Possible implication of bacterial infection in acute graft-versus-host disease after allogeneic hematopoietic stem cell transplantation

Patients admitted in the intensive care unit after solid organ or bone marrow transplantation: Retrospective cohort study

BACKGROUND

Solid organ transplantation (SOT) and hematopoietic stem cell transplantation (HSCT) revolutionized the survival and quality of life of patients with malignant diseases, various immunologic, and metabolic disorders or those associated with a significant impairment in a patient's quality of life.

AIM

To investigate admission causes and treatment outcomes of patients after SOT or HSCT treated in a medical intensive care unit (ICU).

METHODS

We conducted a single-center, retrospective epidemiological study in the medical ICU at the University Hospital Centre Zagreb, Croatia covering the period from January 1, 2018 to December 31, 2023.

RESULTS

The study included 91 patients with either SOT [28 patients (30.8%)] or HSCT [63 patients (69.2%)]. The median age was 56 (43.2-64.7) years, and 60.4% of the patients were male. Patients with SOT had more comorbidities than patients after HSCT [χ² (5, n = 141) = 18.513, P < 0.001]. Sepsis and septic shock were the most frequent reasons for admission, followed by acute respiratory insufficiency in patients following HSCT. Survival rate significantly differed between SOT and HSCT [χ² (1, n = 91) = 21.767, P < 0.001]. ICU survival was 57% in the SOT and 12.7 % in the HSCT group. The need for mechanical ventilation [χ² (1, n = 91) = 17.081, P < 0.001] and vasopressor therapy [χ² (1, n = 91) = 36.803, P < 0.001] was associated with survival. The necessity for acute renal replacement therapy did not influence patients' survival [χ² (1, n = 91) = 0.376, P = 0.54]. In the subgroup of patients with infection, 90% had septic shock, and the majority had positive microbiological samples, mostly Gram-negative bacteria. The ICU survival of patients with sepsis/septic shock cumulatively was 15%. The survival of SOT patients with sepsis/shock was 45%.

CONCLUSION

Patients with SOT or HSCT are frequently admitted to the ICU due to sepsis and septic shock. Despite advancements in critical care, the mortality rate of patients with refractory septic shock and multiorgan failure in this patient population is extremely high. Early recognition and timely ICU admittance might improve the outcome of patients, especially after HSCT.

Pre-engraftment bacteremia after allogeneic hematopoietic cell transplantation without primary fluoroquinolone antibacterial prophylaxis

BACKGROUND

Bacteremia is a common complication in allogeneic hematopoietic cell transplant recipients (alloHCTr), especially during the pre-engraftment period. International guidelines recommend antibacterial prophylaxis (ABP), despite potential selection for multidrug-resistant organisms (MDRO). Limited contemporary data exist on the epidemiology of pre-engraftment bacteremia in alloHCTr, who do not receive ABP.

METHODS

We performed a retrospective observational single-center cohort study including all consecutive adult alloHCTr (2015-2021), investigating the incidence, risk factors, and outcomes of bacteremia during the engraftment period. Primary fluoroquinolone (FQ) ABP is not routinely administered in our center.

RESULTS

Among 421 patients identified, 124 bacteremia episodes were observed in 121/421 (29%) alloHCTr. The median time to the 1st bacteremia episode was 9 days (IQR 6-11). Most (105/124, 85%) episodes were monomicrobial, while >1 pathogens were identified in 19/124 (15%) episodes. Overall, 152 pathogens were isolated, with a predominance of Gram-positive (118/152, 78%), including coagulase-negative staphylococci (n:47), streptococci (n:46), and enterococci (n:15), followed by Gram-negative bacteria (GNB, 30/152, 20%), and anaerobes (4/152, 3%). There were 2/152 (1%) MDRO (extended-spectrum beta-lactamase producing) GNB. Multivariable analyses identified age >40-year-old (OR 2.4, P = 0.02), male gender (OR 1.8, P = 0.02), and a haploidentical/mismatched unrelated donor (OR 2.5, P < 0.001) as independent risk factors for bacteremia. All cause 30-day mortality among alloHCTr with bacteremia was 0.8% (1/121): one patient died due to an HCT-related complication.

CONCLUSION

Despite lack of primary FQ ABP, low rates of bacteremia were observed during the pre-engraftment period, with low MDRO prevalence and mortality. Our findings may allow to revisit the need for primary universal FQ ABP in high-risk neutropenic hematology patients.

Hematopoietic stem-cell transplantation in a zoo of multidrug-resistant organisms: Data from a cancer center in eastern India

BACKGROUND

Infections by multidrug-resistant organisms (MDRO) are a major hurdle in hematopoietic stem-cell transplants (HSCTs). Conditioning regimens lead to mucosal barrier injury, which in-turn leads to transmigration of gut bacteria and sepsis. Pre-transplant stool and throat surveillance cultures can guide empirical antibiotic policy during the neutropenic period. In this paper, we document colonization with MDRO in pre-transplant surveillance cultures and the correlation with bloodstream infections in HSCT patients and analyze transplant outcomes with respect to these infections.

METHODS

A single-center, retrospective study on HSCT was performed between January 2021 and December 2021. The incidence of bacterial infections, percentage of MDROs, correlation with pre-transplant stool/throat surveillance cultures, and their impact on overall 100-day and post-100-day to 6-month post-transplant survival were analyzed.

RESULTS

Sixty-four patients were included in the study. Pre-transplant stool surveillance cultures were positive for MDRO in 85.9% of patients. Almost half (48.5%) of the isolates were positive for carbapenemase-producing genes (mainly New Delhi metallo-beta-lactamase-1 [NDM-1] and oxacillinase-48 [OXA-48]). Eighteen patients (18/64, 28%) had a positive blood culture for MDRO in the peri-engraftment neutropenic period. Correlation between surveillance and blood cultures was seen in 61% (11/18) of patients. All-cause mortality was 14.1% (9/64) and 25% (16/64) in patients at 100 days and 6 months post-HSCT, respectively. The 100-day and post-100-day all-cause mortality rates were higher in patients with Gram-negative MDRO bloodstream infections (p < .012 and <.008, respectively).

CONCLUSION

MDRO infections can adversely affect HSCT outcomes. Pre-transplant stool and throat surveillance cultures may guide empirical antibiotic policy and lead to favorable transplant outcomes.

Hematopoietic Stem Cells Transplant (HSCT)-Related Chronic Pulmonary Diseases: An Overview

Recipients of HSCT have a high risk of infective and non-infective pulmonary diseases. Most patients with pulmonary involvement present multiple pathogenetic mechanisms simultaneously with complex interactions. Therefore, it can be difficult to distinguish the contributions of each one and to perform studies on this subject. In this opinion article, we discuss only chronic pulmonary manifestations, focusing on LONIPCs (late-onset non-infectious pulmonary complications). This term embraces drug-related toxicity, allergies, and chronic pulmonary graft versus host disease (GvHD) in all its recently identified clinical variants. Among LONIPCs, GvHD represents the most critical in terms of morbidity and mortality, despite the rapid development of new treatment options. A recently emerging perspective suggests that pulmonary lung rejection in transplant patients shares striking similarities with the pathogenesis of GvHD. In a pulmonary transplant, the donor organ is damaged by the host immune system, whereas in GvHD, the donor immune system damages the host organs. It constitutes the most significant breakthrough in recent years and is highly promising for both hematologists and thoracic transplant surgeons. The number of patients with LONIPCs is scarce, with heterogenous clinical characteristics often involving several pathogenetic mechanisms, making it challenging to conduct randomized controlled trials. Therefore, the body of evidence in this field is scarce and generally of low quality, leading to jeopardized choices in terms of immunosuppressive treatment. Moreover, it risks being outdated by common practice due to the quick evolution of knowledge about the diagnosis and treatment of LONIPCs. The literature is even more pitiful for children with pulmonary involvement related to HSCT.

The soluble VCAM-1 level is a potential biomarker predicting severe acute graft versus host disease after allogeneic hematopoietic cell transplantation

Background

Severe graft versus host disease (GVHD) is the main reason for non-relapse mortality following allogeneic hematopoietic cell transplantation (HCT). We investigated the serum protein profiles of patients who had undergone HCT to identify predictive biomarkers of severe acute GVHD (aGVHD).

Methods

Serum samples were collected for 30 patients from day − 7 to day + 14 of HCT. The serum levels of plasma beta2-microglobulin (β2-MG), soluble vascular cell adhesion molecule-1 (sVCAM-1), platelet factor 4, and TNFSF-14 were measured by ELISA as potential biomarkers following 310 cytokine profiling array.

Results

The median age of the study patients was 53.5 years (range, 19–69). All grade and grade 2–4 aGVHD developed in 21 (70.0%) and 17 (56.7%) patients, respectively. Compared with their baseline levels on day − 7, β2-MG and sVCAM-1 were significantly increased on day + 14 of the HCT procedure (P = 0.028 and P < 0.001, respectively). Patients with a grade 2–4 severe aGVHD showed a significantly higher sVCAM-1 level at baseline (day-7) and at day + 14, compared with the other group with a grade 1 aGVHD or no aGVHD (P = 0.028 and P = 0.035, respectively).

Conclusion

Higher sVCAM- levels at baseline and on day + 14 in HCT patients could be a significant predictive biomarker of severe aGVHD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10096-3.

Rehabilitation after Allogeneic Haematopoietic Stem Cell Transplantation: A Special Challenge

Simple Summary

After undergoing an allogeneic haematopoietic stem cell transplantation (alloHCT), patients need intensive physiological and psychological rehabilitation. This should start immediately after discharge from the transplant ward as in- or outpatient rehabilitation. The rehabilitation centres should be qualified and experienced because this patient group exhibits problems that differ from those of patients who have undergone oncological therapies or autologous HCT. An experienced multidisciplinary team in close consultation with the primary transplantation centre should perform the rehabilitation therapy. This review will show the special challenges of these patients according to different timepoints after HCT. Because there is so little data available, personal experience and general guidelines on patient care after alloHCT are presented.

Abstract

The general population is getting older and suffer more haematological malignancies despite being physically fit. These malignancies are mainly only curable via an alloHCT, and they are now carried out more frequently. Patients benefit from intensive rehabilitation earlier and may need it repeatedly in cases of severe side effects (e.g., graft-versus-host disease). They can suffer many problems that other cancer patients do not experience, such as severe infections, continued immunosuppression, nutritional restrictions, acute or chronic GvHD, or organ impairments (e.g., lung, eyes). They may also encounter various associated psychological problems, e.g., feeling like a chimera. Rehabilitation centres willing to care for patients after alloHCT should have an experienced multidisciplinary team and should work in close co-operation with the primary transplant centre.

Severe acute graft-versus-host disease increases the incidence of blood stream infection and mortality after allogeneic hematopoietic cell transplantation: Japanese transplant registry study

This study aimed to clarify the risk factors and prognosis associated with blood stream infection (BSI) in allogeneic hematopoietic cell transplantation (allo-HCT), and the relationship between BSI and acute graft-versus-host disease (aGVHD). This retrospective analysis included 11,098 patients in the Japanese national transplant registry. A total of 2172 patients developed BSI after allo-HCT, with 2332 identified pathogens. The cumulative incidences of BSI were 15.5% at 30 days and 20.9% at 100 days after allo-HCT. In a multivariate analysis, severe (grade III-IV) aGVHD was associated with a higher risk of BSI (vs. grade 0-I aGVHD: hazard ratio [HR] 3.34 [95% confidence interval (CI), 2.85-3.92; P < 0.001]). In a multivariate analysis, severe aGVHD before BSI was associated with a higher risk of overall mortality after BSI (vs. grade 0-I aGVHD: HR 2.61 [95% CI 2.18-3.11; P < 0.001]). In addition, BSI (vs. no-BSI: HR 1.20 [95% CI, 1.12-1.29; P < 0.001]) and severe aGVHD (vs. grade 0-I aGVHD: HR 1.97 [95% CI, 1.83-2.12; P < 0.001]) were independent risk factors for overall mortality after allo-HCT. In the setting of allo-HCT, severe aGVHD was associated with increases in both BSI incidence and post-BSI overall mortality. Furthermore, BSI was an independent risk factor for overall mortality.

A Scoring System for Predicting the Prognosis of Late-Onset Severe Pneumonia after Allogeneic Hematopoietic Stem Cell Transplantation

Late-onset severe pneumonia (LOSP) is defined as severe pneumonia developing during the late phase of allogeneic hematopoietic stem cell transplantation (allo-HSCT). Because of the high mortality in patients with LOSP, it is important to identify prognostic factors. In this study, we aimed to develop a risk score system with broad applicability that can help predict the risk of LOSP-associated mortality. We retrospectively analyzed 100 patients with LOSP after allo-HSCT between June 2009 and July 2017. The assessment variables included immune, nutritional, and metabolic parameters at the onset of LOSP. Of these 100 patients, 45 (45%) eventually died, and 55 (55%) were positive for organisms, most commonly viruses. In the multivariate analysis, higher monocyte count (≥0.20 × 10⁹/L versus <0.20 × 10⁹/L; P = .001), higher albumin level (≥30.5 g/L versus <30.5 g/L; P = .044), lower lactic dehydrogenase level (<250 U/L versus ≥250 U/L; P = .008) and lower blood urea nitrogen concentration (<7.2 mmol/L versus ≥7.2 mmol/L; P = .026) at the onset of LOSP were significantly associated with better 60-day survival. A risk score system based on the foregoing results showed that the probability of 60-day survival decreased with increasing risk factors, from 96.3% in the low-risk group to 49.1% in the intermediate-risk group and 12.5% in the high-risk group. Our results indicate that this scoring system using 4 variables can stratify patients with different probabilities of survival after LOSP, which suggests that patients' immune, nutritional, and metabolic status are crucial factors in determining outcome.

Emerging role of microbiota in immunomodulation and cancer immunotherapy

Gut microbiota is emerging as a key modulator of the immune system. Alteration of gut microbiota impacts functioning of the immune system and pathophysiology of several diseases, including cancer. Growing evidence indicates that gut microbiota is not only involved in carcinogenesis but also has an impact on the efficacy and toxicity of cancer therapy. Recently, several pre-clinical and clinical studies across diverse cancer types reported the influence of gut microbiota on the host immune response to immunotherapy. Advancement in our understanding of the mechanism behind microbiota-mediated modulation of immune response is paramount for their utilization as cancer therapeutics. These microbial therapies in combination with conventional immunotherapeutic methods have the potential to transform the pre-existing treatment strategies to personalized cancer therapy. In this review, we have summarized the current status of research in the field and discussed the role of microbiota as an immune system modulator in context of cancer and their impact on immunotherapy.

Donor-Derived CD123-Targeted CAR T Cell Serves as a RIC Regimen for Haploidentical Transplantation in a Patient With FUS-ERG+ AML

Background: Allogeneic hematopoietic stem cell transplantation (allo-HSCT) following chemotherapy is part of standard treatment protocol for patients with acute myeloid leukemia (AML). FUS-ERG+ AML is rare but has an extremely poor prognosis even with allo-HSCT in remission, possibly due to its a leukemia stem cell (LSC)-driven disease resulting in chemotherapy resistance and a novel therapy is urgently required. It has been reported that FUS-ERG-positive AML expresses CD123, a marker of LSC, in some cases. CD123-targeted CAR T cell (CART123) is promising immunotherapy, but how to improve the complete remission (CR) rate and rescue potential hematopoietic toxicity still need to explore.

Case Presentation: We used donor-derived CART123 as part of conditioning regimen for haploidentical HSCT (haplo-HSCT) in a patient with FUS-ERG+ AML who relapsed after allogeneic transplantation within 3 months, resists to multi-agent chemotherapy and donor lymphocyte infusion (DLI) and remained non-remission, aiming to reduce these chemotherapy-resistant blasts and rescue potential hematopoietic toxicity. The blasts in BM were reduced within 2 weeks and coincided with CAR copies expansion after CART123 infusion. The patient achieved full donor chimerism, CR with incomplete blood count recovery, and myeloid implantation.

Conclusion: Our results hints that CART123 reduces the chemotherapy-resistant AML blasts for FUS-ERG+ AML without affecting the full donor chimerism and myeloid implantation.

Regulation of the Immune Balance During Allogeneic Hematopoietic Stem Cell Transplantation by Vitamin D

One of the most promising therapeutic approaches for numerous hematological malignancies represents the allogeneic hematopoietic stem cell transplantation (allo-HSCT). One major complication is the development of the life-threatening graft-vs.-host disease (GvHD) which limits beneficial effects of graft-vs.-leukemia (GvL) responses during allo-HSCT. Strengthening GvL effects without induction of severe GvHD is essential to decrease the relapse rate after allo-HSCT. An interesting player in this context is vitamin D₃ since it has modulatory capacity in both preventing GvHD and boosting GvL responses. Current studies claim that vitamin D₃ induces an immunosuppressive environment by dendritic cell (DC)-dependent generation of regulatory T cells (Tregs). Since vitamin D₃ is known to support the antimicrobial defense by re-establishing the physical barrier as well as releasing defensins and antimicrobial peptides, it might also improve graft-vs.-infection (GvI) effects in patients. Beyond that, alloreactive T cells might be attenuated by vitamin D₃-mediated inhibition of proliferation and activation. Despite the inhibitory effects of vitamin D₃ on T cells, anti-tumor responses of GvL might be reinforced by vitamin D₃-triggered phagocytic activity and antibody-based immunotherapy. Therefore, vitamin D₃ treatment does not only lead to a shift from a pro-inflammatory toward a tolerogenic state but also promotes tumoricidal activity of immune cells. In this review we focus on vitamin D₃ and its immunomodulatory effects by enhancing anti-tumor activity while alleviating harmful allogeneic responses in order to restore the immune balance.

A Pilot Study of Human Milk to Reduce Intestinal Inflammation After Bone Marrow Transplant

OBJECTIVE

Human milk administration in the early peritransplant period would lower intestinal inflammation after bone marrow transplant (BMT).

MATERIALS AND METHODS

Children 0-5 years undergoing BMT received either a ready-to-feed human milk preparation designed for these children (Prolacta Bioscience, Duarte, CA) or standard formula. Babies breastfeeding at the time of BMT were also enrolled on the human milk arm. Human milk was administered from day -3 until day +14 after BMT. Metagenomic shotgun sequencing and metabolomics of stool, plasma cytokines, and regenerating islet-derived 3α (REG3α) levels were measured at enrollment and day +14. Human leukocyte antigen-DR isotype (HLA-DR), CD38, and CD69 expression on T cells were evaluated at day +21.

RESULTS

Forty-six children were enrolled, 32 received human milk (donor milk n = 23, breastfeeding babies n = 9), and 14 were controls who received standard feeds supervised by a BMT dietician. Twenty-four patients received at least 60% of goal human milk and were evaluable. Plasma interleukin (IL)-8 (p = 0.04), IL-10 (p = 0.02), and REG3α (p = 0.03) were decreased in the human milk cohort. Peripheral blood CD69⁺ CD8⁺ T cells were higher in controls (p = 0.01). Species abundance of Adenovirus (p = 0.00034), Escherichia coli (p = 0.0017), Cryptosporidium parvum (p = 0.0006), Dialister invisus (p = 0.01), and Pseudomonas aeruginosa (p = 0.05) from stool was higher in controls. Stool alanine, tyrosine, methionine, and the ratio of fecal alanine to choline and phosphocholine were higher in controls (p < 0.05). No difference was observed in stool propionate and butyrate levels as measures of short-chain fatty acids between the two cohorts.

CONCLUSIONS

Administration of human milk resulted in decreased markers of intestinal inflammation and could be a valuable adjunct for patients after BMT.

A multi-center prospective study randomizing the use of fat emulsion in intensive glucose control after allogeneic hematopoietic stem cell transplantation using a myeloablative conditioning regimen

BACKGROUND & AIMS

Although parenteral nutrition (PN) is often used after allogeneic hematopoietic stem cell transplantation (allo-HSCT), there is controversy regarding PN management, for instance in the use of fat emulsion and glucose control (GC). To clarify these issues, we conducted a multi-center prospective study with intensive GC, randomizing the use of fat emulsion after allo-HSCT using a myeloablative conditioning regimen.

METHODS

The primary endpoint was the cumulative incidence of documented infectious disease, namely bacterial and fungal infection, at day 100 after allo-HSCT. Between August 2007 and March 2012, we enrolled 81 patients at 5 centers. Excluding 5 ineligible patients, 76 patients received the protocol treatment. The target fasting glucose level was 80-110 mg/dL.

RESULTS

The median follow-up of surviving patients was 1796 days. The cumulative incidences of documented infectious disease at day 100 were 16% (95% confidence interval [CI] 6-29%) in the no-fat group and 19% (95% CI 8-32%) in the fat group, indicating no significant difference. The mean glucose level at 28 days after allo-HSCT was 107 mg/dL in the no-fat group and 111 mg/dL in the fat group. Grade 3 hyperglycemia (>250 mg/dL) and grade 3 hypoglycemia (<40 mg/dL) occurred in 4 patients each (5.3%). Overall survival and non-relapse mortality rates at 4 years were 75% and 11% in the no-fat group and 69% and 8% in the fat group, respectively.

CONCLUSIONS

Irrespective of the use of fat emulsion, the long-term clinical outcomes of the enrolled patients were favorable under intensive GC. To further clarify the benefits of GC after allo-HSCT, a prospective study randomizing the level of GC is warranted.

A review of infectious complications after haploidentical hematopoietic stem cell transplantations

BACKGROUND

Allogeneic hematopoietic stem cell transplantation from haploidentical donor is a feasible option for patients with hematological diseases who lack a suitable HLA-matched donor, but viral and fungal infections are still the most common causes of morbidity and mortality in haploidentical transplantation setting because of delayed immune reconstitution, increased risk of graft vs host disease (GvHD) or systemic steroid use. Therefore, this review will focus on the infectious complications after haploidentical hematopoietic stem cell transplantation (HSCT).

MATERIALS AND METHODS

Electronic publications were searched until February 2017 throughout databases, including Pubmed, Cochrane, and Embase. The following keywords were used 'haploidentical transplantation', 'infection', 'T cell replete', and 'T cell deplete'.

RESULTS

An increased incidence of bacterial, fungal, or viral infections is detected in haplo-HSCT compared to related, unrelated, or cord blood transplantations. Neutropenia and use of systemic steroid for GvHD and delayed immune reconstitution are important risk factors for infection after haplo-HSCT.

CONCLUSION

A shift towards T cell repletes haplo-HSCT with post-transplant cyclophosphamide (CY) for GvHD has been emerged in recent years, in which the incidence of viral and fungal infections is detected to be lower. Prophylaxis and pre-emptive treatment strategies should be applied according to patient status.

Hyperglycemia as a possible risk factor for mold infections-the potential preventative role of intensified glucose control in allogeneic hematopoietic stem cell transplantation

Diabetes mellitus (DM) is well-known as a disorder that increases the risk of infectious diseases. Various reports have shown that innate immunity is impaired in patients with DM, which is considered to be a major cause of increased risk of infectious diseases. However, there is a paucity of data about the actual risk of mold infections in patients with DM. Several treatment procedures, such as solid organ transplantation and hematopoietic stem cell transplantation (HSCT), are intrinsically associated with a high risk of mold infections and also correlated with an increased risk of post-transplant DM. Therefore, we could assume that organ transplant recipients or HSCT recipients with DM are at quite high risk of mold infections. Here, we aim to summarize the information about the increased risk of mold infections in patients with DM, and propose possible interventions such as intensive glucose control to reduce this risk in patients with DM.

Selected Topics in Aerobic Bacteriology

Aerobic Gram-positive and Gram-negative bacteria can be important pathogens in the immunocompromised host. These bacteria can be found in many environments, as part of the normal microbiota of the human host and animals, in soil and water, on plants, on fomites in the hospital, and on hospital equipment. This review provides information from relevant studies about what are the most common aerobic bacteria associated with patients who have cancer and/or are being treated for it, or who have other diseases which lead to immunodeficiencies, such as HIV, multiple myeloma, aplastic anemia, chronic diseases, and aging. A discussion of the appropriate laboratory tests needed for diagnosis of aerobic infections and information about antibiotics and susceptibility testing are also included.

Attenuation of graft-versus-host-disease in NOD scid IL-2Rγ(-/-) (NSG) mice by ex vivo modulation of human CD4(+) T cells

NOD.Cg-Prkdc(scid) IL-2rg(tm1Wjl) /SzJ (NSG) mice are a valuable tool for studying Graft-versus-Host-Disease (GvHD) induced by human immune cells. We used a model of acute GvHD by transfer of human peripheral blood mononuclear cells (PBMCs) into NSG mice. The severity of GvHD was reflected by weight loss and was associated with engraftment of human cells and the expansion of leukocytes, particularly granulocytes and monocytes. Pre-treatment of PBMCs with the anti-human CD4 antibody MAX.16H5 IgG1 or IgG4 attenuated GvHD. The transplantation of 2 × 10(7) PBMCs without anti-human CD4 pre-treatment induced a severe GvHD (0% survival). In animals receiving 2 × 10(7) PBMCs pre-incubated with MAX.16H5 IgG1 or IgG4, GvHD development was reduced and survival was increased. Immune reconstitution was measured by flow cytometry and confirmed for human leukocytes (CD45), CD3(+) /CD8(+) cytotoxic T cells and CD3(+) /CD4(+) T helper cells. Human B cells (CD19) and monocytes (CD14) could not be detected. Histopathological analysis (TUNEL assay) of the gut of recipient animals showed significantly less apoptotic crypt cells in animals receiving a MAX.16H5 IgG1 pre-incubated graft. These findings indicate that pre-incubation of an allogeneic graft with an anti-human CD4 antibody may decrease the frequency and severity of GvHD after hematopoietic stem cell transplantation (HSCT) and the need of conventional immunosuppressive drugs. Moreover, this approach most probably provides a safer HSCT that must be confirmed in appropriate clinical trials in the future. © 2016 International Society for Advancement of Cytometry.

Potential protective effect of Helicobacter pylori on the development of gastrointestinal GvHD

Previous reports ascribe a modulating capacity of the immune response to Helicobacter pylori (HP). Our hypothesis was to demonstrate in a prospective study that HP infection could have a protective effect against development of gastrointestinal GvHD in patients receiving allogeneic hematopoietic cell transplantation (HCT). Presence of HP before transplant was determined using C(13) urea breath test. Seventy-nine patients receiving an allogeneic HCT were included and 93.7% of them received PBSC; in 51.9%, the donor was unrelated. Acute gastrointestinal GvHD was diagnosed in 51.9% (n=41). In the multivariable analysis, HP infection was associated with a lower frequency of gastrointestinal GvHD (odds ratio (OR)=0.19 (95% confidence interval (CI): 0.05-0.67); in contrast, an unrelated donor was associated with a higher frequency of gastrointestinal GvHD (odds ratio=5.4 (95% confidence interval: 1.6-18.2). One year overall survival (OS) was 74%. In the multivariate Cox proportional-hazards regression analysis, stages 0-II gastrointestinal GvHD (hazards ratio (HR)=0.19), reduced intensity conditioning (HR=0.04) and tacrolimus-sirolimus GvHD prophylaxis (HR=0.06) were all associated with a better OS. In summary, HP infection could have a role in decreasing gastrointestinal GvHD in patients receiving allogeneic HCT from peripheral blood including related and unrelated donors.

Prognostic value of pretransplant serum C-reactive protein in patients receiving reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation

The impact of pre-transplant serum C-reactive protein (CRP) level on the outcome of reduced-intensity conditioning allogeneic hematopoietic stem cell transplantation (RIC allo-SCT) is unclear. This study retrospectively investigated 78 patients who underwent RIC allo-SCT between 2005 and 2013. The conditioning regimen consisted of fludarabine and melphalan with/without total body irradiation. The 3-year overall survival of high CRP (43.6 % of all patients) patients was significantly worse than that of normal CRP patients in whom CRP was ≤0.3 mg/dl (26.7 vs. 74.1 %, P < 0.001). Both the CRP level before transplantation and disease risk status were independent prognostic factors for overall survival by multivariate analysis. CRP was not a significant predictor of NRM by multivariate analysis (hazard ratio 3.2, 95 % confidence interval 0.8-13.1, P = 0.100). These results suggest that measuring the CRP level before transplantation can be useful to predicting the outcome of RIC allo-SCT.