A case of selective immunoglobulin M deficiency and autoimmune glomerulonephritis

Selective IgM deficiency: evaluation of 75 patients according to different diagnostic criteria

Selective IgM deficiency (SIgMD) has recently been included in the inborn errors of immunity classification. SIgMD has conflicting diagnostic criteria and diverse clinical and immunological findings. We aimed to assess the clinical and laboratory profiles of patients with SIgMD and to compare the data of patients diagnosed using two inclusion criteria. This was a descriptive, retrospective, observational, collaborative study. Patients were included according to the following definitions: Group 1, IgM levels < 0.20 g/L in children and < 0.30 g/L in adults, and Group 2, serum IgM levels below 2SD and, for both, absence of associated immunological diseases or secondary causes. The protocol was approved by the Ethics Committee, and patients provided consent. In total, 75 patients were included: 37 (16 M:21F; mean age, 52.92) and 38 (13 M:25F; mean age, 53.47) in Groups 1 and 2, respectively. The most frequent clinical manifestations were allergic rhinitis (G1, 45.9%; G2, 36.8%), asthma (G1, 37.8%; G2, 28.9%), and pulmonary infections (G1, 27.03%; G2, 21.05%). Chromosomopathies (16.22%) and neoplasia (13.51%) were more frequent in G1, whereas URTI (23.68%) and skin infections (23.68%) were more common in G2. There was no difference in sex or mean age at symptom onset between both groups of patients. Regarding the clinical picture, 90.7% of the lesions were benign (68/75). Chromosomopathies may be associated with SIgMD, suggesting the need to quantify serum IgM levels in these cases. Considering the possibility of developing autoimmunity, neoplasia, and common variable immunodeficiency, it is advisable to follow up patients with SIgMD.

Selective IgM Deficiency: Evidence, Controversies, and Gaps

Selective Immunoglobulin M deficiency (SIgMD) has been recently included in the inborn errors of immunity (IEI) classification by the International Union of Immunological Societies Expert Committee. The understanding of SIgMD is still extremely limited, especially so in cases of SIgMD in the pediatric population. The epidemiology of SIgMD in the pediatric population is still unknown. The pathogenesis of SIgMD remains elusive, and thus far no genetic nor molecular basis has been clearly established as a definitive cause of this primary immunodeficiency. Recurrent respiratory infections represent the main clinical manifestations in children, followed by allergic and autoimmune diseases. No conclusive data on the correct therapeutic management of SIgMD are available. Although, for most SIgMD patients, Ig replacement therapy is not required, it may be recommended for patients with significantly associated antibody deficiency and recurrent or severe infections. Prophylactic antibiotics and the prompt treatment of febrile illness are crucial. There is insufficient evidence on the prognosis of this condition. Therefore, further studies are required to define the disease trajectories and to increase our understanding of the molecular mechanisms underlying SIgMD in order to facilitate a better clinical, immunological, and prognostic characterization of the condition and develop tailored therapeutic management strategies.

Neonatal Exposure to Commensal-Bacteria-Derived Antigens Directs Polysaccharide-Specific B-1 B Cell Repertoire Development

B-1 B cells derive from a developmental program distinct from that of conventional B cells, through B cell receptor (BCR)-dependent positive selection of fetally derived precursors. Here, we used direct labeling of B cells reactive with the N-acetyl-D-glucosamine (GlcNAc)-containing Lancefield group A carbohydrate of Streptococcus pyogenes to study the effects of bacterial antigens on the emergent B-1 B cell clonal repertoire. The number, phenotype, and BCR clonotypes of GlcNAc-reactive B-1 B cells were modulated by neonatal exposure to heat-killed S. pyogenes bacteria. GlcNAc-reactive B-1 clonotypes and serum antibodies were reduced in germ-free mice compared with conventionally raised mice. Colonization of germ-free mice with a conventional microbiota promoted GlcNAc-reactive B-1 B cell development and concomitantly elicited clonally related IgA⁺ plasma cells in the small intestine. Thus, exposure to microbial antigens in early life determines the clonality of the mature B-1 B cell repertoire and ensuing antibody responses, with implications for vaccination approaches and schedules.

Glycan Reactive Natural Antibodies and Viral Immunity

Adaptive antibody responses provide a crucial means of host defense against viral infections by mediating the neutralization and killing infectious pathogens. At the forefront of humoral defense against viruses lie a subset of innate-like serum antibodies known as natural antibodies (NAbs). NAbs serve multifaceted functions in host defense and play an essential role in early immune responses against viruses. However, there remain many unanswered questions with regard to both the breadth of viral antigens recognized by NAbs, and how B cell ontology and individual antigenic histories intersect to control the development and function of antiviral human NAbs. In the following article we briefly review the current understanding of the functions and source of NAbs in the immune repertoire, their role during antiviral immune responses, the factors influencing the maturation of the NAb repertoire, and finally, the gaps and future research needed to advance our understanding of innate-like B cell biology for the purpose of harnessing NAbs for host defense against viral infections.

Acute-onset Autoimmune Hepatitis in a Patient with Selective Immunoglobulin M Deficiency

Selective immunoglobulin M deficiency (SIGMD) is an uncommon primary immunodeficiency disorder. We herein report an SIGMD patient with autoimmune hepatitis. A 21-year-old Japanese man was transferred to our hospital because of acute liver dysfunction. His serum IgM level was low, whereas those of IgG and IgA were normal, indicating that he had SIGMD. We diagnosed him with acute-onset autoimmune hepatitis, and his liver function test findings gradually recovered with corticosteroid administration. Although SIGMD with autoimmune diseases has been reported, the clinical features and pathogenesis have not yet been clarified. We have summarized previous reports on SIGMD patients with autoimmune diseases.

Autoimmunity and immunodeficiency at the crossroad: autoimmune disorders as the presenting feature of selective IgM deficiency

Selective immunoglobulin M deficiency (sIgMD) is an immunodeficiency with undefined pathogenesis and commonly presenting with recurrent infections. ¹ The European Society for Immunodeficiencies Registry defines sIgMD as a serum IgM level repeatedly below 2 SD of normal with normal levels of serum IgA, IgG and IgG subclasses, normal vaccination responses, absence of T-cell defects and absence of causative external factors. Rarely it can also be associated with autoimmune diseases. ^2-7 Here we describe a patient with primary sIgMD; who presented with multiple autoimmune diseases without a history of recurrent infections and we provide a short literature review on sIgMD and autoimmune diseases.

Chronic Pulmonary Histoplasmosis Identified in a Young Patient with Selective Immunoglobulin M Deficiency

Chronic histoplasmosis is typically diagnosed in patients who are immunocompromised or severely debilitated and who either live in or who have travelled to endemic areas. We report the case of a young, otherwise immunocompetent male patient who presented to a New York hospital with lobar consolidation and was found to have chronic pulmonary histoplasmosis. He described no history of travel to an endemic area. Immunological workup later revealed selective immunoglobulin M (IgM) deficiency. The literature has suggested a link between IgM deficiency and fungal infections. Recent research has also proposed a link between autoimmunity and IgM deficiency. Our clinical vignette describes the case of a patient with selective IgM deficiency who was diagnosed with pulmonary histoplasmosis without any clinical evidence of autoimmune disease.

Selective IgM Deficiency-An Underestimated Primary Immunodeficiency

Although selective IgM deficiency (SIGMD) was described almost five decades ago, it was largely ignored as a primary immunodeficiency. SIGMD is defined as serum IgM levels below two SD of mean with normal serum IgG and IgA. It appears to be more common than originally realized. SIGMD is observed in both children and adults. Patients with SIGMD may be asymptomatic; however, approximately 80% of patients with SIGMD present with infections with bacteria, viruses, fungi, and protozoa. There is an increased frequency of allergic and autoimmune diseases in SIGMD. A number of B cell subset abnormalities have been reported and impaired specific antibodies to Streptococcus pneumoniae responses are observed in more than 45% of cases. Innate immunity, T cells, T cell subsets, and T cell functions are essentially normal. The pathogenesis of SIGMD remains unclear. Mice selectively deficient in secreted IgM are also unable to control infections from bacterial, viral, and fungal pathogens, and develop autoimmunity. Immunological and clinical similarities and differences between mouse models of deficiency of secreted IgM and humans with SIGMD have been discussed. Patients with SIGMD presenting with recurrent infections and specific antibody deficiency responses appear to improve clinically on immunoglobulin therapy.

The prevalence of Selective Immunoglobulin M Deficiency (SIgMD) in Iranian volunteer blood donors

BACKGROUND

Selective Immunoglobulin M Deficiency (SIgMD) is known as a rare primary immunodeficiency characterized by an isolated deficiency of serum IgM. Other immunoglobulin levels and T-cell immunity are usually normal; although IgE may be elevated. SIgMD can be asymptomatic or with various bacterial and viral infections. It can also be associated with autoimmune diseases or malignancies. In the present study, we report for the first time, the prevalence of SIgMD in Iranian healthy adult population.

MATERIALS AND METHODS

A total of 3436 healthy donors were examined in the study; from August, 2006 to April, 2008. Serum IgM concentration was measured using the nephelometric method. We considered serum IgM less than 30 mg/dl as IgM deficiency.

RESULTS

Among 3436 participants, 65% were male and 34% were female; aging from 17 to 72 years (38.18±10.78). Thirteen individuals were detected as IgM deficient subjects with the male to female ratio of 11/2, the prevalence of 0.37% and the frequency of 1/265. The mean serum IgM level was 24±4.56 (16-29 mg/dl) in these cases. Among 13 IgM-deficient subjects, 7 cases were available for evaluating the clinical manifestations. In addition to atopic dermatitis which was the most common symptom in these patients, others were allergic rhinitis, food allergy, urinary tract infection and skin fungal infection. Two patients had no history of infectious disease or atopic conditions.

CONCLUSION

In the present study we could determine the prevalence of SIgMD in our adult population (0.37%). The most common comorbid condition was atopy. Neither severe or life-threatening infections, nor autoimmune diseases (based on their history; the antibody screening was not performed as part of this study) or malignancies were found in these patients. Further evaluation is recommended to elucidate the prevalence of SIgMD among patients with recurrent infections.

Primary immunodeficiency association with systemic lupus erythematosus: review of literature and lessons learned by the Rheumatology Division of a tertiary university hospital at São Paulo, Brazil

Primary immunodeficiency disorders (PID) represent a heterogeneous group of diseases resulting from inherited defects in the development, maturation and normal function of immune cells; thus, turning individuals susceptible to recurrent infections, allergy, autoimmunity, and malignancies. In this retrospective study, autoimmune diseases (AIDs), in special systemic lupus erythematosus (SLE) which arose associated to the course of PID, are described. Classically, the literature describes three groups of PID associated with SLE: (1) deficiency of Complement pathway components, (2) defects in immunoglobulin synthesis, and (3) chronic granulomatous disease (CGD). Currently, other PID have been described with clinical manifestation of SLE, such as Wiskott-Aldrich syndrome (WAS), autoimmune polyendocrinopathy candidiasis ectodermal dystrophy (APECED), autoimmune lymphoproliferative syndrome (ALPS) and idiopathic CD4(+) lymphocytopenia. Also we present findings from an adult cohort from the outpatient clinic of the Rheumatology Division of Universidade Federal de São Paulo. The PID manifestations found by our study group were considered mild in terms of severity of infections and mortality in early life. Thus, it is possible that some immunodeficiency states are compatible with survival regarding infectious susceptibility; however these states might represent a strong predisposing factor for the development of immune disorders like those observed in SLE.

Atypical X-linked agammaglobulinaemia caused by a novel BTK mutation in a selective immunoglobulin M deficiency patient

Background

X-linked agammaglobulinaemia (XLA) is the most common inherited humoural immunodeficiency disorder. Mutations in the gene coding for Bruton’s tyrosine kinase (BTK) have been identified as the cause of XLA. Most affected patients exhibit a marked reduction of serum immunoglobulins, mature B cells, and an increased susceptibility to recurrent bacterial infections. However, the diagnosis of XLA can be a challenge in certain patients who have near-normal levels of serum immunoglobulin. Furthermore, reports on XLA with renal involvement are scant.

Case presentation

We report an atypical XLA patient who presented with selective immunoglobulin M (IgM) immunodeficiency and nephropathy. He was diagnosed with selective IgM immunodeficiency, based on his normal serum immunoglobulin G (IgG) and immunoglobulin A (IgA) levels but undetectable serum IgM level. Intravenous immunoglobulin was initiated due to increased infections and persistent proteinuria but no improvement in proteinuria was found. A lupus-like nephritis was detected in his kidney biopsy and the proteinuria subsided after receiving a mycophenolate mofetil regimen. Although he had a history of recurrent bacterial infections since childhood, XLA was not diagnosed until B-lymphocyte surface antigen studies and a genetic analysis were conducted.

Conclusions

We suggest that B-lymphocyte surface antigen studies and a BTK mutation analysis should be performed in familial patients with selective IgM deficiency to rule out atypical XLA.

A novel type of selective immunoglobulin m deficiency in a patient with autoimmune liver cirrhosis with recurrent hepatocellular carcinoma: a case report and review of the literature

A 64-year-old female with advanced liver cirrhosis who had never experienced severe infections presented in 2004 with general malaise. At the time, her serum showed low levels of immunoglobulin (Ig) M (11 mg/dl) with high levels of both IgG (2,942 mg/dl) and IgA (808 mg/dl). Because serum levels of IgG and IgA in previous cases of selective IgM deficiency were normal, this case could have a novel immunological mechanism. By 2006, serum IgM was undetectable (<5 mg/dl). Liver biopsy showed liver cirrhosis from autoimmune hepatitis. She had no other autoimmune diseases or hematological malignancies. She developed hepatocellular carcinoma (HCC) several times and died of liver failure. Immunological analyses performed before the first diagnosis of HCC showed polyclonal γ-globulin elevation, normal chromosome and normal gene rearrangement of immunoglobulin heavy chain Cµ. Peripheral blood showed low count B cells with few surface IgM-positive B lymphocytes, but the percentages of T cell subsets were normal. Expression of activation-induced cytidine deaminase (AID), which plays a critical role in immunoglobin class switching, was found to be overexpressed in the HCC tissue and B cells in bone marrow. This phenomenon could account for the clinical and immunological features of this case. In conclusion, we propose a novel type of selective IgM deficiency in association with the overexpression of AID.