Viral encephalitis after haplo-identical hematopoietic stem cell transplantation: Causative viral spectrum, characteristics, and risk factors

Clinical features and prognostic model for viral encephalitis after allogeneic haematopoietic stem cell transplantation

The objective of this study was to identify independent prognostic factors of viral encephalitis (VE) after allogeneic haematopoietic stem cell transplantation (allo-HSCT) and establish a prognostic model to identify post-transplant VE patients with a greater likelihood of mortality. Among 5380 patients in our centre from 2014 to 2022, 211 patients who developed VE after allo-HSCT were reviewed in this retrospective study. Prognostic factors were selected, and a prognostic model was constructed using Cox regression analysis. The model was subsequently validated and estimated using the area under the receiver operating characteristic curve (AUC), a calibration plot and decision curve analysis (DCA). Glasgow Coma Scale score <9, lesions >3 lobes on magnetic resonance imaging and severe thrombocytopenia were identified as independent prognostic risk factors for VE patients who underwent allo-HSCT. The prognostic model GTM (GTM is an abbreviation for a model composed of three risk factors: GCS score <9, severe thrombocytopenia [platelet count <20 000 per microliter], and lesions >3 lobes on MRI) was established according to the regression coefficients. The validated internal AUC was 0.862 (95% confidence interval [CI], 0.773-0.950), and the external AUC was 0.815 (95% CI, 0.708-0.922), indicating strong discriminatory ability. Furthermore, we constructed calibration plots that demonstrated good consistency between the predicted outcomes and the observed outcomes. DCA exhibited high accuracy in this system, leading to potential benefits for patients.

Viral meningoencephalitis in pediatric solid organ or hematopoietic cell transplant recipients: a diagnostic and therapeutic approach

Neurologic complications, both infectious and non-infectious, are frequent among hematopoietic cell transplant (HCT) and solid organ transplant (SOT) recipients. Up to 46% of HCT and 50% of SOT recipients experience a neurological complication, including cerebrovascular accidents, drug toxicities, as well as infections. Defects in innate, adaptive, and humoral immune function among transplant recipients predispose to opportunistic infections, including central nervous system (CNS) disease. CNS infections remain uncommon overall amongst HCT and SOT recipients, compromising approximately 1% of total cases among adult patients. Given the relatively lower number of pediatric transplant recipients, the incidence of CNS disease amongst in this population remains unknown. Although infections comprise a small percentage of the neurological complications that occur post-transplant, the associated morbidity and mortality in an immunosuppressed state makes it imperative to promptly evaluate and aggressively treat a pediatric transplant patient with suspicion for viral meningoencephalitis. This manuscript guides the reader through a broad infectious and non-infectious diagnostic differential in a transplant recipient presenting with altered mentation and fever and thereafter, elaborates on diagnostics and management of viral meningoencephalitis. Hypothetical SOT and HCT patient cases have also been constructed to illustrate the diagnostic and management process in select viral etiologies. Given the unique risk for various opportunistic viral infections resulting in CNS disease among transplant recipients, the manuscript will provide a contemporary review of the epidemiology, risk factors, diagnosis, and management of viral meningoencephalitis in these patients.

Viral Encephalitis after Hematopoietic Cell Transplantation: A Systematic Review

Viral encephalitis is a rare but serious complication after hematopoietic cell transplantation (HCT). The nonspecific early signs and symptoms and rapid progression can make it difficult to diagnose and treat in a timely fashion. To better inform clinical decision making in post-HCT viral encephalitis, a systematic review of prior studies of viral encephalitis was performed, with the goal of characterizing the frequency of various infectious etiologies and their clinical course, including treatments and outcomes. A systematic review of studies of viral encephalitis was performed. Studies were included if they described a cohort of HCT recipients who were tested for at least 1 pathogen. Of 1613 unique articles initially identified, 68 met the inclusion criteria, with a total of 72,423 patients studied. A total of 778 cases of encephalitis were reported (1.1%). Human herpesvirus 6 (HHV-6) (n = 596), Epstein-Barr virus (n = 76), and cytomegalovirus (n = 33) were the most commonly reported causes of encephalitis, and HHV-6 encephalitis tended to occur the earliest, accounting for most cases prior to day +100 post-transplantation. Of 29,671 patients with available transplantation data, encephalitis was diagnosed in 282 of 4707 (6.0%) cord blood transplantation (CBT) recipients, in 372 of 24,664 (1.5%) non-CBT allogeneic HCT recipients, and in 5 of 300 (1.7%) autologous HCT recipients. Of the 282 CBT encephalitis cases, 270 (95.7%) were caused by HHV-6. Overall, 288 (37.0%) of the 778 patients with encephalitis died, and 75 deaths were attributable to encephalitis, with the time between diagnosis and death ranging from 3 to 192 days. Viral encephalitis occurs in approximately 1% of HCT recipients, and HHV-6 is the most common cause. Mortality following encephalitis in HCT recipients is high, indicating an urgent need for advancement in preventive and therapeutic strategies.

Metagenomic Next-Generation Sequencing vs. Traditional Pathogen Detection in the Diagnosis of Infection After Allogeneic Hematopoietic Stem Cell Transplantation in Children

Infection is a severe complication of allo-HSCT in children, however, the accurate detection of the infection is hard. In this study, we traced the records of 101 pediatric recipients with allo-HSCT to investigate the pathogens of infection, and collected 54 bronchoalveolar lavage fluid, 32 blood, and 15 cerebrospinal fluid samples. In these samples, 87 was with post-transplant infection and 14 without infection. Using the metagenomic next-generation sequencing (mNGS) and traditional pathogen detection, we compared their sensitivity and specificity to detect pathogens of infection. Our results showed that mNGS was more sensitive (89.7%) than conventional pathogen detection (21.8%), with a difference of 67.9% (P < 0.001), However, mNGS was less specific (78.5%) than traditional methods (92.9%), with a difference of 14.4% (P = 0.596). The sensitivity of mNGS for diagnosing pulmonary infections, bloodstream infections or viremia, and CNS infections post-transplant were 91.7, 85.7, and 90.9%, respectively. In contrast, the sensitivity of conventional testing for diagnosing pulmonary infections, bloodstream infections or viremia, and CNS infections post-transplant were 22.9, 21.4, and 18.2%, respectively. There were significant differences in the sensitivity of mNGS and conventional testing in BALF, blood, and CSF samples, with P values of 0.000, 0.000, and 0.002 respectively. Among the patients with pulmonary infection, 11 pathogens were both identified by mNGS and conventional testing, and 33 by mNGS only. The percentage with the mNGS-positive result was 44/48 (91.7%), including viruses (n = 12), bacteria (n = 17), fungi (n = 9) and mixed infections (n = 6). Among the patients diagnosed with fungal pneumonia (n = 9), the most prevalent pathogenic fungi were Pneumocystis jiroveci (n = 6), which were also detected in 4 patients with mixed infectious pneumonia. In the 28 blood specimens of patients with bloodstream infections or viremia, five patients were positive by both mNGS and conventional testing, 19 were positive by mNGS, and 1 was positive by traditional testing only. The percentage with the mNGS-positive results was 24/28 (85.7%), including viruses (n = 12), bacteria (n = 4), fungi (n = 3), and mixed infections (n = 5). Of the 15 CSF specimens enrolled, 11 patients were eventually diagnosed with CNS infections. Ten pathogens were identified by mNGS in the 11 patients, including viruses (n = 8), bacteria (n = 1), and fungi (n = 1). These results suggest that mNGS is more sensitive than conventional pathogen detection for diagnosing infections post HSCT in children which may help the clinic diagnosis. Pneumocystis jiroveci was the most frequent pathogen of pulmonary infections post-transplant, while viruses were the most common pathogens of CNS infections in allo-HSCT recipients.

Predicting mortality from intracranial hemorrhage in patients who undergo allogeneic hematopoietic stem cell transplantation

Intracranial hemorrhage (ICH) is a rare but fatal central nervous system complication of allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, factors that are predictive of early mortality in patients who develop ICH after undergoing allo-HSCT have not been systemically investigated. From January 2008 to June 2020, a total of 70 allo-HSCT patients with an ICH diagnosis formed the derivation cohort. Forty-one allo-HSCT patients with an ICH diagnosis were collected from 12 other medical centers during the same period, and they comprised the external validation cohort. These 2 cohorts were used to develop and validate a grading scale that enables the prediction of 30-day mortality from ICH in all-HSCT patients. Four predictors (lactate dehydrogenase level, albumin level, white blood cell count, and disease status) were retained in the multivariable logistic regression model, and a simplified grading scale (termed the LAWS score) was developed. The LAWS score was adequately calibrated (Hosmer-Lemeshow test, P > .05) in both cohorts. It had good discrimination power in both the derivation cohort (C-statistic, 0.859; 95% confidence interval, 0.776-0.945) and the external validation cohort (C-statistic, 0.795; 95% confidence interval, 0.645-0.945). The LAWS score is the first scoring system capable of predicting 30-day mortality from ICH in allo-HSCT patients. It showed good performance in identifying allo-HSCT patients at increased risk of early mortality after ICH diagnosis. We anticipate that it would help risk stratify allo-HSCT patients with ICH and facilitate future studies on developing individualized and novel interventions for patients within different LAWS risk groups.

Clinical risk factors and prognostic model for idiopathic inflammatory demyelinating diseases after haploidentical hematopoietic stem cell transplantation in patients with hematological malignancies

Idiopathic inflammatory demyelinating diseases (IIDDs) of the central nervous system (CNS) are rare but serious neurological complications of haploidentical hematopoietic stem cell transplantation (haplo-HSCT). However, the risk factors and a method to predict the prognosis of post-transplantation CNS IIDDs are not available. This retrospective study first reviewed data from 4532 patients who received haplo-HSCT during 2008-2019 in our center, and 184 patients (4.1%) with IIDDs after haplo-HSCT were identified. Grades II to IV acute graft-versus-host disease (aGVHD) (p < 0.001) and chronic GVHD (cGVHD) (p = 0.009) were identified as risk factors for developing IIDDs after haplo-HSCT. We then divided the 184 IIDD patients into a derivation cohort and validation cohort due to transplantation time to develop and validate a model for predicting the prognosis of IIDDs. In the multivariate analysis of the derivation cohort, four candidate predictors were entered into the final prognostic model: cytomegalovirus (CMV) infection, Epstein-Barr virus (EBV) infection, IgG synthesis (IgG-syn) and spinal cord lesions. The prognostic model had an area under the receiver operating characteristic curve of 0.864 (95% CI: 0.803-0.925) in the internal validation cohort and 0.871 (95% CI: 0.806-0.931) in the external validation cohort. The calibration plots showed a high agreement between the predicted and observed outcomes. Decision curve analysis indicated that IIDD patients could benefit from the clinical application of the prognostic model. The identification of IIDD patients after allo-HSCT who have a poor prognosis might allow timely treatment and improve patient survival and outcomes.

Application Route and Immune Status of the Host Determine Safety and Oncolytic Activity of Oncolytic Coxsackievirus B3 Variant PD-H

The coxsackievirus B3 strain PD-0 has been proposed as a new oncolytic virus for the treatment of colorectal carcinoma. Here, we generated a cDNA clone of PD-0 and analyzed the virus PD-H, newly generated from this cDNA, in xenografted and syngenic models of colorectal cancer. Replication and cytotoxic assays revealed that PD-H replicated and lysed colorectal carcinoma cell lines in vitro as well as PD-0. Intratumoral injection of PD-H into subcutaneous DLD-1 tumors in nude mice resulted in strong inhibition of tumor growth and significantly prolonged the survival of the animals, but virus-induced systemic infection was observed in one of the six animals. In a syngenic mouse model of subcutaneously growing Colon-26 tumors, intratumoral administration of PD-H led to a significant reduction of tumor growth, the prolongation of animal survival, the prevention of tumor-induced cachexia, and the elevation of CD3+ and dendritic cells in the tumor microenvironment. No virus-induced side effects were observed. After intraperitoneal application, PD-H induced weak pancreatitis and myocarditis in immunocompetent mice. By equipping the virus with target sites of miR-375, which is specifically expressed in the pancreas, organ infections were prevented. Moreover, employment of this virus in a syngenic mouse model of CT-26 peritoneal carcinomatosis resulted in a significant reduction in tumor growth and an increase in animal survival. The results demonstrate that the immune status of the host, the route of virus application, and the engineering of the virus with target sites of suitable microRNAs are crucial for the use of PD-H as an oncolytic virus.

Metagenomic next-generation sequencing for identifying pathogens in central nervous system complications after allogeneic hematopoietic stem cell transplantation

A prospective study was conducted to compare metagenomic next-generation sequencing (mNGS) and conventional testing in investigating the pathogens of central nervous system (CNS) infections in allogeneic hematopoietic stem cell transplantation (allo-HSCT) recipients. A total of 53 patients with CNS disorders after allo-HSCT were enrolled in this study. A total of 35 patients were diagnosed as CNS infections, including 28 viral, 2 bacterial, 1 fungal, 3 mixed infections, and 1 infection with unknown pathogen. Among these 35 patients with CNS infections, mNGS identified 5 patients who were not identified by conventional testing. For the remaining 30 infections, mNGS made concurrent diagnoses with conventional testing in 29, while 1 was diagnosed according to the good response to the antimicrobial treatment without etiological evidence. The presence of Aspergillus detected by mNGS only in one patient was considered false positive due to lack of validation. The sensitivity of mNGS and conventional testing for diagnosing CNS infections post transplant were 97.1% and 82.9%, respectively (P = 0.106), while the specificity of mNGS and conventional testing were 94.4% and 100%, respectively (P = 1.000). These results suggest that mNGS might be a promising technology for diagnosis of CNS infections post transplant. Viruses were the most common pathogens of CNS infections in allo-HSCT recipients.

Risk Factor and Long-Term Outcome Analyses for Acute Limbic Encephalitis and Calcineurin Inhibitor-Induced Encephalopathy in Adults following Allogeneic Hematopoietic Cell Transplantation

Post-transplantation acute limbic encephalitis (PALE) is a rare, severe inflammatory disorder in the bilateral limbic system, including the hippocampus. To date, only a few studies have reported details, including risk factors for PALE; however, further clinical evidence of PALE, especially in cerebrospinal fluid human herpesvirus 6-negative cases, is warranted. In addition, data are sparse regarding the risk factors for calcineurin inhibitor (CNI)-induced encephalopathy (CNIE) following allogeneic hematopoietic cell transplantation (allo-HCT) in adults. Therefore, we examined the risk factors for and clinical details of PALE and CNIE. We retrospectively analyzed consecutive patients who underwent allo-HCT between January 2005 and November 2017. A total of 485 patients age 46 years (median) were eligible. In total, 14 PALE cases and 11 CNIE cases were identified. Multivariable analyses identified older age, use of an HLA-mismatched unrelated donor (URD), graft-versus-host disease (GVHD) prophylaxis with CNI and mycophenolate mofetil, and grade II-IV acute GVHD as significantly associated with an increased risk of PALE. In 13 patients who received high-dose methylprednisolone (mPSL) therapy, 6 (46%) responded to mPSL therapy, and 3 (23%) achieved complete remission at day 90 after mPSL administration. Furthermore, myelodysplastic syndrome (MDS), HLA-mismatched URD, and grade II-IV acute GVHD were significantly associated with an increased risk of CNIE. The 5-year nonrelapse mortality rate was 50% in PALE and 63% in CNIE, suggesting a very poor prognosis. In conclusion, this study provides evidence that HLA-mismatched URD and acute GVHD may independently contribute to the development of PALE, possibly in part through HLA-mismatch-derived alloimmune responses. Other than acute GVHD, we have identified MDS and HLA-mismatched URD as novel predictors of CNIE after allo-HCT.

miR-375- and miR-1-Regulated Coxsackievirus B3 Has No Pancreas and Heart Toxicity But Strong Antitumor Efficiency in Colorectal Carcinomas

Coxsackievirus B3 (CVB3) has strong oncolytic activity in colorectal carcinoma but it also infects the pancreas and the heart. To improve the safety of the virus, here we investigated whether pancreas and cardiac toxicity can be prevented by insertion of target sites (TS), which are complementary to miR-375 and miR-1 into the viral genome. Although miR-375 and miR-1 are abundantly expressed in the pancreas and in the heart, respectively, their expression levels are low in colorectal carcinomas, which allows the carcinomas to be selectively attacked. To investigate the importance of the microRNAs, two viruses were engineered, H3N-375TS containing only miR-375TS and H3N-375/1TS containing miR-375TS and miR-1TS. In vitro, both viruses replicated in and lysed colorectal carcinoma cells, similar to a nontargeted control virus H3N-39TS, whereas they were strongly attenuated in cell lines transiently or endogenously expressing the corresponding microRNAs. In vivo, the control virus H3N-39TS induced strong infection of the pancreas and the heart, which led to fatal disease within 4 days after a single intratumoral virus injection in mice xenografted with colorectal DLD-1 cell tumors. In contrast, three intratumoral injections of H3N-375TS or H3N-375/1TS failed to induce virus-induced sickness. In the animals, both viruses were completely ablated from the pancreas and H3N-375/1TS was also ablated from the heart, whereas the cardiac titers of H3N-375TS were strongly reduced. Long-term investigations of the DLD-1 tumor model confirmed lack of virus-induced adverse effects in H3N-375TS- and H3N-375/1TS-treated mice. There was no mortality, and the pancreas and the heart were free of pathological alterations. Regarding the therapeutic efficiency, the treated animals showed high and long-lasting H3N-375TS and H3N-375/1TS persistence in the tumor and significantly slower tumor growth. These data demonstrate that miR-375- and miR-1-mediated virus detargeting from the pancreas and heart is a highly effective strategy to prevent toxicity of oncolytic CVB3.

Resistant or refractory cytomegalovirus infections after hematopoietic cell transplantation: diagnosis and management

PURPOSE OF REVIEW

Refractory or resistant cytomegalovirus (CMV) infections are challenging complications after hematopoietic cell transplantation (HCT). Most refractory or resistant CMV infections are associated with poor outcomes and increased mortality. Prompt recognition of resistant or refractory CMV infections, understanding the resistance pathways, and the treatment options in HCT recipients are imperative.

RECENT FINDINGS

New definitions for refractory and resistant CMV infections in HCT recipients have been introduced for future clinical trials. Interestingly, refractory CMV infections are more commonly encountered in HCT recipients when compared with resistant CMV infections. CMV terminase complex mutations in UL56, UL89, and UL51 could be associated with letermovir resistance; specific mutations in UL56 are the most commonly encountered in clinical practice. Finally, brincidofovir, maribavir, letermovir, and CMV-specific cytotoxic T-cell therapy expanded our treatment options for refractory or resistant CMV infections.

SUMMARY

Many advances have been made to optimize future clinical trials for management of refractory or resistant CMV infections, and to better understand new resistance mechanisms to novel drugs. New drugs or strategies with limited toxicities are needed to improve outcomes of difficult to treat CMV infections in HCT recipients.

Comparison of different cytomegalovirus diseases following haploidentical hematopoietic stem cell transplantation

Cytomegalovirus (CMV) can cause end-organ diseases including pneumonia, gastroenteritis, retinitis, and encephalitis in hematopoietic stem cell transplantation recipients. Potential differences among different CMV diseases remain uncertain. This study aimed to compare the clinical characteristics, risk factors, and mortality among different CMV diseases. A retrospective nested case-control study was performed based on a cohort of 3862 patients who underwent haploidentical hematopoietic stem cell transplantation at a single-center. CMV diseases occurred in 113 (2.92%) of 3862 haplo-HSCT recipients, including probable CMV pneumonia (CMVP, n = 34), proven CMV gastroenteritis (CMVG, n = 34), CMV retinitis (CMVR, n = 31), probable CMV encephalitis (CMVE, n = 7), and disseminated CMV disease (Di-CMVD, n = 7). Most (91.2%) cases of CMVG developed within 100 days, while most (90.3%) cases of CMVR were late onset. Refractory CMV infection and CMV viral load at different levels were associated with an increased risk of CMVP, CMVG, and CMVR. Compared with patients without CMV diseases, significantly higher non-relapse mortality at 1 year after transplantation was observed in patients with CMVP and CMVR, rather than CMVG. Patients with CMVP, Di-CMVD, and CMVE had higher overall mortality after diagnosis than that of patients with CMVG and CMVR (61.7%, 57.1%, 40.0% vs 27.7%, 18.6%, P = 0.001). In conclusion, the onset time, viral dynamics, and mortality differ among different CMV diseases. The mortality of CMV diseases remains high, especially for CMVP, Di-CMVD, and CMVE.

Comparison of hemorrhagic and ischemic stroke after allogeneic hematopoietic stem cell transplantation

Stroke is an important complication following allogeneic hematopoietic stem cell transplantation (allo-HSCT). Nevertheless, few studies have been published to analyzed the occurrence and prognosis of stroke after allo-HSCT. From January 2007 to December 2018 in Peking University People's Hospital, 6449 patients received HSCT and there were 2.3% of patients diagnosed with stroke after allo-HSCT (hemorrhagic: 1.0%, ischemic: 1.3%). The median time to hemorrhagic and ischemic stroke after HSCT was 161 days and 137 days, respectively. In total, 8.4% of patients experienced neurological sequelae. The outcome was much worse in patients with stroke than in control subjects. The comparison of prognosis showed no statistical differences between patients with hemorrhagic stroke and those with ischemic stroke. Significant risk factors for hemorrhagic stroke were pretransplant central nervous system leukemia (CNSL), and delayed platelet engraftment. Risk factors associated with the occurrence of ischemic stroke included high-risk disease, prior venous thromboembolism (VTE), grade III-IV acute graft-versus-host disease (aGVHD), and thrombotic microangiopathy (TMA). Haplo-identical transplantation was not a risk factor for stroke and had no impact on the prognosis compared with HLA-matched HSCT. Altogether, these results show that stroke is a severe complication after allo-HSCT. The prognosis of posttransplant stroke did not differ between hemorrhagic and ischemic stroke.

Posterior reversible encephalopathy syndrome (PRES) after haploidentical haematopoietic stem cell transplantation: incidence, risk factors and outcomes

Posterior reversible encephalopathy syndrome (PRES) is a gradually recognised neurological complication of allogenic haematopoietic stem cell transplantation (allo-HSCT). However, there is a paucity of information on PRES after haploidentical HSCT (haplo-HSCT). We performed a retrospective nested case-control study in patients following haplo-HSCT for malignant and nonmalignant haematologic diseases between January 2009 and December 2018 in our centre. A total of 45 patients were diagnosed with PRES after transplant, accounting for an incidence of 1.17%. Grades II to IV acute graft-versus-host disease (aGVHD) (HR 2.370, 95% CI 1.277-4.397, p = 0.006) and hypertension (HR 14.466, 95% CI 7.107-29.443, p < 0.001) were identified as risk factors for developing PRES after haplo-HSCT. There was no difference in overall survival (OS), disease-free survival (DFS), the cumulative incidence of relapse or nonrelapse mortality (NRM) between patients with PRES and controls without PRES following haplo-HSCT in either adults or children. All but one patient with PRES showed nearly complete clinical and neurologic recovery. In conclusion, PRES is a rare condition with benign outcomes following haplo-HSCT. Further multicentre prospective studies are needed to confirm the results and help to establish the standard therapy for posttransplant PRES.

Human Polyomaviruses in the Cerebrospinal Fluid of Neurological Patients

BACKGROUND

Central nervous system (CNS) infections by human polyomaviruses (HPyVs), with the exception of JC (JCPyV), have been poorly studied.

METHODS

In total, 234 cerebrospinal fluid (CSF) samples were collected from patients affected with neurological disorders. DNA was isolated and subjected to quantitative real-time PCR (Q-PCR) for the detection of six HPyVs: JCPyV, BKPyV, Merkel cell PyV (MCPyV), HPyV6, HPyV7, and HPyV9. Where possible, the molecular characterization of the viral strains was carried out by nested PCR and automated sequencing.

RESULTS

JCPyV was detected in 3/234 (1.3%), BKPyV in 15/234 (6.4%), MCPyV in 22/234 (9.4%), and HPyV6 in 1/234 (0.4%) CSF samples. JCPyV was detected at the highest (p < 0.05) mean load (3.7 × 10⁷ copies/mL), followed by BKPyV (1.9 × 10⁶ copies/mL), MCPyV (1.9 × 10⁵ copies/mL), and HPyV6 (3.3 × 10⁴ copies/mL). The noncoding control regions (NCCRs) of the sequenced viral strains were rearranged.

CONCLUSIONS

HPyVs other than JCPyV were found in the CSF of patients affected with different neurological diseases, probably as bystanders, rather than etiological agents of the disease. However, the fact that they can be latent in the CNS should be considered, especially in immunosuppressed patients.

Incidence, Risk Factors, and Outcome of Immune-Mediated Neuropathies (IMNs) following Haploidentical Hematopoietic Stem Cell Transplantation

Immune-mediated neuropathies (IMNs) following hematopoietic stem cell transplantation have been described recently, which, excluding Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy, may present with atypical patterns. This retrospective, nested, case-control study reviewed data from 3858 patients who received haploidentical hematopoietic stem cell transplantation (haplo-HSCT) during the past 10 years at a single center, and 40 patients (1.04%) with IMN following haplo-HSCT were identified. Chronic graft-versus-host disease (cGVHD) (P = .043) and cytomegalovirus (CMV) viremia (P = .035) were recognized as independent risk factors for the development of IMN after haplo-HSCT. There were no significant differences in overall survival (P = .619), disease-free survival (P = .609), nonrelapse mortality (P = .87), or the incidence of relapse (P = .583) between patients with and without IMN after haplo-HSCT. However, patients with post-transplant IMN were at higher risk of developing cGVHD (P = .012) than patients who did not develop IMN. Twenty-four of the 40 patients with IMN (60%) attained neurologic improvement after treatments including vitamins B₁ and B₁₂ and/or immunomodulatory agents. However, 19 (47.5%) patients still had persistent motor/sensory deficits despite receiving timely treatment. More studies are needed to help develop standardized diagnostic and therapeutic strategies for patients with post-transplant IMN.

IgG synthesis rate and anti-myelin oligodendrocyte glycoprotein antibody in CSF may be associated with the onset of CNS demyelination after haplo-HSCT

Haploidentical hematopoietic stem cell transplant (haplo-HSCT) is an upfront and effective therapy for hematology patients, but it usually has many complications, such as neurological complications. As one of the neurological complications following haplo-HSCT, immune-mediated demyelinating diseases of the central nervous system (CNS) seriously affect a patient's quality of life. However, the incidence, risk factors, and pathogenesis of CNS demyelination are not very well understood. Thirty of the 1526 patients (1.96%) suffered from CNS demyelination. In univariate analysis, we found that blood-brain barrier (BBB) permeability and the CSF IgG synthesis index (IgG-Syn) were related to the occurrence of CNS demyelination (p < 0.05). In a multivariate analysis, the IgG-Syn (OR = 1.017, 95% CI 1.003-1.031, p = 0.019) and CSF anti-myelin oligodendrocyte glycoprotein antibody (MOG.Ab) (OR = 12.059, 95% CI 1.141-127.458, p = 0.038) were independently associated with the onset of CNS demyelination. We also studied the possible pathogenesis of CNS demyelination. Immune reconstitution (the cell proportions of CD19⁺ B cells, CD3⁺ T cells, and CD4⁺ T cells); the counts of leucocytes, lymphocytes, monocytes, and platelets; and the levels of immunoglobulins A, G, and M 30, 60, and 90 days after HSCT showed no significant differences between CNS demyelination and no demyelination (p > 0.05). The probabilities of overall survival showed no significant differences between patients with and without demyelination (p > 0.05). Only four deaths in 30 patients, but bringing projected survival to less than 20%.We imply that IgG-Syn and CSF MOG. Ab may be associated with the onset of CNS demyelination during 2 weeks of neurological symptoms in patients with brain or spinal cord MRI abnormality. Immune reconstitution may not be the pathogenesis of CNS demyelination.

Ganciclovir and foscarnet dual-therapy for cytomegalovirus encephalitis: A case report and review of the literature

Cytomegalovirus (CMV) is a ubiquitous herpesvirus which establishes lifelong latency following primary infection. It is then capable of reactivating in the face of immunosuppression. Encephalitis is a less common, but particularly devastating syndrome associated with CMV. Here, we describe a case of CMV encephalitis in an allogeneic hematopoietic stem cell transplant recipient who received dual antiviral therapy with ganciclovir and foscarnet. The case presentation is followed by a summary of cases reported in the last ten years, with the goal of describing vulnerable patient populations, treatment courses, and outcomes. Finally, the discussion includes a review of the literature, with a focus on diagnostic criteria and the role for dual antiviral therapy in CMV encephalitis.

Central nervous system complications after allogeneic hematopoietic stem cell transplantation

Allogenic hematopoietic stem cell transplant (alloSCT) is a potentially curative modality of treatment for patients with hematological malignancies. However, CNS complications following transplant pose a risk to survival of the patients. Early recognition and management of these complications are crucial to reduce morbidity and mortality of patients following transplant. Early CNS complications associated with alloSCT are infection, cerebrovascular events, chemotherapy and radiation-induced toxicities while late complications include post-transplant lymphoproliferative disorder, CNS relapse of underlying malignancy and viral and fungal infections. Development of graft-versus-host disease can further increase the risk of CNS complications and outcomes after alloSCT. Strategies aimed to reduce the risk of CNS complications and early management may ameliorate the morbidity and mortality in transplant recipients.