Granulomatous inflammation: The overlap of immune deficiency and inflammation

ANCA-Negative Granulomatosis of Polyngiitis of Paranasal Sinuses with Cerebellar Involvement

Granulomatosis of polyangiitis (GPA) is a multisystem necrotizing vasculitis, which affects small- and medium-sized blood vessels and characterized by frequent involvement of the upper and lower respiratory tract and kidneys. Altough anti-neutrophil cytoplasmic antibodies (ANCA) are higly associated with GPA and play an important role in the pathogenesis of this disease, ANCA positivity is not essential for clinical diagnosis. We describe a patient with ANCA-negative granulamatosis of polyangiitis involving cerebellum, having complaints due to sinusitis.

A Chinese girl of Blau syndrome with renal arteritis and a literature review

BACKGROUND

Blau syndrome is a rare autoinflammatory disease caused by autosomal dominant mutations in the CARD15/NOD2 gene. Vascular involvement is a rare phenotype in Blau syndrome patients. In this study, we aimed to describe a 20-year- old Chinese girl with Blau syndrome complicated by renal arteritis. In addition, we summarized a literature review of published cases of vascular involvement in patients with Blau syndrome.

CASE PRESENTATION

We describe a 20-year-old girl who was initially misdiagnosed with juvenile idiopathic arthritis (JIA) almost 15 years prior. In October 2019, she developed renal arteritis at the age of 17 years and was eventually diagnosed with Blau syndrome. A de-novo M513T mutation was found in her gene testing. A review of the literature on patients with Blau syndrome and vasculitis showed that a total of 18 cases were reported in the past 40 years. The vast majority of them were predominantly involved medium and large vessel arteritis. Of the 18 patients included in our literature review, 14 patients had aorto-arteritis, and 4 of them had renal artery involvement. Two patients presented with renal artery stenosis, 1with a sinus of Valsalva aneurysm, and 1 with retinal vasculitis.

CONCLUSION

A detailed medical history inquiry and a careful physical examination are helpful for the early identification of Blau syndrome, especially for infant onset refractory JIA. Medium-and large-vessel arteritis is a rare clinical manifestation in Blau syndrome patients. Careful examination of the peripheral pulse and measurement of blood pressure at every regular visit may be helpful in the early identification of Blau syndrome-arteritis. Early diagnosis and appropriate treatment may prevent or delay the occurrence of severe symptoms in patients to improve the patient's quality of life.

High Inborn Errors of Immunity Risk in Patients with Granuloma

OBJECTIVE

Granuloma etiology includes infections, vasculitis, chemicals, malignancies, lymphoproliferative disorders, and immunological diseases. We hypothesized that patients with granuloma have an underlying primary immunodeficiency disease (PIDD).

PATIENTS AND METHODS

We retrospectively enrolled 82 patients with immunological evaluation among 294 biopsy-proven granuloma patients (0- to 20-year-old). At the same time frame, we followed up with 1910 patients in the same age group.

RESULTS

Out of 82 patients, male/female ratio was 45/37. Median age at symptom onset was 5 years (28 days-17.4 years), age of granuloma at diagnosis was 8.6 years (36 days-19.4 years). Common symptoms at disease onset were fever (23.2%), lymphadenopathy (19.6%), abdominal pain (12.2%), and cough (12.2%). Granuloma was frequent in lymph nodes (26.8%), skin (19.5%), lung (13.4%), and bone (11%). Common infectious agents isolated were Mycobacterium spp. (23.2%) and EBV (4.9%). We document PIDD in 76.8% (63/82) of patients. 49.4% (40/81) of immunologically evaluated granuloma patients had hypogammaglobulinemia. Granuloma rate in pediatric PIDD was 3.3%(63/1910). Patients with multiple granulomas (n = 16) had a PIDD diagnosis. Lung involvement was three times more in PIDD. Brain involvement was only seen in PIDD. Fibroadipose tissue and liver involvement were more frequent in patients without documented PIDD and patients whose evaluation was not completed. The mortality rate in PIDD with granuloma was 15.9%, whereas there was no mortality in patients without PIDD.

CONCLUSION

As documented here, even in a university hospital, the immunologic evaluation ratio is about one-third. We showed high PIDD frequency in children with granuloma, and higher mortality in PIDD with granuloma. Thus, an immunologic evaluation performed meticulously by immunologists is a must for accurate diagnosis and decision of individualized therapeutic options.

Multinucleated Giant Cells: Current Insights in Phenotype, Biological Activities, and Mechanism of Formation

Monocytes and macrophages are innate immune cells with diverse functions ranging from phagocytosis of microorganisms to forming a bridge with the adaptive immune system. A lesser-known attribute of macrophages is their ability to fuse with each other to form multinucleated giant cells. Based on their morphology and functional characteristics, there are in general three types of multinucleated giant cells including osteoclasts, foreign body giant cells and Langhans giant cells. Osteoclasts are bone resorbing cells and under physiological conditions they participate in bone remodeling. However, under pathological conditions such as rheumatoid arthritis and osteoporosis, osteoclasts are responsible for bone destruction and bone loss. Foreign body giant cells and Langhans giant cells appear only under pathological conditions. While foreign body giant cells are found in immune reactions against foreign material, including implants, Langhans giant cells are associated with granulomas in infectious and non-infectious diseases. The functionality and fusion mechanism of osteoclasts are being elucidated, however, our knowledge on the functions of foreign body giant cells and Langhans giant cells is limited. In this review, we describe and compare the phenotypic aspects, biological and functional activities of the three types of multinucleated giant cells. Furthermore, we provide an overview of the multinucleation process and highlight key molecules in the different phases of macrophage fusion.

Sarcoidosis presenting as bilateral lacrimal gland swelling: a pediatric case report

BACKGROUND

To describe a case of pediatric sarcoidosis which initially presented as papillary conjunctivitis before manifesting as bilateral lacrimal gland swelling without other known systemic involvement.

CASE PRESENTATION

A 10-year-old female presented to the pediatric ophthalmology clinic with complaints of bilateral eyelid swelling, tearing and itching for approximately 1 month. Her history and exam were most consistent with allergic conjunctivitis, for which she was started on a standard topical regimen. Despite initial improvement, she re-presented with significantly worsened eyelid swelling and minimal allergic symptoms. Enlargement of the lacrimal glands were palpable at this time. Lacrimal gland biopsy was obtained which demonstrated noncaseating granulomas. Systemic workup did not reveal evidence of disease involvement elsewhere.

CONCLUSIONS

Sarcoidosis in the pediatric population may present in a myriad of ways and is well-known to mimic other disease entities. We present a case of pediatric sarcoidosis which presented initially as papillary conjunctivitis before manifesting as bilateral lacrimal gland swelling without systemic involvement.

A Novel Pathogenic NOD2 Variant in a Mother and Daughter with Blau Syndrome

BACKGROUND

Blau syndrome (BS) is a rare dominantly-inherited autoinflammatory disorder characterized by the triad of arthritis, uveitis and dermatitis that is consequence of gain-of-function NOD2 mutations. We describe the clinical features and genetic basis of a family with two affected members in consecutive generations affected with childhood onset arthritis and uveitis.

MATERIALS AND METHODS

Clinical features were retrospectively collected from clinical records. Genetic studies were performed using the Sanger method of DNA sequencing.

RESULTS

The proband is a 44 years-old female, who was diagnosed with juvenile onset arthritis at the age of 9 years. She subsequently developed uveitis at age 12 and since then she was managed between the uveitis and rheumatology services. The proband's daughter developed episcleritis at the age of 7 years, and arthritis with bilateral intermediate uveitis two years later. NOD2 analyses revealed in both patients the heterozygous c.1494A>C transversion, predicted to lead the novel, missense p.E498D variant in the NOD2 protein. Additional studies including databases searches and in silico bioinformatic predictions strongly support the "likely pathogenic" classification for this novel variant.

CONCLUSIONS

We report a novel pathogenic NOD2 variant in a multiplex family with clinical features compatible with the BS diagnosis. This condition is inherited as a dominant trait in its familial form and should be considered in patients with granulomatous uveitis in association with arthritis and/or dermatitis. Further insight into NOD2 variants and their downstream effects may have implications in the treatment of BS and other inflammatory granulomatous diseases.

Characterization of macrophages, giant cells and granulomas during muscle regeneration after irradiation

Macrophages play a fundamental role in the different stages of muscle regeneration although the precise mechanisms involved are not entirely understood. Here we investigated the types of macrophages and cytokines that appeared in muscles after local gamma irradiation of mini-pigs that underwent no subsequent treatment or received three successive adipose tissue-derived stem cell (ASC) injections. Although some variability was observed among the three animals included in each study group, a general picture emerged. No macrophages appeared in control muscles from regions that had not been irradiated nor in muscles from irradiated regions derived from two animals. A third irradiated, but untreated animal, with characteristic muscle fibrosis and necrosis due to irradiation, showed invasion of M2 macrophages within small muscle lesions. In contrast, among the three ASC-treated and irradiated animals, one of them had completely recovered normal muscle architecture at the time of sampling with no invading macrophages, muscle from a second one contained mostly M1 macrophages and some M2-like macrophages whereas muscle from a third one displayed granulomas and giant cells. ASC treatment was associated with the presence of similar levels of pro-inflammatory cytokines within the two animals in the process of muscle regeneration whereas the levels of IL-4 and IL-10 expression were distinct from one animal to another. Microspectrofluorimetry and in situ hybridization revealed strong expression of TGF-β1 and TNFα in regenerating muscle. Overall, the data confirm the critical role of macrophages in muscle regeneration and suggest the involvement of a complex network of cytokine expression for successful recovery.

Blau syndrome: a rare cause of exuberant granulomatous synovitis of the knee

Blau syndrome (BS) is a rare autosomal dominant familial granulomatous inflammatory disease presenting in early childhood with dermatitis, arthritis and uveitis. Early-onset sarcoidosis represents the sporadic form, and both are characterised by mutations in the CARD15/NOD2 gene on chromosome 16. We describe a 38-year-old man with known BS who presented for orthopaedic review following right-sided patellar dislocation. MRI of the injured knee demonstrated diffuse synovitis and prominent fatty tissue resembling lipoma arborescens with evidence of recent patellar dislocation. Synovectomy was performed and confirmed granulomatous synovitis. Knee imaging findings are described for the first time. Combining distinct morphological bone changes with synovitis which resembles lipoma arborescens and histology which includes sarcoidal-type granulomatous synovitis should lead the radiologist and pathologist to consider the diagnosis of BS.

Causes of AA amyloidosis: a systematic review

From a clinical perspective, there is a need for a reliable and comprehensive list of diseases causing AA amyloidosis. This list could guide clinicians in the evaluation of patients with AA amyloidosis in whom an obvious cause is lacking. In this systematic review, a PubMed, Embase and Web of Science literature search were performed on causes of AA amyloidosis published in the last four decades. Initially, 4066 unique titles were identified, but only 795 full-text articles and letters were finally selected for analysis. Titles were excluded because of non-AA type of amyloidosis, language, no full-text publication or irrelevance. Hundred and fifty diseases were initially reported to be associated with the development of AA amyloidosis. The presence of AA amyloid was proven in 208 articles (26% of all) of which 140 (67%) showed a strong association with an underlying disease process. Disease associations were categorized and 48 were listed as strong, 19 as weak, 23 as unclear, and 60 as unlikely. Most newly described diseases are not really unexpected because they often cause longstanding inflammation. Based on the spectrum of identified causes, a pragmatic diagnostic approach is proposed for the AA amyloidosis patient in whom an obvious underlying disease is lacking.

Common variable immunodeficiency presenting as sarcoidosis in a 9-year-old child

BACKGROUND

Granulomatous diseases are a heterogeneous group of conditions characterized by an inflammatory infiltrate with a core of macrophages, epithelioid, giant cells and a corona of fibroblasts and lymphocytes. They are associated with a wide range of disorders such as mycobacterial and fungal infections, neoplasms, immunodeficiencies and systemic inflammatory disorders as sarcoidosis.

CASE REPORT

We report the case of a previously healthy 9-year-old male child who presented with persistent cough, diffuse lymphadenopathy, enlargement of liver and spleen and protracted fever. Anemia, lymphopenia and reduced platelet count was reported, with an increase of inflammatory markers. High levels of Angiotensin-converting enzyme and chitotriosidases were noted. A PET-CT scan showed increased uptake of ¹⁸ F-FDG glucose in multiple lymph nodes in thorax and abdomen and in the spleen. Biopsy of inguinal and bronchial nodes showed nodal granulomatous inflammation. The child was diagnosed with sarcoidosis and treated with corticosteroids with only transient efficacy. Further tests reported panhypogammaglobulinaemia and a reduced pool of B-memory lymphocytes. Thus, the diagnosis was revised to common variable immunodeficiency (CVID).

CONCLUSION

Common variable immunodeficiency is a heterogeneous condition with a highly variable clinical phenotype and a strong association with autoimmune disorders. The presence of noncaseating granuloma and pulmonary lesions, along with extrapulmonary features required a step by step approach to differentiate between CVID and sarcoidosis. This enables early introduction of immunoglobulin replacement therapy and decreases the morbidity and mortality of CVID.

Prevalence of Granulomas in Patients With Primary Immunodeficiency Disorders, United States: Data From National Health Care Claims and the US Immunodeficiency Network Registry

PURPOSE

Granulomas are a potentially severe condition that can last for several years in persons with primary immunodeficiency disorders (PIDD). We assessed the prevalence of granulomas in patients with PIDD.

METHODS

We used the Truven Health MarketScan® 2005-2015 Commercial Claims and Encounters and 2006-2015 Medicaid databases and the US Immunodeficiency Network (USIDNET) PIDD registry (a program of the Immune Deficiency Foundation). Our study population consisted of persons age < 65 years with PIDD, defined as persons with ≥ 2 claims with a diagnostic code for PIDD in MarketScan databases, or patients enrolled in USIDNET. Granulomas were identified using diagnostic codes in MarketScan or provider report in USIDNET. We calculated annual prevalence of PIDD and of granulomas among PIDD patients.

RESULTS

We identified 247,474 and 40,395 persons with PIDD among commercially and Medicaid-insured persons, respectively. PIDD prevalence was 6.0/10,000 in 2005 and 11.7/10,000 in 2015 among commercially insured persons and 5.5/10,000 in 2006 and 9.6/10,000 in 2015 among Medicaid-insured persons. The prevalence of granulomas among PIDD patients was 1.2 and 1.5% among commercially and Medicaid-insured persons, respectively. In USIDNET, prevalence of granulomas was 4.4% (177/4021). The proportion with granulomas was similar across age groups in MarketScan, but varied from 2 to 9% in USIDNET. The reported prevalence of granulomas differed depending on PIDD condition: 1-2% in the MarketScan data and 0-13% in USIDNET.

CONCLUSION

Granuloma prevalence in PIDD patients was 1-4%. Our study provides an estimate of the proportion of PIDD patients and suggests that granulomas are an uncommon occurrence among patients with PIDD.

A Role for CD154, the CD40 Ligand, in Granulomatous Inflammation

Granulomatous inflammation is a distinctive form of chronic inflammation in which predominant cells include macrophages, epithelioid cells, and multinucleated giant cells. Mechanisms regulating granulomatous inflammation remain ill-understood. CD154, the ligand of CD40, is a key mediator of inflammation. CD154 confers a proinflammatory phenotype to macrophages and controls several macrophagic functions. Here, we studied the contribution of CD154 in a mouse model of toxic liver injury with carbon tetrachloride and a model of absorbable suture graft. In both models, granulomas are triggered in response to endogenous persistent liver calcified necrotic lesions or by grafted sutures. CD154-deficient mice showed delayed clearance of carbon tetrachloride-induced liver calcified necrotic lesions and impaired progression of suture-induced granuloma. In vitro, CD154 stimulated phagocytosis of opsonized erythrocytes by macrophages, suggesting a potential mechanism for the altered granulomatous inflammation in CD154KO mice. These results suggest that CD154 may contribute to the natural history of granulomatous inflammation.

Pro-inflammatory and anti-inflammatory T cells in giant cell arteritis

Giant cell arteritis is an autoimmune disease defined by explicit tissue tropism to the walls of medium and large arteries. Pathognomic inflammatory lesions are granulomatous in nature, emphasizing the functional role of CD4T cells and macrophages. Evidence for a pathogenic role of antibodies and immune complexes is missing. Analysis of T cell populations in giant cell arteritis, both in the tissue lesions and in the circulation, has supported a model of broad, polyclonal T cell activation, involving an array of functional T cell lineages. The signature of T cell cytokines produced by vasculitic lesions is typically multifunctional, including IL-2, IFN-γ, IL-17, IL-21, and GM-CSF, supportive for a general defect in T cell regulation. Recent data describing the lack of a lymph node-based population of anti-inflammatory T cells in giant cell arteritis patients offers a fresh look at the immunopathology of this vasculitis. Due to defective CD8+NOX2+ regulatory T cells, giant cell arteritis patients appear unable to curtail clonal expansion within the CD4T cell compartment, resulting in widespread CD4T cell hyperimmunity. Why unopposed expansion of committed CD4 effector T cells would lead to invasion of the walls of medium and large arteries needs to be explored in further investigations.

Atypical presentation and manifestations in X-linked agammaglobulinemia patients with novel BTK mutations

X-linked agammaglobulinemia (XLA) is a rare immunodeficiency caused by defects in the Bruton tyrosine kinase (BTK) gene, characterized by impaired B-cell development, reduced immunoglobulin production, and increased susceptibility to bacterial infections at an early age. Some XLA patients show atypical presentations, with most reports concentrating on the diagnosis at a relatively old age. They presented with infections at late age or with unusual pathogens; however, other atypical manifestations have only rarely been reported.

Methods: Description of patients with XLA and novel mutations in BTK who presented with atypical manifestations or developed noninfectious complications.

Results: Four patients presented unique manifestations unusual for XLA. The first with Granulomatous Dermatitis, the second with acute demyelinating encephalomyelitis, the third with “Crohn's disease like” localized protein-losing enteropathy, and the last patient with idiopathic thrombocytopenic purpura, which is an unexpected finding in a patient devoid of endogenous immunoglobulins. Mutations in BTK were found in all domains of the gene; 1 resulted in a stop codon and 3 were missense mutations.

Conclusions: Early recognition of atypical presentations and manifestations of patients with XLA is crucial for timely initiation of life-saving therapy, which may include anti-bacterial and anti-inflammatory treatments in addition to immunoglobulin.

Statement of novelty: In this study we present unique inflammatory and autoimmune phenomenons in XLA patients that were not described previously and are somewhat unexpected. These should alert the immunologist for the possibility of XLA diagnosis.

Granulomatous and lymphocytic interstitial lung disease: a spectrum of pulmonary histopathologic lesions in common variable immunodeficiency--histologic and immunohistochemical analyses of 16 cases

Common variable immunodeficiency is a primary immunodeficiency of unknown etiology characterized by low serum immunoglobulin G, a decreased ability to make specific antibodies, and variable T-cell defects. Approximately 10-30% of patients with common variable immunodeficiency develop clinical evidence of a diffuse parenchymal lung disease with a constellation of histopathologic findings termed granulomatous and lymphocytic interstitial lung disease. In this study, we characterized the histologic and immunohistochemical features in a series of 16 cases diagnosed by open lung biopsy. Peribronchiolar and interstitial lymphocytic infiltration, granulomatous inflammation, and organizing pneumonia were consistent features; interstitial fibrosis with architectural remodeling was also found in a subgroup of patients. By immunohistochemistry, a predominance of CD4+ T lymphocytes with variable numbers of CD8+ T cells and B cells was present, with a striking absence of FOXP3-positive T-regulatory cells. This heretofore unrecognized immunohistochemical finding needs further investigation for a potential role in the pathogenesis of the condition. The presence of interstitial fibrosis with or without architectural remodeling in a subset of patients also needs additional study, for effect on prognosis.

Identification of patients with RAG mutations previously diagnosed with common variable immunodeficiency disorders

PURPOSE

Combined immunodeficiency (CID) presents a unique challenge to clinicians. Two patients presented with the prior clinical diagnosis of common variable immunodeficiency (CVID) disorder marked by an early age of presentation, opportunistic infections, and persistent lymphopenia. Due to the presence of atypical clinical features, next generation sequencing was applied documenting RAG deficiency in both patients.

METHODS

Two different genetic analysis techniques were applied in these patients including whole exome sequencing in one patient and the use of a gene panel designed to target genes known to cause primary immunodeficiency disorders (PIDD) in a second patient. Sanger dideoxy sequencing was used to confirm RAG1 mutations in both patients.

RESULTS

Two young adults with a history of recurrent bacterial sinopulmonary infections, viral infections, and autoimmune disease as well as progressive hypogammaglobulinemia, abnormal antibody responses, lymphopenia and a prior diagnosis of CVID disorder were evaluated. Compound heterozygous mutations in RAG1 (1) c256_257delAA, p86VfsX32 and (2) c1835A>G, pH612R were documented in one patient. Compound heterozygous mutations in RAG1 (1) c.1566G>T, p.W522C and (2) c.2689C>T, p. R897X) were documented in a second patient post-mortem following a fatal opportunistic infection.

CONCLUSION

Astute clinical judgment in the evaluation of patients with PIDD is necessary. Atypical clinical findings such as early onset, granulomatous disease, or opportunistic infections should support the consideration of atypical forms of late onset CID secondary to RAG deficiency. Next generation sequencing approaches provide powerful tools in the investigation of these patients and may expedite definitive treatments.

Immunity to Cryptococcus neoformans and C. gattii during cryptococcosis

The vast majority of infection with cryptococcal species occurs with Cryptococcus neoformans in the severely immunocompromised. A significant exception to this is the infections of those with apparently normal immune systems by Cryptococcus gattii. Susceptibility to cryptococcosis can be broadly categorised as a defect in adaptive immune responses, especially in T cell immunity. However, innate immune cells such as macrophages play a key role and are likely the primary effector cell in the killing and ultimate clearance of cryptococcal infection. In this review we discuss the current state of our understanding of how the immune system responds to cryptococcal infection in health and disease, with reference to the work communicated at the 9th International Conference on Cryptococcus and Cryptococcosis (ICCC9). We have focussed on cell mediated responses, particularly early in infection, but with the aim of presenting a broad overview of our understanding of immunity to cryptococcal infection, highlighting some recent advances and offering some perspectives on future directions.