Morphologic Spectrum of Lymphadenopathy in Adult-onset Immunodeficiency (Anti-interferon-γ Autoantibodies)

Adult-onset immunodeficiency syndrome (AOIS) caused by anti-interferon-γ autoantibodies is an emerging disease. Affected patients present typically with systemic lymphadenopathy, fatigue, and fever. We studied 36 biopsy specimens, 31 lymph nodes, and 5 extranodal sites, of AOIS confirmed by serum autoantibody or QuantiFERON-TB Gold In-Tube assay. We describe the morphologic features and the results of ancillary studies, including special stains, immunohistochemistry, and molecular testing. The overall median age of these patients was 60.5 years (range, 41 to 83 y) with a male-to-female ratio of 20:16. All biopsy specimens showed nontuberculous mycobacterial infection, and most cases showed the following histologic features: capsular thickening with intranodal sclerosing fibrosis, irregularly distributed ill-formed granulomas or histiocytic aggregates with neutrophilic infiltration, interfollicular expansion by a polymorphic infiltrate with some Hodgkin-like cells that commonly effaces most of the nodal architecture and proliferation of high endothelial venules. In situ hybridization analysis for Epstein-Barr virus-encoded RNA showed scattered (<1%) to relatively more common (4% to 5%) positive cells in 29 of 30 (97%) tested specimens, reflecting immune dysregulation due to an interferon-γ defect. In the 31 lymph node specimens, 23 (74%) cases showed increased immunoglobulin G4-positive plasma cells (4 to 145/HPF; mean, 49.7/HPF) with focal areas of sclerosis reminiscent of immunoglobulin G4-related lymphadenopathy, 4 (13%) cases resembled, in part, nodular sclerosis Hodgkin lymphoma, and 9 (29%) cases mimicked T-cell lymphoma. Among 33 patients with available clinical follow-up, 20 (61%) showed persistent or refractory disease despite antimycobacterial therapy, and 1 patient died of the disease. We conclude that the presence of ill-defined granulomas, clusters of neutrophils adjacent to the histiocytic aggregates, and some Epstein-Barr virus-positive cells are features highly suggestive of AOIS. A high index of clinical suspicion and awareness of the morphologic features and differential diagnosis of AOIS are helpful for establishing the diagnosis.

Lymphadenopathy Associated With Neutralizing Anti-interferon-gamma Autoantibodies Could Have Monoclonal T-cell Proliferation Indistinguishable From Malignant Lymphoma and Treatable by Antibiotics: A Clinicopathologic Study

Early recognition of adult-onset immunodeficiency associated with neutralizing anti-interferon gamma autoantibodies (anti-IFNγ Abs) remains difficult, and misdiagnoses have been reported. Although febrile lymphadenopathy is among the most common initial manifestations of this disorder, no comprehensive clinicopathologic analysis of lymphadenopathy in patients with anti-IFNγ Abs has been reported. Here, we describe 26 lymph node biopsy specimens from 16 patients. All patients exhibited concurrent disseminated nontuberculous mycobacterial infections, and 31% received a tentative diagnosis of lymphoma at initial presentation. We found 3 distinct histomorphologic patterns: well-formed granuloma (46%), suppurative inflammation or loose histiocytic aggregates (31%), and lymphoproliferative disorder (LPD, 23%). The latter shared some of the features of malignant T-cell lymphoma, IgG4-related disease, and multicentric Castleman disease. Half of the specimens with LPD had monoclonal T cells, and 33.3% were indistinguishable from angioimmunoblastic T-cell lymphoma as per current diagnostic criteria. All lymphadenopathy with LPD features regressed with antibiotics without administration of cytotoxic chemotherapy or immunotherapy. The median follow-up time was 4.3 years. Our study highlights the substantial challenge of distinguishing between lymphoma and other benign lymphadenopathy in the setting of neutralizing anti-IFNγ Abs. Increased vigilance and multidisciplinary discussion among clinicians and pathologists are required to achieve the most appropriate diagnosis and management.

Inflammation rapidly recruits mammalian GMP and MDP from bone marrow into regional lymphatics

Innate immune cellular effectors are actively consumed during systemic inflammation, but the systemic traffic and the mechanisms that support their replenishment remain unknown. Here, we demonstrate that acute systemic inflammation induces the emergent activation of a previously unrecognized system of rapid migration of granulocyte-macrophage progenitors and committed macrophage-dendritic progenitors, but not other progenitors or stem cells, from bone marrow (BM) to regional lymphatic capillaries. The progenitor traffic to the systemic lymphatic circulation is mediated by Ccl19/Ccr7 and is NF-κB independent, Traf6/IκB-kinase/SNAP23 activation dependent, and is responsible for the secretion of pre-stored Ccl19 by a subpopulation of CD205+/CD172a+ conventional dendritic cells type 2 and upregulation of BM myeloid progenitor Ccr7 signaling. Mature myeloid Traf6 signaling is anti-inflammatory and necessary for lymph node myeloid cell development. This report unveils the existence and the mechanistic basis of a very early direct traffic of myeloid progenitors from BM to lymphatics during inflammation.

Beclin 2 negatively regulates innate immune signaling and tumor development

Beclin 2 plays a critical role in metabolic regulation and obesity, but its functions in innate immune signaling and cancer development remain largely unknown. Here, we identified Beclin 2 as a critical negative regulator of inflammation and lymphoma development. Mice with homozygous ablation of BCL2-interacting protein 2 (Becn2) developed splenomegaly and lymphadenopathy and markedly increased ERK1/2 and NF-κB signaling for proinflammatory cytokine production. Beclin 2 targeted the key signaling kinases MEKK3 and TAK1 for degradation through an ATG9A-dependent, but ATG16L/Beclin 1/LC3-independent, autophagic pathway. Mechanistically, Beclin 2 recruited MEKK3 or TAK1 through ATG9A to form a complex (Beclin 2-ATG9A-MEKK3) on ATG9A+ vesicles upon ULK1 activation. Beclin 2 further interacted with STX5 and STX6 to promote the fusion of MEKK3- or TAK1-associated ATG9A+ vesicles to phagophores for subsequent degradation. Importantly, Becn2-deficient mice had a markedly increased incidence of lymphoma development, with persistent STAT3 activation. Myeloid-specific ablation of MEKK3 (Map3k3) completely rescued the phenotypes (splenomegaly, higher amounts of proinflammatory cytokines, and cancer incidence) of Becn2-deficient mice. Hence, our findings have identified an important role of Beclin 2 in the negative regulation of innate immune signaling and tumor development through an ATG9A-dependent, but ATG16L/Beclin 1/LC3-independent, autophagic pathway, thus providing a potential target for the treatment of inflammatory diseases and cancer.

Ultrasonography findings in immunoglobulin G4-related lymphadenopathy: a report of two cases

Lymphadenopathy is frequently observed in immunoglobulin G4 (IgG4)-related disease in some cases, and such cases are known as IgG4-related lymphadenopathy. The ultrasonography findings associated with IgG4-related lymphadenopathy have not been described in previous reports. Herein, we describe ultrasonography findings in two cases of IgG4-related lymphadenopathy in conjunction with histopathological findings. Combined ultrasound scanning with Doppler examination accurately represented the specific histopathological features of IgG4-related lymphadenopathy.

Clonality testing in the lymph nodes from dogs with lymphadenomegaly due to Leishmania infantum infection

INTRODUCTION

In southern European countries, multicentric lymphoma and leishmaniosis are the main differential diagnoses in dogs presented with generalized lymphadenomegaly. The cytological examination is in some cases inconclusive and polymerase chain reaction (PCR) for antigen receptor rearrangement (PARR) has become a common method to confirm or rule out a lymphoproliferative neoplasia. According to the literature, leishmaniosis may lead to clonal arrangements and therefore to a false diagnosis of lymphoma, but this assumption is made from a single leishmania infected dog. Therefore, the objective of this study was to prospectively evaluate results from PARR in dogs with lymphadenomegaly due to clinical leishmaniosis at the moment of diagnosis.

MATERIALS AND METHODS

31 dogs with a diagnosis of leishmaniosis based on the LeishVet guidelines were included in the study. Samples from enlarged lymph nodes were taken for cytological examination, clonality testing and Leishmania infantum PCR.

RESULTS

All 31 dogs had medium to high positive antibody titers against Leishmania spp. and 30/31 had a positive Leishmania PCR from the lymph node. A polyclonal arrangement for B cells (immunoglobulin heavy chain gene) and T cells (T-cell receptor gamma chain gene) antigen receptors was found in 28/31 dogs. Two out of 31 dogs showed a monoclonal arrangement for Ig with high (1:2) and low (1:7) polyclonal background respectively; and one of the 31 dogs showed a monoclonal arrangement for T cell receptor with low (1:3) polyclonal background.

CONCLUSION

Infections with Leishmania infantum resulted in clonal rearrangement, and therefore in a possible false diagnosis of lymphoma, in 3 out of 31 dogs (9.7%). Although, PARR is a useful method to differentiate lymphoma from reactive lymphoid hyperplasia in dogs with leishmaniosis, mono-/biclonal results should be interpreted carefully, especially in the presence of any degree of polyclonal background, and together with other clinicopathological findings.

Comparison of IgG4-Related Lymphadenopathy and Multicentric Castleman's Disease: a Retrospective Study

BACKGROUND

It can be difficult to distinguish between IgG4-related lymphadenopathy and multicentric Castleman's disease (MCD) because these conditions cannot be differentially diagnosed using immunohistochemical staining alone. In this study, we analyzed the clinical features of IgG4-related lymphadenopathy and MCD patients.

METHODS

We retrospectively analyzed 27 patients with MCD, including 20 with plasma cell-type (PC-type) and 7 with hyaline vascular (HV) features (mixed-type). An additional 15 patients with IgG4-related lymphadenopathy were enrolled. Clinical data and immune pathological characteristics, including serum interleukin-6 (IL-6) levels, lymph node lesion biopsies, IgG4+/IgG+ expression, and 18F-fluorodeoxyglucose (FDG) positron emission tomography/computed tomography (PET/CT) images, were collected.

RESULTS

The serum levels of C-reactive protein (CRP), IgA, and IL-6 were significantly elevated in the PC/mixedtype group compared with the IgG4-related lymphadenopathy group (p < 0.05). By contrast, the mean age, eosinophilia, globulin, and serum levels of IgG and IgG4 were significantly higher in the IgG4-RD lymphadenopathy group (all p < 0.05). Thirty percent of patients with IgG4-RD lymphadenopathy had elevated IL-6 levels, and 50% with MCD had elevated serum IgG4 levels. Immunohistochemical studies demonstrated the presence of numerous IgG4+ plasma cells, which accounted for > 40% of IgG4/IgG+ cells in 7 of 27 cases in the PC/mixed-type group. We first found that the mean maximum standard uptake value (SUVmax) was strongly associated with albumin and IL-6 in the IgG4-RD lymphadenopathy group, but not in the MCD group. The number of involved organs, but not the standard uptake value (SUV), helped to distinguish between the two diseases. Most PC/mixed-type group patients responded poorly to glucocorticoids when administered alone or in combination with immunosuppressant drugs.

CONCLUSIONS

MCD cannot be differentiated from IgG4-related lymphadenopathy using histology alone. Systematic comparative analysis; clinical and laboratory analyses, especially 18F-FDG-PET/CT; and responses to drug treatment are therefore important parameters for distinguishing between these two diseases.

IgG4-related disease: features and treatment response in a multi-ethnic cohort in Singapore

OBJECTIVES

To describe the features and treatment outcomes of IgG4-RD in multi-ethnic patients in Singapore.

METHODS

Retrospective study was performed on IgG4-RD patients identified from patient databases in a tertiary hospital.

RESULTS

Fourty-two patients (76% male) were included; 79% fulfilled the 2011 comprehensive diagnostic criteria for IgG4-RD for definite IgG4-RD. 81% were Chinese and 19% were Malays. Common initial manifestations included jaundice (52%), abdominal pain (36%) and swollen salivary glands (26%). Only 36% had a history of allergy. 83% had ≥ 1 organ involvement. Erythrocyte sedimentation rate, immunoglobulin E, IgG2 and IgG4 levels were elevated in 84%, 100%, 70% and 44% of patients, respectively. The most common histopathological feature was >10 IgG4+ cells per high power field (66%). 94% (34/36) of patients were treated with moderate to high doses of glucocorticoids, including 17 patients with combination immunosuppressants. Of these, all patients responded to therapy by 3 months. With a median (range) follow-up of 4.1 (0.4-13.8) years, 69% (25/36) needed low dose of glucocorticoids to maintain disease remission. Twenty-six per cent had relapse of disease, of which 82% had disease recurrence in the same organs.

CONCLUSIONS

Pancreatitis, lymphoadenopathy and cholangitis were the commonest manifestations in Asians with IgG4-RD. All patients responded to glucocorticoid therapy by 3 months, two-thirds required maintenance therapy with glucocorticoids, and one-quarter developed relapse of disease.

[CLINICAL AND IMMUNOLOGICAL CRITERIA FOR THE ADVERSE COURSE OF INFECTIOUS MONONUCLEOSIS IN CHILDREN]

The article presents the results of our own studies to determine the criteria for the adverse variants of the course of infectious mononucleosis (IM) in children. The study was conducted in the regional children's infectious clinical hospital in Kharkov. 161 children aged three to fifteen years were under observation with diagnosis of infectious moninucleosis. Out of 161 ill children, 140 (86.9%) had moderate severity of disease, and 21 (13.1%) had severe forms. All children were prescribed standard clinical and laboratory-instrumental examinations. The diagnosis of IM was verified by PCR (detection of VEB DNA in the blood) and ELISA (anti-VEB Ig M and Ig G). In 140 children (86.9%) IM proceeded sharply, smoothly (the first group), in 21 (13.1%) - unfavorably (wave and / or prolonged course) - the second group. The groups were comparable according to age, the severity of the disease and other parameters. All children received therapy according to approved protocols (Order of the Ministry of Health of Ukraine No. 354 of 09.07.2004). Immune status of children was assessed by determining the relative contents of CD3 +, CD4 +, CD8 +, CD16 +, CD19 + blood cells with appropriate monoclonal antibodies, serum IgA, IgM, IgG concentration by Mancini and interleukin (IL) -1β cytokine response and - 4, tumor necrosis factor (TNF α) is a solid-phase enzyme-linked immunosorbent assay. Based on the results of observations, it was established that the prognostically unfavorable criteria of IМ at the stages of manifestation of disease include: generalized lymphadenopathy involving 5-6 groups of lymph nodes and a significant increasing of them, purulent tonsillitis, marked increasing of size of liver and spleen on the background of anemia, thrombocytopenia, neutropenia and the absence of atypical mononuclears in the complete blood count. There is a depression of the cellular link and an increase in the humoral mechanisms of immune responses in case of development of adverse course of IM.

Disseminated Mycobacterium genavense Infection in Patient with Adult-Onset Immunodeficiency

We report a case of disseminated Mycobacterium genavense infection resulting from neutralizing anti–interferon-γ autoantibodies in the patient. We identified M. genavense targeting the hsp65 gene in an aspiration specimen of the lymph node. Adult-onset immunodeficiency caused by neutralizing anti–interferon-γ autoantibodies, in addition to HIV infection, can lead to disseminated nontuberculous mycobacterial infection.

[Remission of the disease associated/related with immunoglobulin IgG4 accompanied by multiple lymphadenopathy after treatment with rituximab and dexamethasone: a case report]

A disease associated with immunoglobulin IgG4 is a rare unit with very variable symptoms. We describe the course and treatment of the disease in a patient who presented with multiple lymphadenopathy and infiltrates in the area of the retroperitoneum and pelvis and signs of chronic sclerosing pancreatitis. The disease was clinically manifested by a significant loss of weight, but also by a loss of perception of taste and smell. The diagnosis was made based on a high amount of IgG4 expressing plasma cells in the sampled tissue and an increased concentration of immunoglobulins of type IgG and mainly subclass IG4. Rituximab in 475 mg/m2 dose was used in the treatment, the initial four doses of rituximab were administered at 14-day intervals, always with a one-off administration of a 40 mg dose of dexamethasone. According to FDG-PET/CT, only partial remission of the disease was reached after 4 applications of rituximab and dexamethasone. The patient recovered its sense of smell and taste. In another 4 cycles ritu-ximab was administered on day 1 of a 28-day cycle. On days 1 and 15 of the cycle dexamethasone at 40 mg and cyclophosphamide at 600 mg were administered by intravenous infusion. After the completion of 8 cycles of treatment based on rituximab and dexamethasone and with cyclophosphamide added in the second half of the treatment, the control FDG-PET/CT examination proved the complete remission. Before the treatment commencement the concentration of the subclass of immunoglobulin IgG4 was equal to 51.0 g/l, after the completion of the aforementioned treatment it dropped to 3.5 g/l. The patient tolerated the treatment without any adverse effects. Ritu-ximab, dexamethasone and cyclophosphamide induced the complete remission of this disease.Key words: IgG4-associated/releated disease - rituximab.

Clinical characterization of 52 patients with immunoglobulin G4-related disease in a single tertiary center in Japan: Special reference to lung disease in thoracic high-resolution computed tomography

BACKGROUND

Immunoglobulin G4-related disease (IgG4-RD) is a rare multi-organ disorder. Physicians rarely encounter patients with IgG4-RD and its range of symptoms.

METHODS

To elucidate the clinical characterization of IgG4-RD, along with the clinical significance of lung involvement, we retrospectively reviewed the medical records of patients who satisfied the comprehensive diagnostic criteria for IgG4-RD.

RESULTS

We identified 52 patients with IgG4-RD. Of these, 32 patients underwent tissue biopsies, resulting in categorization as definite (n = 23) or possible (n = 9) IgG4-RD cases. Among the 23 definite IgG4-RD cases, those with positive lung involvement (n = 8) had significantly higher values of serum LDH (median 220 IU/L, interquartile range (IQR) 175-378 vs. median 184, IQR 136-249, p = 0.039), IgG (median 2769 mg/dL, IQR 2028-7807 vs. median 2048, IQR 1168-4376, p = 0.009), and soluble interleukin-2 receptors (median 1620 U/mL, IQR 871-2250 vs. median 733, IQR 271-1600, p = 0.003) than those with negative lung involvement (n = 15). Similarly, a significant number of patients with positive lung involvement were positive for rheumatoid factor (71.4% vs. 23.1%, p = 0.041) or hypocomplementemia (50% vs. 0%, p = 0.036). Sixteen patients also showed lung involvement (definite n = 8, possible n = 8); thoracic computed tomography (CT) of these patients revealed mediastinal lymphadenopathies (n = 14, 87.5%), ground glass opacity (n = 11, 68.8%), consolidation (n = 8, 50%), thickening of the bronchovascular bundles (n = 7, 43.8%), small nodules (n = 5, 31.3%), bronchiectasis (n = 4, 25%), and reticular shadows (n = 4, 25%), and pulmonary function tests, using a standard technique involving a single breath, revealed decreased diffusion capacity for carbon monoxide.

CONCLUSIONS

IgG4-RD is associated with diverse thoracic CT findings and a decreased diffusion capacity, and careful multidisciplinary assessment is needed to enable differentiation of IgG4-RD from lymphoproliferative disorders.

Anti-interferon-γ autoantibody-associated disseminated Mycobacterium abscessus infection mimicking parotid cancer with multiple metastases: A case report

RATIONALE

Among the nontuberculous mycobacteria, Mycobacterium abscessus is a common cause of skin, soft tissue, and bone infections. However, disseminated M. abscessus infection that mimics cancer metastasis with an underlying relatively immunocompetent condition has rarely been reported.

PATIENT CONCERNS

A nonsmoking 73-year-old man with an underlying relatively immunocompetent condition reported a 2-month history of a mass in the region of his right parotid gland that had been steadily increasing in size.

DIAGNOSES

The head and neck computed tomography showed an avidly enhancing tumor with central necrosis in the right parotid region and lymphadenopathy bilaterally at neck levels II-V (<6 cm) with a necrotic core. The radiologist and otolaryngologist both suspected a diagnosis of right parotid gland cancer with metastasis.

INTERVENTIONS

The necrotic tissue was removed surgically, and Mycobacterium culture showed M. abscessus. We collected a blood sample and detected anti-interferon-γ autoantibody.

OUTCOMES

After 6 months of anti-M. abscessus treatment, physical examination showed remission of the parotid tumor, and axillary and supraclavicular lymphadenopathy.

LESSONS

We report a case of disseminated M. abscessus infection, which involved parotid glands with multiple lymphadenopathies in a person with an underlying relatively immunocompetent condition. Possible underlying mechanisms such as anti-interferon-γ autoantibody-associated immunodeficiency should be considered in a patient with disseminated M. abscessus infection without a known immunocompromised condition.

IgG4-related disease: a disease we probably often overlook

IgG4-related disease (IgG4-RD) is an increasingly recognised entity characterised by tumefied lesions that can affect multiple organs. Awareness of IgG4-RD is important, as it has been shown to mimic other diseases and may result in irreversible organ damage if not treated. If suspected, immunostaining for IgG4-positive plasma cells is essential for diagnosis and revision of old biopsies may be necessary.