Normal Serum Immunoglobulin Levels Research Articles

Primary Immunodeficiency: Specific antibody deficiency with normal IgG.

Specific antibody deficiency (SAD) is a common primary immunodeficiency disorder that should be considered in older children and adults with recurrent and/or severe sinopulmonary infections. The diagnosis is characterized by inadequate antibody response to polysaccharide vaccine, specifically, pneumococcal, with normal responses to protein antigens and normal levels of serum immunoglobulins as well as immunoglobulin G (IgG) subclasses. The underlying mechanism for SAD is not completely elucidated. It is understood that young children have limited polysaccharide responsiveness, which develops with increased age. Due to this phenomenon, the consensus is that there is adequate immune maturity after age 2 years, which is the earliest for the SAD diagnosis to be established. There remains a lack of consensus on thresholds for polysaccharide nonresponse, and there are several commercial laboratories that measure a range of serotypes, with the recommendation for patients to have their diagnostic evaluation with serotype testing both before vaccination and after vaccination to be conducted by the same laboratory. Once a diagnosis has been made, the management of SAD is based on the clinical severity. Clinicians may consider prophylactic antibiotics as well as immunoglobulin replacement. These patients should be closely followed up, with the possibility of discontinuation of IgG replacement after 12 to 24 months. Children are more likely to demonstrate resolution of SAD than are adolescents and adults. Patients with SAD may also progress to a more severe immunodeficiency; therefore, continued monitoring remains a crucial principle of practice in the care of patients with SAD.

#5076 MONOCLONAL GAMMOPATHY IN C3 GLOMERULOPATHY: DOES THE BUCKET STOP THERE?

Abstract Background and Aims C3 glomerulopathy (C3G) is a rare diagnosis, characterized by dysregulation of the alternative pathway of complement, classically presenting in children and young adults. Recently, it has been reported the association between the production of a monoclonal protein and the development of C3G, affecting a larger age span. Method We report the case of a 53-year-old male patient, that attended the emergency department due to persistent holocranial headache. He was an IV drug abuser with a history of treated Hepatitis C infection and free lambda light chain monoclonal protein, being studied by the Haematology Department. On admission, he was hypertensive (187/98 mmHg), and labs showed an acute on chronic kidney disease (serum creatinine 2.35 mg/dL from a basal of 1.5 mg/dL) with an active urinary sediment (38 erythrocytes/field, with dysmorphia), a urinary protein/creatinine ratio of 626 mg/g, and C3 consumption (0.52 g/L). The patient was admitted, and a kidney biopsy was performed. Results Further lab results confirmed a serum IgG Lambda monoclonal protein. Autoantibodies screening (ANCAs, ANAs, Anti-GBM), ASLO and Rheumatoid Factor were negative. Cryoglobulinemia was detected, and the cryoprecipitate's immunofixation revealed monoclonal proteins IgG Lambda and IgM Kappa. HCV viral load was negative. Bone marrow biopsy revealed a small population (< 3%) of plasma cells with Lambda light chain restriction. Kidney biopsy's light microscopy showed increased mesangial matrix and cells, endocapillary hypercellularity, and some glomeruli with lobulated appearance. Five out of 15 glomeruli presented fibrocellular crescents. Immunofluorescence showed C3 dominant staining on capillary walls and in the mesangium, with absent IgG and light chain deposits. A presumptive diagnosis of C3 glomerulopathy was made and the patient was empirically started on corticosteroids (3 pulses of intravenous methylprednisolone, followed by oral prednisolone 1mg/Kg/day), which was followed by paraprotein-directed chemotherapy with bortezomib, cyclophosphamide and dexamethasone (VCD). The patient is currently on the third VCD cycle, presenting both renal and haematological responses: recovery of serum creatinine to basal levels (1.54 mg/dL), resolution of haematuria and proteinuria, normalisation of C3 levels. Serum immunofixation is currently negative for monoclonal protein, with normal serum immunoglobulin levels. Electron microscopy revealed electron-dense deposits in the mesangium, and mesangium-capillary transition, supporting the diagnosis of C3 glomerulonephritis. Genetic testing of complement-related genes revealed a rare missense variation of unknown significance (c.4855A>C) on the C3 gene, that has been previously reported in association with C3 glomerulopathy and atypical Haemolytic-Uremic syndrome. Conclusion This case represents a monoclonal gammopathy associated-C3 glomerulonephritis with a favourable response to paraprotein-directed chemotherapy. Although the association between monoclonal gammopathy and C3G rests on epidemiologic findings, experimental evidence suggests that several monoclonal proteins have complement dysregulation features, which may enhance alternate complement pathway activation. Our patient's response is in line with observational data that have shown improved renal outcomes in patients who achieve a haematological response following clone-directed chemotherapy, which further supports the role of monoclonal gammopathy in C3G pathogenesis [1]. Interestingly, the genetic variation identified in our patient might have provided a favourable genetic background for the development of C3G, which is thought to rely upon a complex interaction of triggering events, such as a monoclonal gammopathy, and underlying complement abnormalities, such as genetic variants in complement genes.

Mycobacterium avium Complex Infections: Detailed Phenotypic and Functional Immunological Work-Up Is Required despite Genetic Analyses

Introduction: Cervical scrofulous lymphadenitis due to Mycobacterium avium complex (MAC) in immunocompetent adults is a rare disease. The presence of MAC infections demands meticulous clinical evaluation of patients along with detailed phenotypic and functional evaluation of their immune system including next-generation sequencing (NGS) analyses of target genes. Methods: Exact clinical histories of the index patients both suffering from retromandibular/cervical scrofulous lymphadenitis were obtained along with phenotypic and functional immunological evaluations of leukocyte populations followed by targeted NGS-based sequencing of candidate genes. Results: Immunological investigations showed normal serum immunoglobulin and complement levels, but lymphopenia, which was caused by significantly reduced CD3+CD4+CD45RO+ memory T-cell and CD19+ B-cell numbers. Despite normal T-cell proliferation to a number of accessory cell-dependent and -independent stimuli, the PBMC of both patients elaborated clearly reduced levels of a number of cytokines, including IFN-γ, IL-10, IL-12p70, IL-1α, IL-1β, and TNF-α upon TCR-dependent T-cell stimulation with CD3-coated beads but also superantigens. The IFN-γ production deficiency was confirmed for CD3+CD4+ helper and CD4+CD8+ cytotoxic T cells on the single-cell level by multiparametric flow cytometry irrespective of whether PMA/ionomycin-stimulated whole blood cells or gradient-purified PBMC was analyzed. In the female patient L1, targeted NGS-based sequencing revealed a homozygous c.110T>C mutation in the interferon-γ receptor type 1 (IFNGR1) leading to significantly reduced receptor expression on both CD14+ monocytes and CD3+ T cells. Patient S2 presented with normal IFNGR1 expression on CD14+ monocytes but significantly reduced IFNGR1 expression on CD3+ T cells, despite the absence of detectable homozygous mutations in the IFNGR1 itself or disease-related target genes. Exogenous addition of increasing doses of IFN-γ resulted in proper upregulation of high-affinity FcγRI (CD64) on monocytes from patient S2, whereas monocytes from patient L1 showed only partial induction of CD64 expression after incubation with high doses of IFN-γ. Conclusion: A detailed phenotypic and functional immunological examination is urgently required to determine the cause of a clinically relevant immunodeficiency, despite detailed genetic analyses.

How to Treat Isolated Leptomeningeal Relapse of Multiple Myeloma 11 Years after Autologous Stem Cell Transplantation (ASCT)

Post transplant relapse of Multiple Myeloma (MM) in the central nervous system (CNS) is rare and it is almost always associated with systematic relapse and in most instances, shortly after initial treatment. We did not encounter reports of relapse isolated to the CNS ten years post-transplant. In October 2009, a 49-year-old male presented with an IgG lambda MM, ISS II. He was treated with Bortezomib/Dexamethasone, autologous PBSCT, followed by two years maintenance with Lenalidomide, attaining stringent CR, confirmed by PET/CT. He discontinued follow up and returned after 11y/8m progression free survival, in June 2021 with paraplegia due to cauda equina syndrome. NMR consistent with leptomeningeal infiltration, single focal intramedullary lesion at L1 level without bone affectation. No MM defining criteria (CRAB). Normal levels of serum Immunoglobulins (IGs), serum and urine immunofixation, and serum free light chains. Flow cytometry negative in bone marrow. Spinal tap was unsuccessful and through an Ommaya reservoir, that was placed after NMR showed evidence of cranial leptomeningeal involvement, CSF showed infiltration by countless malignant plasma cells. Patient received immediate conformational radiotherapy and biweekly IT methotrexate and hydrocortisone. A month later his course was complicated by left leg proximal deep vein thrombosis and pulmonary embolism which was treated with Apixaban. Given the rarity of this type of relapse, we questioned the appropriateness of the treatment and searched the literature with respect to the accessibility of the CNS by the different novel drugs used to treat MM in order to determine the most effective strategy. In addition to corticosteroids, there is clinical evidence that thalidomide crosses the blood-brain barrier (BBB), in murine models pomalidomide also has good penetration into the CNS. Both have a penetration of 30 to 40% into the CSF. Among proteasome inhibitors, only marizomib has been observed to cross the BBB in a murine model, while bortezomib does not. With respect to anti CD38 monoclonal antibodies, mass spectrometry at 12, 15, and 19 days after daratumumab infusion showed antibody levels in CSF 71 times less than in serum on the three sample days. It is not known if weekly doses of daratumumab could attain therapeutic levels in CSF. We found only 14 cases of isolated CNS relapse in patients with MM treated with ASCT with a median interval between transplant and relapse of 3 months (0.5-96m), with only one reported relapse 7.5 years after autologous transplant and the median overall survival was only 3 months. Two cases died in less than a month and only one case survived for a year after the CNS relapse.To date, our patient has received 12 cycles of Pomalidomide/dexamethasone with progressive improvement, now he is able to carry on his life unassisted and there is no evidence of MM relapse anywhere. The rarity of this case scenario highlights the lack of knowledge regarding the best approach to CNS MM relapse. There is no evidence of the effectiveness of methotrexate and Ara C, in MM, and no novel drug can be instilled into the CSF. We conclude that the systemic use of pomalidomide and dexamethasone should be the best approach of MM isolated CNS relapse. Further investigations will clarify if other novel drugs are active in this context.

Lymphoplasmacytic Lymphoma with Only Lambda Light Chain Monoclonal Paraprotein Expression.

IntroductionLymphoplasmacytic lymphoma (LPL) is a rare low-grade B-cell neoplasm that accounts for approximately 2% of all haematological malignancies. Most patients have the clinical syndrome of Waldenstrom macroglobulinemia (WM), which is defined as LPL with an associated immunoglobulin M (IgM) serum monoclonal protein. Roughly 5% of LPL patients secrete non-IgM paraproteins (e.g., IgG, IgA, kappa, lambda) or are non-secretory.Case descriptionWe report the case of a 41-year-old woman who was diagnosed with non-IgM LPL with lambda light chain monoclonal paraprotein production and normal serum immunoglobulin levels. The MYD88 L265P mutation was detected on fluorescence in-situ hybridization (FISH) analysis of the bone marrow. The patient underwent treatment with a combination of ibrutinib and rituximab. There was an initial response but she died 8 months after diagnosis.DiscussionNon-IgM LPL poses diagnostic and therapeutic challenges to clinicians as it is an exceptionally rare malignancy with a heterogeneous clinicopathological presentation and scarce literature. Among non-IgM LPL cases, those with lambda light chain production are even more rare. To the best of our knowledge, none have been reported to date. The addition of MYD88 L265P testing to the diagnostic armamentarium of non-IgM LPL cases is advisable for potential therapeutic reasons.LEARNING POINTSOur case report and literature review provide insight into non-IgM lymphoplasmacytic lymphoma (LPL), an extremely rare malignancy.Our case report highlights the importance of the need for new treatments for non-IgM LPL.

Deficiency of Leukocyte Surface Glycoproteins Mol, LFA-1, and Leu M5 in a Dog With Recurrent Bacterial Infections: An Animal Model

A dog with severe recurrent bacterial infections, impaired pus formation, delayed wound healing, and severe persistent leukocytosis was the result of a mother-son mating. Assessment of leukocyte function revealed profound abnormalities in adherence-dependent activities including impaired granulocyte adhesion to glass/plastic surfaces or nylon wool, decreased granulocyte aggregation and chemotaxis, and diminished lymphocyte blastogenesis, but normal neutrophil oxidative activity, serum immunoglobulin, and complement levels. By immunofluorescence analysis, CD11b and CD18 monoclonal antibodies specific for the 155-kd alpha polypeptide of Mo1 (gp 155, 94) and the 94 kd beta peptide common to Mo1, LFA-1 (gp 170, 94), and Leu M5 (p 150, 94) (surface molecules that promote leukocyte adhesion) failed to bind to unstimulated and A23187 calcium ionophore-stimulated granulocytes or mononuclear cells of the affected dog as compared with strong specific binding to canine control cells. The Mo1 glycoproteins were only barely detectable by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) of immunoprecipitates from lysates of 125I surface-labeled neutrophils from the affected dog as compared with intense bands seen with canine control cell precipitates. We conclude that this dog has a severe leukocyte surface glycoprotein deficiency syndrome that is similar, if not identical, to that recently recognized in humans. Dogs with deficiency of leukocyte Mo1, LFA-1, and Leu M5 expression may represent a useful animal model to characterize further the molecular basis for an inherited disorder in leukocyte effector function.

Achromobacter xylosoxidans Sepsis Unveiling X-linked Agammaglobulinemia Masquerading as Systemic-onset Juvenile Idiopathic Arthritis

X-linked agammaglobulinemia, a primary immunodeficiency, can present with musculoskeletal manifestations. A 4-year-old boy, diagnosed as systemic juvenile idiopathic arthritis at the age of 3 years and treated with biological agents, presented with fever, dyspnea and chest pain. Blood culture and pericardial fluid culture revealed Achromobacter xylosoxidans. Investigation revealed normal serum ferritin but low levels of serum immunoglobulins. Further immunological work-up revealed diagnosis of X-linked agammaglobulinemia. Child improved on antibiotic therapy; treatment with steroids and biological was discontinued. Underlying immunodeficiency disease must be looked for in children suspected to have juvenile arthritis, more so if they develop unusual serious infection in response to immunomodulatory therapy.

A TODDLER WITH ALTERNATIVE PATHWAY COMPLEMENT DEFICIENCY

Introduction Complement system is an important component of innate immunity and can be activated through the classical, alternative, and lectin pathways. Patients with complement deficiency (CD) usually present with autoimmune disorders or recurrent infections. Case Description A 3-year-old Bosnian male presented with failure to thrive and recurrent infections including otitis media, pneumonia, and croup. He had mildly dysmorphic facial features, small stature (3rd%tile for weight, 14th%tile for height), developmental delay, and cervical lymphadenopathy. Immune evaluation revealed normal levels of serum immunoglobulins (IgG, IgA, IgM, and IgE), lymphocyte subsets, protein and pneumococcal vaccine titers, total hemolytic complement (CH50), and mannose-binding lectin. He had absent alternative complement activity (AH50) on three occasions. Further investigation showed low factor B and D levels, low factor D function, absent factor B function, and low properdin. Chromosomal microarray analysis is consistent with consanguinity at a level of fourth degree mating or beyond. Antibiotic prophylaxis was initiated while additional genetic evaluation and alternative pathway complement assays are underway. Discussion Although rare, alternative pathway CD should be considered in patients presenting with recurrent infections. Evaluation requires a thorough immunologic investigation including the use of CH50 and AH50 as screening assays for CD. Absent AH50 in the context of a normal CH50 is strongly indicative of an alternative pathway defect. There is an increased likelihood of autosomal recessive disorders in our case as suggested by the chromosome analysis findings.

Infantile-onset primary alveolar proteinosis with hypogammaglobulinemia caused by heterozygous mutations of 2′-5′-oligoadenylate synthase 1

Abstract 2′-5′-oligoadenylate synthase 1 (OAS1) is one of the interferon-stimulated genes (ISG) which plays a critical role in innate anti-viral immunity. Stimulated by viral double strand RNA (dsRNA), OAS1 produces 2′-5′ linked oligomer of adenylates (2′-5′A) and the produced 2′-5′A activates ribonuclease-L (RNase-L) which results in degradation of viral RNA and inhibition of viral replications. We identified autosomal inherited OAS1 missense mutations in three Japanese pedigrees with infantile-onset primary alveolar proteinosis with hypogammaglobulinemia. Patients’ peripheral blood monocytes and CD11c+ myeloid dendritic cells (mDC) were progressively decreased; CD27+ memory B cells were lacking. The alveolar macrophages showed decreased phagocytosis activity; and the enlarged and foamy form was scarcely observed, which were typical in conventional pulmonary alveolar proteinosis (PAP). Their bone marrow monocyte progenitors were decreased and showed reduced colony forming potentials. One of the patients is currently alive without PAP after hematopoietic stem cell transplantation. The recombinant mutant OAS1 protein had unaltered dsRNA binding activity. Patient-derived lymphoblastoid cell lines showed normal expression of OAS1 protein and mRNA, and unaltered function in OAS1 - RNase-L pathway. We generated model OAS1 knock-in mice by CRISPR/Cas9 based gene editing and analyzed immune-phenotypes. The mice show normal B and DC numbers and normal serum immunoglobulin levels so far. Detailed functional study on mutant OAS1 protein with the multi-Omics approach is currently underway.

An Unusual Myeloma Case with Normal Erythrocyte Sedimentation Rate and Serum Immunoglobulins

Multiple Myeloma (MM) is a disease characterized by the increase of plasma cells in bone marrow or in other tissues and increased production of abnormal immunoglobulin (Ig) or Ig parts. In this report, we aimed to present a case of myeloma whom showed in our clinic with complaints of diarrhea, vomiting, fatigue and difficulty in walking. A 68- year-old male patient presented with diarrhea, fatigue, nausea, vomiting, and loss of appetite. He had splenomegaly in physical examination. Laboratory test revealed erythrocyte sedimentation rate: 4 mm/h and corrected calcium: 11.1 mg/dl. In conclusion, despite it is rare, multiple myeloma case may present with normal erythrocyte sedimentation rate and serum immunoglobulin levels. Anemia, bone lesions and hypercalcemia in an elderly may prompt diagnostic effort for multiple myeloma.

Diagnosis of GATA2 haplo-insufficiency in a young woman prompted by pancytopenia with deficiencies of B-cell and dendritic cell development

BackgroundGATA2 deficiency presents with a spectrum of phenotypes including increased susceptibility to viral and bacterial infections, multi-lineage cytopenias, aplastic anemia, leukemic transformation and lymphedema. Allogeneic transplantation is only curative therapy for GATA2 deficiency, but is associated with significant treatment related morbidity and mortality. Given the spectrum of clinical presentation, accurate diagnosis of GATA2 deficiency is necessary to identify patients early in their disease course when allogeneic bone marrow transplantation may be of clinical benefit.Case presentationIn this report, we present a GATA2 mutation diagnosed in 23-year-old woman presenting with pancytopenia, recurring oral blisters, fatigue and chronic pain. We describe markedly low levels of mature B-cells in the blood and bone marrow and the absence of detectable blood dendritic cells with normal serum immunoglobulin levels and normal numbers of marrow plasma cells. She was ultimately diagnosed with GATA2 haplo-insufficiency due to a GATA2 germ-line mutation and underwent a successful allogeneic bone marrow transplant from a 10/10 HLA matched unrelated donor.ConclusionsThe case illustrates the diagnostic difficulties in identifying GATA2 deficiencies and the importance of family history and genetic testing. GATA2 plays an important role in B-cell and dendritic cell development, and decreased numbers of those cells is a characteristic feature that should prompt consideration of GATA2 deficiency in a patient with pancytopenia. Maturation of B-cells to long-lived plasma cells is relatively unaffected in GATA2 deficiency. Allogeneic stem cell transplantation can correct immune-deficiencies and prevent leukemic transformation in patients with GATA2 deficiency.

Flow cytometry as an important tool in the diagnosis of immunodeficiencies demonstrated in a patient with ataxia-telangiectasia

Abstract Background: Ataxia-telangiectasia (AT) is a rare hereditary genetic disease caused by one of more than 500 mutations in the ataxia-telangiectasia mutated gene (ATM). AT is characterized by cerebellar ataxia, telangiectasia of blood vessels, immunodeficiency with frequent lung infections, susceptibility to cancer, and sensitivity to ionizing radiation. A correct immunophenotyping of lymphocytes is necessary to identify the cause of the immunodeficiency. Methods: We evaluated a patient (female, 15 years) with AT by estimation of antibody titers, characterization of peripheral B- and T-cell subsets and investigation of proliferation response of B- and T-cells undergoing specific stimulation with PHA, CD3/CD28, and R848/CD40L. A healthy volunteer was used as a control. Results: The patient showed a heterozygous mutation in the ATM gene (c.5932G>T[p.E1978X]/c.7788+3A>G). Interestingly, despite a very low level of class-switched memory B-cells normal levels of serum immunoglobulins and antibody titers to viral and bacterial antigens could be observed. Furthermore, the analysis revealed an increase in total numbers of T-cells, caused by an extraordinarily high amount of γ/δ T-cells (CD3+CD4–CD8) (>75% of T-cells). Remaining CD4+/CD8+T-cells were decreased, naïve cells and recent thymic emigrants (RTEs) were strongly deficient. Subsequently, the proliferation activity of T-cells was strongly impaired, in contrast to normal B-cell proliferation both compared to the healthy control. Conclusions: Initial lymphocyte immunophenotyping suggested a defect in T- and B-cell differentiation, but normal humoral antibody titers and B-cell proliferation were inconsistent with this suspicion. Therefore, the results revealed an underlying T-cell defect and low levels of class-switched B-cells results from the lacking assistance from T-cells.

Clinical significance and origin of leukocytes that lack HLA-A allele expression in patients with acquired aplastic anemia.

To gain insight into the origin and clinical significance of leukocytes that lack human leukocyte antigen A (HLA-A) allele expression caused by a copy-number-neutral loss of heterozygosity in the short arm of chromosome 6 in patients with acquired aplastic anemia (AA),weused a high-sensitivity flow cytometry assay to investigate the presence of HLA-A allele-lacking leukocytes(HLA-LLs) in 144 AA patients. HLA-LLs, accounting for0.2-99.8% of each leukocyte population, were detected in 18 of 71 (25.4%) newly diagnosed patientsand in 25 of 73 (34.2%) previously treated patients. The lineage combination patterns of the HLA-LLs in the 43 HLA-LL(+)patients were granulocytes (Gs), monocytes (Ms), Bcells (Bs), and Tcells (Ts; GMBT) in 13 cases, GMB in 16 cases, GM in 11 cases, and B alone in three cases. The response rate to antithymocyte globulin plus cyclosporine therapy (100%) and the 2-year, failure-free survivalrate (100%) in 8 newly diagnosed HLA-LL(+) patients were significantly higher than in 23 HLA-LL(-) patients (52.2% for both). These data suggest that HLA-LLs are a useful marker of the presence of immune pathophysiology in AA and that T-cell attacks against hematopoietic progenitor cells, rather than against hematopoietic stem cells, can trigger bone marrow failure in AA patients.

Revisiting Hypogammaglobulinemia in Chronic Lymphocytic Leukemia: A Combined Clinicobiological Approach

Chronic lymphocytic leukemia (CLL) is characterized by progressive hypogammaglobulinemia that can affect one or more immunoglobulin subclasses. Although many underlying mechanisms have been suggested, the pathogenesis of this phenomenon remains to be elucidated. In the present study, we revisit hypogammaglobulinemia in CLL through a combined clinicobiological approach aiming at identifying associations with particular disease profiles that would offer pathogenetic insight and guidance for further research. The study group included 412 CLL patients with available information about serum immunoglobulins either at diagnosis (n=380) or before treatment initiation (n=32). Patient characteristics were as follows: median age: 65 years; males/females: 266/146; Binet stage A: 272/335, unmutated IGHV genes (U-CLL): 140/412 cases (34%); CD38 expression: 59/330 cases (18%); clonotypic IG of the MD or G isotype: 250 and 43 cases, respectively; isolated del(13q): 64/136 (47%); trisomy 12: 18/183 (10%); del(11q): 18/186 (10%); del(17p): 11/189 (6%); NOTCH1 del7544-45/p.P2514Rfs*4: 8/219 (4%). With a median follow up of 5 years, 152/329 cases (46%) received treatment. Decreased immunoglobulin serum levels in at least one subclass were identified in 220/412 patients (53%), as follows: (i) decreased IgM, 172/412 cases (41%); (ii) decreased IgG, 78/412 cases (19%); (iii) decreased IgA, 100/412 cases (24%). In 36/412 cases (9%), a decrease in all serum immunoglobulin subclasses was noted. No statistically significant differences were identified between patients with normal serum immunoglobulin levels versus those with hypogammaglobulinemia regarding age, gender, disease burden at diagnosis, IGHV gene mutational status, CD38 expression, cytogenetic aberrations, NOTCH1 mutations and the incidence of a second malignancy. However patients with hypogammaglobulinemia exhibited increased need for treatment compared to patients with normal serum immunoglobulins (91/175 vs 61/154 respectively, p=0.025). Among cases with hypogammaglobulinemia, 90 (41%) and 26 (12%) exhibited isolated IgM and IgA subclass deficiency, respectively; isolated IgG decrease, was relatively rare (10/220 cases, 4%). Interestingly, when comparing isolated IgA versus other subclass deficiencies, statistically significant associations were identified with (i) advanced clinical stage (Binet B/C, Rai III/IV) (p=0.002); (ii) female gender (p=0.041); and, (iii) NOTCH1 mutations (p=0.004). A propos of the latter, it is noteworthy that in 5/8 (63%) mutant NOTCH1 cases with hypogammaglobulinemia, the affected subclass was IgA. Within our cohort, we identified cases belonging to one of three different, well characterized subsets with stereotyped B-cell receptor immunoglobulin (BcR IG), namely: (1) subset #1 (clan I IGHV genes/IGKV1(D)-39): U-CLL, clinically aggressive, n=12; (2) subset #2 (IGHV3-21/IGLV3-21), mixed IGHV mutational status, noted clinical aggressiveness, n=5; and, (3) subset #4, mutated IGHV4-34/IGKV2-30 BcR IG, clinically indolent, n=12. Notably, all subset #2 cases showed low levels of at least one serum subclass, while in 4/5 and 3/5 cases, two or all three immunoglobulin subclasses were affected. Although numbers are small, the incidence of hypogammaglobulinemia in subset #2 was significantly (p<0.05) higher compared to either subset #1 or subset #4). Univariate analysis revealed clinical stage, CD38 expression and IGHV mutational status as statistically important parameters (p<0.05) for both time-to-first–treatment (TTFT) and overall survival (OS); in contrast, hypogammaglobulinemia had no impact either on on TTFT or OS. In multivariate analysis, clinical stage and IGHV gene mutational status retained independent significance. In conclusion, abnormalities of serum immunoglobulins are detected in CLL patients with heterogeneous clinicobiological profiles, including different disease burden (clinical stage), cytogenetic aberrations and IGHV gene mutational status. However, certain observations reported herein, in particular the high incidence of hypogammaglobulinemia in subset #2 and the association of NOTCH1 mutations with IgA subclass deficiency, are noteworthy and indicate the need for research towards unraveling causal mechanisms among the observed interwined events. DisclosuresNo relevant conflicts of interest to declare.

Perigranuloma Localization and Abnormal Maturation of B Cells

Recent observations of abnormal immunoglobulin responses and case reports describing successful B-cell ablative therapy suggest involvement of B cells in the pathogenesis of sarcoidosis. To investigate how abnormal B-cell maturation and function in patients with sarcoidosis contribute to disease. Patients with sarcoidosis (n = 32) were included for detailed analysis by immunohistochemistry of tissue, flow cytometry of blood B-cell subsets, and serum immunoglobulin levels. Vaccination responses in patients with sarcoidosis to influenza virus and encapsulated bacteria and molecular analysis of immunoglobulin heavy chain transcripts were studied for functional analysis of immunoglobulin responses. Perigranuloma localization of IgA-producing plasma cells and numerous B cells were found in affected tissues. Total blood B-cell numbers were normal, CD27(+) memory B cells were significantly reduced, and CD27(-)IgA(+) B cells were significantly increased; the results are normalized in patients treated with TNF-α blockers. Despite this, patients had normal serum immunoglobulin levels and normal antigen-specific immunoglobulin responses. IgA and IgG transcripts, however, showed high frequencies of somatic hypermutations and increased usage of downstream IgG subclasses, suggestive for prolonged or repetitive responses. The large B-cell infiltrates in granulomatous tissue and increased molecular signs of antibody maturation are indicative of direct involvement of B cells in local inflammatory processes in patients with sarcoidosis. Moreover, CD27(-)IgA(+) B cells could be a marker for treatment with TNF-α blockers. These findings of B cells as emerging key players provide a rationale for a systematic study on B-cell ablative therapy in patients with sarcoidosis.

Serum Immunoglobulin Levels in Healthy Thai Infants and Children Aged 0-2 Years Determined by Nephelometry

Normal serum immunoglobulin levels (Ig) are important for the diagnosis of immunologic disorders. Data of Ig evaluated by nephelometry are limited in healthy Asian children especially those under 2 years old.

Successful Treatment of Sepsis Caused by Staphylococcus lugdunensis in an Adult with 22q11.2 Deletion Syndrome

A 27-year-old woman visited our hospital because of high fever. She had been diagnosed as 22q11.2 deletion syndrome (22q11.2DS) due to her cardiac history (tetralogy of Fallot), thymic hypoplasia and 22q11.2 deletion. She had a normal CD4/CD8 ratio, a slightly decreased lymphocyte count and normal serum immunoglobulin levels. Blood cultures were positive for Staphylococcus lugdunensis (S. lugdunensis). Infection route of S. lugdunensis in this case was unclear. The patient was successfully treated with several intravenous antibiotics. Infection should be considered when managing patients with 22q.11.2DS. regardless of whether their immune system is impaired.

Glycotranscriptome study reveals an enzymatic switch modulating glycosaminoglycan synthesis during B‐cell development and activation

B-cell fate and responses are modulated by soluble mediators and direct cellular interactions. Migration properties also vary during differentiation, commitment and activation. In many cells, modulation of responses to stimuli involves cell surface glycans, whose architecture depends on the simultaneous expression of multiple enzymes. By looking at the glycosylation-related gene expression patterns among B-cell populations, we determined in this study that the strongest variations were observed for CSGalNAcT-1 and EXTL1. These are enzymes involved in the biosynthesis of alternative forms of glycosaminoglycans (GAGs), namely chondroitin sulfate and heparan sulfate, respectively. These two enzymes showed inverse fluctuations in progenitors, resting B cells and activated B cells, suggesting a developmentally regulated switch between chondroitin and heparan sulfate synthesis. To explore whether these variations contributed to optimal B-cell differentiation, we overexpressed EXTL1 in the B-cell lineage of transgenic mice, yielding a partial differentiation blockade at the pro-B to pre-B transition. In the periphery, this defect was almost fully compensated for in vivo, with normal-size B-cell compartments and normal serum immunoglobulin levels in the transgenic EXTL1 mice. The peripheral B cells from EXTL1 transgenics were only affected with regard to their in vitro responses to polyclonal activation, showing reduced proliferation. Together the data suggest that despite their low amounts in lymphocytes, the heparan sulfate chains decorating the endogenous GAGs appear to be regulators of B-cell physiology.

Behcet disease and celiac disease: to screen or not?

Behcet’s disease (BD) is a chronic, relapsing, inflammatory disease characterized by recurrent oral aphthae and any of the several systemic manifestations including genital aphthae, ocular disease, skin lesions, gastrointestinal involvement, neurologic disease, vascular disease, or arthritis. BD is an autoimmune disorder and may be associated with other autoimmune diseases, but the underlying pathogenetic mechanism of the disease is not well understood [1]. Up to now, only a few cases have been described with BD and celiac disease (CD). Herein, we report a case of BD overlap with CD. A 17-year-old young was admitted to our clinic because of diarrhea, bloating, and abdominal distension. The patient’s medical history included BD. In addition, he had been taking colchicine for 2 years for BD. Microscopic examination of stool was normal. Serum biochemical parameters were within the normal range. Complete blood count revealed mild anemia with hb: 13.2 g/l and iron: 87(70–180) and total iron binding capacity: 417(227–428) and ferritine: 12 ng/ml (15–140). Because of iron deficiency, diarrhea and abdominal symptoms serum tissue transglutaminase (tTG) and gliadin antibodies were checked for celiac disease. Immunoglobulin A class tTG and IgG gliadin antibodies were found positive with normal serum immunoglobulin levels. In order to confirm the diagnosis of CD, an upper gastrointestinal system endoscopy with duodenal biopsy was performed. It showed scalloping of folds, and histopathological examination showed subtotal villous atrophy (Marsh 3a). Gluten-free diet was instituted, and all the symptoms significantly decreased in follow-up. Celiac disease can be defined as a small-bowel disorder characterized by mucosal inflammation, villous atrophy, and crypt hyperplasia, which occur upon exposure to dietary gluten and which demonstrate improvement after withdrawal of gluten from the diet [2]. Patients affected by CD have greater risk of developing autoimmune diseases, among them rheumatic diseases. BD and CD share many clinical presentations, such as recurrent aphthous stomatitis, as well as gastrointestinal, musculoskeletal, and neurologic involvements. There are only three studies concerning the association of BD and CD in the literature [3–5]. In these reports, patients with BD were screened for CD and only two of them were diagnosed with histologically proven CD. In addition, two other cases with CD and BD have been reported in the literature. Most of these cases showed alarm symptoms for early further investigations. In our case, patient referred to our clinic because of diarrhea and bloating. Colchicine is commonly used in the treatment of BD and has many gastrointestinal side effects including abdominal pain, cramping, nausea, vomiting, and diarrhea. Differential diagnosis of CD and colchicine side effects may be difficult because of similar symptoms and may result interruption of treatment. In conclusion, despite the rarity of this combination, both disease have immunogenic mechanism and share many clinical manifestations. It is still unclear whether all patients with BD should be screened for CD or not, and in addition, colchicine treatment may cause differential diagnosis more difficult. If diarrhea and iron deficiency are seen in a patient with BD, the serologic tests with smallbowel biopsy should be performed to exclude CD. B. Ergul E. Kocak (&) S. Koklu Department of Gastroenterology, Ankara Education and Research Hospital, Keklikpinari mahallesi, 240 sokak, Duru apartmani, 8/6, Dikmen, Cankaya, Ankara, Turkey e-mail: kocak67@hotmail.com

Antibody responses to tetanus and diphtheria vaccine in chronic and recurrent rhinosinusitis

Chronic rhinosinusitis may be accompanied by impaired immunity despite normal levels of serum immunoglobulins. Immune responses in sinusitis patients have previously been evaluated using polysaccharide vaccines. Our AIM was to assess the immune status by evaluating responses to diphtheria and tetanus vaccine. Specific antibodies were measured before and 2 weeks after vaccination in 25 patients with chronic or recurrent sinusitis and in 30 healthy individuals. The mean age of the patients was 46 years and that of healthy controls 43 years. After vaccination the patients had on average 4.08-fold lower responses to diphtheria toxoid and 2.20-fold lower responses to tetanus than the controls. Fourteen out of 25 patients had antibody levels that did not reach the 95% normal distribution range of healthy controls after either diphtheria or tetanus vaccination. All the patients had normal levels of serum immunoglobulins. A significant proportion of patients with persisting symptoms of rhinosinisitis may have impaired responses to protein vaccines. Responses to protein vaccines may be used to evaluate immune function of sinusitis patients.