Immune-mediated Cytopenias Research Articles

Allogeneic Hematopoietic Cell Transplant For Bone Marrow Failure or Myelodysplastic Syndrome in Dyskeratosis Congenita/Telomere Biology Disorders: Single-Center, Single-Arm, Open-Label Trial of Reduced-Intensity Conditioning Without Radiation

BackgroundDyskeratosis congenita/Telomere biology disorders (DC/TBD) often manifest as bone marrow failure (BMF) or myelodysplastic syndrome (MDS). Allogeneic hematopoietic cell transplant (alloHCT) rescues hematologic complications, but radiation and alkylator-based conditioning regimens cause diffuse whole-body toxicity and may expedite DC/TBD-specific non-hematopoietic complications. Optimization of conditioning intensity in DC/TBD to allow for donor hematopoietic cell engraftment with the least amount of toxicity remains a critical goal of the alloHCT field. Objectives/Study DesignWe report prospectively collected standard alloHCT outcomes from a single-center single-arm open-label clinical trial of bone marrow or peripheral blood stem cell alloHCT for DC/TBD-associated BMF or MDS. Conditioning was reduced intensity (RIC) including alemtuzumab 1mg/kg, fludarabine 200 mg/m2, and cyclophosphamide 50 mg/kg. A previous single-arm open-label phase II clinical trial for the same patient population conducted at the same center, differing only by inclusion of 200 centigray of total body irradiation (TBI), served as a control cohort. ResultsThe Non-TBI cohort included 10 patients (ages 1.7-65.9 years, median follow-up of 3.9 years) compared to the control TBI cohort which included 12 patients (ages 2.2-52.2 years, median follow-up of 10.5 years). Baseline characteristics differed only in total CD34+ cells received, with a median of 5.6 (Non-TBI) compared to 2.6 (TBI) x 106/kg (p=0.02; no difference in total nucleated cells). The cumulative incidence of day +100 grade II-IV acute and 4-year chronic graft-versus-host disease (GvHD) were low at 0 and 10% (Non-TBI) and 8 and 17% (TBI), respectively (acute, p=0.36; chronic, p=0.72). Primary graft failure was absent. Secondary non-neutropenic graft failure occurred in one (Non-TBI cohort). The Non-TBI cohort demonstrated delayed achievement of full donor chimerism but superior lymphocyte recovery. There was no difference in 4-year overall survival at 80% (Non-TBI) and 75% (TBI; p=0.78).MDS as an indication for alloHCT was uncommon, but overall associated with poor outcomes. There were 3 MDS patients in the Non-TBI cohort: 1 relapsed and died at day+387; 1 relapsed at day+500 and is alive 5.5 years later following salvage with a 2nd alloHCT; 1 relapsed at day+1093 and is alive at day +100 after a 2nd alloHCT. There was 1 MDS patient in the TBI cohort who achieved 100% donor myeloid engraftment without relapse but died at day+827 from a bacterial infection in the setting of immune mediated cytopenia. ConclusionElimination of TBI from the RIC regimen for DC/TBD was not associated with significant changes in rates of graft failure, GvHD, and overall survival, but was associated with delayed achievement of full donor chimerism and improved lymphocyte reconstitution. For DC/TBD-associated BMF, TBI appears to be dispensable. Optimal approaches to DC/TBD-associated MDS remain unclear. Larger cohorts are needed to better assess the unique contribution of TBI and donor CD34+ cell dose. Longer follow-up is required to assess differences in DC/TBD complications and late effects.

T-cell recruiting immunotherapies in B-cell lymphoma - the future backbone for all therapy lines?

The introduction of immunologically targeted therapies has represented a significant advancement in the treatment of B-cell lymphomas, particularly aggressive B-cell lymphoma. CD19 CAR-T cells such as Axicabtagen-Ciloleucel (Axi-cel) and Lisocabtagen Maraleucel (Liso-cel) have been approved since 2022 and 2023, respectively, for second-line therapy of Diffuse Large B-Cell Lymphomas (DLBCL), when there is primary refractory disease or relapse within 12 months after the end of first-line therapy. These therapies result in a significant improvement in progression-free survival compared to the previous standard therapy (salvage chemotherapy followed by high-dose chemotherapy and autologous stem cell transplantation). Especially in elderly patients or patients with underlying medical conditions, CAR-T cell therapies like Axi-cel and Liso-cel demonstrate acceptable tolerability and high efficacy.Furthermore, bispecific T-cell-engaging antibodies ("bispecifics") such as Glofitamab, Epcoritamab, and Mosunetuzumab also represent promising treatment options for patients with relapsed disease after failure of second- or later line therapy and show efficacy even in a subset of patients relapsing after CD19 CAR-T cells. However, randomized study results for these substances are not yet available. They are expected to be used in earlier lines of therapy in the future, especially in combination with standard chemotherapy regimens. Common side effects of bispecific antibody therapies are cytokine release syndrome (CRS) and immune-mediated cytopenias, whereas immune-cell associated neurotoxicity syndrome (ICANS) is relatively rare compared to CD19 CAR T cells. In summary, bispecifics represent a novel, highly effective immunotherapy for the treatment of lymphomas with a very favourable toxicity profile.

Unveiling the Spectrum of Inborn Errors of Immunity: Lessons from T-Cell LGL Clonal Expansions

T-cell LGL clonal proliferations occur in the context of various diseases of the immune system. These associations constitute a unique research framework to discern whether the expanded clones are triggers or sequels of the concomitant disorders and, more importantly, when and how they should be targeted. While the relationship of LGL leukemia (LGLL) with autoimmune diseases is well established, the exact pathogenic connection between them remains unknown and, probably, it is not a one-way process. We previously described a syndrome whereby LGLL co-occurred with pure red cell aplasia (PRCA), thymoma, and Ig deficiency. 1 Thus, one could speculate that, paradoxically, certain forms of immunodeficiency may lead to compensatory overreactions, resulting in autoimmunity and, ultimately, in clonal LGL proliferations. Indeed, Ig deficiency is frequently encountered in our series of LGLL (n=62, 32%). While acquired conditions ( e.g., thymoma, B-cell dyscrasia) may explain some (31/62, 48%) of these cases, congenital immune defects may have a complementary, even overlapping, pathogenic contribution. Here, we identified a 36-year-old woman with history of candidiasis, IgA deficiency, T1DM and Crohn's disease, with concurrent diagnosis of PRCA and LGLL. NGS revealed a germline heterozygous variant of uncertain significance (VUS) in BACH2, a gene involved in a recently reported inborn error of immunity (IEI) characterized by lymphocyte defects, Ig deficiency, and intestinal inflammation -features all depicted in our index case. This patient inspired us to posit that germline variants involved in IEI may also contribute to the pathogenesis of LGLL. To that end, we assessed the presence of IEI defects in 90 LGLL cases by performing WGS. We screened for variants in 90 IEI genes, covering different immune pathways. After applying a stringent variant calling, rare variants were defined as those with allele freq.<1% across genome resources. Variant pathogenicity was assessed according to ACMG criteria. For analysis, we selected all pathogenic/likely pathogenic (P/LP) variants, and VUS overrepresented in our cohort (significant p-values for Obs. vs Exp. freq. after multiple-testing correction). We found 21 variants in 15 IEI genes, carried by 20 LGLL patients (22%). The combined allelic burden for these variants was 12% ( vs the expected 2% in normal population). According to the role in immunity, the variants clustered in 2 main IEI categories: autoimmunity/immune dysregulation, and combined T-/ B-cell defects ( FigA). All variants were heterozygous, and 10/21 involved genes associated with dominant traits. Four defects in 3 patients were P/LP, and mono-allelic burden of 3/4 of these variants, involving the genes PRF1, AIRE and TNFAIP3, appeared to be a sufficient basis for immune imbalance leading to disease. When we analyzed the clinical features of the carriers of IEI variants, we observed that they were associated with diagnosis of LGLL at a younger age (median: 58 vs 64 yrs., FigB), including the patient with the earliest diagnosis of LGLL in our cohort, 17 yrs., who carried a PRF1 pathogenic variant. Carriers vs non-carriers had a higher proportion of autoimmunity (63 vs 43%), Ig deficiency (33 vs 23%) and other B-cell dyscrasias (58 vs 39%). Finally, carriers also had a significantly higher prevalence of cytopenias (94 vs 73%, p=.05) and particularly immune-mediated cytopenias (42 vs 17%, p=.02) than non-carriers. Most of these associations, including the predisposition to bone marrow failure (BMF) and immune cytopenias, persisted for the carriers of P/LP and dominant defects (since VUS in genes involved in dominant vs recessive traits are more likely to be of clinical relevance). Our findings suggest that variants predisposing to IEI can be found in the setting of LGLL. For some of these cases, the genetic burden might be strong enough to overshoot autoimmunity, promoting clonal LGL expansions. Environmental agents may have cooperative roles, and particularly infections, to which these patients may be intrinsically predisposed. Such atypical cases might exhibit distinct features, e.g., earlier onset of LGLL diagnosis, or concurrent BMF, which may serve as red flags tied to the underlying adult-onset IEI. Our study proposes an alternative pathogenesis for a significant fraction of cases with LGLL, and gives us the impetus to expand the IEI spectrum to the field of BMF and clonal hematological disorders.

Splenectomy outcomes in immune cytopenias: Treatment outcomes and determinants of response.

Splenectomy is commonly used to treat refractory immune-mediated cytopenia, but there are no established factors that are associated with response to the procedure. A cohort study was conducted to evaluate the hematologic and surgical outcomes of splenectomy in adult patients with immune cytopenias and identify preoperative factors associated with response. Data from the Cleveland Clinic Foundation for 1824 patients aged over 18 who underwent splenectomy from 2002 to 2020 were analyzed. The study found that the most common indications for splenectomy were immune thrombocytopenic purpura (ITP) and autoimmune hemolytic anemia, with a median age of 55 years and median time from diagnosis to splenectomy of 11 months. Hematologic response rates were 74% overall, with relapse in 12% of cases. Postsplenectomy discordant diagnoses were present in 13% of patients, associated with higher relapse rates. Surgery-related complications occurred in 12% of cases, whereas only 3% of patients died from disease complications. On univariate analysis, preoperative factors associated with splenectomy treatment failure were ≥3 lines of pharmacologic treatment, whereas isolated thrombocytopenia, primary ITP, and age ≤40 years had a strong association with response. The multivariable regression confirmed that treatment failure with multiple lines of medical therapy was associated with the failure to respond to splenectomy. Overall, the study demonstrates that splenectomy is an effective treatment option for immune-mediated cytopenias with a low complication rate.

LGL in MGUS or MGUS in LGL? Lessons of Nature and Their Clinical Implications

Associations between seemingly unrelated entities often reveal important lessons of nature, instructive for the understanding of mutual pathogenic roots. While investigating the clinical features of T-cell large granular lymphocytic leukemia (LGL), we noted the frequent presence of plasma cell dyscrasias/monoclonal gammopathies (MGs), chiefly MGUS. There are several potential explanations for this co-occurrence: 1) similar demographics (both conditions mostly presenting in the elderly); 2) the possibility that the two precursors originate from an initial polyclonal immune response to a common target; and 3) as alternative, that monoclonal plasma cells or the Ig product may be the targets of cytotoxic T-LGL cells in a context of tumor surveillance reaction. For instance, clonal TCR may recognize the M protein idiotype or vice versacausing aberrant activations. In addition, while MGUS should not be associated with cytopenias, responses to anti-myeloma therapies have been observed in LGL with MGUS refractory to traditional immunosuppressive therapies. We hypothesized that the study of clinical and epidemiologic features of MGs and LGL may be helpful to elucidate some of these fundamental questions. To address this, a dual approach was applied: 1) MG-forward strategy: screening of LGL in 2348 individuals with documented diagnosis of MGs and available bone marrow exam; 2) LGL-forward strategy: search of MGs in 235 LGL cases with M protein assessment. Overall, among 2348 cases with MGs, we identified 42 cases (1.8%) with concurrent evidence of LGL. We then selected an exploratory cohort of 787 MG patients with clinical annotations for further phenotypic dissection and comparative analyses. Within 533 patients with non-active MGs (i.e., MGUS or smoldering myeloma -SM), 144 (27%) had cytopenias of any type and grade, which could not be attributable to plasma cell infiltration. Screening for comorbid conditions explaining cytopenias left 32 cases (22%) presumed to be idiopathic. LGL was overrepresented in MGUS-SM with cytopenias (6 vs 0.3% in cases without counts alterations, p< .001). This frequency was higher when considering only cases with idiopathic cytopenias (22 vs 1.8% in cases with cytopenias of other causes, p< .001) ( FigA). Reverse analysis of the LGL cohort demonstrated that 71 (30%) LGL cases had M proteins. Overall, the MG/LGL dyad was more frequently associated with concurrent autoimmune conditions (54%), as well as monoclonal B-cell lymphocytosis and other B-cell lymphoid neoplasms (19%). Next, we compared cases with MG/LGL vs those with MGs (N = 775) or LGL (N = 157) exclusively. When compared to the MGs cohort, MG/LGL cases presented a younger age (median 64 vs 70 years, p < .001), had higher frequency of M protein of the IgM type (21 vs 10%, p= .002), and oftentimes exhibited small/transient paraproteinemia (42 vs 2%, p< .001). No specific features were enriched in the MG/LGL cases when compared to the LGL cohort, except for a higher proportion of proliferations of NK-cell subtype (12 vs 4%, p= .02). Finally, to confirm the observed association, we focused on the subgroup of non-active MGs by excluding cases with initial diagnosis of MM or lymphoma. Multivariable analysis (adjusting by sex, age and MG risk) revealed a lower risk of immunoparesis (aOR: 0.4, 95%CI: 0.2 - 0.7, p= .002) in MG/LGL as opposed to MG without LGL, whereas no effect was found in progression to MM/lymphoma (aHR: 0.9, 95%CI: 0.4 - 2.1, p= .81 in a competitive-risk setting). Moreover, when opposed to its MG and LGL counterparts, MG/LGL more frequently presented with severe cytopenias (aOR vsMGs: 28.9, 95%CI: 14.0 - 59.0, p< .001; aOR vsLGL: 2.7, 95%CI: 1.7 - 5.6, p= .008), and with immune-mediated cytopenias (aOR vsMGs: 10.5, 95%CI: 4.9 - 22.2, p< .001; aOR vsLGL: 2.8, 95%CI: 1.0 - 4.8, p= .04) ( FigB). In conclusion, our study reveals that: 1) the association between MGUS and LGL is more than an age-related epidemiological coincidence; 2) distinctive nosologic features for the MG/LGL dyad; and 3) that even “non-active” MGs associated with LGL might be of hematological clinical significance through humoral or cellular immune mechanisms. These findings point towards alternative treatment strategies of cytopenias in MGUS and LGL (immunosuppression vs anti-myeloma therapies, respectively), and provide impetus for the investigation of tumor surveillance in MGUS vs common etiologic factors intertwining these clonopathies.

Incidence and Outcome of Atypical Manifestations of Chronic Graft-versus-Host Disease: Results From a Retrospective Single-Center Analysis

Chronic graft-versus-host disease (cGVHD) is the leading cause of late nonrelapse mortality (NRM) after allogeneic hematopoietic stem cell transplantation (alloHSCT) and defined by 8 diagnostic target organs. Recently, provisional criteria for atypical manifestations of cGVHD that include manifestations in nonclassic organs as well as atypical manifestations in National Institutes of Health (NIH)-defined organs, were proposed by a NIH task force. Little is known about the incidence, risk factors, and impact on survival of atypical cGVHD, however. The aim of the present study was to analyze these parameters in a sequential patient population. We retrospectively screened 623 patients who underwent alloHSCT at the University Medical Center Regensburg between January 2008 and December 2020 for atypical cGVHD manifestations, applying the provisional NIH taskforce criteria. A total of 102 patients (16.4%) met the criteria, representing 25% of all cGVHD cases, and 14 patients (2.2%) had only atypical cGVHD. The most frequent manifestations were immune-mediated cytopenias (24.5%), renal cGVHD (13.7%) and (poly)serositis (13.7%). Multivariate analysis identified prior acute GVHD (odds ratio [OR], 2.28 and 2.93) and infusion of donor lymphocytes (OR, 1.77 for both) as risk factors for classic cGVHD and atypical cGVHD, whereas total body irradiation was an independent risk factor for atypical cGVHD manifestations only (OR, 1.76). Compared to patients without cGVHD, those with atypical and NIH-defined cGVHD showed similarly better overall survival (P=.034 and < .001) and low relapse-related mortality (P < .001 for both). NRM was significantly increased by atypical GVHD, but not by NIH-defined cGVHD (P=.019 and .10), which was driven only by a few atypical organ manifestations (eg, renal, restrictive lung disease, peripheral neuropathy), whereas others did not contribute to NRM (eg, thyroid gland, musculoskeletal, pancreas). In summary, atypical cGVHD is more common than previously estimated and has both similarities with and differences from NIH-defined cGVHD. In particular, the increased NRM and a subset of patients with only atypical cGVHD point to the urgent need to capture these manifestations in cGVHD cohorts, including analysis of treatment outcomes.

Systemic Lupus Erythematosus in Children.

Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, that mainly affects skin, joints and kidneys but can affect any organ in the body. It is characterized by presence of multiple autoantibodies like ANA, antibodies to dsDNA and RNA associated proteins. The major mechanism leading to tissue damage includes immune complex mediated complement activation, interferon alpha release by plasmacytoid dendritic cells, NETosis by neutrophils as well as defects in monocytes leading to poor clearance of cellular debris and direct cellular dysfunction mediated by antibodies. A child can present with pyrexia of unknown origin, immune mediated cytopenias, malar rash, oral ulcers, serositis, glomerulonephritis or nervous system dysfunction. As renal disease has a bearing on the long term impact, all children should have urine exam and blood pressure measurement done to rule out renal disease.The treatment varies depending on the severity and organs involved. In life or organ threatening situations, pulse methylprednisolone is used. Hydroxychloroquine, Mycophenolate mofetil, Azathioprine and Cyclophosphamide are the commonly used drugs in SLE. Over the years the prognosis of SLE has improved probably due to early diagnosis and better use of immunosuppressive treatment, regular follow up and treatment of co-morbidities. The 10-year survival now approaches 90% and with advent of new and targeted therapy it is hoped that the morbidity and organ damage can also be minimized.

Use of steroids in the management of low-risk myelodysplastic syndromes with autoimmune features.

The boundaries between myelodysplastic syndromes (MDS) and immune-mediated cytopenias are often difficult to establish and both conditions may benefit from immunosuppressive therapy. The optimal timing and doses of immunosuppressants are largely unknown. We systematically evaluated a retrospective cohort of 79 patients with low-risk MDS tested for anti-erythrocyte or anti-platelet autoantibodies to assess their frequency and the efficacy of immunosuppression, particularly with steroids. We found autoantibody positivity in 43% of cases and overt autoimmune diseases in 18%, including autoimmune hemolytic anemia, immune thromboctyopenia, and Evans syndrome. Steroid treatment improved cytopenia in about half of patients, with 26% achieving a complete recovery lasting for a median of 12 months. Better responses were observed in anemic patients with anti-erythrocyte autoantibodies than in those with anti-platelet autoantibodies, and the combination with recombinant erythropoietin (7/10) had a possible synergistic effect. Steroid doses were heterogeneous depending on the clinical intent (i.e., anti-inflammatory, immunosuppressive, anabolizing). Patients treated with a dose of 1 mg/kg day of prednisone for overt autoimmune cytopenia showed high rates of complete responses (60%). This observation suggests a trial with a short course (2-3 weeks) of standard steroid doses to ascertain efficacy and properly silence the autoimmune pathogenic mechanism. Steroid-related adverse events (16% of cases) should be monitored carefully in this elderly, frail population. In conclusion, features of autoimmunity are present in more than two-thirds of low-risk MDS patients and a trial with prednisone 0.5-1 mg/kg day for 2-3 weeks, with proper monitoring of adverse events, may be useful to improve cytopenias in selected cases.

COVID-19 in Patients with Hematologic Diseases.

The COVID-19 outbreak had a strong impact on people's lives all over the world. Patients with hematologic diseases have been heavily affected by the pandemic, because their immune system may be compromised due to anti-cancer or immunosuppressive therapies and because diagnosis and treatment of their baseline conditions were delayed during lockdowns. Hematologic malignancies emerged very soon as risk factors for severe COVID-19 infection, increasing the mortality rate. SARS-CoV2 can also induce or exacerbate immune-mediated cytopenias, such as autoimmune hemolytic anemias, complement-mediated anemias, and immune thrombocytopenia. Active immunization with vaccines has been shown to be the best prophylaxis of severe COVID-19 in hematologic patients. However, the immune response to vaccines may be significantly impaired, especially in those receiving anti-CD20 monoclonal antibodies or immunosuppressive agents. Recently, antiviral drugs and monoclonal antibodies have become available for pre-exposure and post-exposure prevention of severe COVID-19. As adverse events after vaccines are extremely rare, the cost-benefit ratio is largely in favor of vaccination, even in patients who might be non-responders; in the hematological setting, all patients should be considered at high risk of developing complications due to SARS-CoV2 infection and should be offered all the therapies aimed to prevent them.

Autoimmune Hematological Toxicities of Immune Checkpoint Inhibitors: A Real-World Pharmacovigilance Database Analysis

BACKGROUND: Autoimmune hematological toxicities are rarely reported from the use of checkpoint inhibitors. However, there have been several cases of autoimmune hemolytic anemia, immune thrombocytopenia, hemophagocytic lymphohistiocytosis (HLH), and immune mediated cytopenias that have been reported in patients who were treated with checkpoint inhibitors. We performed a retrospective analysis of data of adverse effects of drugs that has been made available to public by the FDA. METHODS: The FDA has made data on adverse effects of various treatments available to the public through the FDA Adverse Events Reports System (FAERS) public dashboard. We investigated the autoimmune hematological toxicities of various checkpoint inhibitor therapies available at FAERS for the years 2020-2022. RESULTS: We reviewed the reported side effects of PD-1 inhibitors (pembrolizumab, nivolumab, cemiplimab, dostarlimab), PDL-1 inhibitors (atezolizumab, avelumab, durvalumab), and CTLA-4 inhibitors (ipilimumab) from FAERS. A total of 5,195 hematological toxicities from immunotherapies were reported from 2020-2022. Out of those, 483 (9.3%) were autoimmune hematological toxicities. The most common autoimmune complications were autoimmune hemolytic anemia (21.9%), immune thrombocytopenia (36%), autoimmune neutropenia (4.1%), HLH (36.2%) and thrombotic/idiopathic thrombocytopenic purpura (ITP/TTP) (1.8%). Nivolumab had the highest incidence of autoimmune hematological events out of all immune checkpoint inhibitors. Since cemiplimab and dostaralimab are relatively newly being utilized for treatment, there has not been much reported data. CONCLUSIONS: Out of the reported cases of hematological adverse reaction to check point inhibitor, 9.3% were autoimmune toxicities. There was no statistical difference in rate of autoimmune toxicities caused by PD1, PDL1 or CTLA 4 inhibitors. As utilization of newer immune checkpoint inhibitors increase, we would need to re-evaluate incidence of autoimmune hematological adverse reactions. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Bodyweight and Absolute Lymphocyte Count Based Dosing of Rabbit Anti-Thymocyte Globulin Results in Early CD4+ Immune Reconstitution in Patients with Inborn Errors of Metabolism Undergoing Umbilical Cord Blood Transplantation

Background Rabbit anti-thymocyte globulin (rATG) is used in allogeneic hematopoietic cell transplantation (HCT) to prevent graft failure through depletion of host T cells and decrease the risk of graft-versus-host disease (GVHD) through partial depletion of donor T cells. However, it has highly variable pharmacokinetics. Previous reports suggest rATG dosing should be based on recipient bodyweight and absolute lymphocyte count (ALC) prior to initiating rATG. This new dosing nomogram reduces rATG overexposure, potentially leading to faster immune reconstitution and subsequently superior overall outcomes. Methods Since January 12, 2017, we use a previously described rATG dosing nomogram based on bodyweight and ALC before administering rATG in patients with inborn errors of metabolism receiving an umbilical cord blood transplant at the University of Minnesota Masonic Children's Hospital. The proposed rATG dosing varied from 2 to 10 mg/kg based on bodyweight and recipient ALC prior to initiating rATG, starting 8 or 9 days before HCT. The myeloablative conditioning regimen was Busulfan based, with addition of Fludarabine and Cyclophosphamide for lymphodepletion, as well as Rituximab and/ or Bortezomib for prevention of immune-mediated cytopenia. For GVHD prophylaxis cyclosporin A or tacrolimus were used with methylprednisolone. The primary endpoint was CD4+ immune reconstitution (>50 CD4+ T-cells/mL) within 100 days after transplantation. Secondary endpoints included overall survival, graft failure, acute and chronic GVHD, myeloid and T cell donor chimerism at one year post transplant, time to neutrophil engraftment and viral reactivations of cytomegalovirus, adenovirus and Epstein Barr virus. The study protocol was approved by the Institutional Review Board of University of Minnesota. Results Between February 20, 2017, and June 28, 2021, 27 patients were included in the study. Median follow-up time was 31 months (IQR 22.0 to 38.5) and median age was 1.45 years (IQR 0.7 to 3.9). Ten (37%) of 27 patients were female. The baseline characteristics are presented in Table 1. rATG dose was adjusted below 10 mg/kg recipient body weight in 7 (26%) of 27 patients on average by 29% (SD 14.9%). The CD4+ recovery at 100 days post HCT was reached in 22 (85%) of 26 patients (Figure 1A). Overall, four (15%) patients died resulting in overall survival of 83% (95%CI 67% to 100%). Causes of death were intracranial bleeding due to immune-mediated thrombocytopenia (this patient was transplanted before introduction of bortezomib and rituximab for immune-mediated cytopenia prevention), diffuse alveolar hemorrhage, respiratory syncytial virus infection and disease progression. Median time to neutrophil engraftment was 14 days (IQR 12.5 to 18.0), and no graft failure was observed. All surviving patients had full myeloid chimerism and 14 of 23 (61%) of patients had full T cell donor chimerism at one year post HCT. Two (7%) patients developed acute GVHD grade II to IV (Figure 1B), and no patients had chronic GVHD. Six patients (22%) had cytomegalovirus viremia, five of them were seropositive before transplant, one patient was seronegative as was the mother of the donor. One patient, who was seronegative before transplant, had Epstein-Barr virus reactivation requiring treatment, no patient had adenovirus reactivation. Conclusion In pediatric patients with inborn errors of metabolism individualized dosing of rATG was associated with a robust and early CD4+ immune reconstitution, with low therapy related mortality, low GVHD incidence compared to historical findings and stable full myeloid chimerism. These results are in line to the findings of the PARACHUTE trial previously published. However, the PARACHUTE trial included only small number of patients with inborn errors of metabolism. Table 1. Baseline characteristicsFigure 1A. Cumulative incidence of CD4+ immune reconstitutionFigure 1B. Cumulative incidence of acute Graft-versus-host disease Grade 2 to 4Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Splenectomy for Immune Cytopenias: Treatment Outcomes and Predictors of Response

The pathogenesis of immune cytopenias involves diverse processes including production, inhibition, and destruction of specific blood cell types mediated by antibodies and/or T cells. Classic examples of immune-mediated cytopenias are immune thrombocytopenic purpura (ITP), autoimmune hemolytic anemia (AIHA), and autoimmune neutropenia (AIN) as well as T cell-mediated idiopathic neutropenia and pure red cell aplasia. Both antibody and autoimmune T cell responses may often coexist, and assignment of the proper pathogenic importance, albeit difficult, is crucial for rational therapeutic approaches. Clonal processes such as T-cell large granular lymphocytic leukemia (T-LGL) or various B cell dyscrasias may also occur. While the results of splenectomy have been studied in individual conditions such as Evans syndrome (ES), AIN, and AIHA, the availability of new therapies and improvement of surgery outcomes have provided an impetus to update the older and smaller series. We retrospectively reviewed a cohort of 339 adult patients who underwent splenectomy at the Cleveland Clinic Foundation between 2002-2020 (Fig.1A), for whom the main indication for the procedure was: ITP (n= 235), AIHA (n=68), ES (n=26) and AIN (n=10). Among these subtypes, there were 15 patients with an established diagnosis of T-LGL. Our aim was to determine the hematologic response of patients who receive splenectomy for immune cytopenia following treatment failure with conventional therapies and identify factors that were associated with responses. Overall, the median age of the patients was 55 years (IQR:68-36), M:F ratio=0.98, with a median time from diagnosis to splenectomy of 11 months (IQR:31-3). Prior to the procedure, all patients had failed multiple lines of medical therapies (mode 1, range1-4). The median preoperative platelet count was 19 (IQR:44-5) x109/L, median preoperative hemoglobin (Hb) of 9 (IQR:10-8) g/dl and median preoperative ANC of 0.28 (IQR:1.19-0.23) x109/L. A total of 306 patients underwent laparoscopic splenectomy, while 33 patients had an open approach. In 16 cases (5%), we recorded an intraoperative conversion from laparoscopic to open splenectomy. The mean spleen weight was 477 gr (SD±687). The average operative time was 2.3 hours, with four days median hospital length of stay (range:1-50). The overall rate of postoperative complications with 30-day readmissions was 0.1%, with no mortality. Of note is that up to 20% of the cases had a post-operative diagnosis that was discordant with the original indication for splenectomy. These discordant diagnoses included benign conditions such as Felty's syndrome (n=2), as well as hematologic malignancies such as mature B-cell neoplasm (28), T-cell lymphoma (n=8), NK-LGL (n=1), and T-LGL (n=15). The overall response rate (ORR) to splenectomy was 74%, of which 86% complete response (CR) and 14% partial response (PR) with relapse occurring in 12% of cases. In the subset of thrombocytopenic patients, CR reached 69% of patients (P<.0001) as early as one week following the procedure. At 1-year, the mean platelet count was 246 (SD±170) x 109/L and relapse occurred in 13% of patients. Conversely, in anemic patients, a CR was observed only in 55% (P<.0001) within two weeks following splenectomy. At 1-year, the mean Hb level was 11.7 (SD±1.3) g/dl, with relapse occurring in 6% of patients. Comparatively, 80% of patients who underwent splenectomy for neutropenia responded at 26 weeks post-splenectomy with relapse in 10% of cases. In known and newly diagnosed patients with LGL (n=16), the response with regard to the cytopenia resulting in splenectomy indication was 81%. The response in Felty's syndrome was 100%. When analyzing predictors of response, failed pharmacologic therapies with either intravenous immunoglobulin (IVIg) or rituximab was predictive of non-response to splenectomy (Fig.1B). No significant differences in spleen weight between responders and non-responders were observed. Our results show a significant and durable response to splenectomy in immune-mediated cytopenia of various etiologies refractory to conventional therapies indicating that, in selected patients, splenectomy remains a rational salvage treatment with a low complication rate. Figure 1View largeDownload PPTFigure 1View largeDownload PPT Close modal

Diagnosis and Management of Autoimmune Hemolytic Anemias

Autoimmune hemolytic anemia (AIHA) is usually categorized, as other immune-mediated cytopenias, in so-called benign hematology, and it is consequently managed in various settings, namely, internal medicine, transfusion centers, hematology and, more rarely, onco-hematology departments [...].

Allogeneic hematopoietic stem cell transplantation for inherited metabolic disorders.

Allogeneic hematopoietic stem cell transplantation (HSCT) has been used to treat patients with inherited metabolic disorders (IMDs) for more than 40years. In the first two decades, various IMDs were treated by HSCT with a wide variety of donor sources and conditioning regimens selected at the institutional level. However, HSCT was not always successful due to post-transplant complications such as graft failure. In the third decade, myeloablative conditioning with targeted busulfan-based pharmacokinetic monitoring was established as an optimal conditioning regimen, and unrelated cord blood was recognized as an excellent donor source. During the fourth decade, further improvements were made to transplant procedures, including modification of the conditioning regimen, and the survival rate after HSCT markedly improved. Simultaneously, several long-term observational studies for patients after HSCT clarified its therapeutic effects on growth and development of cognitive function, fine motor skills, and activities of daily living when compared with enzyme replacement therapy. Although immune-mediated cytopenia was newly highlighted as a problematic morbidity after HSCT for IMDs, especially in younger patients who received unrelated cord blood, a recent study with rituximab added to the conditioning raised expectations that this issue can be overcome.

Granulocyte Transfusions in Patients with Chronic Granulomatous Disease Undergoing Hematopoietic Cell Transplantation or Gene Therapy.

Granulocyte transfusions are sometimes used as adjunctive therapy for the treatment of infection in patients with chronic granulomatous disease (CGD). However, granulocyte transfusions can be associated with a high rate of alloimmunization, and their role in CGD patients undergoing hematopoietic cell transplantation (HCT) or gene therapy (GT) is unknown. We identified 27 patients with CGD who received granulocyte transfusions pre- (within 6 months) and/or post-HCT or GT in a retrospective survey. Twelve patients received granulocyte transfusions as a bridge to cellular therapy. Six (50%) of these patients had a complete or partial response. However, six of 10 (60%) patients for whom testing was performed developed anti-HLA antibodies, and three of the patients also had severe immune-mediated cytopenia within the first 100 days post-HCT or GT. Fifteen patients received granulocyte transfusions post-HCT only. HLA antibodies were not checked for any of these 15 patients, but there were no cases of early immune-mediated cytopenia. Out of 25 patients who underwent HCT, there were 5 (20%) cases of primary graft failure. Three of the patients with primary graft failure had received granulocyte transfusions pre-HCT and were subsequently found to have anti-HLA antibodies. In this small cohort of patients with CGD, granulocyte transfusions pre-HCT or GT were associated with high rates of alloimmunization, primary graft failure, and early severe immune-mediated cytopenia post-HCT or GT. Granulocyte transfusions post-HCT do not appear to confer an increased risk of graft failure.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10875-022-01261-1.

Anemia among Patients Attending Anti-retroviral Therapy at a Tertiary Care Center: A Descriptive Cross-sectional Study.

Hematologic abnormalities are among the most common complications of infection with Human Immunodeficiency Virus. These abnormalities are due to: impaired hematopoiesis, immune mediated cytopenias and altered coagulation mechanisms. Anemia is the most frequent,however, leukopenia, lymphopenia, and thrombocytopenia have also been observed. The aim of the study was to find the prevalence of anemia in patients attending anti-retroviral therapy at a tertiary care center of Nepal. The study was a descriptive cross-sectional study conducted from August 2018 to August 2019 in patients attending anti-retroviral therapy at a tertiary care hospital. Ethical approval was obtained from the Institutional Review Board of National Academy of Medical Sciences before starting the study (Reference number 267). Convenient sampling was used for this study. Data were analysed using the Statistical package for Social Sciences version 20. Point estimate at 90% confidence interval was calculated along with frequency and proportion for the binary data. The prevalence of anemia among patients attending anti-retroviral therapy centers in our study was found in 29 (58%) (46.55-69.45 at 90% Confidence Interval). Out of those patients, 20 (63%) were male and 9 (50%) were female. The mean hemoglobin value was 11.946±2.51g/dl. The prevalence of anemia among patients attending antiretroviral therapy in our study was found to be high which is consistent with the findings of other similar international studies. These patients should be routinely monitored and treated for the occurrence of hematological abnormalities.

B-cell depletion abrogates immune mediated cytopenia and rejection of cord blood transplantation in Hurler syndrome

Umbilical cord blood is the preferred donor cell source for children with Inherited Metabolic disorders undergoing Hematopoietic Cell Transplant (HCT), and its use has been associated with improved “engrafted survival” and higher donor chimerism compared to other cell sources. However, as in other pediatric cord blood transplants for non-malignant disease, immune-mediated cytopenia and primary graft failure limit its use, and the latter remains the commonest cause of death following cord blood transplant for non-malignant disease. We have previously shown an association between immune-mediated cytopenia and graft failure in inherited metabolic diseases suggesting that both immune-mediated cytopenia and graft failure could be mediated by antibodies from the residual recipient B cells. Since rituximab is effective in depletion of B cells and management of refractory immune-mediated cytopenia following HCT, we have added rituximab to the conditioning regimen. We studied 57 patients in 2 centers who received myeloablative conditioning for cord blood transplant in Hurler syndrome, and report a significant improvement in event-free survival with reduced incidence of graft failure and without any evidence of immune-mediated cytopenia in those patients that had received rituximab.

Detection of Anti-Erythrocyte Antibodies in Dogs with Inflammatory Bowel Disease (IBD).

Simple SummaryIn human patients with intestinal inflammation, many other diseases may occur due to it, but their presence in dogs is rarely described. The aim of the study was to prove if antibodies against red blood cells (RBC) were present in dogs with chronic intestinal inflammation (IBD), as it is demonstrated for humans, and to described other RBC abnormalities. IBD was diagnosed using the current consensus and a disease severity score was assessed for each dog, as well as score from endoscopy and intestinal histology. Our results showed that most of dogs had antibodies against RBC and 50% of dogs showed RBC regeneration in addition to chronic inflammation hematologic findings. In IBD dogs, the presence of anti-RBC antibodies and the other RBC alterations may suggest a subclinical RBC damaged (hemolysis).Several extra-intestinal manifestations, including immune-mediated cytopenias, are reported in human inflammatory bowel disease (IBD), whereas they are poorly documented in dogs. Hypothesizing that immune-mediated subclinical anemia can occur in canine IBD, the study aim was to evaluate the erythrogram and the presence of anti-RBC antibodies in dogs with IBD. IBD was diagnosed according to the following criteria: chronic gastrointestinal signs, ruling out of extra-intestinal diseases, no improvement with diet trial, histological evidence of inflammatory infiltration, and improvement after immunosuppressant therapy. Canine Chronic Enteropathy Clinical Activity Index (CCECAI) endoscopic and histopathological scores were assessed for each dog. Twenty-five dogs were enrolled, and each dog had a CBC evaluation prior to endoscopy. The CBC was performed using laser hematology analyzer and blood smears were carefully reviewed for the presence of nucleated RBC, anisocytosis, polychromasia, and Howell–Jolly bodies. IgG and IgM anti-RBC antibodies were evaluated with flow cytometry. A high frequency of positive cases for anti-RBC antibodies in dogs with IBD (17/25 dogs) was ascertained. Approximatively 50% of dogs showed some hematologic features of RBC regeneration in addition to hematologic findings consistent with chronic inflammation. Anti-RBC antibodies and signs of erythroid regeneration may suggest possible subclinical chronic immune-mediated hemolysis that can cause anemia in dogs with IBD, together with the chronic inflammation.

Case of a young girl with marked bone marrow plasmacytosis

Marked plasmacytosis in the bone marrow is a rare finding in young people. If present it is secondary to an underlying disease condition. Castleman disease is a rare form of lymphoproliferative disorder. Due to its rarity, it is not frequently considered in the differential diagnosis of lymphadenopathy. As in any other lymphoproliferative disorder Castleman disease can also be associated with various immune mediated cytopenia. This case report is on a teenager with persistent lymphadenopathy of whom the presence of marked bone marrow plasmacytosis led to the diagnosis of plasma cell type Castleman disease which went into complete remission with single agent vincristine and radiotherapy with subsequent severe immune thrombocytopenia during follow up.

Secondary Thrombocytopenia with Primary Sjogren's Syndrome

Primary Sjogren's syndrome (pSS) is a chronic systemic autoimmune rheumatic disorder that is characterized by lymphoplasmacytic infiltration of the salivary and lacrimal glands. pSS is the most frequent connective tissue disorder after rheumatoid arthritis, affecting 0.3%–3% of the population. The prevalence of pSS is more common in women than men, with a sex ratio of 9:1. Occult pSS can rarely present as immune-mediated cytopenia. In this case report, we exemplify an atypical presentation of pSS that presented as thrombocytopenia. Hence, we should always consider pSS in the differential diagnosis of patients with unexplained cytopenias.