Non-malignant Lymphoproliferation Research Articles

Functional status of blood neutrophils in congenital defects of antibody production

We evaluated some functional indices of neutrophils in 100 adult patients with a verified diagnosis of primary antibody production deficiency (44 patients with common variable immunodeficiency – CVID, and 56 patients with selective IgA deficiency – SigAD). The diagnosis was made according to the criteria of the Pan-American Group for Immunodeficiency and European Society for Immunodeficiency. The criteria for diagnosis were based on clinical data, medical history and results of laboratory tests. All patients with CVID received regular immunoglobulin replacement therapy, and the SIgAD patients received symptomatic treatment on demand. The examination was performed beyond the infectious episodes, inflammatory events or exacerbation of chronic disorders upon admission for planned hospitalisation, before any therapeutic and diagnostic procedures. In addition to standard clinical and laboratory examination appointed for the mentioned diseases, we assessed fnctional status of neutrophils: superoxide-anion radical production, NETosis, phagocytosis and apoptosis. Taking into account clinical manifestations, the patients with CVID were divided into 6 clinical subgroups: without CVID-related complications (13.6%); with infectious complications, i.e., bronchiectatic disease (15.9%), autoimmune syndromes (22.7%), polyclonal lymphoid infiltration (13.6%), enteropathic syndrome (34.1%), and malignant neoplasms (9.1%). Four phenotypes were identified in the patients with SIgAD: absence of SIgAD-related complications (28.6%); autoimmune syndrome (16.1%), non-malignant lymphoproliferation (3.6%) and enteropathy (28.6%). Higher incidence of non-infectious complications (autoimmune syndrome, non-malignant lymphoproliferation, enteropathies) was found in СVID compared to SIgAD patients (χ2 = 10.27; p = 0.001). Patients from the both groups showed changes in neutrophil reactivity compared to control values expressing higher basal generation of superoxide radicals (p < 0.001), NETosis activity (p = 0.005) and apoptosis (p < 0.001) with decreased phagocytic function (p < 0.001) and lower reserve for reactive oxygen species formation (p < 0.001). The maximal degree of changes in phagocytosis and superoxide-producing activity was observed in СVID; altered NETosis was revealed in SIgAD. The development of non-infectious complications was accompanied by a significant increase in stimulated NETosis indexes, thus suggesting a promising index in order to assess stability of clinical course and to predict development of complications in congenital defects of antibody production.

Clinical and immunological characteristics of primary immunodeficiencies with chronic non-malignant lymphoproliferation

Clinical and immunological characteristics of primary immunodeficiencies with chronic non-malignant lymphoproliferation

Detection of Signature Double-Negative T Cells Is a Reliable Marker for ALPS Associated with FAS Mutation

Defects in FAS mediated apoptosis lead to a rare autoimmune disease called autoimmune lymphoproliferative syndrome (ALPS), which is manifested by a variety of symptoms including chronic lymphoproliferation, splenomegaly and autoimmune cytopenia. ALPS is mainly caused by germline or somatic FAS mutations, but gene analysis is time and cost intensive. Therefore, a tool is needed to screen for patients that are likely to harbor such a mutation to reduce costs and allow a faster diagnosis and treatment. One hallmark of the disease is the pathognomonic accumulation of TCRαβ+ CD4-/CD8- double-negative T (DNT) cells, which show high mitotic activity and unique expression profile. In this study, we compared the immune phenotype of ALPS patients with germline or somatic FAS mutation (ALPS-FAS/sFAS, n=11), patients who fulfill ALPS diagnostic criteria without FAS mutation (ALPS-U, n=11), and patients with ALPS-like disorders (two major diagnostic criteria without further criteria or at least one major criterion and autoimmune cytopenia, n=22). In addition, healthy donors, patients with chronic autoimmune cytopenia (AC, n=9), and patients with chronic non-malignant lymphoproliferation (LP, n=9) with no other major or minor criteria for ALPS diagnosis were used as controls. ALPS-FAS/sFAS patients showed accumulation of DNT cells with increased mitotic activity, terminal differentiation and expression of CD45RA/CD38 compared to healthy donors, AC and LP patients. Using receiver operating characteristic analyses, we could demonstrate that Ki67 and CD45RA/CD38 expression within DNT cells clearly distinguish ALPS-FAS/sFAS patients and ALPS-U and ALPS-like patients. To further strengthen specificity and sensitivity of the test, we assessed whether combination of DNT cell frequency with one additional marker is useful in supporting ALPS diagnosis. We found that a combination of DNT cell frequency with the expression of CD38 and CD45RA or Ki67 is most efficient to predict FAS mutation in ALPS patients. Taken together, flow cytometric analysis of these signature markers is a highly effective tool to discriminate patients with ALPS-FAS/sFAS and ALPS-related diseases and may also be useful for monitoring of treatment efficacy.

Beyond Infections: New Warning Signs for Inborn Errors of Immunity in Children.

Patients with inborn errors of immunity (IEI) are susceptible to developing a severe infection-related clinical phenotype, but the clinical consequences of immune dysregulation, expressed with autoimmunity, atopy, and lymphoproliferation could represent the first sign in a significant percentage of patients. Therefore, during the diagnostic work-up patients with IEI are frequently addressed to different specialists, including endocrinologists, rheumatologists, and allergologists, often resulting in a delayed diagnosis. In this paper, the most relevant non-infectious manifestations of IEI are discussed. Particularly, we will focus on the potential presentation of IEI with autoimmune cytopenia, non-malignant lymphoproliferation, severe eczema or erythroderma, autoimmune endocrinopathy, enteropathy, and rheumatologic manifestations, including vasculitis and systemic lupus erythematosus. This paper aims to identify new warning signs to suspect IEI and help in the identification of patients presenting with atypical/non-infectious manifestations.

MO1033: Kidney and Bone Marrow Involvement in Ipex Syndrome with Atypical Presentation: the ‘Fil Rouge’ of Treg Between Ipex Features and Other Clinical Entities

Abstract BACKGROUND AND AIMS The transcription factor Forkhead box protein P3 (FOXP3) is central to the function of regulatory T cells (Treg). Mutations in the FOXP3 gene lead to a systemic disease called immune dysregulation, polyendocrinopathy and enteropathy, X-linked syndrome (IPEX). Some FOXP3 mutations were associated with atypical presentation including rare diseases such as IgG4 related disease (IgG4 RD) and autoimmune lymphoproliferative syndrome (ALPS). IgG4 RD is characterized by fibro-inflammatory tissue damage and often by elevated serum IgG4, whereas ALPS is presented by early-onset, chronic, nonmalignant lymphoproliferation, splenomegaly and autoimmune manifestations due to defective lymphocyte apoptosis, due mainly to mutation of genes involved in the apoptosis pathway. Kidney involvement in ALPS is uncommon, whereas in IPEX and IgG4 RD is more frequent, with different renal manifestations. METHOD We reported two atypical cases of IPEX characterized by the kidney and haematologic involvement. These cases are anecdotal for the wide spectrum of possible phenotypes associated with FOXP3 mutations. RESULTS Case 1. A 16-year male with clinical diagnosis of ALPS was treated with an mTOR inhibitor. Due to the onset of proteinuria until 650 mg/day and estimated glomerular filtration rate (eGFR) 66 mL/min, a kidney biopsy was performed and light microscopy showed a membranous pattern. The M-type phospholipase A2 receptor (PLA2R) on serum was negative as well as immunofluorescence (IF) on tissue. IgG-IgG4 immunohistochemical (IHC) staining was negative. We decided to re-evaluate the genetics of the patient, implementing the HPO (Human Phenotype Ontology) code. We found a mutation of the FOXP3 gene (NM_014009.3): c.779T > A (p.L260Q), never reported before on the GnomAD database and predicted to be ‘Likely Pathogenic’ by the suite of variant annotation. The patient does not present the classical triad of IPEX and Treg resulted normal. He was treated with steroids and continues mTOR inhibitor with good control of proteinuria and stable kidney function. Case 2. A 2-year boy was diagnosed with a trilinear bone marrow failure, genetic investigations were negative. He presented elevated serum levels of IgG4 subclass and kidney failure with tubular acidosis. A renal biopsy showed MGP associated with TIN. IF and IHC for PLA2R resulted positive. IHC staining for IgG4 showed overlapping positivity for IgG and IgG4. After the diagnosis of IgG4 RD, steroid therapy was started, without clinical response. Thereafter the patient underwent a bone marrow transplant from his brother (HLA-identical). In consideration of the rarity of IgG4 RD in children, we decided to perform a new genetic exam. A whole-exome sequencing on the proband and relatives was done. A hemizygous mutation of the FOXP3 gene (NM_014009.3), c.1087A > G (p.I363V), was found. This variant, inherited by the mother and found also in the proband's brother, was already described in the literature, thus a diagnosis of IPEX was done. Therefore, Treg resulted normal for brother and mother but not in our patient (0.3%). The patient underwent kidney transplantation, and after 1 year he presents normal kidney function. CONCLUSION MGP and IgG4 RD are rare in paediatrics, and they encouraged us to perform further investigations and reconsider the previous diagnosis. MGP pathogenesis in IPEX is consistent with recent evidence of unbalance of Th17/Treg in idiopathic MGP, with a significant reduction of Treg cell and FOXP3 expression. Th17/Treg may be implicated also in the pathogenesis of IgG4 RD as sources of cytokines production responsible for fibrosis and IgG4-producing B cells. FOXP3 + Treg and FAS-ligand are crucial for autoimmunity and self-tolerance. In ALPS patients a reduced expression of FOXP3 + Treg subsets but with the normal suppressive function was found. IPEX poses a diagnostic challenge considering the spectrum of different phenotypes, but to recognize kidney involvement, together with the growing use of wide genomic analysis, could play a central role.

A unique phenotype of longitudinal extensive transverse myelitis in autoimmune lymphoproliferative syndrome

A 49-year-old patient with a history of lymphoproliferation and autoimmune cytopenias presented with unexplained longitudinal extensive transverse myelitis. Flow cytometry on peripheral blood showed an elevated level of double negative T lymphocytes, a finding typical for autoimmune lymphoproliferative syndrome (ALPS). Inborn error of immunity (IEI) gene panel demonstrated a heterozygous variant in the FAS gene (c.857G > A, p.(Gly286Glu)), formally confirming the diagnosis. Autoimmune neurological conditions in a context of predisposition for infection and lymphoproliferation should raise suspicion of IEI. Specific testing for ALPS should be considered in patients with a history of non-malignant lymphoproliferation, multilineage cytopenias and unexplained autoimmune (neurological) manifestations.

Общая вариабельная иммунная недостаточность: сложности своевременной диагностики (клинический случай)

Common variable immunodeficiency (CVID) belongs to the group of primary immunodeficiencies with a predominant deficiency in antibody synthesis and the most common diagnosis among clinically significant cases of primary immunodeficiency in adults. The main laboratory criterion for this disease is considered to be hypogammaglobulinemia (a decrease in the level of IgG less than 4.5 g/l with a decrease in the level of IgA, with/without a decrease in the level of IgM). Clinical manifestations of CVID are diverse: infectious syndrome (chronic infections of the lower respiratory tract, sinusitis, otitis, infectious diarrhea, septic arthritis), autoimmune syndrome (cytopenias, systemic rheumatic diseases), non-infectious pathology of the gastrointestinal tract (celiac-like or IBD-like syndromes , nodular hyperplasia of the mucosa), interstitial lung diseases, pathological non-malignant lymphoproliferation (lymphadenopathy, hepatosplenomegaly), oncological diseases, the formation of non-caseating granulomas in the internal organs). Due to the lack of a typical clinical picture, the diagnosis of CVID in adults is often made many years late, especially if the clinical picture is dominated by non-infectious manifestations. The article presents a clinical case when the patient had recurrent lymphadenopathy as the main symptom for several years. After examination by various specialists, she was referred to an immunologist because hypoproteinemia and a sharp decrease in the gamma fraction of globulins have been revealed. An immunological study revealed agammaglobulinemia and a pronounced imbalance of T-lymphocyte subpopulations (a significant decrease in the number of CD4+ cells and an increase in CD8+ cells). The clinical significance of T-lymphocyte disorders in CVID, the need for treatment with adequate doses of intravenous immunoglobulins are discussed.

HL-444: Autoimmune Lymphoproliferative Syndrome: A Case Presentation

<h3>Context</h3> Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of lymphocyte homeostasis caused by defects in the FAS apoptotic pathway. ALPS is characterized by non-malignant lymphoproliferation, autoimmune disorders (primarily multilineage cytopenias), and an increased risk of B-cell lymphoma. <h3>Patient</h3> A 4-year-old girl presented with severe anemia and splenomegaly. Hb: 5 g/dL; Hct 16.6%; plt 82 × 10³; WBC: 2.3. Reticulocytosis, high LDH, and indirect bilirubin. Direct antiglobulin test (DAT) was negative, as was a super-Coombs assay. Osmotic gradient ektacytometry in red blood cells was compatible with antibody-mediated decreased surface-to-volume ratio. IVIG was given, with a good response, so the patient was diagnosed with warm-ab autoimmune hemolytic anemia. ALPS panel criteria were met, with increased double-negative T cells (DNTCs) by flow cytometry. A pathogenic variant, c.755delA, was identified in FAS. <h3>Interventions</h3> Sirolimus was targeted to a therapeutic dosage, with great response. The FAS gene is associated with autosomal dominant autoimmune lymphoproliferative syndrome (ALPS-FAS). Lymphadenopathy and hepatosplenomegaly, which are presenting symptoms in most affected individuals and usually manifest in early childhood, often improve with age. Autoimmunity typically develops 2–3 years later and shows no permanent remission with age. <h3>Results</h3> Penetrance of symptoms is highly variable, and some individuals are clinically unaffected. A more severe presentation is seen in individuals with biallelic pathogenic FAS variants. The risk of non-Hodgkin lymphoma is 60 times more than in healthy individuals and more than 150 times as high for Hodgkin lymphoma. Close relatives have an up to 50% chance of being carriers. Most distant relatives may also be carriers. Parental testing may clarify the inheritance of FAS gene mutations. <h3>Conclusions</h3> Autoimmune lymphoproliferative syndrome should be suspected in children with lymphadenopathy, splenomegaly, and multilineage cytopenias. Sirolimus is a disease-modifying therapy that is well-tolerated and efficacious for these patients.

Natural Course of Activated Phosphoinositide 3-Kinase Delta Syndrome in Childhood and Adolescence.

Activated phosphoinositide 3-kinase delta syndrome (APDS), caused by mutations in PI3Kδ catalytic p110δ (PIK3CD) or regulatory p85α (PIK3R1) subunits, is a primary immunodeficiency affecting both humoral and cellular immunity, which shares some phenotypic similarities with hyper-IgM syndromes and common variable immunodeficiency (CVID). Since its first description in 2013, over 200 patients have been reported worldwide. Unsurprisingly, many of the newly diagnosed patients were recruited later in life from previously long-standing unclassified immunodeficiencies and the early course of the disease is, therefore, often less well-described. In this study, we report clinical and laboratory features of eight patients followed for APDS, with particular focus on early warning signs, longitudinal development of their symptoms, individual variations, and response to therapy. The main clinical features shared by our patients included recurrent bacterial and viral respiratory tract infections, gastrointestinal disease, non-malignant lymphoproliferation, autoimmune thyroiditis, and susceptibility to EBV. All patients tolerated vaccination with both attenuated live and subunit vaccines with no adverse effects, although some failed to mount adequate antibody response. Laboratory findings were characterized by dysgammaglobulinaemia, elevated serum IgM, block in B-cell maturation with high transitional B cells, and low naïve T cells with CD8 T-cell activation. All patients benefited from immunoglobulin replacement therapy, whereas immunosuppression with mTOR pathway inhibitors was only partially successful. Therapy with specific PI3K inhibitor leniolisib was beneficial in all patients in the clinical trial. These vignettes, summary data, and particular tell-tale signs should serve to facilitate early recognition, referral, and initiation of outcome-improving therapy.

Multicentric Castleman disease revealing complete signal transducer and activator of transcription 1 deficiency treated by JAK1/2 inhibition

Castleman disease (CD) is a rare and poorly understood nonmalignant lymphoproliferation of unclear pathogenesis. First described in 1954, CD has two main clinical presentations: a localized or unicentric CD (UCD) and a multifocal or multicentric CD (MCD), which is frequently associated with systemic inflammation through the secretion of IL-6. The UCD phenotype is the most commonly reported in children and has the most favorable outcome.1 The diagnosis of CD remains histopathologic with two defined pathologic types: (1) the hyaline vascular type, which is characterized by abnormal germinal centers, penetrating hyalinized vessels, and abnormal follicular dendritic cells; and (2) the plasma cell variant, in which normal or enlarged germinal centers are associated with interfollicular plasma cell infiltration.

The paradigm of hematological malignant versus non-malignant manifestations, driven by primary immunodeficiencies: a complex interplay.

Hematological malignancies (HM) developed on underlying primary immunodeficiencies (PID) are rare and of unusual features. Differentiating between malignant and non-malignant lymphoproliferation in cases of pediatric hematology and oncology and revealing their molecular predisposition demonstrate the complex interplay between PID and HM. We retrospectively studied a case series of seven pediatric patients, all with PID with manifestations raising suspicion for HM or hypereosinophilic syndrome (HES) or confirmed HM of lymphoid origin. Combined immunodeficiency (CID) without detection of a known mutated gene or with ataxia-telangiectasia (AT), STAT3 gain of function (GOF), DOCK8 deficiency, and CTLA4 deficiency were diagnosed in three, one, one, one, and one patient, respectively. Acute lymphoblastic leukemia and Hodgkin lymphoma followed by second primary Burkitt lymphoma were diagnosed in one patient with CID each, while lymphomatoid granulomatosis in one patient with AT. Lymphoproliferative disease occurred in STAT3 GOF, CTLA4 deficiency and CID, one patient each, and idiopathic HES in DOCK8 deficiency (median age at presentation of PID or any hematological manifestation: four years). Four patients underwent hematopoietic cell transplantation (HCT) for STAT3 GOF, DOCK8 deficiency and CID in one, one, and two cases, respectively (median age: 10years). At the last follow-up, all transplanted patients were alive. Reporting on patients' phenotype, genotype and course of disease shed light on the prevalence, characteristics, and pathophysiology of HM complicating PID. Discriminating the non-yet malignant lymphoproliferation from its malignant equivalent on the same pathophysiology background proved of additional value. Outcomes of PID after HCT, herein reported, are favorable.

Autoimmune Cytopenias in Nonmalignant Lymphoproliferative Disorders: Thinking Beyond ALPS(Autoimmune Lymphoproliferative Syndrome)

The ALPS Clinic at NIH has studied autoimmune lymphoproliferative disorders for over 30 years elucidating the genetic underpinnings and natural history of Autoimmune Lymphoproliferative Syndrome (ALPS) due to FAS gene defects (Blood 2014). Over the years, we continue to receive and work-up numerous referrals for diseases that masquerade like ALPS-FAS, presenting with multi-lineage cytopenias due to autoimmune peripheral destruction and splenic sequestration in the setting of non-malignant lymphoproliferation. In a review of 259 cases evaluated by our team, there were 150 ALPS-FAS, 54 Activated PI3K-delta Syndrome (APDS), 31 CTLA-4 Haploinsufficiency (CTLA4), 7 LRBA deficiency (LRBA), and 17 MAGT-1 deficiency (XMEN) patients. Non-malignant lymphadenopathy and splenomegaly occurred on average in 83% and 71% of all patients, respectively. Anemia, thrombocytopenia, and neutropenia were seen in 65%, 58%, and 46%, respectively. Thus, autoimmune cytopenias in the setting of non-malignant lymphoproliferation in themselves are not adequate to rule in or rule out a presumptive diagnosis of ALPS-FAS. Timely and accurate genetic diagnosis of ALPS-like conditions will improve the morbidity and mortality associated with these disease processes. Rapamycin, an m-TOR inhibitor provides salutary benefits for many of these conditions by restoring the TREG function and reversing immune-dysregulation. For example, in addition to lymphadenopathy and splenomegaly associated with an increased risk of malignant lymphoma like ALPS-FAS patients, APDS patients usually present with recurrent sinopulmonary and ear infections. Their serum IgM tends to be elevated with low IgG levels. Unlike for ALPS-FAS patients, a potential targeted treatment for APDS exists: Leniolisib, a targeted PI3Kinase p-110 delta inhibitor is currently undergoing clinical trials (Blood 2016). CTLA-4 is critical for T-cell activation and immune check-point regulation by tempering regulatory T cell function. Patients affected by CTLA4 and LRBA variants present with symptoms of lymphocytic infiltration of the bone marrow (often leading to hypoplastic anemia), gut (colitis, bowel obstruction), lungs (bronchiectasis, restrictive airway disease), and central nervous system (seizures and neurological deficits due to brain and spinal cord lesions). They also tend to have B cell lymphopenia, low IgG and IgM levels. CTLA4 and LRBA patients share pathophysiology as well as clinical phenotype because LRBA gene regulates intracellular lysosomal trafficking and recycling of CTLA-4 protein. Hence CTLA-4 haploinsufficiency or LRBA deficiency renders both patient types CTLA-4 deficient. This can be directly addressed with abatacept infusions, a CTLA-4 hybridized immunoglobulin given as a combination immunosuppressive therapy with rapamycin. Abatacept replaces the CTLA-4 molecule and reverses some of the immune dysregulation and thus morbidity associated with both CTLA4 and LRBA deficiency. Like APDS patients, XMEN patients are also prone to recurrent ear and sinopulmonary infection, but key differentiating features of this X-linked disorder are that only males are affected, these patients are unable to clear Epstein-Barr virus (EBV) once exposed, and they have a propensity to develop EBV-driven lymphomas. These patients also usually have a strong family history of multiple lymphomas in males. Even though a targeted treatment does not yet exist, steroid-sparing measures such as rituximab, rapamycin and mycophenolate mofetil are the first-line treatments often used in managing their refractory autoimmune cytopenias. Hence accurate early genetic diagnosis is key to accessing the appropriate treatment, thus decreasing the morbidity and mortality associated with these childhood onset ALPS-like rare inherited disorders (table). Table Disclosures No relevant conflicts of interest to declare. OffLabel Disclosure: Rapamycin, Abatacept, Mycophenolate Mofetil.

The French paediatric cohort of Castleman disease: a retrospective report of 23 patients

BackgroundCastleman disease (CD) is a rare non-malignant lymphoproliferation of undetermined origin. Two major disease phenotypes can be distinguished: unicentric CD (UCD) and multicentric CD (MCD). Diagnosis confirmation is based on histopathological findings in a lymph node. We attempted to survey all cases of paediatric CD identified to date in France to set up a national registry aiming to improve CD early recognition, treatment and follow-up, within the context of a new national reference center (http://www.castleman.fr).MethodsIn 2016, we e-mailed a questionnaire to members of the French paediatric immunohaematology society, the paediatric rheumatology society and the Reference Centre for Castleman Disease to retrospectively collect cases of paediatric CD (first symptoms before age 18 years). Anatomopathological confirmation was mandatory.ResultsWe identified 23 patients (12 girls) with a diagnosis of UCD (n = 17) and MCD (n = 6) between 1994 and 2018. The mean age at first symptoms was 11.47 ± 4.23 years for UCD and 8.3 ± 3.4 years for MCD. The mean diagnosis delay was 8.16 ± 10.32 months for UCD and 5.16 ± 5.81 years for MCD. In UCD, the initial symptoms were isolated lymph nodes (n = 10) or lymph node associated with other symptoms (n = 7); fever was present in 3 patients. Five patients with MCD presented fever. No patients had HIV or human herpesvirus 8 infection. Autoinflammatory gene mutations were investigated in five patients. One patient with MCD carried a K695R heterozygous mutation in MEFV, another patient with MCD and Duchenne myopathy carried two variants in TNFRSF1A and one patient with UCD and fever episodes carried two heterozygous mutations, in IL10RA and IL36RN, respectively. Treatment of UCD was mainly surgical resection, steroids, and radiotherapy. Treatment of MCD included tocilizumab, rituximab, anakinra, steroids, chemotherapy, and splenectomy. Overall survival after a mean of 6.1 ± 6.4 years of follow-up, was 100% for both forms.ConclusionPaediatric CD still seems underdiagnosed, with a significant diagnosis delay, especially for MCD, but new international criteria will help in the future. Unlike adult CD, which is strongly associated with HIV and human herpesvirus 8 infection, paediatric CD could be favored by primary activation of innate immunity and may affect life expectancy less.

Spare the Spleen in ALPS: It Is Not an Expendable Vestigial Organ

Background:Autoimmune lymphoproliferative syndrome (ALPS-FAS) due to inherited and somatic FAS genetic defects is associated with childhood onset lymphadenopathy, splenomegaly, multilineage cytopenias, and an increased life-time risk of B-cell lymphoma. More than two hundred patients with ALPS-FAS and their relatives have been followed at NIH and CHOP since 1993. Though splenectomy was the go to remedy until early 2000s, steroid and spleen sparing immunomodulatory regimens have been the mainstay of long term therapy in recent years for many ALPS patients with refractory cytopenias secondary to autoimmune destruction and splenic sequestration. This included mycophenolate mofetil (n=54), rapamycin (n=17 at NIH and n=22 at CHOP), rituximab (n=25), plaquenil (n=4), and TPO-mimetics (n=4).Patients and Observations:In our cohort; 80 patients had a splenectomy before 2005, compared to only 26 patients that endured a splenectomy between 2005 and 2018 among NIH cohort and none at CHOP. Post splenectomy sepsis related morbidity and mortality were noted to be considerable. More ALPS patients in our cohort have perished due to overwhelming post splenectomy sepsis(n=10) and non-availability of timely medical care than all other causes of death cumulatively, including deaths due to lymphoma (n=5). This change of practice was predicated upon the success of regimens containing long term use of mycophenolate mofetil (Rao VK et al. Use of mycophenolate mofetil for chronic, refractory immune cytopenias in children with autoimmune lymphoproliferative syndrome. Br J Haematol. 2005 May; 129(4):534-8) or rapamycin (Bride KL et al. Sirolimus is effective in relapsed/refractory autoimmune cytopenias: results of a prospective multi-institutional trial. Blood. 2016 Jan 7;127(1):17-28. doi: 10.1182/blood-2015-07-657981). Though rapamycin was more potent against the underlying lymphoproliferative process of ALPS, some patients could not tolerate its side effects: mouth ulcers, increased lipids, molluscum, warts, deep vein thrombosis and peripheral edema. Notable toxicities were persistent secondary hypogammaglobulinemia (n=20/25) following rituximab and prolonged use of mycophenolate mofetil.Conclusion:Splenectomy and rituximab should be avoided in ALPS-FAS. Though successfully used in many patients, we still need to be wary of the short and long-term toxicities of both rapamycin and MMF. Though it may sound self-evident to avoid splenectomy today, even in early 2010s we have had a 1year old child with ALPS-FAS undergoing unwarranted splenectomy. Splenectomy for an enlarged spleen for a diagnostic or therapeutic purpose should be avoided under many circumstances unless indicated as a last resort. (Kristinsson SY et al. Long-term risks after splenectomy among 8,149 cancer-free American veterans: a cohort study with up to 27 years follow-up. Haematologica. 2014 Feb;99(2):392-8. doi: 10.3324/haematol.2013.092460. PMID: 24056815).Experience gained from long term management of nonmalignant lymphoproliferation in rare disorders like ALPS can also be applicable to lymphadenopathy, splenomegaly and hypersplenism in patients with sporadic ITP and other inherited disorders of immune system, due to defects in genes like PIK3CD, PIK3R1, CTLA4, LRBA and STAT3GOF etc. using spleen sparing long term immunosuppressive/immunomodulatory medications.Future Directions:It is desirable to create an all cause iatrogenic/surgical asplenia registry for all patients (both pediatric and adults) under the auspices of ASH. This registry should prospectively collect data about patients that have undergone splenectomy and follow them for the long term and document their associated life time comorbidities. This will help us in developing standardized prophylactic asplenia care protocols. (A registry for patients with asplenia/hyposplenism reduces the risk of infections with encapsulated organisms. Arnott A, Jones P, Franklin LJ, Spelman D, Leder K, Cheng AC. Clin Infect Dis. 2018 Feb 17. doi: 10.1093/cid/ciy141. [Epub ahead of print])Targeted physiological restoration of the fas or other affected protein function is desirable in symptomatic patients with ALPS and similar inherited disorders of non-malignant lymphoproliferation as a long-term therapeutic approach starting from childhood and continued into late adulthood. DisclosuresRao:novartis: Research Funding. Uzel:Novartis: Research Funding. Teachey:La Roche: Consultancy; Amgen: Consultancy.

Stabilized β-Catenin Ameliorates ALPS-Like Symptoms of B6/lpr Mice.

Autoimmune lymphoproliferative syndrome (ALPS) is an incurable disease mainly caused by the defect of Fas-mediated apoptosis and characterized by nonmalignant autoimmune lymphoproliferation. Stabilized β-catenin could not only potentiate Fas-mediated T cell apoptosis via upregulating the expression of Fas on activated T cells, but also potentiate T cell apoptosis via intrinsic apoptotic pathway. In the present study, we introduced β-catTg into lpr/lpr mice and aimed to explore the potential role of stabilized β-catenin (β-catTg) in the development of ALPS-like phenotypes of lpr/lpr mice. We found that the total splenocyte cells and some compositions were slightly downregulated in β-catTglpr/lpr mice, especially the CD4 and CD8 TEM cells were significantly reduced. Meanwhile, stabilized β-catenin obviously decreased the numbers of spleen TCRβ+CD4−CD8− T (DNT) cells, and the levels of some serum proinflammatory factors also were lowered in β-catTglpr/lpr mice. Beyond that, stabilized β-catenin slightly lowered the levels of the serum autoantibodies and the scores of kidney histopathology of β-catTglpr/lpr mice compared with lpr/lpr mice. Our study suggested that stabilized β-catenin ameliorated some ALPS-like symptoms of lpr/lpr mice by potentiating Fas-independent signal-mediated T cell apoptosis, which might uncover a potential novel therapeutic direction for ALPS.

Abnormal thymic maturation and lymphoproliferation in MRL-Fas lpr/lpr mice can be partially reversed by synthetic oligonucleotides: implications for systemic lupus erythematosus and autoimmune lymphoproliferative syndrome.

MRL-Fas lpr/lpr mice represent an excellent animal model for studying non-malignant lymphoproliferation, regeneration and systemic autoimmunity. Retro-transposon insertion into the second intron of the pro-apoptotic Fas gene appears to be responsible for both lymphoproliferation and autoimmunity, while other genes are more likely to contribute to the regenerative healing characteristic of this mouse strain. Previous studies have shown that neonatal thymectomy can halt the development of abnormal lymphoproliferation. Whereas at four weeks of age primary and secondary lymphoid organs appear to be grossly intact, vigorous lymphoproliferation and autoantibody production subsequently ensues. This is first noticeable at six weeks of age, at which time lymph nodes, spleens and thymuses, but not the bone marrow, become infiltrated with abnormal B220+CD3+CD4-CD8- T cells. Around the same time, thymuses show a significant drop in CD4+CD8+double-positive T cells generating an abnormal ratio between double-positive and single-positive thymocytes. The objective of current study was to evaluate the effect of synthetic oligonucleotides-toll-like receptor antagonists on early lymphoid development in this strain of mice. Herein, we demonstrate the ability of synthetic oligonucleotides made with the nuclease-resistant phosphorothioate backbone to partially reverse abnormal lymphoproliferation and thymic involution in pre-diseased MRL-Fas lpr/lpr mice when administered intraperitoneally starting from week four of age. This curative effect of oligonucleotides was primary sequence/secondary oligonucleotide structure-independent, suggesting an effect through the toll-like receptor 7. A similar approach may potentially benefit patients with autoimmune lymphoproliferative syndrome who, like MRL-Fas lpr/lpr mice, carry a mutation in the Fas gene.

Optimal Management of Autoimmune Lymphoproliferative Syndrome in Children.

Autoimmune lymphoproliferative syndrome (ALPS) is a disorder of abnormal lymphocyte homeostasis, resulting from mutations in the Fas apoptotic pathway. Clinical manifestations include noninfectious and nonmalignant lymphadenopathy, splenomegaly, and autoimmune pathology-most commonly, autoimmune cytopenias. Rarely, and in association with specific genetic mutations, patients with ALPS may go on to develop secondary lymphoid malignancies. Though ALPS is a rare disorder, it should be suspected and ruled out in children presenting with chronic and refractory multilineage cytopenias associated with nonmalignant lymphoproliferation. Revised diagnostic criteria and insights into disease biology have improved both diagnosis and treatment. Sirolimus and mycophenolate mofetil are the best-studied and most effective corticosteroid-sparing therapies for ALPS, and they should be considered first-line therapy for patients who need chronic treatment. This review highlights practical clinical considerations for diagnosis and management of ALPS.

Autoimmune Lymphoproliferative Syndrome: A Case Report

Autoimmune lymphoproliferative syndrome is an impairment of lymphocyte apoptosis expressed by generalized non-malignant lymphoproliferation, lymphadenopathy and/or splenomegaly. We report the case of a 7-year-old male patient presentingwith relapsing generalized lymphadenopathy, splenomegaly, bicytopenia (autoimmune hemolytic anemia and thrombocytopenia), and lymphocytosis. Immunological investigations concluded to defective in vitro tumor necrosis factor receptor superfamily member 6 (Fas)-mediated apoptosis and T cells that express the alpha/beta T-cell receptor and lack of both CD4 and CD8(so-called α/β-DNT cells), and expansion of an unusual population of α/βCD3+CD4-CD8- (double-negative T cells>1%). Treatment consisted ofcorticosteroids, intravenous immunoglobulin, and cyclosporine, with favorable outcome.

Avances en el conocimiento y manejo del síndrome linfoproliferativo autoinmune

Autoimmune lymphoproliferative syndrome (ALPS) represents a failure of apoptotic mechanisms to maintain lymphocyte homeostasis. ALPS often manifest in childhood with cytopenias, chronic non-malignant lymphoproliferation and autoimmune complications. A number of new insights have improved the understanding of the genetics and biology of ALPS. The treatment of the disease has changed and mycophenolate mofetil and sirolimus have been demonstrated to have marked activity against the disease, improving quality of life for many patients. These will be discussed in this review.

514 The Autoimmune Lymphoproliferative Syndrome: A Case Report

BackgroundThe Autoimmune Lymphoproliferative Syndrome (ALPS) is an impairment of lymphocyte apoptosis expressed by generalized non-malignant lymphoproliferation, lymphadenopathy and/or splenomegaly. Majority of patients with ALPS harbor heterozygous germline mutations in the...