Treatment and outcomes of immune cytopenias following solid organ transplant in children

Childhood autoimmune hemolytic anemia: A scoping review

BACKGROUND AND OBJECTIVE

Autoimmune hemolytic anemia (AIHA) is a rare but important cause of morbidity in pediatric hematology patients. Given its rarity, there is little high-quality evidence on which to base the investigation and management of pediatric AIHA. This scoping review aims to summarize the current evidence and highlight key gaps to inform future studies.

METHODS

This review searched MEDLINE and the Cochrane CENTRAL Trials Register from 2000 to November 03, 2023. Experimental and observational studies reporting AIHA diagnostic criteria, laboratory workup, or treatment/management in populations with at least 20% of patients ≤18 years were included.

RESULTS

Forty-three studies were included, with no randomized controlled trials identified. AIHA diagnostic criteria, diagnostic tests, and treatments were highly variable. First-line treatment approaches include corticosteroids, intravenous immunoglobulin, or both. Approaches to AIHA resistance to first-line therapy were widely variable between studies, but most commonly included rituximab and/or cyclosporine.

CONCLUSIONS

We identify a heterogenous group of observational studies into this complex, immune-mediated disorder. Standardized definitions and classifications are needed to guide collaborative efforts needed to study this rare disease. The work done by the CEREVANCE group provides an important paradigm for future studies.

An adult case of refractory autoimmune neutropenia after liver transplantation

Autoimmune neutropenia (AIN) is an exceptionally rare condition that occurs after liver transplantation. Here, we report an adult case of refractory AIN 3.5 years after liver transplantation. A 59-year-old man who underwent brain-dead donor liver transplantation in August 2018 developed rapid neutropenia (0.07 × 10⁹/L) in December 2021. The patient was diagnosed with AIN based on positivity for anti-human neutrophil antigen-1a antibody. There was no response to granulocyte colony-stimulating factor (G-CSF), prednisolone, or rituximab, and intravenous immunoglobulin (IVIg) therapy induced only a temporary recovery in neutrophil count. The patient continued to have a low neutrophil count for several months. However, the response to IVIg and G-CSF improved after the post-transplant immunosuppressant was changed from tacrolimus to cyclosporine. Post-transplant AIN has many unknown aspects. Tacrolimus-induced immunomodulation and graft-associated alloimmunity may be involved in its pathogenesis. Further studies are needed to elucidate the underlying mechanisms and explore new treatment options.

Neutropenia in pediatric solid organ transplant

Neutropenia is generally defined as an absolute neutrophil count in the circulation of less than 1500/mm³ and occurs in up to 25%-30% of pediatric solid organ transplant recipients (SOT) within the first year after transplantation. In the SOT population, neutropenia is most often a result of drug-induced bone marrow suppression but can also be secondary to viral infection, nutritional deficiencies, lymphoproliferative infiltrate, and inherited causes. Outcomes for patients with neutropenia vary by degree of neutropenia and type of solid organ transplant. Management of neutropenia should begin by addressing the underlying cause, including reducing or removing medications when appropriate, treating infections, and addressing nutrient deficiencies; however, consultation with an experienced pediatric hematologist and use of granulocyte colony-stimulating factor (G-CSF) may be helpful in some cases. Overall, data on clinical outcomes for G-CSF use remain limited, but observational studies may support its use in patients with infections or severe neutropenia.

Characteristics, risk factors, and outcomes of neutropenia after liver or kidney transplantation in children

BACKGROUND

While prior adult studies have shown that approximately 20%-38% of subjects undergoing solid-organ transplant develop neutropenia, similar analyses in pediatric subjects are scarce.

METHODS

We conducted a retrospective chart review of liver transplant (LT) and kidney transplant (KT) recipients at our center during the period 2008-2018. All of the KT and none of the LT subjects during this time period had induction with either anti-thymocyte globulin (ATG) or basiliximab at time of transplant. Neutropenia was defined as absolute neutrophil count (ANC) value ≤1000/mm3 .

RESULTS

One hundred subjects with LT and 82 subjects with KT were included. The incidence of neutropenia within the first year of transplant in KT was higher compared to LT (54.8% vs 39%, p = .01). The median number of hospitalizations (p = .001) and infectious complications (p = .04) was significantly higher only in the KT subjects who developed neutropenia (compared to those who did not). Multivariate analysis identified factors associated with severity of liver disease at transplant, namely h/o upper gastrointestinal bleeding (p = .02), weight deficit (p = .01), and pre-LT ANC (p = .01), along with high or moderate risk cytomegalovirus status (p = .05) as predictors of neutropenia in LT subjects. Female gender (p = .03) predicted neutropenia, while BK virus infection was protective for neutropenia (p = .04) in KT subjects.

CONCLUSIONS

The incidence of and morbidity associated with neutropenia within 1 year post-transplant is higher in KT subjects compared to LT subjects. The likely reason for this is the use of induction therapy (ATG, basiliximab) at the time of transplant in KT subjects.

Complete Remission of Refractory Immunothrombocytopenic Purpura After Tacrolimus Replacement With Cyclosporine in a Case of Living Related Liver Transplant

Immunothrombocytopenic purpura is a possible complication after liver transplant. The therapy for immunothrombocytopenic purpura after liver transplant is similar to that of primary immunothrombocytopenic purpura. This therapy consists of corticosteroids, intravenous immunoglobulin, and immunosuppressive agents such as cyclosporine and rituximab. There are a few cases of immunothrombocytopenic purpura in patients who recovered after cessation of tacrolimus administration. Here, we show an intractable case of immunothrombocytopenic purpura in a living related liver transplant recipient treated with some of these. We observed complete remission after switch ofthe immunosuppressive agent from tacrolimus to cyclosporine. The patient was an infant girl aged 18 months who underwent livingr elated liver transplant for biliary atresia when she was 6 months old. Liver graft was a left lateral segment from her father. Purpura and severe thrombocytopenia developed after 11 months.There was no effect of the first-line therapies, as described in the Japan guidelines for immunothrombocytopenic purpura.Thrombocytopenia was extreme, as shown by a blood count of 0 platelets/μL. Administration of rituximab was started. However, her platelet count had not increased 8 weeks after rituximab initiation. As a trial therapy, we switched tacrolimus to cyclosporine. She showed complete remission 1 month after this drug conversion. Thus, a switch from tacrolimus to other immunosuppressive agents as a therapy for immunothrombocytopenic purpura after living related liver transplant should be considered.

Romiplostim as a Therapeutic Intervention for Tacrolimus-induced Immune Thrombocytopenia in a Pediatric Cardiac Transplant Patient

Tacrolimus-induced immune thrombocytopenia (ITP) is a rare entity that can occur years after initiation of tacrolimus therapy following solid organ transplantation, and platelet recovery can be substantially delayed following discontinuation of tacrolimus. Romiplostim, a thrombopoietin receptor agonist approved by the FDA in 2018 for the treatment of chronic ITP in children, may be a useful therapy to hasten platelet recovery in the acute ITP setting in place of immunomodulating agents. We present a case of tacrolimus-induced ITP successfully treated with romiplostim in a child following cardiac transplantation.

Transplant-associated thrombotic microangiopathy and immune haematological complications following intestine-containing organ transplantation: experience from over 100 consecutive cases

Descriptions of passenger lymphocyte syndrome (PLS), immune cytopenias and transplant-associated thrombotic microangiopathy (TA-TMA) after intestine-containing transplants remain scarce. We describe our centre's experience of these complications from 2007 to 2019. Ninety-six patients received 103 transplants. PLS occurred in 9 (9%) patients (median 12 days post-transplant); all due to ABO antibodies. There were 31 minor ABO mismatch transplants. No patient required change in immunosuppression. Immune cytopenias (excluding PLS) occurred in six patients at an incidence of 1·7/100 patient years; three immune haemolysis, one immune thrombocytopenia, one acquired Glanzmann's and one immune neutropenia; 50% occurred with other cytopenias. All cases eventually responded to treatment, with a median of four treatments (range 1-8) and 5/6 were treated with rituximab. One patient with immune haemolysis required bortezomib. Complications were common in patients with immune cytopenias; 4/6 with infection needing intravenous antibiotics and 3/6 with venous thromboembolism. In 3/6 cases, a secondary cause for the immune cytopenia was evident. Switching from tacrolimus to ciclosporin was not necessary. There were five cases of transplant-associated thrombotic microangiopathy (TA-TMA; 1·5/100 patient years) requiring calcineurin inhibitor withdrawal; two cases associated with acute rejection. Two cases were managed with plasma exchange, one with plasma infusions and one with eculizumab. Further research in this patient group is required.

Expanded utilization of rituximab in paediatric cardiac transplant patients

WHAT IS KNOWN AND OBJECTIVE

Epstein-Barr virus (EBV) viraemia and autoimmune cytopenias (AICs) are significant complications that occur following paediatric solid organ transplantation. A variety of treatment methods have been investigated but limited research has focused on the utilization of rituximab in paediatric cardiac transplant recipients for these indications. Rituximab is a monoclonal antibody that binds the CD20 antigen on the surface of B-type lymphocytes resulting in B-cell cytotoxicity. It is considered a second-line therapy for treatment of autoimmune cytopenias and EBV viraemia following adult solid organ transplant (SOT) and haematopoietic stem cell transplant (HSCT). However, data for its use in the paediatric population for treatment of autoimmune cytopenias are lacking. Dosing is based on adult studies, and the frequency and length of therapy associated with resolution of EVB viraemia and AICs in paediatric cardiac transplant recipients is unknown. The objective of this retrospective study was to describe the dosing and length of therapy of expanded off-label use of rituximab for the management of refractory EBV viraemia and AICs, specifically in paediatric cardiac transplant patients.

METHODS

A retrospective chart review was conducted evaluating children <18 years of age who underwent cardiac transplantation, were diagnosed with EBV viraemia or autoimmune cytopenia, and subsequently received treatment with rituximab between June 1995 and October 2018. Data were analysed descriptively.

RESULTS AND DISCUSSION

Of all (n = 188) paediatric cardiac transplant recipients since 1995, 10 patients met the inclusion/exclusion criteria. Primary diagnoses were EBV viraemia (n = 6), immune haemolytic anaemia (n = 3) and immune thrombocytopenic purpura (n = 1). Complete responses were observed in 83.3% and 100% of patients with EVB viraemia and AICs treated with rituximab, respectively. All patients (n = 10) received rituximab 325 mg/m² at weekly intervals. The number of total doses associated with complete resolution was 4-6 doses for EBV viraemia and 2-4 doses for AICs. The most common adverse events reported were neutropenia (n = 3), thrombocytopenia (n = 4), infusion reactions (n = 1) and significant anaemia (n = 2).

WHAT IS NEW AND CONCLUSION

Although the efficacy of rituximab for treatment of EBV viraemia and autoimmune cytopenia in the paediatric cardiac transplant population remains unclear, our study supported the benefit of rituximab when added to therapy for treatment of EBV viraemia and ACIs.

Haematological disorders following kidney transplantation

Transplantation offers cure for some haematological cancers, end-stage organ failure, but at the cost of long-term complications. Renal transplantation is the best-known kidney replacement therapy and it can prolong end-stage renal disease patient lives for decades. However, patients after renal transplantation are at a higher risk of developing different complications connected not only with surgical procedure but also with immunosuppressive treatment, chronic kidney disease progression and rejection processes. Various blood disorders can develop in post-transplant patients ranging from relatively benign anaemia through cytopenias to therapy-related myelodysplasia and acute myeloid leukaemia (AML) and post-transplant lymphoproliferative disorders followed by a rare and fatal condition of thrombotic microangiopathy and haemophagocytic syndrome. So far literature mainly focused on the post-transplant lymphoproliferative disease. In this review, a variety of haematological problems after transplantation ranging from rare disorders such as myelodysplasia and AML to relatively common conditions such as anaemia and iron deficiency are presented with up-to-date diagnosis and management.

Autoimmune pancytopenia occurring late after simultaneous pancreas and kidney transplantation

A 35-year-old woman presented with a widespread petechial rash and pancytopenia. She underwent simultaneous pancreas and kidney transplantation for type 1 diabetes 8 years previously followed by a renal transplant 1 year prior to presentation, and was taking tacrolimus as long-term immunosuppression. The full blood count showed haemoglobin 97 g/L, platelet count 2×10⁹/L and neutrophil count 0.22×10⁹/L. Peripheral blood film examination confirmed genuine thrombocytopenia in the absence of any haemolytic or malignant features. Serological testing identified autoantibodies against all three blood lineages, consistent with a diagnosis of autoimmune pancytopenia. Treatment with steroids, intravenous immunoglobulins, romiplostim and mycophenolate mofetil achieved only fleeting remissions. Blood counts eventually normalised following the administration of rituximab and a change from tacrolimus to ciclosporin immunosuppression. Cytopenias are a well-recognised complication of post-transplantation care but we believe this to be the first reported case of autoimmune pancytopenia following solid organ transplantation. In this case report, we discuss the approach to investigation of haematological abnormalities post-transplant and the rationale for, and outcome of, the management of this rare case.

Conversion from tacrolimus to sirolimus as a treatment modality in de novo allergies and immune-mediated disorders in pediatric liver transplant recipients

De novo PTAID may develop in pediatric solid organ transplant recipients, have a diverse spectrum, and are occasionally treatment resistant. Previous reports showed resolution of immune cytopenias in solid organ transplant recipients following replacement of the calcineurin inhibitor tacrolimus with the mTOR inhibitor sirolimus. Herein we describe a retrospective review (2000-2017) of subjects who developed PTAID in whom immunosuppression was changed to sirolimus. Eight recipients (6 males) of either liver (n = 7) or multivisceral transplant (n = 1) suffered from severe, treatment-resistant PTAID and were switched from tacrolimus to sirolimus. The median age at transplant was 1 year (range 0.5-2.4 years). Six (75%) recipients developed de novo allergy and 2 immune-mediated diseases. The median age at presentation of PTAID was 2.7 (1.4-9) years at a median of 1.3 (0.25-8) years after transplantation. The median time from PTAID presentation to conversion to sirolimus was 1.8 (0.45-10) years. Complete resolution of symptoms was seen in 4 (50%) patients after a median of 12 (range 4-24) months including 2 patients with immune-mediated disease, 1 eczema, and 1 with eosinophilic colitis. One patient with multiple food allergies had a partial response and 3 (38%) had no response. None of the 8 recipients developed sirolimus-attributed adverse events or acute rejection during a median follow-up of 5 (0.6-8) years after the conversion. Immunosuppression conversion from tacrolimus to sirolimus can be an effective therapy in patients suffering severe or treatment-resistant PTAID, suggesting a potential role for tacrolimus in the pathogenesis of PTAID.

High Frequency of Concomitant Food Allergy Development and Autoantibody Formation in Children Who Have Undergone Liver Transplantation

BACKGROUND

Allergy and other immune-mediated diseases are more frequently reported in children who have undergone liver transplantation. Furthermore, autoantibodies are also prevalent, suggesting a state of immune dysregulation in these patients. Whether or not these processes occur simultaneously in the same individual has not been studied previously.

METHODS

A cohort of 43 children who had undergone liver transplantation for nonautoimmune liver disease at median age of 1.3 years was investigated for allergy and autoimmune disease. Sensitization to food and inhalant allergens was assessed, and autoantibodies were measured.

RESULTS

The prevalence of food allergy was 26% and that of respiratory allergy was 23%, whereas 33% and 26% of the subjects were sensitized to food and inhalant allergens, respectively. Autoimmune disease (ie, autoimmune hepatitis) occurred in a single individual (2%), whereas autoantibodies were present in 44% of the children. Food allergy and autoantibodies occurred concomitantly in 19% of the children, which was almost twice the frequency expected by chance (11%, P = 0.04). Respiratory allergy and the presence of autoantibodies were unrelated (12% concurrence versus the expected 10%, P = 0.73). In the logistic regression analysis, autoantibody formation was associated with discontinued immunosuppression and food allergy, with odds ratios of 13 (P = 0.01) and 7.1 (P = 0.03), respectively.

CONCLUSIONS

In contrast to respiratory allergy, food allergy and autoantibody formation occurred together in the same children who underwent liver transplantation at a frequency higher than would be expected by chance. This may reflect an underlying immune dysregulation that impairs immune tolerance to both food allergens and autoantigens.

Bortezomib for autoimmune hemolytic anemia after intestinal transplantation

AIHA is rare in the general population and associated with a mortality of 8%. In contrast, AIHA occurs in up to 12.2% of cases after intestinal transplantation and is associated with mortality up to 50%. Treatment entails a "step-up" approach including corticosteroids, IvIg, plasmapheresis, and rituximab. However, AIHA after transplantation often is refractory to this strategy, contributing to a poor outcome. We describe a child with microvillous inclusion disease who developed AIHA 1 year after multivisceral transplantation that was refractory to standard therapy and was subsequently treated with bortezomib.We observed remission of AIHA within 1 week after the start of bortezomib. Bortezomib was associated with transient diarrhea, leucopenia, and elevated liver enzymes. Three years later, he remains in remission without important complications. Published data on bortezomib for autoimmune cytopenias outside SOT are discussed. This is the first report to support bortezomib as an important therapeutic alternative for AIHA after SOT. The occurrence and treatment of AIHA after SOT, and specifically intestinal transplantation, should be the subject of future registry studies to collect additional experience and explore the optimal therapeutic approach.

Immune-Mediated Cytopenias After Hematopoietic Cell Transplantation: Pathophysiology, Clinical Manifestations, Diagnosis, and Treatment Strategies

PURPOSE OF REVIEW

Discuss the pathophysiology, clinical presentation, diagnosis, and treatment of immune-mediated cytopenias (IMC) after hematopoietic cell transplantation (HCT).

RECENT FINDINGS

Key risk factors for post-HCT IMC include younger age, non-malignant disease, and umbilical cord blood stem cell source. While anemia predominates, any or all three hematopoietic cell lines can be affected. In rare cases, IMC can cause graft failure or death. IMC is hypothesized to result from immune dysregulation upon reconstitution of donor hematopoietic cells (i.e., dysfunctional regulatory T cells). Aside from blood product transfusions, IMC treatment includes immune-suppressive or ablative agents. First-line therapies, including corticosteroids and intravenous immunoglobulin, are often inadequate, prompting use of additional agents aimed at antibody production/T cell dysfunction or direct antibody removal via plasmapheresis. IMC occurs in up to 20% of high-risk HCT populations. Morbidity and mortality from IMC post-HCT have been reduced by improved recognition and aggressive early interventions.

Autoimmune hemolytic anemia and immune thrombocytopenia following hematopoietic stem cell transplant: A critical review of the literature

Autoimmune cytopenias (AIC) post-hematopoietic stem cell transplant (HSCT) are rare but exceptionally challenging complication. We conducted a comprehensive literature review and identified a pooled incidence of post-HSCT autoimmune hemolytic anemia and/or immune thrombocytopenia of 2.66% (SE = 0.27) in pediatric patients. Nonmalignant disease, unrelated donor transplant, peripheral or cord blood stem cell source, conditioning regimen without total body irradiation, and presence of chronic graft-versus-host disease were prominent risk factors. Treatment was highly variable, and cytopenias were commonly refractory. AIC represent a significant post-HSCT complication. We report here the incidence, risk factors, and possible biology behind the development of AIC in pediatric post-HSCT patients.

Liver-associated immune abnormalities

In recent years, the cross talk between the liver and the immune system is being uncovered, in part by studying liver involvement in primary immune deficiencies (PID) and in part by investigating the alterations of the immune system following orthotopic liver transplantation (OLT). Here we review some of the reciprocal interactions between the liver and the immune system. Patients with PID, particularly those involving inherited defects in T and B cells or innate immunity are prone to infections and inflammatory responses that often involve the liver. Omenn's syndrome, familial hemophagocytic lymphohistiocytosis, AIRE, FOXP3 and CD25 deficiencies, common variable immunodeficiency, CD40 ligand deficiency, chronic granulomatous disease and autoimmune lymphoproliferative syndrome are some of the notable PID associated with typical hepatobiliary abnormalities. Knowledge gained from studying these PID together with laboratory and histological evaluations can assist in managing PID-associated liver dysfunction. The liver itself also has important effects on the immune system, as evident from the growing experience with patients surviving OLT. Up to 40% of pediatric patients who receive OLT suffer from post transplantation allergy, autoimmunity, and immune-mediated disorders (PTAA). PTAA is more common after liver and heart transplantations than kidney transplantations. Potential contributing factors for the increased frequency of PTAA after OLT include the age of the patients, the prolonged use of tacrolimus and the reduced regulatory immune function with a shift towards a TH2 immune response. Better understanding of the mechanisms leading to the development of PTAA after OLT will also improve the management of these conditions.

Autoimmune hemolytic anemia: An unusual presentation of hemophagocytic lymphohistiocytosis in a pediatric post-liver transplant patient

Hemophagocytic lymphohistiocytosis (HLH), a rare condition characterized by immune dysfunction with uncontrolled activation of macrophages and hypersecretion of cytokines, has only been reported in a small number of pediatric patients following solid organ transplant (SOT). The diagnosis of HLH after SOT is especially difficult, as several of the diagnostic criteria, including fever, splenomegaly, and cytopenias, are nonspecific and can be seen with other post-transplant complications. Autoimmune hemolytic anemia (AIHA) has also been reported after pediatric SOT and is thought to be related to immunosuppression, specifically tacrolimus. Although HLH and AIHA have been separately described following SOT, there have been no reports of them occurring together in post-liver transplant (LT) patients. We report the first case of autoimmune hemolysis as the presenting symptom of HLH in a pediatric post-LT patient.

Recurrent oral ulcerations following heart transplant in a pediatric patient: A diagnostic dilemma

Oral ulceration is a non-specific clinical finding with many potential causes. The persistence of oral ulcers in the context of a patient post-SOT is concerning for PTLD. There is growing evidence that SOT recipients may also be at higher risk of autoimmune diseases. This case report describes a pediatric patient with persistent oral ulcers after heart transplant, who underwent an extensive workup for PTLD, including repeat investigations, with a subsequent diagnosis of Behçet's disease.

Factors associated with immune hemolytic anemia after pediatric liver transplantation

Immune-mediated hemolytic anemia following SOT is a rare disorder, the risk factors for which are unknown. Our purpose was to analyze a seemingly increased incidence in our center with the aim to identify predisposing factors. This recipients single-center retrospective study reviewed the medical records of 96 pediatric LT between 2000 and 2013. IHA was defined as acute anemia with a positive direct antiglobulin test. Seven cases of immune-mediated hemolytic anemia were identified (incidence 8.5%). Three cases presented during the first 3 months following LT (early IHA), and 4 presented later (late IHA). All patients with late IHA required rituximab. Using univariate analysis, the following factors were associated with IHA onset: BA (P = .04), younger age (P = .04), and the use of IGL-1 preservation solution (P = .05). Late IHA was associated with viral infections occurring beyond 3 months following LT, younger age, and BA (P = .01). Overall, CMV infection was associated with the development of both early and late IHA: CMV-negative recipients who received an organ from a CMV-positive donor were more likely to develop IHA (P = .035), and de novo CMV infection during the first year post-LT was associated with late IHA (P = .03). IHA is a rare complication following pediatric LT, occurring more frequently in younger patients and patients with an initial diagnosis of BA. CMV-negative recipients and patients who experience a de novo CMV infection in the first year following LT seem particularly vulnerable. IGL-1 preservation solution may be associated with an increased likelihood of developing IHA, a novel finding which warrants further investigation.

Neutropenia in pediatric heart transplant recipients

Neutropenia has been reported in pediatric heart transplant recipients, but its association with infectious morbidity and mortality is unknown. We sought to determine neutropenia's prevalence and impact on infection, rejection, and survival. A retrospective analysis of pediatric heart transplant recipients from March 2005 to August 2015 was performed. Demographics, medications, infection, and rejection data were collected. Of 142 pediatric heart transplant recipients, 77 (54.2%) developed neutropenia within 4.7 months [3.3-12.1 months] of transplant. In all patients, the adjusted 5-year cumulative incidence of neutropenia was 30.2%. Fifty-one patients (66.2%) had recurrent neutropenia. Six of 14 tested had positive antineutrophil antibodies. Medications associated with neutropenia were decreased in 15 (19.5%) and discontinued in 42 (54.4%) patients with no change in 1-year rejection rates compared to published data. Fifteen patients developed infection within 30 days of neutropenia and two from 30 days to 1 year, with an infection rate similar to the non-neutropenic group. There was no significant difference in survival, ANC, rate of rejection or PTLD in neutropenic patients with and without infection at median follow-up (5.5 years). Neutropenia is common in pediatric heart transplant recipients. Neutropenia had <20% risk of associated infection, similar to non-neutropenic patients. Infection in neutropenic patients did not increase mortality.

De Novo Allergy and Immune-Mediated Disorders Following Solid-Organ Transplantation-Prevalence, Natural History, and Risk Factors

OBJECTIVES

To describe the prevalence, natural course, outcome, and risk factors of post-transplant de novo allergy and autoimmunity.

STUDY DESIGN

A cross-sectional, cohort study of all children (<18 years) who underwent a solid-organ transplantation, between 2000 and 2012, in a single transplant center, with a follow-up period of 6 months or more post-transplant and without history of allergy or immune-mediated disorder pretransplant.

RESULTS

A total of 626 eligible patients were screened, and 273 patients (160 males; 59%) met the inclusion criteria; this included 111 liver, 103 heart, 52 kidney, and 7 multivisceral recipients. Patients were followed for a median period of 3.6 years. A total of 92 (34%) patients (42 males, 46%) developed allergy or autoimmune disease after transplantation, with a high prevalence among liver (41%), heart (40%), and multivisceral (57%) transplant recipients compared with kidney recipients (4%; P < .001). Post-transplant allergies included eczema (n = 44), food allergy (22), eosinophilic gastrointestinal disease (11), and asthma (28). Autoimmunity occurred in 18 (6.6%) patients, presenting mainly as autoimmune cytopenia (n = 10). In a multivariate analysis, female sex, young age at transplantation, family history of allergy, Epstein-Barr virus infection, and elevated eosinophil count >6 months post-transplantation were associated with an increased risk for allergy or autoimmunity. Two patients (0.7%) died from autoimmune hemolytic anemia and hemophagocytic lymphohistiocytosis, and 52 episodes of post-transplant allergy, autoimmunity, and immune-mediated disorders (37%) did not improve over time.

CONCLUSIONS

Allergy and autoimmunity are common in pediatric liver, heart, and multivisceral transplant recipients and pose a significant health burden. Further studies are required to clarify the mechanisms behind this post-transplant immune dysregulation.

Outcomes following proton therapy for pediatric ependymoma

BACKGROUND

Proton therapy can reduce the low and intermediate radiation dose to uninvolved brain tissue in children with intracranial ependymomas, which may improve functional outcomes and reduce second malignancies in survivors. Accordingly, ependymoma has become the most common pediatric tumor treated with proton therapy, yet data on efficacy and toxicity are limited.

MATERIAL AND METHODS

Between June 2007 and February 2017, 179 children (≤21 years old) with nonmetastatic grade II/III intracranial ependymoma received proton therapy at our institution. Median age, 3.5 years (range, 0.7-21); 58% were male. Most (66%) tumors were in the posterior fossa and classified as WHO grade III (67%). 27% underwent multiple operations to maximize the extent of resection; ultimately 85% had a gross total or near total tumor resection before radiotherapy. 33% received preradiation chemotherapy. Median radiation dose in children ≤3 years old, 54 Gy(RBE). Most (>90%) children over 3 years old received 59.4 Gy(RBE). Patient and treatment variables were assessed for correlation with disease control.

RESULTS

Median follow-up, 3.2 years. 3-year local control, progression-free survival, and overall survival rates were 85%, 76%, and 90%, respectively. First site of progression was local, metastatic, or simultaneous in 14, 17 and 6 patients, respectively. On multivariate analysis, subtotal resection was associated with inferior local control (67% vs. 88%; p ≤ .01) and progression-free survival (59% vs. 79%; p < .05). Male sex was associated with inferior progression-free (67% vs. 87%; p< .05) and overall survival (84% vs. 99%; p < .01). The 3-year CTCAE grade 2 + brainstem toxicity rate was 5.5% (95% CI: 2.9-10.2), including 1 grade 5 toxicity.

CONCLUSIONS

This series of proton therapy for pediatric intracranial ependymoma demonstrates disease control comparable to photon series without unexpected toxicity. Subtotal resection and male sex were associated with inferior disease control. Additional follow-up to quantify the expected reductions in late toxicity with proton therapy is ongoing.

Autoimmune hemolytic anemia in solid organ transplantation-The role of immunosuppression

Hemolysis after solid organ transplantation can be caused by both immune and non-immune-mediated mechanisms, and the evaluation must take into account issues distinctive to the post-transplant period. Autoimmune hemolytic anemia usually occurs within the first year and has been attributed to immunosuppressive treatment, infections, or underlying post-transplant lymphoproliferative disorder. Review of the literature revealed 59 cases with autoimmune hemolytic anemia mostly in children after liver transplantation. Almost all of the patients at the time of diagnosis received immunosuppression with tacrolimus, and first-line treatment with steroids and/or intravenous immunoglobulin was ineffective for complete remission. Rituximab was used as second-line treatment especially in patients with underlying lymphoproliferative disorders whereas sirolimus showed encouraging results.

Efficacy and safety of tacrolimus in systemic lupus erythematosus patients with refractory thrombocytopenia: a retrospective study

Objective

We evaluated the efficacy and safety of tacrolimus in systemic lupus erythematosus patients with refractory thrombocytopenia.

Methods

We retrospectively reviewed the data for 20 systemic lupus erythematosus patients with refractory thrombocytopenia and treated with tacrolimus during the period January 2013 to January 2015. In addition to glucocorticoids, all patients were treated with tacrolimus, 1 mg taken twice daily. The clinical effect of tacrolimus treatment in patients was evaluated by analysis of platelet counts at baseline and after one, three and six months of tacrolimus treatment. Levels of anti-double-stranded DNA antibodies and complement C3, C4 were determined individually.

Results

After one month of tacrolimus treatment, three patients (15%) did not respond, three patients (15%) achieved a complete response and the other 14 patients (75%) achieved a partial response. After three months of tacrolimus treatment, the platelet counts of all patients were significantly improved. A partial response was seen in 14 patients (75%) and the complete response rate increased to 25% (five patients). After six months, all patients attained partial response or complete response without relapse, and the rate of complete response increased to 75%. Compared to pretreatment, anti-double-stranded DNA antibody levels and the disease activity index score were markedly decreased after tacrolimus treatment. The levels of serum C3 and C4 were increased significantly ( P < 0.05).

Conclusions

Our survey revealed that a six-month course of tacrolimus is a safe and effective treatment for systemic lupus erythematosus patients with refractory thrombocytopenia.

Cytopenia Occurrence in Kidney Transplant Recipients Within Early Post-transplant Period

Objective:

This study assessed incidence, severity, and time to occurrence of drug-induced leukopenia/thrombocytopenia within 1^st month after kidney transplantation.

Methods:

This cross-sectional study was conducted on newly kidney transplant recipients from two hospitals, Iran. Patients with thrombocytopenia due to acute antibody-mediated rejection were excluded from the study. Demographic, clinical, and laboratory data of patients within the 1^st month after transplantation were collected.

Findings:

Of 213 patients, 14.1% and 66.2% experienced leukopenia and thrombocytopenia, respectively. Cytopenia happened more commonly among patients with thymoglobulin-containing regimen (for leukopenia: 24.6% vs. 0%, P < 0.001; for thrombocytopenia 84.4% vs. 41.8%, P < 0.001). Most leukopenia patients experienced Grades 1 and 2 of leukopenia (46.6% and 40% of patients). Most thrombocytopenic patients showed Grade 1 of thrombocytopenia (78.7%). Cumulative dose of thymoglobulin did not differ between patients with and without leukopenia (5.57 ± 1.13 vs. 5.9 ± 1.96 mg/kg; P = 0.613) or with and without thrombocytopenia (5.87 ± 1.86 vs. 5.56 ± 1.38 mg/kg; P = 0.29). Cytopenia were more common among recipients from deceased compared with from living donors (91.3% vs. 8.7% for leukopenia patients, P = 0.001; 69.9% vs. 33.1% for thrombocytopenia, P = 0.02). More patients with kidney from deceased donors received thymoglobulin in their immunosuppressive regimen (82% vs. 37%; P < 0.001). The median time to leukopenia and thrombocytopenia were 3 days and 1 day, respectively.

Conclusion:

Among immunosuppressive and prophylactic antimicrobial agents, thymoglobulin is more related to cytopenia; therefore, thymoglobulin dose reduction is recommended as the first intervention to manage cytopenia without need for reduction of its cumulative dose. The higher prevalence of cytopenia among recipients from deceased donors may be related to the higher use of thymoglobulin in these patients.