Lymphadenopathy Type Research Articles

Factorial Review Design Analysis of Different Types of Lymphadenopathy and Causative Factor

Lymphadenopathy is considered as chronic infection in which individuals are incompetent to follow up about stepwise clinical management procedures such as factorial design of different types of microorganisms and related infections, control measurements of preventive care, detoxification procedures, immune-stimulant merits and demerits and immuno suppressant action merits and demerits. This infection can be managed via stepwise clinical procedures such as SOP for cleaning of washing hands and WHO SAFE handling system procedures, controlling of antimicrobial resistance, Dosing errors such as over use and under use medications, Obesity related factors, Enzymatic inhibition and stimulation activity, systematic ADME modification, Vaccination procedures in different races and culture intake of foods, pharmacodynamics variation, Genetic and Heredictary disorders and drug addiction. This paper describe about different plants are categorized to manage stepwise infection on the basis of toxicological data pertaining to Idio-syncratic response reaction factors such as form and innate chemical activity, exposure route,presence of other chemicals in form of toxins, Psychological changes, role of circadian rhythum with gut toxicity, toxin rich intake nutrition packed and unpacked foods.

The possibilities of ultrasound elastography in diagnostics of lymphomatous changes of superficial lymph nodes

Objective: to evaluate the possibilities of strain elastography (SE) in eSie Touch mode and shear wave elastography (SWE) with ARFI (Acoustic Radiation Force Impulse) technology in Virtual TouchTM Tissue Imaging (VTI) for diagnostics lymphomatous superficial lymph nodes (LN).Materials and methods. The prospective study included 168 patients with enlarged superficial LN. Based on a previous histological examination, patients were divided into three groups: group 1 (n = 108) – patients with lymphomas; group 2 (n = 30) – patients with metastatic superficial LN; group 3 (n = 30) – patients with reactive (inflammatory) changes in superficial LN. All patients underwent SE and SWE elastography of the enlarged LN using eSie Touch and VTI modes respectively.Results. The SE data: reactive LN was characterized by elastotypes 1 and 2 with a predominance of elastic structure in 90.0 % of cases. In patients with lymphomas, the elastotype 3 was more often determined (58.3 %). The stiffest LN with the elastotype 4 were metastatic LN, detected in 66.7 % of patients from this group. The results of VTI elastography showed that the stiffest structure is typical for metastatic LN (elastotypes 5–6 in 63.3 % of cases). Lymphomas had an intermediate degree of stiffness (elastotypes 3–4 in 81.5 % of cases). The lowest indicators of elasticity were found in patients with reactive LN (elastotypes 1–2 in 73.4 % of cases).Conclusion. The qualitative assessment of superficial LN stiffness, both using SE and VTI elastography, demonstrated statistically significant differences in the frequency of various types of superficial LN elastograms with lymphomatous, metastatic and reactive changes, which allows for more accurate differential diagnosis between these types of lymphadenopathy.

Pathomorphology of lymph nodes in patients with severe SARS-CoV-2 infection observed in Primorsky Krai

Introduction. When studying COVID-19 pathology, considerable attention is paid to the damage to the respiratory and cardiovascular systems, which are associated with the manifestation of the infection. Data on changes in the organs of the lymphatic system are yet scarce. To date, COVID-19 is sure to cause the dysfunction of the immune system; however, information about the damage to the lymph nodes is ambiguous. The aim of the study was to characterize morphological changes in the hilar lymph nodes of patients who died from a new coronavirus infection COVID-19 in Vladivostok in 2021. Materials and methods. A morphological study of the lymph nodes was performed in 20 patients who died from the new coronavirus infection, diagnosed in vivo using a PCR test. The controls were patients who did not have diseases of the hematopoietic and lymphoid tissue in their medical histories but who died a violent death. The material for histological examination was processed according to generally accepted methods. Results. In all patients, we identified lymphadenopathy with hypoplasia of lymphoid tissue of varying severity. In the cortex, lymphatic follicles were detected, mainly without light (germinal) centers, as well as follicles with a pronounced rarefaction of cells and exposure to the reticular stroma, with no visualization of the paracortical zone. According to the severity of reactive changes in the T- and B-dependent zones of the lymph nodes, we distinguished two types of lymphadenopathy: 1) mixed follicular type; 2) follicular involution with lymphoid depletion. Conclusion. Pathological changes in the hilar lymph nodes of the lungs in patients who died from COVID-19 indicated immunosuppressive effects of the SARS-CoV-2. The pathologic changes in lymph nodes manifested with lymphocytic depletion in T- and B-dependent zones. This indicates a deficiency of cellular and humoral immunity in moderate and severe COVID-19. Keywords: coronavirus infection, COVID-19, pathomorphology, lymph nodes, lymphocytic depletion, immunodeficiency

Pattern of Lymphadenopathy on Fine Needle Aspiration Cytology in a Tertiary Level Hospital in Kathmandu

Introduction: Fine Needle Aspiration Cytology is a relatively simple, inexpensive and rapid diagnostic procedure for identifying cause of lymphadenopathy without need for surgical procedures. This study aims to explain the pattern of lymphadenopathy seen on fine needle aspiration cytology in a tertiary level hospital in KathmanduMaterials and Methods: This study was conducted at Shree Birendra Hospital Nepal. Cases of lymph node FNAC done in the years 2073 and 2074 BS were included in the study. The cases were classified into reactive lymphadenitis, granulomatous lymphadenitis, tubercular lymphadenitis, lymphomas, leukemias, and metastases.Results: A total of 215 patients were included in the study, ranging in age from 2 to 84 years, out of which 98 were female and 117 were male. Reactive lymphadenitis was the most common diagnosis (n=126; 58.6%), followed by granulomatous lymphadenitis (n=34; 15.8%) and tubercular lymphadenitis (n=18; 8.4%). There were 18 cases of metastatic malignancies, 15 cases of suppurative lymphadenitis, and 2 cases of Hodgkin lymphoma and 2 cases of non-Hodgkin lymphoma.Conclusions: Reactive lymphadenitis is the most common type of lymphadenopathy encountered in FNAC, while in the elderly, metastases are more common.

Automated Detection of Lymphadenopathy in Neck Resulting from Oral SCC on 3D CT Imaging

Background/Objectives: Detection of lymphadenopathy is challenging issue in medical field. Squamous Cell Carcinoma (SCC) can lead to a certain type of lymphadenopathy which is different from all other pathological factors. Nowadays detection of these cases is done by expert radiologists, Computing Tomography (CT), and sonography and etc., challenges in detection of this type of lymphadenopathy in neck is mainly due to neck anatomy which similar objects are close to each other. Methods/Statistical Analysis: In this paper, was presented a method to detect this type of the lymphadenopathy in neck by 3 dimensional (3D) image processing techniques and Computer-Aided Diagnosis (CAD) systems. This method consists of four steps. The first is preprocessing, the second is thresholding and morphological operation, the third is feature extraction and the last is classification. By using this method, detection of lymphadenopathy will be done more accurate and less time consuming. Findings: This method is done in 18 neck CT data sets, consisting of lymphadenopathy by SCC cells. The sensitivity of using this method is 94%. Applications/Improvements: The goal is to introduce a sensitive, accurate and generalizable method with the least false positive.

Algunos aspectos anatomopatológicos del síndrome de inmunodeficiencia adquirida (SIDA)

Se presenta dos casos de SIOA con estudios de biopsias y autopsias, pertenecientes al Hospital Central de la Fuerza Aérea del Perú. Uno de ellos corresponde a paciente varón de 27 años de edad, homosexual, quién radicó en los Estados Unidos de Norte América durante ocho años hasta 1982. El otro caso corresponde a una mujer de 35 años de edad, casada, habiéndose probado, una semana después de su fallecimiento, que su esposo estaba infectado por el virus HIV-1. En el material de biopsias y autopsias se observó linfoadenopatía tipo 11, seguida de linfoadenopatía tipo 111 en el paciente varón. También se encontró atrofia del tejido Iinfoide en bazo y tracto gastrointestinal. En el paciente varón se observó otras lesiones causadas por acción directa del HIV-1, consistentes en desmielinización, infiltrado inflamatorio y nódulos microgliales en el cerebro y cerebelo. En el paciente varón se encontró infección generalizada por Criptococcus neoformans y, en la mujer, infección generalizada por Citomegalovirus con neumopatía aguda. En ambos casos hubo antecedentes de psoriasis, persistiendo las lesiones de piel en el paciente varón hasta producido el deceso. La mujer desarrolló sarcoma de Kaposi en piel. Se discute los cambios patológicos encontrados en ambos casos de SIOA (An Fac Med UNMSM 11 Epoca 1989; 1 (1-2): 19-26).

Histodemography of Lymphadenopathy

Background: Lymph node enlargement presents a clinical problem whose significance can range from trivial to critical, depending on the cause of lymphadenopathy. Diseases involving the lymph node fall primarily into three categories, which include lymphadenitis, metastatic malignancies, malignant lymphoma. It is not feasible to excise every enlarge lymph node. So clinical selection of patients must take place and diagnosis of definite causes of lymphadenopathy by histological examination is essential for appropriate treatment. Objective: The aim was to find the relation and association of proportion of different types of lymphadenopathy with age and gender. Materials and method: This cross sectional study was done in Delta Hospital Limited, Dhaka, Bangladesh during the period of May 2010 to December 2010. A total 88 cases were studied irrespective of age, sex along with clinical diagnosis. Results: Among the study subjects 55.7% was being benign lesions and remaining were with malignant lesions. Among the benign lesions majority (31.8%) were tuberculosis with female predominance which commonly occurs below the age of 20 years, where as non-Hodgkin’s lymphoma (33.3%) was the commoner form among malignant cases with male predominance occurs in older age group. Mean (±) age of benign and malignant cases was 22.1 (±12.73) years and 44.1 (±17.37) years respectively. Conclusion: The present study revealed that lymphadenopathy occurs more commonly in the middle age group with predominance of benign lesions. Among the benign lesions tuberculosis is the most common one and non-Hodgkin’s lymphoma is the commonest malignant lesion.DOI: http://dx.doi.org/10.3329/dmcj.v1i1.14969 Delta Med Col J. Jan 2013;1(1):8-12

Spectrum Of Cytological Findings In Patients With Lymphadenopathy In Rural Population Of Southern Haryana, India - Experience In A Tertiary Care Hospital

Lymphadenopathy is of great clinical significance as underlying diseases may range from a treatable infectious etiology to malignant neoplasms. In fact, it is also essential to establish that the swelling in question is a lymph node. Fine Needle Aspiration Cytology (FNAC) plays a vital role in solving these issues, nowadays being recognized as a rapid diagnostic technique because of its simplicity, cost effectiveness, early availability of results, accuracy and minimal invasion. This study was conducted to evaluate the usefulness of FNAC as a diagnostic tool in the management of patients with superficial lymphadenopathy. The study was also carried out to know the distribution of various lesions among the different age groups. The present randomized study was undertaken to study cytological features of non-neoplastic and neoplastic lesions of enlarged lymph nodes by FNAC in 182 patients presenting with lymphadenopathy in the Maharaja Agrasen Medical College, Agroha village over a period of one year from January to December 2011. There were 100 male and 82 female patients with an age range of 1 �70 years. Tuberculous lymphadenitis, reactive hyperplasia, metastatic carcinoma, suppurative lymphadenitis and lymphomas were seen in 35.7%, 31.3%, 20.3%, 9.9% and 2.7% respectively. Reactive hyperplasia was seen most often (60%) in first two decades of life, 58.9% tuberculous lymphadenitis in the second and third decades (66%) and incidence of metastatic carcinoma are high during and after 40 years of age. Cervical lymph nodes were involved in all types of lymphadenopathy. Metastatic lesions of lymph nodes were seen to be more common in males. Squamous cell carcinoma is the most common metastatic lesion.

Children with significant cervical lymphadenopathy: clinicopathological analysis and role of fine-needle aspiration in Indian setup

To study the clinicopathological profile of children from India with cervical lymphadenopathy and the role of fine-needle aspiration cytology with special emphasis on tuberculosis as a cause. A total of 89 children in the age group of 10 months to 12 years, presenting to our hospital from April 2004 to March 2005, were included. All the patients underwent thorough clinical and investigational assessment vis-à-vis cervical lymphadenopathy. Outcome measurements included clinical status and ability of conventional tests to categorize different types of lymphadenopathy and their utility in diagnosing tubercular lymphadenitis. Interobserver variability was analyzed measuring kappa test and was found to be in agreement. Reactive hyperplasia was the most common type of lymphadenitis, followed by granulomatous involvement. Unilateral posterior triangle lymph nodes were the most commonly affected in the tubercular cervical lymphadenopathy group. Fine-needle aspiration followed by Ziehl-Neelsen staining, histopathology and culture in combination were able to perform the diagnosis in 85.7% of cases affected with tubercular etiology. Fine-needle aspiration is a valuable diagnostic tool in the management of children with the clinical presentation of enlarged cervical lymph nodes. The technique reduces the need for more invasive and costly procedures, especially in a Third World country. Culture and histopathology, however, should be considered in cases where repeated fine-needle aspiration cytology is non-diagnostic.

Clinical Implications of Idiopathic Multicentric Castleman Disease Among Japanese: A Report of 28 Cases

To clarify the clinicopathologic findings of idiopathic multicentric Castleman disease among Japanese, 28 cases were studied. Two variants were delineated by the clinicopathologic findings (1) idiopathic plasmacytic lymphadenopathy with polyclonal hyperimmunoglobulinemia (n = 18) and (2) nonidiopathic plasmacytic lymphadenopathy type (n= 10). Clinicopathologically, idiopathic plasmacytic lymphadenopathy was defined by the prominent polyclonal hyperimmunoglobulinemia, normal germinal centers, and sheet-like infiltration of plasma cells in the interfollicular area of the lymph node. Histologically, the nonidiopathic plasmacytic lymphadenopathy type was characterized by hyaline-vascular germinal centers of the lymph node lesion. In comparison with idiopathic plasmacytic lymphadenopathy, patients with nonidiopathic plasmacytic lymphadenopathy showed infrequent prominent polyclonal hyperimmunoglobulinemia and frequent association with autoimmune disease. However, there was no difference in the overall 5-year survival between the 2 subtypes. Compared with idiopathic multicentric Castleman disease in Western countries, the chronic course of the disease of idiopathic multicentric Castleman disease in Japan appears to be related to negativity for human herpesvirus 8 infection.

Cytologic patterns of lymphadenopathy in dogs infected with Leishmania infantum

Lymphadenopathy in canine leishmaniosis has been reported as reactive lymphoid hyperplasia or granulomatous (histiocytic) lymphadenitis. However, we are unaware of information on the effect of latent Leishmania infection on lymph node cytology compared with clinically affected dogs. The aim of the present study was to investigate cytologic patterns of lymphadenopathy in dogs with clinical and subclinical forms of leishmaniosis and to correlate cytologic findings with the density of Leishmania amastigotes in fine needle aspiration (FNA) smears. FNA cytology of prescapular or popliteal lymph nodes was evaluated on 32 dogs with clinical evidence of leishmaniosis (group A), 24 subclinically infected dogs (group B), and 17 clinically healthy noninfected dogs (group C); groups were based on the results of serologic and PCR tests for Leishmania sp. Differential nucleated cell counts (based on 300 cells) and amastigote density were determined microscopically. Cytologic findings were categorized and compared among groups. Cytologic abnormalities were found in 19 of 32 (59.4%) dogs in group A, 1 of 24 (4.2%) dogs in group B, and 2 of 17 (11.8%) dogs in group C and were significantly more frequent in group A than group B (P <.001) or C (P = .001). In group A, 68.7% of the dogs had lymphoid hyperplasia, 12.5% had lymphoid hyperplasia and histiocytic lymphadenitis, 6.3% had histiocytic lymphadenitis, and 3.1% had lymphoid hyperplasia and neutrophilic lymphadenitis. Lymphoid hyperplasia was also noted in 1 dog in group B, and lymphoid hyperplasia and eosinophilic lymphadenitis were each found in 1 dog in group C. Lymph node smears from 31 (96.9%) dogs in group A and 6 (25%) dogs in group B were positive for Leishmania amastigotes; however, no correlation was found between the density of amastigotes and cytopathologic patterns of lymphadenopathy. Abnormal lymph node cytology is much more common in dogs with clinical leishmaniosis than in dogs with subclinical infection, and primarily involves lymphoid hyperplasia. Despite finding no association between the density of amastigotes and type of lymphadenopathy, lymph node cytology still is a valuable diagnostic tool for diagnosing canine leishmaniosis.

Two Cases of the Angioimmunoblastic Lymphadenopathy Type of Peripheral T - cell Lymphoma : Different Clinical Courses According to Positivity to Epstein-Barr Virus

Two Cases of the Angioimmunoblastic Lymphadenopathy Type of Peripheral T - cell Lymphoma : Different Clinical Courses According to Positivity to Epstein-Barr Virus

Significance of cytogenetic findings for the clinical outcome in patients with T-cell lymphoma of angioimmunoblastic lymphadenopathy type.

The aim of this study was to evaluate the significance of cytogenetic findings for the clinical outcome of patients with Angioimmunoblastic Lymphadenopathy (AILD)-Type T-cell lymphoma. In a retrospective analysis, the cytogenetic findings of 50 patients with AILD-type T-cell lymphoma were correlated with the frequency of spontaneous and therapy-induced remissions and with survival using the statistical methods of Kaplan and Meier and the model of Cox for multivariate analysis. Treatment was not uniform because the patients were treated in different hospitals during a period of 8 years and because a standard therapy has not yet been established. The following cytogenetic findings were associated with a significantly lower incidence of therapy-induced remissions and a significantly shorter survival duration: presence of aberrant metaphases in unstimulated cultures (P = .04 for both parameters); clones with an additional X chromosome (P = .0001 and P = .03, respectively); structural aberrations of the short arm of chromosome 1, preferentially involving 1p31-32 (P < .001 and P = .04, respectively); and complex aberrant clones with more than four aberrations (P = .0003 and P = .005, respectively). Multivariate analysis showed that these cytogenetic findings had a significant influence on survival, but therapy modalities did not. Only the presence of complex aberrant clones was an independent prognostic factor. Trisomy 3 had no effect on survival, but patients without trisomy 5 (P = .08) tended to live longer. This is the first study that seems to indicate that cytogenetic findings have prognostic significance in AILD-type T-cell lymphoma. These results must be proven in prospective studies of homogeneously treated patients.

Patterns of Cytokine Gene Expression in Peripheral T-Cell Lymphoma of Angioimmunoblastic Lymphadenopathy Type

Peripheral T-cell lymphoma of angioimmunoblastic lymph-adenopathy type (AILD-TCL) is histologically characterized by a mixed infiltrate of atypical T cells, B cells including B immunoblasts, and plasma cells, as well as eosinophilic granulocytes accompanied by proliferated high endothelial venules, while, clinically, fever and weight loss are often observed. These morphologic and clinical pecularities are widely believed to reflect abnormal patterns of cytokine expression. To evaluate this hypothesis, 11 lymph nodes with AILD-TCL were studied for the presence of tumor necrosis factor-alpha (TNF), lymphotoxin (LT), interleukin-6 (IL-6), and IL-1 beta transcripts by in situ hybridization (ISH) using [35S]-labeled cytokine-specific RNA probes in seven cases subsequent to immunohistology for cell type characteristic antigens. Expression of all four cytokines was strongly enhanced in AILD-TCL when compared with the control groups of lymphoblastic lymphomas and peripheral T-cell lymphomas, other than AILD-TCL. TNF and LT transcripts were present in atypical T cells and in a variable proportion of B immunoblasts in all AILD-TCL cases, whereas IL-6 and IL-1 beta specific transcripts were mainly found in nonlymphoid cells. To verify a possible cytokine expression by Epstein-Barr virus (EBV)-infected cells, which are frequently present in AILD-TCL, the detection of EBV-encoded nuclear RNAs (EBER) was combined with ISH for cytokine transcripts. It became evident that expression of LT and TNF by EBV-infected cells was largely restricted to B immunoblasts, which were only infrequently present in most AILD-TCL cases, whereas the expression of IL-6 was very rare, and IL-1 beta was not found in EBV-infected cells. These data suggest that expression of TNF and LT genes may contribute to the characteristic histologic and clinical features of AILD-TCL and that cytokine expression by EBV-infected cells does not, in most cases, contribute significantly to the overall cytokine expression. Because it has been shown that LT is an autocrine growth factor for EBV-infected B cells, expression of this cytokine could contribute to the proliferation of EBV-infected B cells in AILD-TCL and, in the setting of immunosuppression, may ultimately play a role in the development of B-immunoblastic lymphomas.

Heterogeneity of Epstein-Barr virus infection in angioimmunoblastic lymphadenopathy type T-cell lymphoma.

To investigate the relationship of Epstein-Barr virus (EBV) and angioimmunoblastic lymphadenopathy with dysproteinemia, we performed DNA analysis using the polymerase chain reaction (PCR), Southern blot, in situ hybridization, and immunohistochemical analysis of lymph nodes in five patients who were followed up and biopsied more than once. In the course of the disease, nodal architecture diminished, cellular atypia worsened, and clear cells increased in number. In the DNA analysis of the receptor genes, the clonal population increased in number. EBV nucleic acid sequences were found by either PCR or in situ hybridization in all examined nodes. The number of EBV-positive cells varied widely among the cases and throughout the course of the disease in the same patients. The analysis of EBV terminal repeats or lymphocyte-determined membrane antigen genes showed polyclonal populations of EB-infected cells. EBV-positive cells possessed intermediate- to large-sized nuclei, and the cells with large nuclei, especially, expressed latent membrane protein of EBV. These large cells varied among the cases. Double-labelling immunohistochemistry/in situ hybridization studies demonstrated that most of the EBV-positive cells expressed B-cell antigen (CD20). The presence of EBV seems to be associated with the selective defects of the immune system, rather than with the direct pathogenesis of angioimmunoblastic lymphadenopathy.

Angioimmunoblastic lymphadenopathy type of T-cell lymphoma and angioimmunoblastic lymphadenopathy: a clinicopathological and molecular biological study of 13 Chinese patients using polymerase chain reaction and paraffin-embedded tissues

Angioimmunoblastic lymphadenopathy type of T-cell lymphoma and angioimmunoblastic lymphadenopathy: a clinicopathological and molecular biological study of 13 Chinese patients using polymerase chain reaction and paraffin-embedded tissues

Angioimmunoblastic lymphadenopathy type of T-cell lymphoma and angioimmunoblastic lymphadenopathy: a clinicopathological and molecular biological study of 13 Chinese patients using polymerase chain reaction and paraffin-embedded tissues.

The morphological classification of angioimmunoblastic lymphadenopathy (AILD) or T-cell lymphoma of AILD-type (AILD-TCL) is still a subject of considerable difficulty and controversy. The aim of the current study was to examine the value of clinical, morphological, immunohistochemical variables in paraffin-embedded tissues in predicting the clonality of the respective lesion. Fifteen lymph node biopsies derived from 13 patients from Chengdu, China, were diagnosed as AILD or AILD-TCL and included in this study. The specimens were examined using a panel of monoclonal antibodies and a scoring system of morphological features. Clonality of the paraffin-embedded material was investigated using a novel polymerase chain reaction-technique to amplify rearranged T-cell receptor (TCR)-gamma sequences. Additional experiments were carried out to investigate the presence of clonal rearrangements of the immunoglobulin heavy chain (IgH) locus. We found clonal rearrangements of the TCR-gamma locus in 9 out of 15 lymph node biopsies. In 3 patients, the predominant cell clones carried clonal IgH and TCR-gamma rearrangements whereas 1 patient with polyclonal TCR-gamma pattern displayed IgH-monoclonality. The statistical evaluation of morphological and immunohistochemical data indicated that no single variable was able significantly to predict the clonality of the lesion. Furthermore, demonstrable clonality for the TCR-gamma or the IgH loci of a lesion did not correlate with a bad clinical course. Our data correlate with findings of other studies investigating AILD-TCL in Caucasian populations.

Autoimmunity in mice bearing lprcg: a novel mutant gene.

A novel mutation at the lpr (lymphoproliferation)(Fas) locus, lprcg, that can complement gld (generalized lymphoproliferative disease) in induction of lymphadenopathy was discovered in CBA/K1Jms mice. The lpr and lprcg mutations are a defective allele of the Fas locus that encodes an apoptosis-mediating receptor. The former does not express the receptor and the latter expresses the point-mutated nonfunctional receptor. The gld locus is hypothesized to encode a ligand for the receptor and the gld mutation to have a defect that leads to incompetent expression of the ligand. The absence and non-functioning of the receptor in lpr/lpr and lprcg/lprcg mice, respectively, and the lack of the ligand in gld/gld mice may arrest apoptosis of lymphoid cells in the thymus, resulting in the same type of lymphadenopathy characterized by expansion of unusual CD4-CD8- (DN) T cells. Less severe lymphadenopathy induced by complementarity between lprcg and gld may be explained by less efficient apoptosis resulting from competition for the ligand between the functional and nonfunctional receptors. Phenotypically, lpr and lprcg are different from gld in the function at bone marrow (BM) and lymph node (LN) levels: lpr/lpr and lprcg/lprcg BM cause atrophy but gld/gld BM hyperplasia of wild-type (+/+) LNs, and lpr/lpr and lprcg/lprcg LNs but not gld/gld LNs allow the homing of lpr- and lprcg-induced DN T cells. Lymphadenopathy is equally prominent in CBA-lprcg/lprcg and MRL-lprcg/lprcg mice. Hypergammaglobulinemia, autoantibodies and circulating immune complexes are detectable at significant levels in both lprcg/lprcg mice but at higher levels on the MRL background. Pathological signs like glomerulonephritis and vasculitis are clinically unimportant in CBA-lprcg/lprcg but strikingly severe in MRL-lprcg/lprcg mice. Noticeably, clinically significant glomerulonephritis and vasculitis also develop with slight but significant serological aberrations in MRL-lprcg/+ heterozygotes. Graft-vs.-host disease-like syndrome in the lprcg/lprcg BM-->+/+ chimera is minimal on the CBA but as severe as life-threatening on the MRL background as in the MRL-lpr/lpr BM-->MRL(-)+/+ chimera. Thus, autoimmune diseases induced by the lpr, lprcg and gld genes are actually indistinguishable in the clinical, serological and pathological aspects on the same strain background and the disease caused by the interaction between lprcg and gld is less severe in all the aspects, consistent with the receptor-ligand theory. The lprcg/lprcg mice with different strain backgrounds together with lpr/lpr and gld/gld mice will serve as a powerful tool for elucidation of the mechanism of development of single-gene autoimmune diseases at a molecular biological level.

Epstein-Barr virus subtype distribution in angioimmunoblastic lymphadenopathy.

The tissues of 16 patients bearing a T-cell lymphoma of angioimmunoblastic lymphadenopathy type (AILD-TCL) were investigated for the distribution of Epstein-Barr virus (EBV) subtypes 1 and 2. EBV-association had been proven in these cases by polymerase chain reaction (PCR) for EBV-DNA, in situ hybridization (ISH) for EBV-encoded small nuclear RNAs (EBER) and immunohistology for EBV-encoded latent membrane protein (LMP). PCR and EBER-ISH produced mostly identical results, but some cases were positive with only one of the 2 methods employed. LMP was detected in a few large cells of 8/13 cases. Twelve cases were investigated for the distribution of EBV subtypes. One case contained EBV genome of subtype 2, 3 cases contained subtype 1 and 4 cases contained both subtypes. Four cases could not be typed. These findings suggest that in AILD, as in AIDS-associated lymphomas and lymphomas of the lethal midline granuloma type, subtype 2 of EBV may occur, perhaps in relation to an immunodysfunction developing progressively in these patients.

Heterogeneous Epstein-Barr virus infection patterns in peripheral T- cell lymphoma of angioimmunoblastic lymphadenopathy type

In this study, 32 cases of T-cell lymphoma of angioimmunoblastic lymphadenopathy type (AILD-TCL) were investigated for their association with Epstein-Barr virus (EBV). For this purpose, three different approaches were applied: polymerase chain reaction (PCR) for the presence of EBV-DNA, in situ hybridization (ISH) for EBV-encoded small nuclear RNAs (EBER), and immunohistology for EBV-encoded latent membrane protein (LMP). PCR and EBER-ISH produced almost identical results, showing that all but one case of AILD-TCL contained EBV genomes. Three distinctive patterns of EBV infection were observed after immunophenotypical characterization of EBER-positive cells: (1) in 26% of the cases, B and T cells were infected, the majority of which were B cells of immunoblastic morphology located in the remnants of lymphoid follicles; (2) in 42% of the cases, the vast majority of infected cells were neoplastic T cells diffusely distributed in the lymph nodes, but infected B cells were also present; and (3) in 32% of the cases, there were only a few infected small lymphoid cells. Detectable LMP was frequent in cases exhibiting patterns 1 and 2. These findings suggest that in AILD-TCL patients, B cells and especially T cells are highly susceptible to a persistent EBV infection, which often leads to a growth advantage of the infected cells. Thus EBV, in conjunction with genetic abnormalities and selective defects of the immune system, might be involved in the pathogenesis of AILD-TCL.