Hypersensitivity to mosquito bites: A versatile Epstein-Barr virus disease with allergy, inflammation, and malignancy.

Hypersensitivity to mosquito bites (HMB) is a rare disease characterized by transient intense skin reaction and systemic inflammation. Clinical presentation of HMB resembles other mosquito allergic responses, and it can also be difficult to clinically distinguish HMB from other severe allergic reactions. However, a distinctive pathophysiology underlies HMB. HMB belongs to a category of Epstein-Barr virus (EBV)-associated natural killer (NK) cell lymphoproliferative disorders (LPD). Hence, HMB may progress to systemic diseases, such as hemophagocytic lymphohistiocytosis, chronic active EBV disease, and EBV-associated malignancies. A triad of elevated serum IgE, NK lymphocytosis, and detection of EBV DNA in peripheral blood is commonly observed, and identification of EBV-infected NK cells usually facilitates the diagnosis. However, the effective treatment is limited, and its precise etiology remains unknown. Local CD4+ T cell proliferation triggered by mosquito bites appears to help induce EBV reactivation and EBV-infected NK-cell proliferation. These immunological interactions may explain the transient HMB signs and symptoms and the disease progression toward malignant LPD. Further research to elucidate the mechanism of HMB is warranted for better diagnosis and treatment of HMB and other forms of EBV-associated LPD.

Hypopigmented Interface T-Cell Dyscrasia and Hypopigmented Mycosis Fungoides: A Comparative Study.

Hypopigmented interface T-cell dyscrasia (HITCD) is a distinct form of lymphoid dyscrasia that may progress to hypopigmented mycosis fungoides (HMF). We compared both diseases as regards their CD4/CD8 phenotype and expression of granzyme B and tumor necrosis factor-alpha (TNF-α) and how these are affected by narrow-band UVB (nb-UVB). The study included 11 patients with HITCD and 9 patients with HMF. They received nb-UVB thrice weekly until complete repigmentation or a maximum of 48 sessions. Pretreatment and posttreatment biopsies were stained using anti CD4, CD8, TNF-α, and granzyme B monoclonal antibodies. Epidermal lymphocytes were CD8 predominant in 54.5% and 66.7% of HITCD and HMF cases, respectively, whereas dermal lymphocytes were CD4 predominant in 63.6% and 66.7%, respectively. Significantly, more dermal infiltrate was encountered in HMF (P = 0.041). In both diseases, granzyme B was only expressed in the dermis, whereas TNF-α was expressed both in the epidermis and dermis. No difference existed as regards the number of sessions needed to achieve repigmentation or cumulative nb-UVB dose reached at end of study. (P > 0.05). Narrow-band UVB significantly reduced only the epidermal lymphocytes in both diseases (P ≤ 0.05) with their complete disappearance in 8 (72.7%) HITCD and 6 (66.7%) HMF cases. In both diseases, nb-UVB did not affect granzyme B or TNF-α expression (P > 0.05). In conclusion, both diseases share the same phenotype, with HITCD being a milder form of T-cell dysfunction. In both diseases, epidermal lymphocytes are mainly CD8-exhausted cells lacking cytotoxicity, whereas dermal cells are mostly reactive cells exerting antitumor cytotoxicity. Tumor necrosis factor-alpha mediates hypopigmentation in both diseases and prevents disease progression. Repigmentation after nb-UVB in both diseases occurs before and independently from disappearance of the dermal infiltrate.

Altered lymphopoiesis and immunodeficiency in miR-142 null mice.

MicroRNAs (miRNAs) are a class of powerful posttranscriptional regulators implicated in the control of diverse biological processes, including regulation of hematopoiesis and the immune response. To define the biological functions of miR-142, which is preferentially and abundantly expressed in immune cells, we created a mouse line with a targeted deletion of this gene. Our analysis of miR-142(-/-) mice revealed a critical role for this miRNA in the development and homeostasis of lymphocytes. Marginal zone B cells expand in the knockout spleen, whereas the number of T and B1 B cells in the periphery is reduced. Abnormal development of hematopoietic lineages in miR-142(-/-) animals is accompanied by a profound immunodeficiency, manifested by hypoimmunoglobulinemia and failure to mount a productive immune response to soluble antigens and virus. miR-142(-/-) B cells express elevated levels of B-cell-activating factor (BAFF) receptor (BAFF-R) and as a result proliferate more robustly in response to BAFF stimulation. Lowering the BAFF-R gene dose in miR-142(-/-) mice rescues the B-cell expansion defect, suggesting that BAFF-R is a bona fide miR-142 target through which it controls B-cell homeostasis. Collectively, our results uncover miR-142 as an essential regulator of lymphopoiesis, and suggest that lesions in this miRNA gene may lead to primary immunodeficiency.

[Light-chain deposition disease is a hematologic problem]. / Bolezn' depozitov legkikh tsepei ­ gematologicheskaia problema.

AIM: To analyze clinical and laboratory data and treatment results in patients with light-chain deposition disease (LCDD). SUBJECTS AND METHODS: Nine patients with LCDD and kidney injury were examined. The diagnosis was based on the results of light and immunofluorescence microscopy of renal biopsy specimens. All the patients received bortezomib, cyclophosphamide, and dexamethasone (VCD) induction therapy. RESULTS: Six patients were diagnosed with multiple myeloma; in 3 patients LCDD was considered within monoclonal gammopathy manly involving the kidney. By the initiation of therapy, all the patients were diagnosed as having chronic kidney disease (Stage III (n=2), Stage IV (n=2), and dialysis-related renal failure (n=5)). After the VCD treatment, 7 of 9 patients achieved a hematologic response. Second-line therapy with lenalidomide proved to be effective in the other 2 cases. Five patients achieved complete remission; 3 had a very good partial remission. Thereafter, 2 patients received high-dose melphalan chemotherapy and autologous hematopoietic stem cell transplantation. Better renal function was noted in only 2 cases. CONCLUSION: Despite the high efficiency of therapy aimed to reduce monoclonal light chains; improved renal function was observed in only 2 (22%) patients. Such low rates of a renal response were due to the late initiation of therapy.

[30 Years of the Tragedy in Chernobyl. Clinical and Immunological Effects in Liquidators of Consequences of the Chernobyl Accident. Main Results of Long-Term Monitoring].

Results of long-term immunological monitoring of liquidators of consequences of the Chernobyl accident and the revealed regularities are presented. Earlier the unknown phenomenon of the activating influence of radiation at small doses on the T-cellular link of the immune status (IS), mainly on T-lymphocytes/helper was for the first time established. This phenomenon came to light among participants of LPA working in an extreme situation of 1986 in the zones of the CN PP and further was confirmed by inspection of the personnel of a 30-km zone of the CNPP in 1990; the personnel at radiation dangerous nuclear power plants and the population living near these objects, the population polluted by radionuclides on the territories of the Bryansk region. This effect in the presence of clinical symptoms which can be caused by influence of a radiation factor was most expressed. Prognostic value of the changes in the development of IS immune insufficiency (ID), cellular and humoral link in the near future after taking part in clean-up workers are established. These laws have a theoretical value for immunology and radiobiology, and practical health care as well, as the formation of a phenotype of IS defines approaches to immunoprophylactics and immunocorrection, as in extreme situations, and in the following years. During the delayed periods development of an imbalance, immune in- sufficiency in T-lymphocytes and natural killer cells is revealed. By the end of the 3rd - the beginning of the 4th fifth anniversary after the accident the high frequency of clinical manifestations of immune dysfunction and chronic somatic diseases was defined. The immunological characteristic of an immunoproliferative syn- drome that allowed one to reveal predictors of early diagnostics of malignant new growths in immune status is for the first time established. Clinical-immunological signs of early aging of liquidators and features of changes in liquidators in the lipidic status depending on the age and risk factors of Chernobyl accident are revealed. Features of antiviral protection of an organism ofliquidators that is defined by changes in the cluster of genes of cytokines (IL28A, IL28B and IL29) localized on the 19th chromosome (19ql3) of the person are established. Establishment of genotypes can be associated with a positive effect of treatment, steady and long remission of GVI.

The memory-enhancing effects of hippocampal estrogen receptor activation involve metabotropic glutamate receptor signaling.

Our laboratory has demonstrated that 17ß-estradiol (E2) enhances hippocampal memory consolidation via rapid activation of multiple intracellular signaling cascades, including the ERK/MAPK cascade (Fernandez et al., 2008; Fan et al., 2010). However, the receptor mechanisms responsible for these effects of E2 remain unclear. In vitro, estrogen receptor α (ERα) signaling through metabotropic glutamate receptor 1a (mGluR1a) leads to ERK-dependent CREB phosphorylation (Boulware et al., 2005), suggesting that interactions between ERs and mGluR1a may be vital to the memory-enhancing effects of E2. As such, the present study tested the roles of classical estrogen receptors (ERα and ERß) and mGluR1a in mediating the effects of E2 on hippocampal memory consolidation. Dorsal hippocampal (DH) infusion of ERα (PPT) or ERß (DPN) agonists enhanced novel object recognition and object placement memory in ovariectomized female mice in an ERK-dependent manner, suggesting that these receptors influence memory by rapidly activating hippocampal cell signaling. Next, DH infusion of the mGluR1a antagonist LY367385 blocked the object and spatial memory facilitation induced by E2, PPT, and DPN, demonstrating that ER/mGluR1a signaling is critical for the memory-enhancing effects of E2. Finally, we show that ERα, ERß, mGluR1, and ERK all reside within specialized membrane microdomains of the DH, and that ERα and ERß physically interact with mGluR1, providing a means through which ERs may activate mGluRs and downstream signaling. Together, these findings provide the first in vivo evidence demonstrating that ER/mGluR signaling can mediate the beneficial effects of E2 on hippocampal memory consolidation.

Utility of immunologic testing in suspected rheumatologic disease.

The use of diagnostic testing in the clinical practice of medicine has been a shifting landscape from the time that the first blood test was utilized. This is no different in the field of immunology and in particular rheumatology. As the field of immunology is relatively young, the clinical tests are not well established and therefore guidelines for use are still under debate. In this review, we seek to look at some of the key autoantibodies, as well as other tests that are available to diagnose suspected rheumatologic disease, and examine how to best use these tests in the clinic. In particular, we will focus on the anti-nuclear antibodies, anti-neutrophil cytoplasmic antibodies, complement, cryoglobulins, rheumatoid factor, and anti-citrullinated protein antibodies.

Somatic KRAS mutations associated with a human nonmalignant syndrome of autoimmunity and abnormal leukocyte homeostasis.

Somatic gain-of-function mutations in members of the RAS subfamily of small guanosine triphosphatases are found in > 30% of all human cancers. We recently described a syndrome of chronic nonmalignant lymphadenopathy, splenomegaly, and autoimmunity associated with a mutation in NRAS affecting hematopoietic cells, and initially we classified the disease as a variant of the autoimmune lymphoproliferative syndrome. Here, we demonstrate that somatic mutations in the related KRAS gene can also be associated with a nonmalignant syndrome of autoimmunity and breakdown of leukocyte homeostasis. The activating KRAS mutation impaired cytokine withdrawal-induced T-cell apoptosis through the suppression of the proapoptotic protein BCL-2 interacting mediator of cell death and facilitated proliferation through p27(kip1) down-regulation. These defects could be corrected in vitro by mitogen-activated protein kinase/extracellular signal-regulated kinase kinase 1 or phosphatidyl inositol-3 kinase inhibition. We suggest the use of the term RAS-associated autoimmune leukoproliferative disease to differentiate this disorder from autoimmune lymphoproliferative syndrome.

Morphologic features of extrahepatic manifestations of hepatitis C virus infection.

Cirrhosis and hepatocellular carcinoma are the prototypic complications of chronic hepatitis C virus infection in the liver. However, hepatitis C virus also affects a variety of other organs that may lead to significant morbidity and mortality. Extrahepatic manifestations of hepatitis C infection include a multitude of disease processes affecting the small vessels, skin, kidneys, salivary gland, eyes, thyroid, and immunologic system. The majority of these conditions are thought to be immune mediated. The most documented of these entities is mixed cryoglobulinemia. Morphologically, immune complex depositions can be identified in small vessels and glomerular capillary walls, leading to leukoclastic vasculitis in the skin and membranoproliferative glomerulonephritis in the kidney. Other HCV-associated entities include porphyria cutanea tarda, lichen planus, necrolytic acral erythema, membranous glomerulonephritis, diabetic nephropathy, B-cell non-Hodgkin lymphomas, insulin resistance, sialadenitis, sicca syndrome, and autoimmune thyroiditis. This paper highlights the histomorphologic features of these processes, which are typically characterized by chronic inflammation, immune complex deposition, and immunoproliferative disease in the affected organ.

RANKL induces heterogeneous DC-STAMP(lo) and DC-STAMP(hi) osteoclast precursors of which the DC-STAMP(lo) precursors are the master fusogens.

Osteoclasts (OC) are multinucleated bone resorbing cells that form via RANKL-induced fusion of heterogeneous mononuclear OC precursors (OCP). Currently, there are no unique surface markers to distinguish these OCP populations, which are diagnostic for erosive and metabolic bone diseases using culture assays. Thus, we investigated expression of DC-STAMP, a surface receptor required for OCP fusion, during osteoclastogenesis in vitro using a novel monoclonal antibody (1A2). Immunoprecipitation-Western blot analysis of OCP membrane proteins detected 106 kDa dimeric and 53 kDa monomeric DC-STAMP in non-denaturing and denaturing conditions, respectively, with greater sensitivity versus rabbit anti-sera (KR104). 1A2 also detected 99.9% of undifferentiated monocytes as a single population by flow cytometry with a MFI 100-fold over background, while KR104 was not useful in this assay. Functionally, 1A2 inhibited OCP fusion in vitro. RANKL stimulation of OCP induced DC-STAMP(lo) and DC-STAMP(hi) cells, which mature into OC and mononuclear cells respectively as determined by fluorescent microscopy and TRAP assays. Addition of DC-STAMP(hi) cells to purified DC-STAMP(lo) cultures produced larger, more nucleated OC vs. pure DC-STAMP(lo) cultures. RT-qPCR analysis of these two populations showed that OC markers (Trap and Oc-stamp) and fusogenic gene expression (Cd9 and Cd47), were significantly increased in DC-STAMP(lo) vs. DC-STAMP(hi) cells. Collectively, these results demonstrate that DC-STAMP is expressed on OCP as a dimer, which is efficiently detected by 1A2 via flow cytometry. RANKL induces osteoclastogenesis by stimulating DC-STAMP internalization in some OCP, and these DC-STAMP(lo) cells display the "master fusogen" phenotype. In contrast, DC-STAMP(hi) OCP can only act as mononuclear donors.

[Evolution and treatment of storm cytoquine syndrome associated to SARS-CoV-2 infection among octogenarians]. / Tratamiento y evolución del síndrome de tormenta de citoquinas asociados a infección por SARS-CoV-2 en pacientes octogenarios.

INTRODUCTION: Cytokine storm syndrome (CTS) is a serious complication of patients with SARS-CoV-2 infection. Treatment and evolution in octogenarians are not well defined. Our objective is to describe its clinical characteristics, the treatments and its clinical evolution. PATIENTS AND METHOD: Retrospective observational study of consecutive patients admitted in the period between March 23 and April 12, 2020 with confirmed SARS-CoV-2 infection, with pneumonia by radiological study or chest tomography, whith STC criteria and who received treatment. We classified patients as those who received only glucocorticoid (GC) pulses, or GC and tocilizumab pulses. We determined serum levels of ferritin, CRP and D-dimers. The final variable was survival. RESULTS: 21 patients, (80-88 years). The mean ferritin was 1056 microg/L (317-3,553), CRP 115.8mg/dL (22-306) and D-dimers 2.9m/L (0.45-17.5). All patients received GC pulses and in 2 cases simultaneously tocilizumab. The mean follow-up time was 13.7 days (8-21). The overall mortality was 38.1% (8/21 patients). The 2 patients who received tocilizumab died. The deceased had significantly higher levels of ferritin (1,254 vs. 925microg/L; P=.045) and CRP (197.6 vs. 76mg / dL; P=.007). At the end of the follow-up, a decrease in the biochemical parameters was observed with ferritin of 727microg/L, CRP of 27mg/dl and D-dimers of 1.18mg/L. In 13/21 patients (61.9%), the CTS was controlled without the need to add other treatments. CONCLUSIONS: STC mortality from SARS-CoV-2 is high despite treatment. A greater inflammatory response was associated with a higher mortality. Although it seems that the early use of GC pulses could control it, and the use of other treatments such as tocilizumab shouldo be, with the study design and its limitations, this conclusion cannot be stablished.

Screening panels for detection of monoclonal gammopathies.

BACKGROUND: The repertoire of serologic tests for identifying a monoclonal gammopathy includes serum and urine protein electrophoresis (PEL), serum and urine immunofixation electrophoresis (IFE), and quantitative serum free light chain (FLC). Although there are several reports on the relative diagnostic contribution of these assays, none has looked at the tests singly and in combination for the various plasma cell proliferative disorders (PCPDs). METHODS: Patients with a PCPD and all 5 assays performed within 30 days of diagnosis were included (n = 1877). The diagnoses were multiple myeloma (MM) (n = 467), smoldering multiple myeloma (SMM) (n = 191), monoclonal gammopathy of undetermined significance (MGUS) (n = 524), plasmacytoma (n = 29), extramedullary plasmacytoma (n = 10), Waldenström macroglobulinemia (WM) (n = 26), primary amyloidosis (AL) (n = 581), light chain deposition disease (LCDD) (n = 18), and POEMS syndrome (n = 31). RESULTS: Of the 1877 patients, 26 were negative in all assays. Omitting urine from the panel lost an additional 23 patients (15 MGUS, 6 AL, 1 plasmacytoma, 1 LCDD), whereas the omission of FLC lost 30 patients (6 MM, 23 AL, and 1 LCDD). The omission of serum IFE as well as urine lost an additional 58 patients (44 MGUS, 7 POEMS, 5 AL, 1 SMM, and 1 plasmacytoma). CONCLUSIONS: The major impact of using a simplified screening panel of serum PEL plus FLC rather than PEL, IFE, and FLC is an 8% reduction in sensitivity for MGUS, 23% for POEMS (7 patients), 4% for plasmacytoma (1 patient), 1% for AL, and 0.5% for SMM. There is no diminution in sensitivity for detecting MM, macroglobulinemia, and LCDD.

Targeted inhibition of beta-adrenergic receptor kinase-1-associated phosphoinositide-3 kinase activity preserves beta-adrenergic receptor signaling and prolongs survival in heart failure induced by calsequestrin overexpression.

OBJECTIVES: Desensitization and down-regulation of beta-adrenergic receptors (betaARs) are prominent features of heart failure largely mediated by increased levels of betaAR kinase-1 (betaARK1). BACKGROUND: beta-adrenergic receptor kinase 1 interacts with phosphoinositide-3 kinase (PI3K), and upon agonist stimulation, the betaARK1/PI3K complex is recruited to agonist-stimulated betaARs. Here we tested the hypothesis that in vivo selective inhibition of betaARK1-associated PI3K activity would preserve betaAR signaling and, therefore, improve cardiac function and survival in experimental heart failure. METHODS: We used a murine model of heart failure induced by calsequestrin (CSQ) cardiac-specific overexpression; CSQ mice were crossed with mice overexpressing in the heart a catalytically inactive PI3Kgamma (PI3Kgamma(inact)) to competitively displace endogenous PI3K from betaARK1. RESULTS: Catalytically inactive PI3KgammaPI3K overexpression in CSQ mice inhibited betaARK1-associated PI3K activity, normalized betaAR levels, and preserved betaAR responsiveness to isoproterenol (ISO). Restoration of betaAR signaling via PI3Kgamma(inact) overexpression resulted in marked improvement of cardiac function and a significant prolongation of survival. Importantly, the effects of PI3Kgamma(inact) overexpression were restricted to betaAR signaling, because cellular PI3K signaling was unaltered, as shown by the similar activation of multiple downstream signaling pathways in both CSQ and CSQ/PI3Kgamma(inact) mice. CONCLUSIONS: These data in the CSQ model of cardiac dysfunction indicate that membrane-targeted PI3K activity plays a detrimental role in heart failure, and its inhibition represents a novel therapeutic approach to ameliorate cardiac dysfunction and improve survival.

Intravenous Immunoglobulin G Improves Pregnancy Outcome in Women with Recurrent Pregnancy Losses with Cellular Immune Abnormalities.

PROBLEM: We investigated the therapeutic effect of intravenous immunoglobulin (IVIG) in women with recurrent pregnancy loss (RPL). METHOD OF STUDY: This was a retrospective observational study. Total 189 RPL women who experienced ≥2 miscarriages were enrolled and investigated conventional etiologies, thrombophilia, and cellular immunity. Patients were divided into four groups; known etiology with (Gr1) and without cellular immune abnormality (Gr2), unknown etiology with (Gr3) and without cellular immune abnormality (Gr4). IVIG was administrated from early pregnancy to 30 weeks of gestation to women with cellular immune abnormality (Gr1 + Gr3). RESULTS: Cellular immune abnormalities (increased level or cytotoxicity of NK cells and Th1/Th2 ratio) were present in 111 of 189 RPL women (58.7%). Live birth rates of women with and without cellular immune abnormality were not different (Gr1 + Gr3, 84.8% versus Gr2 + Gr4, 89.7%). Furthermore, IVIG success rates were the same between Gr1 and Gr3, those who had cellular immune abnormality. Nevertheless lack of an appropriate control in this study, our IVIG outcome demonstrated better live birth rate compared with those of other investigators. CONCLUSION: Treatment modalities stratified by underlying etiologies of RPL may improve pregnancy outcome. Administration of IVIG is likely to have clinical efficacy in RPL women with cellular immune abnormality.

Angiocentric immunoproliferative lesion and angiocentric lymphoma of lymph node in children. A report of two cases.

AIM: To report two examples of an angiocentric immunoproliferative lesion (AIL) and angiocentric angiodestructive lymphoma (AL) presenting in lymph nodes in children. Most commonly involving extranodal sites, AIL/AL rarely presents in the spleen and lymph nodes. METHODS/RESULTS: Case 1 presented as a cervical lymphadenopathy in a 3 year old girl being treated for pre-B cell acute lymphoblastic leukaemia. Histological and immunohistochemistry studies revealed an Epstein-Barr virus positive (EBV+), large B cell (CD20 and CD30+) AIL with large areas of necrosis, the whole resembling lymphomatoid granulomatosis. Case 2 presented as a large supraclavicular lymphadenopathy in a 13 year old boy. Histology and immunohistochemistry revealed an EBV-, large T cell (CD45RO, CD56, and CD30+) AL, presenting the features of so called angiocentric T cell/natural killer cell lymphoma, nasal type. CONCLUSIONS: The term AIL/AL refers to a heterogeneous group of conditions not unique to a particular type of lymphoid cell. These lesions are easily recognised by the histopathologist because of their extremely unusual angiocentric pattern. Although rare, AIL/AL may present as nodal lesions in children ab initio.

Angiocentric immunoproliferative lesion associated with chronic active Epstein-Barr virus infection in an 11-year-old boy. Clonotopic proliferation of Epstein-Barr virus-bearing CD4+ T lymphocytes.

We report a pulmonary angiocentric immunoproliferative lesion (AIL) in an 11-year-old boy with chronic active Epstein-Barr virus (EBV) infection. The phenotypes of the proliferating lymphoid cells in the biopsied pulmonary lesion were CD2+, CD3+, CD4+, CD5+, CD7+, and HLA-DR+. EBV DNA was detected in the tumorous and the nontumorous tissue by Southern-blotting studies. Dual immunostains and combined immunohistochemistry/in situ hybridization showed the simultaneous presence of EBV-determined nuclear antigen or EBV-encoded small RNAs and T-cell markers in the lymphoid cells. Molecular genetic analysis of the tumorous lesion diagnosed as AIL grade III showed no clonal rearrangement of the T-cell receptor beta gene but a single type of fused terminal band of EBV. No such evidence of monoclonality was identified in the surrounding nontumorous tissue diagnosed as AIL grade I or II. The present case was a rare example of AIL in childhood and provides further histopathologic and molecular biological evidence supporting the concept of AIL as a continuous spectrum from premalignant lymphoproliferative disorders to monoclonal, overt malignant lymphoma.

The biologic significance of human natural autoimmune responses: relationship to the germline, early immune and malignant B cell variable gene repertoire.

The potential for autoreactivity that has been well documented in normal individuals implies that natural autoimmune responses must serve some physiologic function. To investigate the genetic mechanisms involved in the emergence of such responses, we have determined the sequences of heavy (VH) and light (VL) chain variable region genes for several human monoclonal autoantibodies and compared these with corresponding sequences reported for other antibodies and autoantibodies. Our data reveal that natural autoantibodies can be encoded by nonmutated germline VH and VL genes which are essentially identical to V genes expressed in early B cell ontogeny as well as in some B-lineage tumors. Taken together with other structural data on human autoantibodies, these findings suggest that natural autoimmune responses originate early in ontogeny and that such antibodies may play a regulatory role in development of the normal immune repertoire and possibly in suppressing pathogenic autoimmune or malignant responses.

Angiocentric immunoproliferative lesions of the lung associated with diffuse renal involvement.

A 62-year-old Japanese man presented with high fever, cough, and sputa. Computed tomography (CT) scan of the chest revealed lung infiltrates with air bronchogram of the right middle lobe and mediastinal lymphadenopathy. Bronchoscopic examination was performed, and Mycobacterium avium complex was detected from bronchoalveolar lavage fluid. Although the administration of clarithromycin and levofloxacin improved the patient's symptoms, the lung infiltrates on chest CT scan gradually worsened. Lung biopsy of segments 4 and 8 by video-assisted thorachoscopy revealed angiocentric and angiodestructive massive lymphoplasmocytic infiltrations with multinucleated giant cells, which were compatible with grade II angiocentric immunoproliferative lesions. The patient was found to have deterioration of renal function, and glomerular filtration rate was 32.6 mL/min. His kidneys were enlarged and showed prominent and diffuse uptake of gallium-67 citrate. Percutaneous renal biopsy revealed massive infiltration of CD4+ mononuclear cells, plasma cells, and eosinophils in the interstitium and destruction of normal structure of tubules. Blood vessels were destroyed and replaced by inflammatory cells. The combination chemotherapy achieved a remission, and the patient has remained free of disease at 2 years after onset of the illness. We recommend the imaging of kidneys for diagnosis and following renal biopsy to evaluate the renal involvement of angiocentric immunoproliferative lesions.

Role of cytokines in the pathogenesis of monoclonal gammopathies.

OBJECTIVE: To review data that postulate a role for cytokines and oncogenes in the pathogenesis of monoclonal gammopathies. DESIGN: Published studies that provide evidence of the clinical progression of normal B cells to monoclonal gammopathy of undetermined significance (MGUS) to active myeloma are discussed. RESULTS: On the basis of mouse plasmacytoma models, increased expression of c-myc in B lymphocytes may be the initial oncogenic event that leads to MGUS in humans. Over time, this monoclonal subpopulation may acquire additional genetic abnormalities, such as aberrant interleukin (IL) 1 beta expression. Because IL 1 beta has potent osteoclast activating factor activity, increased production of IL 1 beta by monoclonal plasma cells may be the genetic event responsible for the progression of MGUS to myeloma. The in vivo plasma cell labeling index (proliferative rate) is the most powerful prognostic factor in patients with myeloma. The proliferative compartment observed in myeloma may parallel normal B-cell development because cytoplasmic immunoglobulin-positive cells with the ability to proliferate exist normally. With continued progression of disease, the ratio of proliferating monoclonal plasmablasts to nonproliferating monoclonal plasma cells may increase under the influence of cytokines such as IL 6. CONCLUSION: A more complete understanding of the basic biologic features of myeloma should lead to innovative therapies in the future.