) 2–4 aGVHD occurred. Early BSI was independently associated with an increased occurrence of subsequent aGVHD gr 2–4. Cytomegalovirus seropositivity was independently associated with decreased occurrence of aGVHD. Acute GVHD gr 2–4 independently predicted subsequent first BSI. Both BSI and aGVHD gr 2–4 were significant independent predictors of death within 100 days after HSCT. There is a strong, independent association between BSI and aGVHD. Potential explanations include the elaboration of cytokines during BSI favoring the development of aGVHD and/or the immunosuppressive treatment of aGVHD favoring the development of BSI. Future studies should be directed at mechanistic investigations of this association.

Spiritual absence and 1-year mortality after hematopoietic stem cell transplant

Religiosity and spirituality have been associated with better survival in large epidemiologic studies. This study examined the relationship between spiritual absence and 1-year all-cause mortality in allogeneic hematopoietic stem cell transplant (HSCT) recipients. Depression and problematic compliance were examined as possible mediators of a significant spiritual absence-mortality relationship. Eighty-five adults (mean = 46.85 years old, SD = 11.90 years) undergoing evaluation for allogeneic HSCT had routine psychologie evaluation prior to HSCT admission. The Millon Behavioral Medicine Diagnostic was used to assess spiritual absence, depression, and problematic compliance, the psychosocial predictors of interest. Patient status at 1 year and survival time in days were abstracted from medical records. Cox regression analysis was used to examine the relationship between the psychosocial factors of interest and mortality after adjusting for relevant biobehavioral factors. Twenty-nine percent (n = 25) of participants died within 1 year of HSCT. After covarying for disease type, individuals with the highest spiritual absence and problematic compliance scores were significantly more likely to die 1-year post-HSCT (hazard ratio [HR] = 2.49, P = .043 and HR = 3.74, P = .029, respectively), particularly secondary to infection, sepsis, or graft-versus-host disease (GVHD) (HR = 4.56, P = .01 and HR = 5.61, P = .014), relative to those without elevations on these scales. Depression was not associated with 1-year mortality, and problematic compliance did not mediate the relationship between spiritual absence and mortality. These preliminary results suggest that both spiritual absence and problematic compliance may be associated with poorer survival following HSCT. Future research should examine these relations in a larger sample using a more comprehensive assessment of spirituality.

Polyfunctional cytomegalovirus-specific CD4+ and pp65 CD8+ T cells protect against high-level replication after liver transplantation

To determine whether polyfunctional CD4+ T-cell responses coupled with CD8+ T-cell responses against human cytomegalovirus (HCMV) are key to the control of HCMV replication we prospectively analyzed 29 liver transplant recipients for CD4+ T-cell responses against soluble HCMV antigen, pp65 and IE1 proteins, CD8+ T-cell responses against pp65 and IE1 proteins and a range of T helper (Th) 1 and Th2 cytokines. Eleven patients (38%) developed HCMV DNAemia at a median of 21 days post-liver transplantation (range 17-31 days). There was a significantly lower frequency and absolute number of total HCMV CD4+ T cells producing IFNgamma, IFNgamma+IL2 and IL2 and pp65-CD8+ T cells producing IFNgamma in patients with DNAemia. The quantities of Th1 and Th2 cytokines present during the first 20 days posttransplant were not predictive of DNAemia. Cut-off levels during the first 20 days posttransplant of 0.1% of lysate stimulated CD4+ T cells producing IL2, and pp65-CD8+ T cells producing IFNgamma above 0.4% had positive and negative predictive values for DNAemia of 54% and 100% and 50% and 92%, respectively. Measuring polyfunctional CD4+ T cells against HCMV early posttransplant may allow targeted intervention to minimize the occurrence and acute and long-term consequences of HCMV replication.