Hypogammaglobulinemia and infection risk in solid organ transplant recipients

The time-dependent changes in serum immunoglobulin after kidney transplantation and its association with infection

Introduction

Kidney transplant recipients often experience significant alterations in their immune system, which can lead to increased susceptibility to infections. This study aimed to analyze time-dependent changes in serum immunoglobulin and complement levels and determine the risk factors associated with infection.

Methods

A retrospective analysis of serum samples from 192 kidney transplant recipients who received transplantations between August 2016 and December 2019 was conducted. The serum samples were obtained at preoperative baseline (T0), postoperative 2 weeks (T1), 3 months (T2), and 1 year (T3). The levels of serum C3, C4, IgG, IgA, and IgM were measured to evaluate immune status over time.

Results

The analysis revealed significant decreases in IgG and IgA levels at T1. This period was associated with the highest occurrence of hypogammaglobulinemia (HGG) and hypocomplementemia (HCC), as well as an increased incidence of severe infection requiring hospitalization and graft-related viral infections. Using a time-dependent Cox proportional hazards model adjusted for time-varying confounders, HGG was significantly associated with an increased risk of infection requiring hospitalization (HR, 1.895; 95% CI: 1.871-1.920, P-value<0.001) and graft-related viral infection (HR, 1.152; 95% CI: 1.144-1.160, P-value<0.001).

Discussion

The findings suggest that monitoring serum immunoglobulin levels post-transplant provides valuable insights into the degree of immunosuppression. Hypogammaglobulinemia during the early post-transplant period emerges as a critical risk factor for infection, indicating that serum immunoglobulins could serve as feasible biomarkers for assessing infection risk in kidney transplant recipients.

Ukrainian War Refugee Children With Particularly Severe Viral Infections: A Case Series Report

The humanitarian crisis in Ukraine in 2022 led to a massive migration of refugees to Poland. Immigrant children, living in overcrowded humanitarian hubs, were exposed to multiple stressful factors likely affecting their immune systems. This case series study aimed to describe a particularly severe course of common viral infections, in Ukrainian refugee children. We present 2 case series of Ukrainian refugee children: 5 hospitalized due to either adenovirus (AdV) and 8 with rotavirus (RV) infection, admitted within 3 months in each case series, recruited retrospectively. Most patients lived in humanitarian hubs and were neglected on admission (dehydrated, with poor hygiene and anxious). All RV infection cases had symptoms of severe gastroenteritis requiring intravenous rehydration. Metabolic acidosis was present in 6 children, and hypoglycemia in 4 participants. None of them were vaccinated against RV. All children with AdV infection had prolonged fever, dyspnea requiring oxygen therapy and hyperinflammation. In 2 AdV infection cases with no clinical improvement and increasing inflammatory markers, intravenous immunoglobulins and glucocorticosteroids were used. The combination of stressful factors and living in overcrowded hubs during the high prevalence of viral infections led to a particularly severe course of viral infections in Ukrainian refugee children.

Signal detection of adverse events associated with gabapentinoid use for chronic pain

INTRODUCTION

Gabapentinoids (GABA) prescribing as a potential and conceivably safer substitute for opioids has substantially increased. Understanding all potential adverse drug events (ADEs) associated with GABA will guide clinical decision-making for pain management.

METHODS

A 20% sample of Medicare enrollees with new chronic pain diagnoses in 2017-2018 was selected. GABA users were those with >=30 consecutive days prescription in a year without opioid prescription. Opioid users were similarly defined. The control group used neither of these drugs. Propensity score match across three groups based on demographics and comorbidity was performed. We used proportional reporting ratio (PRR), Gamma Poisson Shrinker, and tree-based scan statistic (TBSS) to detect ADEs within 3, 6, and 12 months of follow-up.

RESULTS

Immunity disorder was detected within 3 months of follow-up by PRR compared to opioid use (PRR:2.33), and by all three methods compared to controls. Complications of transplanted organs/tissues and schizophrenia spectrum/other psychotic disorders were consistently detected by PRR and TBSS within 3 months. Skin disorders were detected by TBSS; and stroke was detected by PRR within 3 months compared to opioid use (PRR:4.74). Some malignancies were detected by PRR within 12 months. Other signals detected in GABA users were neuropathy and nerve disorders.

CONCLUSIONS

Our study identified expected and unexpected ADE signals in GABA users. Neurological signals likely related to indications for GABA use. Signals for immunity, mental/behavior, and skin disorders were found in the FDA adverse event reporting system database. Unexpected signals of stroke and cancer require further confirmatory analyses to verify.

Impact of SARS-CoV-2 Infection on Humoral and Cellular Immunity in a Cohort of Vaccinated Solid Organ Transplant Recipients

The aim of the present study was to determine humoral and T-cell responses after four doses of mRNA-1273 vaccine in solid organ transplant (SOT) recipients, and to study predictors of immunogenicity, including the role of previous SARS-CoV-2 infection in immunity. Secondarily, safety was also assessed. Liver, heart, and kidney transplant recipients eligible for SARS-CoV-2 vaccination from three different institutions in Barcelona, Spain were included. IgM/IgG antibodies and T cell ELISpot against the S protein four weeks after receiving four consecutive booster doses of the vaccine were analyzed. One hundred and forty-three SOT recipients were included (41% liver, 38% heart, and 21% kidney). The median time from transplantation to vaccination was 6.6 years (SD 7.4). In total, 93% of the patients developed SARS-CoV-2 IgM/IgG antibodies and 94% S-ELISpot positivity. In total, 97% of recipients developed either humoral or cellular response (100% of liver recipients, 95% of heart recipients, and 88% of kidney recipients). Hypogammaglobulinemia was associated with the absence of SARS-CoV-2 IgG/IgM antibodies and S-ELISpot reactivity after vaccination, whereas past symptomatic SARS-CoV-2 infection was associated with SARS-CoV-2 IgG/IgM antibodies and S-ELISpot reactivity. Local and systemic side effects were generally mild or moderate, and no recipients experienced the development of de novo DSA or graft dysfunction following vaccination.

Respiratory viral infections including COVID-19 in solid organ transplantation

PURPOSE OF REVIEW

Respiratory viral infections are prevalent and contribute to significant morbidity and mortality among solid organ transplant (SOT) recipients. We review updates from literature on respiratory viruses, including severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), in the SOT recipient.

RECENT FINDINGS

With the wider availability and use of molecular diagnostic tests, our understanding of the epidemiology and impact of respiratory viruses in the SOT population continues to expand. While considerable attention has been given to the coronavirus disease 2019 (COVID-19) pandemic, the advances in prevention and treatment strategies of SARS-CoV-2 offered valuable insights into the development of new therapeutic options for managing other respiratory viruses in both the general and SOT population.

SUMMARY

Respiratory viruses can present with a diverse range of symptoms in SOT recipients, with potentially associated acute rejection and chronic lung allograft dysfunction in lung transplant recipients. The epidemiology, clinical presentations, diagnostic approaches, and treatment and preventive strategies for clinically significant RNA and DNA respiratory viruses in SOT recipients are reviewed. This review also covers novel antivirals, immunologic therapies, and vaccines in development for various community-acquired respiratory viruses.

Clinical outcomes following cessation of parenteral immunoglobulin therapy following lung transplantation

Broad use of parenteral immunoglobulin (IgG) therapy in lung transplant (LTx) patients occurs without robust clinical evidence or guidelines. Main indications include secondary hypogammaglobulinemia, antibody-mediated rejection (AMR), and treatment or prevention of graft rejection where the use of conventional immunosuppressive therapies is contraindicated. As part of routine auditing of IgG use in our LTx service, we assessed for adverse clinical outcomes related to IgG therapy cessation between November 2017 and February 2022. Of 220 LTx recipients receiving IgG therapy at our center during this period (approximately 20% of our total LTx cohort), 48 patients ceased therapy. No adverse outcomes were experienced in 83.3% patients. About 10.4% recommenced therapy for the same indication within 6 months with no longer term sequelae. One AMR patient developed progressive Chronic lung allograft dysfunction and died within 12 months, where therapy cessation was patient-initiated and associated with general noncompliance. These data provide reassurance that physician-directed cessation of IgG therapy is safe when based on sound clinical information and part of a robust clinical auditing process.

Intravenous immunoglobulin in kidney transplantation: Mechanisms of action, clinical applications, adverse effects, and hyperimmune globulin

Intravenous immunoglobulin (IVIG) has been developed for over 40 years. The mechanisms of action of IVIG are complex and diverse, and there may be multiple mechanisms that combine to influence it. IVIG has been used in kidney transplantation for desensitization, treatment of antibody-mediated rejection, and ABO-incompatible transplantation. and treatment or prevention of some infectious diseases. Hyperimmune globulins such as cytomegalovirus hyperimmune globulin (CMV-IG) and hepatitis B hyperimmune globulin (HBIG) have also been used to protect against cytomegalovirus and hepatitis B virus, respectively. However, IVIG is also associated with some rare but serious adverse effects and some application risks, and clinicians need to weigh the pros and cons and develop individualized treatment programs to benefit more patients. This review will provide an overview of the multiple mechanisms of action, clinical applications, adverse effects, and prophylactic measures of IVIG, and hyperimmune globulin will also be introduced in it.

Thawed plasma (TP) as a substitute for intravenous immune globulin (IVIG) to prevent hypogammaglobulinemia post-therapeutic plasma exchange

Intravenous immune globulin (IVIG) is a common treatment given after plasma exchange procedures to either prevent secondary hypogammaglobulinemia or as an adjunctive treatment for organ transplant rejection. However, side-effects are relatively common with this medication during and after infusion. This case-report describes our alternative to IVIG infusions post-plasma exchange. We hypothesize that in patients unable to tolerate IVIG, using thawed plasma as a replacement fluid provides a suitable increase in the patients post procedure immunoglobulin G (IgG) levels for patients with secondary hypogammaglobulinemia that are unable to tolerate IVIG infusions.

The recent outbreak of acute severe hepatitis in children of unknown origin - what is known so far

At the beginning of April 2022, 10 cases of severe acute hepatitis of unknown origin in children <10 years of age were reported across central Scotland. Since then, case numbers have increased rapidly, with 191 probable cases identified across Europe, the United States of America, Israel and Japan. Until now, 17 children required liver transplantation and 1 died. Accordingly, the Centers for Disease Control and Prevention and the European Centre for Diseases Prevention and Control have both issued a warning on a hepatitis of unknown origin in children. This review focuses on the available information concerning this recent outbreak and introduces some of the potential explanations for its development.

Practical guidance for the diagnosis and management of secondary hypogammaglobulinemia: A Work Group Report of the AAAAI Primary Immunodeficiency and Altered Immune Response Committees

Secondary hypogammaglobulinemia (SHG) is characterized by reduced immunoglobulin levels due to acquired causes of decreased antibody production or increased antibody loss. Clarification regarding whether the hypogammaglobulinemia is secondary or primary is important because this has implications for evaluation and management. Prior receipt of immunosuppressive medications and/or presence of conditions associated with SHG development, including protein loss syndromes, are histories that raise suspicion for SHG. In patients with these histories, a thorough investigation of potential etiologies of SHG reviewed in this report is needed to devise an effective treatment plan focused on removal of iatrogenic causes (eg, discontinuation of an offending drug) or treatment of the underlying condition (eg, management of nephrotic syndrome). When iatrogenic causes cannot be removed or underlying conditions cannot be reversed, therapeutic options are not clearly delineated but include heightened monitoring for clinical infections, supportive antimicrobials, and in some cases, immunoglobulin replacement therapy. This report serves to summarize the existing literature regarding immunosuppressive medications and populations (autoimmune, neurologic, hematologic/oncologic, pulmonary, posttransplant, protein-losing) associated with SHG and highlights key areas for future investigation.

Review: immunosuppression for the lung transplant patient

Lung transplantation (LTx) has evolved significantly since its inception and the improvement in LTx outcomes over the last three decades has predominantly been driven by advances in immunosuppression management. Despite the lack of new classes of immunosuppression medications, immunosuppressive strategies have evolved significantly from a universal method to a more targeted approach, reflecting a greater understanding of the need for individualized therapy and careful consideration of all factors that are influenced by immunosuppression choice. This has become increasingly important as the demographics of lung transplant recipients have changed over time, with older and more medically complex candidates being accepted and undergoing LTx. Furthermore, improved survival post lung transplant has translated into more immunosuppression related comorbidities long-term, predominantly chronic kidney disease (CKD) and malignancy, which has required further nuanced management approaches. This review provides an update on current traditional lung transplant immunosuppression strategies, with modifications based on pre-existing recipient factors and comorbidities, peri-operative challenges and long term complications, balanced against the perpetual challenge of chronic lung allograft dysfunction (CLAD). As we continue to explore and understand the complexity of LTx immunology and the interplay of different factors, immunosuppression strategies will require ongoing critical evaluation and personalization in order to continue to improve lung transplant outcomes.

Pneumococcal pneumonia in adult hospitalised solid organ transplant recipients: Nationwide, population-based surveillance

BACKGROUND

Pneumococcal disease poses a burden to the community in high risk population. Most early studies focused on invasive pneumococcal disease. However, the epidemiology of pneumococcal pneumonia (PP) requiring hospitalisation in solid organ transplant recipients (SOTRs) is poorly defined.

METHODS

We conducted a retrospective cohort study (January 1, 2000 and December 31, 2012) to evaluate the risk of PP requiring hospitalisation in SOTRs. SOTRs and non-SOT cohorts, propensity score-matched at a 1:1 ratio for age, sex, index date and underlying comorbidities, were identified from the National Health Insurance Research Database.

RESULTS

Each cohort consisted of 7507 patients. In the SOT cohort, 26 episodes of PP requiring hospitalisation were identified (incidence rate of 52.4 per 100,000 person-years). The risk of PP requiring hospitalisation in the SOT cohort was 1.50 times greater than in the non-SOT cohort [adjusted hazard ratio: 1.50, 95% confidence interval = 1.31-1.71, P < .001]. The nested case control study identified older age, kidney transplant, and concomitant chronic obstructive pulmonary disease, chronic kidney disease and heart failure as predictors of PP requiring hospitalisation in the SOT cohort. The highest risk period for PP requiring hospitalisation occurred within the first year of transplantation (36.47 per 1000 patients). Amongst kidney transplant recipients, patients with PP requiring hospitalisation exhibited higher cumulative incidences of graft failure than those without PP (log-rank test: P value = .004).

CONCLUSIONS

SOTRs are at risk of PP requiring hospitalisation with its attendant morbidity. Strategies to reduce risk of PP requiring hospitalisation using preventive vaccinations warrant further study.

Serum free light chains in solid organ transplant recipients

Immunoglobulin is built by a pair of identical heavy and a pair of identical light chains. Light chains are produced in excess compared to heavy chains. Free light chains (FLCs) are those which are not combined with heavy chains. Currently, numerous assays are available for the measurement of serum FLCs (sFLCs). These assays cannot be used interchangeably, and renal function should be taken into account in interpreting test results. Levels of kappa and lambda sFLCs are usually used to diagnose and monitor plasma cell dyscrasias. However, the clinical relevance of sFLCs is being investigated in patients with a variety of diseases, including patients after transplantation. There are contradictory results regarding the usefulness of sFLCs in the prediction of post-transplant lymphoproliferative disorder (PTLD). However, it seems that sFLCs may be helpful in the prediction of early-onset PTLD. Some studies have shown that low levels of sFLCs are associated with a higher risk of infection in patients after transplantation. This review summarizes and highlights recent advances in the utility of sFLCs in the prediction of PTLD and infection, and inflammation assessment in patients after solid organ transplantation. Moreover, the influence of immunosuppressive treatment on sFLCs levels is described briefly.

Hypogammaglobulinemia following heart transplantation: Prevalence, predictors, and clinical importance

Hypogammaglobulinemia (HGG) can occur following solid organ transplantation. However, there are limited data describing the prevalence, risk factors, and clinical outcomes associated with HGG following heart transplantation. We retrospectively reviewed data of 132 patients who had undergone heart transplantation at our institution between April 2014 and December 2018. We classified patients into three groups based on the lowest serum IgG level post-transplant: normal (≥700 mg/dL), mild HGG (≥450 and <700 mg/dL), and severe HGG (<450 mg/dL). We compared clinical outcomes from the date of the lowest IgG level. Mean age was 57 (47, 64) years, and 94 (71%) patients were male. Prevalence of severe HGG was the highest (27%) at 3-6 months following heart transplantation and then decreased to 5% after 1 year. Multivariate analysis showed that older age and Caucasian race were independent risk factors for HGG. Overall survival was comparable between the groups; however, survival free of infection was 73%, 60%, and 45% at 1 year in the normal, mild HGG, and severe HGG groups, respectively (P = .013). In conclusion, there is a high prevalence of HGG in the early post-heart transplant period that decreases over time. HGG is associated with an increased incidence of infection.

Discontinuation of immunoglobulin replacement therapy in patients with secondary antibody deficiency

INTRODUCTION

Secondary immunodeficiency is becoming a greater medical concern as the usage of immunosuppressive and biological treatments has increased. Individuals with certain medical conditions, such as hematological malignancies, can also have secondary immunodeficiency. Immunoglobulin replacement therapy (IGRT), which has been used for decades in inherited or primary immunodeficiency, provides some protection to patients with acquired and predominant antibody deficiency, i.e. secondary antibody deficiency (SAD). However, IGRT is costly, and supplies are limited. Although there are clinical guidelines on when to initiate IGRT, there is no guideline on when to discontinue it.

AREAS COVERED

The authors reviewed existing literature and provided an overview of the current state of knowledge regarding IGRT discontinuation in SAD patients.

EXPERT OPINION

Long-term supplementary immunoglobulin may not be necessary. Although it is possible to successfully transition away from IGRT in individuals with SAD, evidence-based practices are limited. Without clear guidelines and reliable prognostic markers, IGRT discontinuation practices are restricted to clinical judgment. For this reason, additional research should be conducted to identify markers that indicate the recovery of humoral immunity. Furthermore, the derivation and validation of a set of combined clinical and laboratory criteria to allow safe and timely IGRT discontinuation is warranted.

Cyclosporine a directly affects human and mouse b cell migration in vitro by disrupting a hIF-1 αdependent, o2 sensing, molecular switch

BACKGROUND

Hypoxia is a potent molecular signal for cellular metabolism, mitochondrial function, and migration. Conditions of low oxygen tension trigger regulatory cascades mediated via the highly conserved HIF-1 α post-translational modification system. In the adaptive immune response, B cells (Bc) are activated and differentiate under hypoxic conditions within lymph node germinal centers, and subsequently migrate to other compartments. During migration, they traverse through changing oxygen levels, ranging from 1-5% in the lymph node to 5-13% in the peripheral blood. Interestingly, the calcineurin inhibitor cyclosporine A is known to stimulate prolyl hydroxylase activity, resulting in HIF-1 α destabilization and may alter Bc responses directly. Over 60% of patients taking calcineurin immunosuppressant medications have hypo-gammaglobulinemia and poor vaccine responses, putting them at high risk of infection with significantly increased morbidity and mortality.

RESULTS

We demonstrate that O 2 tension is a previously unrecognized Bc regulatory switch, altering CXCR4 and CXCR5 chemokine receptor signaling in activated Bc through HIF-1 α expression, and controlling critical aspects of Bc migration. Our data demonstrate that calcineurin inhibition hinders this O 2 regulatory switch in primary human Bc.

CONCLUSION

This previously unrecognized effect of calcineurin inhibition directly on human Bc has significant and direct clinical implications.

Epidemiologic perspectives on immunosuppressed populations and the immunosurveillance and immunocontainment of cancer

The advent in the last several years of effective immunotherapy for cancer has renewed interest in the role of the immune system in controlling cancer. The idea that the immune system can help control cancer has a long history. Solid organ transplant recipients (SOTRs) as well as human immunodeficiency virus (HIV)-infected people are affected by cell-mediated immune dysfunction. Epidemiologic studies of these populations reveal a pattern characterized by a strongly increased incidence of virus-related cancers (eg, Kaposi sarcoma, non-Hodgkin lymphoma, and anogenital cancers). In addition, recent epidemiologic studies have evaluated cancer-specific mortality among SOTRs and HIV-infected people following a cancer diagnosis. For a wider range of cancers-not limited to those caused by viruses, and including melanoma and cancers of the colorectum, lung, and breast- these immunosuppressed cancer patients have higher cancer-specific mortality than other cancer patients. This latter group of cancers somewhat mirrors those for which immunotherapy with checkpoint inhibitors is approved. These epidemiologic observations suggest that there are 2 distinct immune selection processes in humans: immunosurveillance directed against premalignant cells before cancer diagnosis (most relevant for preventing virus-related cancers), and "immunocontainment" directed against established cancers. These processes thus appear relevant for different groups of malignancies and may have different mechanisms.

Acquired hypogammaglobulinemia and pathogen-specific antibody depletion after solid organ transplantation in human immunodeficiency virus infection: A brief report

Hypogammaglobulinemia (HGG) frequently occurs in recipients after types of (SOT). The incidence and significance of HGG in HIV+ recipients of SOT are just being explored. We reported that 12% of the recipients in the SOT in multi-center HIV-TR (HIV-TR) Study developed moderate or severe HGG at 1 year. In LT recipients, this was associated with serious infections and death. We have now further characterized the decreased antibodies in HIV+ SOT recipients who developed HGG. We measured the levels of pathogen-specific antibodies and poly-specific self-reactive antibodies (PSA) in relation to total IgG levels from serial serum samples for 20 HIV+ SOT recipients who developed moderate to severe HGG following SOT. Serum antibody levels to measles, tetanus toxoid, and HIV-1 were determined by EIA. Levels of PSAs were determined by incubating control lymphocytes with patient serum, staining with anti-human IgG Fab-FITC, and analysis by flow cytometry. Levels of PSA were higher compared to healthy, HIV-uninfected controls at pre-transplant baseline and increased by weeks 12 and 26, but the changes were not significant. Likewise, anti-HIV antibody levels remained unchanged over time. In contrast, antibody levels against measles and tetanus were significantly reduced from baseline by week 12, and did not return to baseline, even after 2 years. For HIV patients who develop moderate to severe HGG after transplant, the reduction in IgG levels is associated with a significant decrease in pathogen-specific antibody titers, while PSA levels and anti-HIV antibodies are unchanged. This may contribute to infectious complications and other clinical endpoints.

Clinical outcomes of polyvalent immunoglobulin use in solid organ transplant recipients: A systematic review and meta-analysis

Polyvalent immunoglobulin is commonly used for desensitization and treatment of antibody-mediated rejection in kidney transplantation but its impact on other outcomes is not known. This systematic review investigated the impact of immunoglobulin prophylaxis on infection, rejection, graft loss, and death following kidney transplantation. A comprehensive literature search located 18 studies (n = 8 randomized controlled trials). None examined the effect of immunoglobulin prophylaxis in transplant recipients with hypogammaglobulinemia. Quality of included studies was variable with high to very high risk of bias. In the randomized trials, immunoglobulin use did not reduce cytomegalovirus infection (OR 0.68 [0.39, 1.21]; 6 studies, n = 295), rejection (OR 0.96 [0.50, 1.82]; 4 studies, n = 187), or graft loss (OR 1.03 [0.46, 2.30]; 6 studies, n = 265). In non-randomized studies, immunoglobulin did not reduce cytomegalovirus infection (OR 0.63 [0.20, 1.94]; 6 studies, n = 361) or death (OR 1.32 [0.05, 38.79]; 3 studies, n = 222) but reduce rejection (OR 0.47 [0.24, 0.94]; 4 studies, n = 268) and graft loss (OR 0.15 [0.05, 0.43]; 2 studies, n = 118). Data were scarce and sample size of current evidence was small. Adequately powered randomized trials are needed to determine if immunoglobulin is an effective intervention to reduce infection, rejection, graft loss, or death following kidney transplantation with and without hypogammaglobulinemia.

Adenovirus in solid organ transplant recipients: Guidelines from the American Society of Transplantation Infectious Diseases Community of Practice

These updated guidelines from the Infectious Diseases Community of Practice of the American Society of Transplantation review the diagnosis, prevention, and management of adenovirus infections after solid organ transplantation. Adenovirus is an important cause of infectious complications in both stem cell transplant and SOT patients, causing a range of clinical syndromes including pneumonitis, colitis, and disseminated disease. The current update of the guidelines highlights that adenovirus surveillance testing should not be performed in asymptomatic recipients. Serial quantitative PCR might play a role in the decision to initiate or assess response to therapy in a symptomatic patient. The initial and most important components of therapy remain supportive care and decrease in immunosuppression. The use of antiviral therapy is not supported by prospective randomized clinical trials. However, intravenous cidofovir is considered the standard practice for treatment of severe, progressive, or disseminated adenovirus disease in most transplant centers. Intravenous immunoglobulin may be beneficial, primarily in a select group of patients with hypogammaglobulinemia. Future approaches to treatment of adenovirus disease may include administration of adenovirus-specific T-cell therapy.

Viral Diagnostics

This chapter discusses recent developments in diagnostics for cytomegalovirus (CMV), Epstein-Barr virus (EBV), BK virus (BKV), community respiratory viruses (CRVs), parvovirus, hepatitis viruses, HIV, and other viral agents of importance in solid organ and hematopoietic stem cell transplantation.

Impact of pretransplant CMV-specific T-cell immune response in the control of CMV infection after solid organ transplantation: a prospective cohort study

INTRODUCTION

Although solid organ transplant (SOT) recipients with pretransplant serology for cytomegalovirus (CMV-R+) are considered at intermediate risk for CMV infection post transplantation, CMV infection remains a major cause of morbidity in this population. We prospectively characterized whether having pretransplant CMV-specific cellular immunity is independently associated with controlling infection after transplantation in R + SOT recipients.

METHODS

A prospective cohort of consecutive R + SOT recipients that received pre-emptive treatment for CMV infection was monitored after transplantation and variables were recorded during the follow-up. The cytomegalovirus-specific T-cell immune response was characterized by intracellular cytokine staining and viral loads determined using real-time PCR.

RESULTS

One hundred and thirty-five R + SOT recipients were included (67 kidney, 64 liver, four liver-kidney). Only one-third of the patients (42; 31.85%) had CMV-specific T-cell immunity (CD8⁺CD69⁺INF-γ⁺ T cells >0.25%) before transplantation. Patients with negative pretransplant immunity had more CMV infection (49, 52.7% vs. 15, 35.7%; p 0.07) and received more antiviral therapy than those with immunity (32, 34.4% vs. 6, 14.3%, p 0.016). Having CMV specific immunity was an independent factor for protection from developing viraemia ≥2000 IU/mL (OR 0.276, 95% CI 0.105-0.725, p < 0.01) and lower administration of treatment (OR 0.398, 95% CI 0.175-0.905, p 0.028). Only patients with no pretransplant CMV-specific T-cell response were diagnosed with CMV-disease (8, 8.6% vs. 0, 0%, p 0.05).

DISCUSSION

Our results show that having a pretransplant CMV specific T-cell response may be associated with a lower rate of CMV viraemia and less antiviral treatment after transplantation; however, more prospective studies are needed to confirm these findings.

Complex interplay of multiple biological systems that contribute to post-stroke infections

Stroke is a leading contributor of death and disability around the world. Despite its recognised debilitating neurological deficits, a devastating clinical complication of surviving stroke patients that needs more attention is infection. Up to half of the patients develop infections after stroke, and a high proportion of them will die as a direct consequence. Major clinical trials that examined preventive antibiotic therapy in stroke patients have demonstrated this method of prevention is not effective as it does not reduce incidence of post-stroke pneumonia or improve patient outcome. Additionally, retrospective studies evaluating the use of β-blockers for the modulation of the sympathetic nervous system to prevent post-stroke infections have given mixed results. Therefore, there is an urgent need for more effective therapeutic options that target the underlying mechanisms of post-stroke infections. The understanding that infections are largely attributable to the "stroke-induced systemic immunosuppression" phenomenon has begun to emerge, and thus, exploring the pathways that trigger post-stroke immunosuppression is expected to reveal potential new therapeutics. As such, we will outline the impacts that stroke has on several biological systems in this review, and discuss how these contribute to host susceptibility to infection after stroke. Furthermore, the emerging role of the gut and its microbiota has recently come to surface and intensifies the complex pathways to post-stroke infection. Finally, we identify potential avenues to combat infection that target the pathways of stroke-induced systemic immunosuppression to ultimately improve stroke patient outcome.

Diagnostic utility of monitoring cytomegalovirus-specific immunity by QuantiFERON-cytomegalovirus assay in kidney transplant recipients

Background

Despite universal prophylaxis, late cytomegalovirus (CMV) infection occurs in a high proportion of kidney transplant recipients. We evaluated whether a specific viral T-cell response allows for the better identification of recipients who are at high risk of CMV infection after prophylaxis withdrawal.

Methods

We conducted a prospective study in 19 pretransplant anti-CMV seronegative kidney graft recipients R- (18 from seropositive donors [D+] and one from a seronegative donor [D-]) and 67 seropositive recipients R(+) (59 from seropositive donors and eight from seronegative donors) who received antiviral prophylaxis with valganciclovir. The QuantiFERON-CMV (QF-CMV) assay was performed within the first and third months after transplantation. Blood samples were monitored for CMV DNAemia using a commercial quantitative nucleic acid amplification test (QNAT) that was calibrated to the World Health Organization International Standard.

Results

Twenty-one of the 86 patients (24%) developed CMV viremia after prophylaxis withdrawal within 12 months posttransplantation. In the CMV R(+) group, the QF-CMV assay yielded reactive results (QF-CMV[+]) in 51 of 67 patients (76%) compared with 7 of 19 patients (37%) in the CMV R(−) group (p = 0.001). In the CMV R(+) group, infection occurred in seven of 16 recipients (44%) who were QF-CMV(−) and eight of 51 recipients (16%) who were QF-CMV(+). In the CMV R(−) group, infection evolved in five of 12 recipients (42%) who were QF-CMV(−) and one of 7 recipients (14%) who were QF-CMV(+). No difference was found in the incidence of CMV infection stratified according to the QF-CMV results with regard to the recipients’ pretransplant CMV IgG serology (p = 0.985). Cytomegalovirus infection occurred in 15 of 36 patients (42%) with hypogammaglobulinemia (HGG) 90 days posttransplantation compared with two of 34 patients (6%) without HGG (p = 0.0004). Cytomegalovirus infection occurred in seven of 13 patients (54%) with lymphocytopenia compared with 14 of 70 patients (20%) without lymphocytopenia (p = 0.015). The multivariate analysis revealed that the nonreactive QuantiFERON-CMV assay was an independent risk factor for postprophylaxis CMV infection.

Conclusions

In kidney transplant recipients who received posttransplantation prophylaxis, negative QF-CMV results better defined the risk of CMV infection than initial CMV IgG status after prophylaxis withdrawal. Hypogammaglobulinemia and lymphocytopenia were risk factors for CMV infection.

Research status of pulmonary infection after renal transplantation

Recipients with a low immunity are under a high risk of infection due to the extensive use of immunosuppressive drugs after renal transplantation. Pulmonary infection after renal transplantation is a prevalent postoperative complication characterized by a wide range of pathogens and high mortality. If the disease cannot be diagnosed in time, then the therapeutic effect will not be effective. This article reviews susceptible factors, high onset time, common pathogens, clinical manifestations, and therapy of pulmonary infection after renal transplantation to provide reference for disease prevention and treatment.

Case Report: Renal Transplantation in Patients with Pre-existing Hypogammaglobulinemia

Hypogammaglobulinemia (HGG) is well-characterized as a common phenomenon after kidney transplantation. However, no reports of pre-existing HGG from kidney transplantation seem to be available. We have reviewed three patients who developed HGG prior to kidney transplantation, and all three were treated successfully with immunoglobulin replacement therapy before and after kidney transplantation. The kidney grafts were functioning at follow-up 1.5-8 years (mean: 3.6 years) after transplantation, and there were no diagnosed episodes of clinical rejections and no severe infection complications post-transplantation.

Impact of Immunoglobulin Therapy in Intestinal Transplant Recipients With Posttransplantation Hypogammaglobulinemia

BACKGROUND

Severe hypogammaglobulinemia (HGG) (IgG <400 mg/dL) following intestinal transplantation is common. Although IgG replacement therapy is commonly used, clinical outcomes associated with increasing IgG levels to >400 mg/dL are not well described.

METHODS

Kaplan-Meier analysis was performed to estimate survival, the log-rank test to compare survival distributions between groups, and the Fisher exact test to determine the association between HGG and rejection.

RESULTS

A total of 23 intestinal transplant (IT) recipients with a median age of 2.3 years (range, 0.7-41 years) at the time of HGG diagnosis were included. The types of transplants were liver-small bowel (73.9%), liver-small bowel-kidney (8.7%), and small bowel only (17.4%). The 3-year survival after the diagnosis of HGG was 50.2% (95% confidence interval [CI] = 28.2%-68.7%). There was no difference in survival (P = .67) when patients were dichotomized based upon IgG level at last follow-up (IgG ≥400 mg/dL, n = 14; and IgG <400 mg/dL, n = 9). There was no also evidence of an association between survival and: total dose (P = .58), frequency (P = .11), and number of IgG doses administered (P = .8). There was no difference in survival between patients receiving (n = 12) or not receiving (n = 11) cytomegalovirus hyperimmunoglobulin (P = .10).

CONCLUSIONS

Improved survival rates were not found in our IT recipients with severe HGG with immunoglobulin therapy to IgG levels of ≥400 mg/dL, even when cytomegalovirus hyperimmunoglobulin was administered.

Clinical outcomes of immunoglobulin use in solid organ transplant recipients: protocol for a systematic review and meta-analysis

BACKGROUND

Transplantation improves survival and the quality of life of patients with end-stage organ failure. Infection, due to surgical issues, host factors such as diabetes, immunosuppression, and hypogammaglobulinemia, is a major post-transplant complication. Clinical outcomes of prophylaxis or treatment of hypogammaglobulinemia in solid organ transplant recipients are not well established and are in need of further study.

METHODS/DESIGN

We will conduct a systematic review of studies investigating clinically relevant outcomes of immunoglobulin use either as prophylaxis or treatment of hypogammaglobulinemia after solid organ transplantation. Both randomized and non-randomized studies (excluding case reports and case series of less than 20 subjects) will be included. Outcomes of interest will include the overall rate of infection, hospital admission, hospital length of stay, intensive care unit admission, 1-year all-cause mortality, incidence of acute organ rejection, allograft survival within 1 year, and adverse events. We will search MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, Transplant library, and the International Clinical Trials Registry Platform for randomized and non-randomized studies on adult solid organ transplant patients who received prophylactic immunoglobulin or immunoglobulin treatment. Two reviewers will conduct all screening and data collection independently. We will assess study level of risk of bias using the Cochrane Risk of Bias Assessment Tool for randomized controlled trials and for non-randomized studies. If meta-analysis of outcome data is deemed appropriate, we will use random effects models to combine data for continuous and dichotomous measures.

DISCUSSION

The results of this systematic review may inform guideline development for measuring immunoglobulin level and use of immunoglobulin in solid organ transplant patients and highlight areas for further research.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015017620.

Serum immunoglobulin G levels and peritonitis in peritoneal dialysis patients

BACKGROUND

Peritonitis is a frequent and serious complication of peritoneal dialysis (PD). Whether low immunoglobulin level is associated with PD-related peritonitis is unknown.

METHODS

We conducted a prospective study to assess whether immunoglobulin levels at PD onset could predict the occurrence of peritonitis. All patients starting peritoneal dialysis between 01/2005 and 12/2010 at the University hospital of Besançon, France, were included in the study.

RESULTS

Of 240 consecutive PD patients enrolled (mean follow-up 25 ± 12 months), 76 (32%) had at least one episode of peritonitis. Mean immunoglobulin (Ig)G level at PD start was lower in patients who subsequently experienced peritonitis (7.9 + 3.4 vs. 9.7 + 3.4 g/l, p = 0.005). An increased IgG level at PD onset was associated with a reduced risk of peritonitis [hazard ratio (HR) 0.88, 95% confidence interval (CI) 0.80-0.97 for each increase of 1 g/l in IgG, p = 0.008]. IgG level ≤6.4 g/l ("low IgG") was the best predictive value for the occurrence of subsequent peritonitis: 52 patients (24%) had low IgG levels. At multivariate analysis, both low IgG level (HR 2.49, 95% CI 1.32-4.69, p = 0.005) and diabetes (HR 2.78, 95% CI 1.49-5.20, p = 0.001) were predictive of the occurrence of peritonitis.

CONCLUSION

Low IgG levels predict the occurrence of PD-related peritonitis. Randomized studies should determine whether such patients could benefit from intravenous immunoglobulin administration.

Does increasing immunoglobulin levels impact survival in solid organ transplant recipients with hypogammaglobulinemia?

BACKGROUND

Severe hypogammaglobulinemia (IgG < 400 mg/dL) has adverse impact on mortality during the first year post-transplantation. The aim of the study was to determine whether increasing IgG levels to ≥400 mg/dL improved outcomes.

METHODS

Kaplan-Meier analyses were performed to estimate survival, log-rank test to compare survival distributions between groups, and Fisher's exact test to determine the association between hypogammaglobulinemia and rejection or graft loss.

RESULTS

Thirty-seven solid organ transplant (SOT) recipients were included. Hypogammaglobulinemia was diagnosed at median of 5.6 months (range: 0-291.8 months) post-transplantation. Types of transplants: liver-small bowel (17); liver-small bowel-kidney (2); liver (5); small bowel (4); liver-kidney (1); kidney/kidney-pancreas (3); heart (3); heart-kidney (1); and heart-lung (1). The three-yr survival after the diagnosis of hypogammaglobulinemia was 49.5% (95% CI: 32.2-64.6%). Patients were dichotomized based upon IgG level at last follow-up: IgG ≥ 400 mg/dL (23 patients) and IgG < 400 mg/dL (14 patients). There was no evidence of a difference in survival (p = 0.44), rejection rate (p = 0.44), and graft loss censored for death (p = 0.99) at one yr between these two groups. There was no difference in survival between patients receiving or not immunoglobulin (p = 0.99) or cytomegalovirus hyperimmunoglobulin (p = 0.14).

CONCLUSION

Severe hypogammaglobulinemia after SOT is associated with high mortality rates, but increasing IgG levels to ≥400 mg/dL did not seem to translate in better patient or graft survival in this cohort.

Bilateral lung transplantation in a patient with humoral immune deficiency: a case report with review of the literature

Humoral immune deficiencies have been associated with noninfectious disease complications including autoimmune cytopenias and pulmonary disease. Herein we present a patient who underwent splenectomy for autoimmune cytopenias and subsequently was diagnosed with humoral immune deficiency in the context of recurrent infections. Immunoglobulin analysis prior to initiation of intravenous immunoglobulin (IVIG) therapy was notable for low age-matched serum levels of IgA (11 mg/dL), IgG2 (14 mg/L), and IgG4 (5 mg/L) with a preserved total level of IgG. Flow cytometry was remarkable for B cell maturation arrest at the IgM+/IgD+ stage. Selective screening for known primary immune deficiency-causing genetic defects was negative. The disease course was uniquely complicated by the development of pulmonary arteriovenous malformations (AVMs), ultimately requiring bilateral lung transplantation in 2012. This is a patient with humoral immune deficiency that became apparent only after splenectomy, which argues for routine immunologic evaluation prior to vaccination and splenectomy. Lung transplantation is a rare therapeutic endpoint and to our knowledge has never before been described in a patient with humoral immune deficiency for the indication of pulmonary AVMs.

Clinical immune-monitoring strategies for predicting infection risk in solid organ transplantation

Infectious complications remain a leading cause of morbidity and mortality after solid organ transplantation (SOT), and largely depend on the net state of immunosuppression achieved with current regimens. Cytomegalovirus (CMV) is a major opportunistic viral pathogen in this setting. The application of strategies of immunological monitoring in SOT recipients would allow tailoring of immunosuppression and prophylaxis practices according to the individual's actual risk of infection. Immune monitoring may be pathogen-specific or nonspecific. Nonspecific immune monitoring may rely on either the quantification of peripheral blood biomarkers that reflect the status of a given arm of the immune response (serum immunoglobulins and complement factors, lymphocyte sub-populations, soluble form of CD30), or on the functional assessment of T-cell responsiveness (release of intracellular adenosine triphosphate following a mitogenic stimulus). In addition, various methods are currently available for monitoring pathogen-specific responses, such as CMV-specific T-cell-mediated immune response, based on interferon-γ release assays, intracellular cytokine staining or main histocompatibility complex-tetramer technology. This review summarizes the clinical evidence to date supporting the use of these approaches to the post-transplant immune status, as well as their potential limitations. Intervention studies based on validated strategies for immune monitoring still need to be performed.

Effects of Rituximab on the Development of Viral and Fungal Infections in Renal Transplant Recipients

Background. Rituximab is becoming increasingly utilized in renal transplant recipients; however, its association with infections remains unclear. Methods. We reviewed the incidence of viral and fungal infections in kidney transplant recipients treated with () or without () rituximab (RTX) in addition to standard immunosuppression. Results. Infections occurred in 134 (30%) patients, with a greater proportion in RTX versus no RTX patients (47% versus 28%; ). Viral infections occurred in 44% and 27% of RTX and no RTX patients, respectively (). This was largely driven by the frequency of BK viremia and noncytomegalovirus/non-BK viruses in RTX patients (27% versus 13% () and 15% versus 2% (), resp.). Fungal infections also occurred more often in RTX patients (11% versus 3 %; ). Multivariate analysis revealed deceased donor recipient (odds ratio = 2.5; ) and rituximab exposure (odds ratio = 2.2; ) as independent risk factors for infection. Older patients, deceased donor recipients, those on dialysis longer, and those with delayed graft function tended to be at a greater risk for infections following rituximab. Conclusions. Rituximab is associated with an increased incidence of viral and fungal infections in kidney transplantation. Additional preventative measures and/or monitoring infectious complications may be warranted in those receiving rituximab.

What is the impact of hypogammaglobulinemia on the rate of infections and survival in solid organ transplantation? A meta-analysis

Hypogammaglobulinemia has been described after solid organ transplantation and has been associated with increased risk of infections. The aim of the study was to evaluate the rate of severe hypogammaglobulinemia and its relationship with the risk of infections during the first year posttransplantation. Eighteen studies (1756 patients) that evaluated hypogammaglobulinemia and posttransplant infections were included. The data were pooled using the DerSimonian and Laird random-effects model. Q statistic method was used to assess statistical heterogeneity. Within the first year posttransplantation, the rate of hypogammaglobulinemia (IgG < 700 mg/dL) was 45% (95% CI: 0.34-0.55; Q = 330.1, p < 0.0001), the rate of mild hypogammaglobulinemia (IgG = 400-700 mg/dL) was 39% (95% CI: 0.22-0.56; Q = 210.09, p < 0.0001) and the rate of severe hypogammaglobulinemia (IgG < 400 mg/dL) was 15% (95% CI: 0.08-0.22; Q = 50.15, p < 0.0001). The rate of hypogammaglobulinemia by allograft type: heart 49% (21%-78%; Q = 131.16, p < 0.0001); kidney 40% (30%-49%; Q = 24.55, p = 0.0002); liver 16% (0.001%-35%; Q = 14.31, p = 0.0002) and lung 63% (53%-74%; Q = 6.85, p = 0.08). The odds of respiratory infection (OR = 4.83; 95% CI: 1.66-14.05; p = 0.004; I(2) = 0%), CMV (OR = 2.40; 95% CI: 1.16-4.96; p = 0.02; I(2) = 26.66%), Aspergillus (OR = 8.19; 95% CI: 2.38-28.21; p = 0.0009; I(2) = 17.02%) and other fungal infections (OR = 3.69; 95% CI: 1.11-12.33; p = 0.03; I(2) = 0%) for patients with IgG < 400 mg/dL were higher than the odds for patients with IgG > 400 mg/dL. The odds for 1-year all-cause mortality for severe hypogammaglobulinemia group was 21.91 times higher than those for IgG > 400 mg/dL group (95% CI: 2.49-192.55; p = 0.005; I(2) = 0%). Severe hypogammaglobulinemia during the first year posttransplantation significantly increased the risk of CMV, fungal and respiratory infections, and was associated with higher 1-year all-cause mortality.

Acquired hypogammaglobulinemia in HIV-positive subjects after liver transplantation

INTRODUCTION

As more solid organ transplantations are performed in patients infected with human immunodeficiency virus (HIV), post-transplant complications in this population are becoming better defined.

METHODS

Using serum samples from the Solid Organ Transplantation in HIV: Multi-Site Study, we studied the epidemiology of acquired hypogammaglobulinemia (HGG) after liver transplantation (LT) in 79 HIV-infected individuals with a median CD4 count at enrollment of 288 (interquartile range 200-423) cells/μL. Quantitative immunoglobulin G (IgG) levels before and after LT were measured, with moderate and severe HGG defined as IgG 350-500 mg/dL and <350 mg/dL, respectively. Incidence, risk factors, and associated outcomes of moderate or worse HGG were evaluated using Kaplan-Meier estimator and proportional hazards (PH) models.

RESULTS

The 1-year cumulative incidence of moderate or worse HGG was 12% (95% confidence interval [CI]: 6-22%); no new cases were observed between years 1 and 2. In a multivariate PH model, higher pre-transplant model for end-stage liver disease score (P = 0.04) and treated acute rejection (P = 0.04) were both identified as significant predictors of moderate or worse HGG. There was a strong association of IgG levels <500 mg/dL with non-opportunistic serious infection (hazard ratio [95% CI]: 3.5 [1.1-10.6]; P = 0.03) and mortality (3.2 [1.1-9.4]; P = 0.04). These associations held after adjustment for important determinants of infection and survival among the entire cohort.

CONCLUSION

These results suggest that a proportion of HIV-positive LT recipients will develop clinically significant HGG after transplantation.

Incidence, timing, and significance of early hypogammaglobulinemia after intestinal transplantation

BACKGROUND

Despite recent advances in intestinal transplantation (ITx), infection (INF) and acute cellular rejection (ACR) remain major causes of patient and graft loss. Studies in other solid-organ transplantations indicate that low levels of serum immunoglobulin G (IgG) negatively impact outcomes. To date, there have been no studies on IgG after ITx.

METHODS

A retrospective review of an IgG measurement protocol in primary ITx recipients between 2007 and 2011 was undertaken. IgG levels were measured at the time of evaluation, transplantation, and at weekly intervals for 2 months. Hypogammaglobulinemia (HGG) was defined as IgG levels below the lower limit of the 95% confidence interval for age. Associations between HGG, INF, and ACR were tested, and the incidence and timing of INF and ACR were compared.

RESULTS

Thirty-four patients were transplanted at a mean (SD) age of 12.4 (17.2) years. Most were Latino children with gastroschisis who received multivisceral grafts. Relative to pre-ITx levels, a statistically significant decrease in IgG levels was observed after ITx (P<0.05). Twenty patients (59%) developed HGG during the post-ITx period at a mean (SD) of 9.8 days. No significant associations were identified between HGG and INF or ACR.

CONCLUSIONS

This is the first study to describe serum IgG levels after ITx. A marked decrease in serum IgG levels was observed early on, in most patients. The etiology is potentially related to immunotherapy. HGG was not associated with INF or ACR, possibly related to the sample size and our practice of exogenous intravenous immunoglobulin replacement.

Plasma markers of B-cell activation and clonality in pediatric liver and hematopoietic stem cell transplant recipients

BACKGROUND

Transplant recipients are at risk of posttransplant lymphoproliferative disease (PTLD).

METHODS

Thirty-six pediatric transplant recipients were evaluated (18 hematopoietic stem cell and 18 liver recipients; 12 had PTLD). We studied 207 longitudinal plasma samples from these recipients for three markers of B-cell activation or clonality: immunoglobulin free light chains (FLCs), soluble CD30 (sCD30), and monoclonal immunoglobulins (M-proteins).

RESULTS

Kappa FLCs, lambda FLCs, and sCD30 were elevated in 20.8%, 28.0%, and 94.2% of plasma specimens, respectively. Free light chain and sCD30 levels increased significantly 1.18 to 1.82 fold per log10 Epstein-Barr virus (EBV) load in peripheral blood. Five PTLD cases manifested elevated FLCs with an abnormal kappa/lambda ratio, suggesting monoclonal FLC production. M-proteins were present in 91% of PTLD cases versus 50% to 67% of other recipients with high or low EBV loads (P=0.13). Concordance of FLCs, M-proteins, and PTLD tumor light chain restriction was imperfect. For example, one PTLD case with an IgG lambda M-protein had a tumor that was kappa restricted, and another case with an M-protein had a T-cell PTLD. In an additional case, an IgM kappa M-protein and excess kappa FLCs were both detected in plasma at PTLD diagnosis; although the tumor was not restricted at diagnosis, kappa restriction was present 5 years later when the PTLD relapsed.

CONCLUSIONS

Plasma markers of B-cell dysfunction are frequent after transplantation and associated with poor EBV control. These abnormal markers may be produced by oligoclonal B-cell populations or PTLD tumor cells and could potentially help identify recipients at high risk of PTLD.

What do we know about adenovirus in renal transplantation?

Adenoviruses are common pathogens that have the potential to cause opportunistic infections with significant morbidity and mortality in immunocompromised hosts. The significance of adenoviral infection and disease is incompletely known in the setting of kidney transplantation. Reported adenovirus infections in renal transplant recipients have typically manifested as hemorrhagic cystitis and tubulointerstitial nephritis, less severe diseases than often seen in other solid organ transplant recipients (i.e. pneumonia, hepatitis and enteritis). The prevalent adenovirus subgroups associated with cystitis and nephritis are B1 and B2 with the serotypes 7, 11, 34, 35. However, disseminated or severe adenovirus infections, including fatal cases, have been described in renal transplant recipients. There is uncertainty regarding monitoring of and treatment of this virus. Although not supported by randomized clinical trials, cidofovir is used for the treatment of adenovirus disease not responding to reduction of immunosuppression.

ImmuKnow as a diagnostic tool for predicting infection and acute rejection in adult liver transplant recipients: a systematic review and meta-analysis

Immune status monitoring of transplant recipients could identify patients at risk of acute rejection, infection, and cancer, which are important sources of morbidity and mortality in these patients. The ImmuKnow assay provides an objective assessment of the cellular immune function of immunosuppressed patients. Inconclusive results concerning the ability of the ImmuKnow test to predict acute rejection and infection have raised concerns about the predictive value of ImmuKnow in liver transplant recipients. We conducted a systematic literature review to identify studies published up to March 2012 that documented the use of ImmuKnow for monitoring immune function in liver transplant recipients. The study quality was assessed with the Quality Assessment of Diagnostic Accuracy Studies 2 score. We identified 5 studies analyzing ImmuKnow performance for infection and 5 studies analyzing ImmuKnow performance for acute rejection. The pooled sensitivity, specificity, positive likelihood ratio, diagnostic odds ratio, and area under the summary receiver operating characteristic curve were 83.8% [95% confidence interval (CI) = 78.5%-88.3%], 75.3% (95% CI = 70.9%-79.4%), 3.3 (95% CI = 2.8-4.0), 14.6 (95% CI = 9.6-22.3), and 0.824 ± 0.034, respectively, for infection and 65.6% (95% CI = 55.0%-75.1%), 80.4% (95% CI = 76.4%-83.9%), 3.4 (95% CI = 2.4-4.7), 8.8 (95% CI = 3.1-24.8), and 0.835 ± 0.060, respectively, for acute rejection. Heterogeneity was low for infection studies and high for acute rejection studies. In conclusion, the ImmuKnow test is a valid tool for determining the risk of further infection in adult liver transplant recipients. Significant heterogeneity across studies precludes the conclusion that ImmuKnow identifies liver transplant patients at risk for rejection.

Monitoring of immunoglobulin levels identifies kidney transplant recipients at high risk of infection

We aimed to analyze the incidence, risk factors and impact of hypogammaglobulinemia (HGG) in 226 kidney transplant (KT) recipients in which serum immunoglobulin (Ig) levels were prospectively assessed at baseline, month 1 (T(1) ), and month 6 (T(6) ). The prevalence of IgG HGG increased from 6.6% (baseline) to 52.0% (T(1) ) and subsequently decreased to 31.4% (T(6) ) (p < 0.001). The presence of IgG HGG at baseline (odds ratio [OR] 26.9; p = 0.012) and a positive anti-HCV status (OR 0.17; p = 0.023) emerged as risk factors for the occurrence of posttransplant IgG HGG. Patients with HGG of any class at T(1) had higher incidences of overall (p = 0.018) and bacterial infection (p = 0.004), bacteremia (p = 0.054) and acute pyelonephritis (p = 0.003) in the intermediate period (months 1-6). Patients with HGG at T(6) had higher incidences of overall (p = 0.004) and bacterial infection (p < 0.001) in the late period (>6 month). A complementary log-log model identified posttransplant HGG as an independent risk factor for overall (hazard ratio [HR] 2.03; p < 0.001) and bacterial infection (HR 2.68; p < 0.0001). Monitoring of humoral immunity identifies KT recipients at high risk of infection, offering the opportunity for preemptive immunoglobulin replacement therapy.