Lymphoid Hyperplasia Research Articles

Progressively transformed germinal center-like follicular T-cell lymphoma:a clinicopathological analysis of 14 cases

Objective: To investigate the clinicopathologic features of progressively transformed germinal center-like follicular T-cell lymphoma (PTGC-like FTCL). Methods: The clinicopathologic data of 14 PTGC-like FTCL cases that were diagnosed at the Beijing Friendship Hospital Affiliated to the Capital Medical University from January 2017 to January 2022 were retrospectively collected. Clinicopathological features, immunophenotype, and Epstein-Barr virus (EBV) infection status were analyzed in these cases. Polymerase chain reaction (PCR) was performed to detect the clonal gene rearrangements of T cell receptor (TCR) and the immunoglobulin (Ig) in 10 and 8 cases, respectively. Results: The male to female ratio was 5∶2. The median age was 61 years (range 32-70 years). All patients had lymphadenopathy at the time of diagnosis. By using the Ann Arbor system staging, seven cases were classified as stage Ⅰ-Ⅱ, and seven cases as stage Ⅲ-Ⅳ. Seven cases had B symptoms, four cases had splenomegaly, and two cases had skin rash and pruritus. Previously, three cases were diagnosed as classic Hodgkin's lymphoma, three cases as small B-cell lymphoma, two cases as atypical lymphoid hyperplasia unable to exclude angioimmunoblastic T-cell lymphoma (AITL), one case as EBV-associated lymphoproliferative disorder, and one case as peripheral T-cell lymphoma (PTCL) associated with the proliferation of B cells. All the 14 cases showed that the large nodules were composed of mature CD20+, IgD+B lymphocytes admixed with small aggregates of neoplastic cells with pale to clear cytoplasm. Moreover, hyperplastic germinal centers (GCs) and Hodgkin/Reed-Sternberg-like (HRS-like) cells were seen within these nodules in two and five cases, respectively. The neoplastic cells expressed CD3 (14/14), CD4 (14/14), PD1 (14/14), ICOS (14/14), CD10 (9/14), bcl-6 (12/14), CXCL13 (10/14), and CD30 (10/14). The HRS-like cells in five cases expressed CD20 (2/5), PAX5 (5/5), CD30 (5/5), CD15 (2/5), LCA (0/5), OCT2 (5/5) and BOB1 (2/5). Moreover, neoplastic T cells formed rosettes around HRS-like cells. EBV-encoded RNA (EBER) in situ hybridization showed scattered, small, positive bystander B lymphocytes in 8/14 cases, including 3/5 cases containing HRS-like cells. All tested cases (including five with HRS-like cells) showed monoclonal TCR gene rearrangement and polyclonal Ig gene rearrangement. Conclusions: PTGC-like FTCL is a rare tumor originated from T-follicular helper cells. It could be distinguished from angioimmunoblastic T-cell lymphoma by the formation of follicular structure, and lack of follicular dendritic cell proliferation outside the follicles and the polymorphous inflammatory background. In addition, it should be differentiated from lymphocyte-rich classical Hodgkin's lymphoma and low-grade B cell lymphoma.

Mucosa-Associated Microbiota Dysbiosis in the Terminal Ileum Correlates With Bowel Symptoms in Diarrhea-Predominant Irritable Bowel Syndrome.

The mucosa-associated microbiota (MAM) is not as frequently studied in diarrhea-predominant irritable bowel syndrome (IBS-D) compared with the fecal microbiota. In this study, we examined the MAM in the terminal ileum and its correlation with bowel symptoms in IBS-D. Mucosal biopsies of the terminal ileum from 25 patients with IBS-D and 25 healthy controls were collected for 16S ribosomal RNA gene sequencing. Correlation analysis was performed. Compared with healthy controls, the MAM in the terminal ileum showed a decreased alpha diversity in the IBS-D cohort (Chao1 and Shannon indexes, P < 0.05). And the overall MAM profile clustered separately into 2 groups (ADONIS [PERMANOVA, permutational multivariate analysis of variance], P < 0.05). At the phylum level, the relative abundance of Proteobacteria was significantly higher in the ileal MAM of patients with IBS-D while that of Firmicutes was significantly lower. At the genus level, the relative abundance of Pseudomonas was significantly higher in the IBS-D cohort, with lower Bacteroides and Ruminococcus . Moreover, 40.0% of patients with IBS-D had multiple small nodules (nodular lymphoid hyperplasia) on the mucosal surface of the terminal ileum, which indicated a low-grade inflammation. In patients with IBS-D with nodular lymphoid hyperplasia, the changes of Pseudomonas and Bacteroides were more overt. Correlation analysis revealed that the relative abundance of Pseudomonas positively correlated with abdominal pain and the severity of IBS. Patients with IBS-D showed a dysbiosis of MAM in the terminal ileum, which may be associated with bowel symptoms. Moreover, 40.0% of them displayed mucosal low-grade inflammation, with a more severe mucosal microbial disturbance.

Radiological Characteristics of Immunization Adenitis in the Axilla Following the Covid-19 Vaccine

It was aimed to investigate the ultrasonography (US) features of axillary COVID-19 immunization adenitis. Patients with axillary COVID-19 immunization adenitis detected between April 2021 and January 2022 were included. US features of the lymph nodes identified at the patient's initial US were all recorded. Radiological follow-up information and if exists pathology results were investigated. 104 immunization adenitis in the axilla following Covid-19 vaccine were detected. Only 18.3 percent had axillary pain or edema. Biopsy was recommended for 4 patients and follow-up was recommended for the other 100 patients. Core biopsy results were lymphoid tissue with focal micro-abscess formations, reactive lymphoid hyperplasia and plasma cell increase. All of the patients had a history of vaccination in the last 3 months. After immunization, initial US imaging was conducted mean 24-days later. The mean long and short axis were 22-mm and 13-mm, respectively. The mean long-short axes ratio was 2.2. The mean thickness of the cortex was 4.8-mm. The long and short axes of the lymph nodes in the first US and control examinations were compared statistically and they decreased in time. The hilum existed (96%). Elastography revealed soft features. The majority of the immunization adenitis are just enlarged benign-appearing lymph nodes. The majority were found during the extensive immunization campaign and were asymptomatic. Patients and their physicians should be aware of the vaccination and imaging evaluation of specific patient groups considering that these vaccinations will continue to be used for a while in the next years.

Clinical characteristics, radiologic features, and histopathology of biopsied lacrimal gland tumors

Herein, we described the clinicopathologic and radiologic features of biopsied lacrimal gland tumors. A retrospective case series of 79 patients treated between 2004 and 2021 was reviewed. The median age was 48.9 years (range 18.3–88.3 years), with 51.9% females. The histopathologic diagnoses were as follows: immunoglobulin G4-related disease (IgG4-RD) = 23, reactive lymphoid hyperplasia = 14, lymphoma = 14, nonspecific inflammation = 10, adenoid cystic carcinoma (ACC) = 9, and pleomorphic adenoma = 9. The proportion of histopathologic diagnoses did not differ significantly over the range of symptom durations (≤ 1 month, > 1–3 months, > 3 months). Patients with ACC had significantly shorter symptom duration and more frequent proptosis than those with pleomorphic adenoma (p = 0.040 and p = 0.009, respectively). Patients with IgG4-RD were older (median 54.3 years) than those with nonspecific inflammation (36.2 years; p = 0.046). Patients with ACC were more likely to present with diplopia than those with lymphoma (p < 0.001). The superior wedge sign increased the likelihood of ACC compared with that of non-epithelial non-malignant lacrimal gland tumors (relative risk ratio = 13.44, p = 0.002). The overall survival of patients with ACC and lymphoma did not differ significantly. Although these patients present with a short symptom duration, urgent orbital imaging, tissue biopsy, and prompt treatment should be performed in patients with lacrimal gland tumors.

Idiopathic multicentric castleman’s disease mimicking immunoglobulin G4-related disease responding well to Bortezomib: a case report

BackgroundCastleman’s disease (CD) is a rare disease that has clinical and pathological similarities to lymphoma and is characterized by a high frequency of associated immunological dysfunction. ImmunoglobulinG4-related disease (IgG4-RD) is a collection of systemic disorders that affect numerous organs and are also referred to as IgG4-associated sclerosing diseases. CD and IgG4-RD are difficult to separate because they may manifest similar commin clinical features.Case presentationThis case describes a 53-year-old female who, during routine medical check-up, exhibited a progressive increase in serum globulin levels and a simultaneous worsening of anemia symptoms, raising concern for a clonal plasma cell disease such as myeloma. However, bone marrow punctures did not reveal any abnormal plasma cells. Also, serum and urine immunofixation electrophoresis demonstrated no abnormal monoclonal protein bands. In addition, several laboratory findings excluded chronic liver disease, chronic infections caused by bacteria or viruses. Later, we found elevated serum IgG4 levels (10,700 mg/L), and identified multiple enlarged lymph nodes throughout the patient’s body. Axillary lymph node aspiration revealed no abnormal lymphocytes, ruling out the possibility of lymphoma. Pathological morphology of the axillary lymph revealed a large number of plasma cells in the lymphatic follicles. In addition, there was a reduction in lymphatic follicle size and apoptosis of the germinal centres. Immunohistochemistry revealed IgG4+/IgG + in > 40% of cells, and more than 100 IgG4 + cells per high powered field (HPF) of specimen. As of now, finding strongly suggested IgG4-RD. This patient was treated with glucocorticoids and various immunosuppressive drugs, such as prednisone, cyclosporine, methotrexate, cyclophosphamide, mycophenolate mofetil, azathioprine and hydroxychloroquine. Unfortunately, the patient did not recover. Ultimately, idiopathic multicentric Castleman disease (iMCD) was diagnosed in relation to the patient’s clinical presentation and laboratory tests, and after combination chemotherapy (VCD: Bortezomib, Cyclophosphamide and Dexamethasone), durable remission was achieved without serious adverse effects. During the follow-up period of one year and ten months, the patient remained stable.ConclusionThe diagnosis of Castleman must be distinguished from other disorders such as IgG4-RD, malignant lymphoma, reactive hyperplasia of various lymph nodes (mostly caused by viral infections), plasmacytoma, advanced HIV and rheumatic diseases. Besides observing systemic symptoms, laboratory tests such as immunoglobulin levels, complement levels, interleukin levels, and C-reactive protein levels should also be performed in order to determine a diagnosis.

S1729 Intestinal Nodular Lymphoid Hyperplasia Diagnosis and Practice Management: A Systematic Review and Treatment Algorithm for Quality Improvement

S1729 Intestinal Nodular Lymphoid Hyperplasia Diagnosis and Practice Management: A Systematic Review and Treatment Algorithm for Quality Improvement

Micronodular thymic carcinoma with lymphoid hyperplasia : A case report and review of the literature

Cases of micronodular thymic carcinoma with lymphoid hyperplasia are rare and are easily treated like common thymic carcinoma in clinical treatment. The clinical data of a 64-year-old woman admitted to the Seventh Affiliated Hospital of Sun Yat-sen University who was diagnosed with micronodular thymic carcinoma with lymphatic stroma after surgery are reported, and its characteristics and treatment methods are discussed in combination with literature.

Blockade of PD-1 and LAG-3 expression on CD8+ T cells promotes the tumoricidal effects of CD8+ T cells.

The diffuse large B-cell lymphoma (DLBCL) has the highest incidence of all lymphomas worldwide. To investigate the functions of lymphocyte activation gene 3 (LAG-3) and programmed cell death 1 (PD-1) in tissues and peripheral blood of patients with DLBCL, the expression of LAG-3 and PD-1 genes in DLBCL-TCGA were analyzed. LAG-3 and PD-1 mRNA levels in DLBCL were analyzed using data from The Cancer Genome Atlas (TCGA) database. Utilize the Genotype-Tissue Expression (GTEx) database for assessing the variance in the expression of LAG-3, PD-1, and other associated factors between the tissues of DLBCL patients and healthy individuals. Immunohistochemistry was applied to detect the expression of LAG-3 and PD-1 levels in 137 cases of DLBCL tissues and 20 cases of reactive lymphoid hyperplasia. The prognostic value of LAG-3 and PD-1 were assessed using the Kaplan-Meier curve. The Estimation of Stromal and Immune cells in Malignant Tumor tissues using Expression data (ESTIMATE) and ssGSEA algorithm were used to explore the immune microenvironment of DLBCL. Additionally, the expression and co-expression of LAG-3 and PD-1 were detected on CD4 and CD8 T cells in peripheral blood samples from 100 cases of DLBCL tissues and 30 cases of healthy individuals using flow cytometry. According to TCGA database, LAG-3 and PD-1 gene expression levels were significantly up-regulated in DLBCL tissues. LAG-3 and PD-1 levels were also strongly positively correlated with those of most infiltrating immune cells. Overall survival of patients with high LAG-3 and PD-1 co-expression was significantly shorter than that of patients with low co-expression. In DLBCL patients, LAG-3 and PD-1 were highly expressed in peripheral blood CD8+ T cells. In addition, LAG-3 was highly expressed in CD4+ T cells, while the expression of PD-1 in CD4+ T cells of DLBCL patients showed no significant difference compared to healthy individuals. Additionally, CD8+ T cells and SU-DHL6/OCI-LY3 from patients with DLBCL were co-cultured in vitro; after addition of LAG-3 and/or PD-1 inhibitors alone, an increased perforin and granzyme B secretion levels by CD8+ T cells were detected, as well as an increase in the overall proportion of tumor cells undergoing apoptosis. High LAG-3 and PD-1 levels significantly inhibit CD8+ T cell function, resulting in weakened ability to kill tumor cells. Combined LAG-3 and PD-1 blockade can restore CD8+ T cell function and provides a potential avenue for development of personalized cellular immunotherapy for DLBCL.

Newly identified common variable immunodeficiency in an elderly patient with rheumatoid arthritis

Common variable immunodeficiency is a group of heterogeneous diseases that are primary immunodeficiencies with a predominant lack of antibody synthesis. The most common manifestation is chronic infectious pathology of the respiratory tract, less often of the gastrointestinal tract, as well as septic arthritis. Non-infectious manifestations include autoimmune diseases, non-infectious diarrhea, cancer, benign lymphoid hyperplasia. In one patient, a combination of several syndromes is possible. Unlike most other primary immunodeficiencies that debut in early childhood, this pathology often manifests in the third or fourth decade of life, and sometimes later in apparently healthy people. Although the routine laboratory method for determining the concentration of the main classes of immunoglobulins makes it quite easy to identify patients with common variable immunodeficiency, often the diagnosis is made many years after the onset of the first clinical symptoms, when serious complications have already developed. The disease is characterized by a gradual onset, chronic progressive course and ineffectiveness of standard therapy. The main method of treatment is lifelong replacement therapy with intravenous immunoglobulins. The article considers a clinical case when an elderly patient with seronegative rheumatoid arthritis with a juvenile onset was diagnosed many years later. The results of immunological studies, including immunophenotyping of peripheral blood and bone marrow lymphocytes, are presented. Issues of differential diagnosis with secondary hypogammaglobulinemia and lymphoproliferative diseases are highlighted. It has been stated that until now, doctors of various specialties are not sufficiently familiar with the problem of primary immunodeficiencies, especially when it comes to adults, and non-infectious manifestations dominate in the clinical picture.

Rupture of 40-year-old silicone gel breast implants: a case report

BackgroundImplant rupture is one of the complications of breast augmentation surgery. The rupture of silicone implants is often insidious, potentially causing problems at any time. This is a case report of the rupture of 145-cc breast implants manufactured by Dow Corning Corporation and their removal at 40 years after augmentation.Case PresentationA 70-year-old female patient was admitted for the removal of a lump in the upper and inner quadrants of the right breast. After a detailed examination, a rupture of the bilateral breast implants was diagnosed. Explantation without replacement was performed; the entire procedure proceeded smoothly. Immunohistochemical staining revealed siliconoma with lymphoid hyperplasia and calcification in the bilateral breasts with no signs of malignancy.ConclusionsSilicone breast augmentation is one of the most popular aesthetic surgical procedures worldwide. Therefore, it is important to educate patients on the need for close monitoring of their implants after augmentation through magnetic resonance imaging or ultrasound to facilitate early detection of any changes before a rupture occurs. Early detection of the implant rupture, in turn, will facilitate early and effective management.

Angiolymphoid hyperplasia with eosinophilia of the tongue – A case report

Angiolymphoid lymphoid hyperplasia with eosinophilia (ALHE) represents a heterogenous group of benign vascular lesions that is characterized by proliferation of small to medium sized vascular structures lined by plump epitheloid (histiocytoid)endothelial cells surrounded by mixed inflammatory infiltrate predominantly eosinophils. Intraoral lesions of ALHE are uncommon and tongue involvement is extremely rare. Here we report a case of ALHE of tongue in a 60 yr old female diagnosed on histopathology and confirmed by IHC.

A case of difficult-to-diagnose hepatic reactive lymphoid hyperplasia finally diagnosed by using PCR analysis of IgH-gene rearrangements: a case report.

Reactive lymphoid hyperplasia (RLH) of the liver is extremely rare. Despite advancements in diagnostic imaging technology, it is still difficult to distinguish from hepatocellular carcinoma (HCC). Herein, we present a case of hepatic RLH mimicking HCC that was postoperatively diagnosed using several imaging modalities. A 78-year-old female was referred to our hospital with a positive hepatitis C virus antibody (HCV Ab) test. Ultrasonography revealed a 13mm isoechoic lesion in segment 8 of the liver. Contrast-enhanced computed tomography (CE-CT) demonstrated arterial hyperintensity and washout during the later phase. On ethoxybenzyl magnetic resonance imaging (EOB-MRI), the lesion was hyperenhanced in the arterial phase and of low intensity in the hepatocyte phase. Although the tumor markers were all within normal limits, the pattern of contrast enhancement of the tumor on CT and MRI was consistent with that of HCC. We performed S8 segmentectomy of the liver. Histological examination of the resected specimen revealed dense lymphoid tissue of variable sizes and shapes with expanded germinal centers. Immunohistochemical examination was positive for CD3, CD10 (germinal center), and CD20, and negative for B-cell lymphoma 2 (bcl-2) (germinal center) and Epstein-Barr virus (EBV). A polymerase chain reaction (PCR) analysis of IgH-gene rearrangements revealed polyclonality. Based on these findings, hepatic RLH was diagnosed. The postoperative course was uneventful, and the patient was discharged on the 10th postoperative day. She had a good quality of life after surgery and no liver nodule recurrence was detected at the 4-month medical follow-up. Hepatic RLH is an extremely rare disease and preoperative diagnosis is difficult. This should be considered in the differential diagnosis of single small hepatic tumors. An echo-guided biopsy and careful observation of imaging may help diagnose hepatic RLH, and a PCR analysis of IgH-gene rearrangements would be necessary for the definitive diagnosis of hepatic RLH.

P-203 - Treatment of refractory cutaneous B-cell lymphoid hyperplasia with intralesional rituximab

P-203 - Treatment of refractory cutaneous B-cell lymphoid hyperplasia with intralesional rituximab

Orbital Lymphoproliferative Disorders (OLPDs) in a 3-year-old Child: Case Report and Review of Literature

Background: Orbital lymphoproliferative disorders (OLPDs) consist of a spectrum of diseases ranging from benign to malignant lesions including reactive lymphoid hyperplasia, atypical lymphoid hyperplasia, and lymphoma. OLPDs rarely present as an orbital mass lesion in children. Accurate discrimination of OLPDs is crucial for treatment planning. We report a case to investigate the clinical and pathological features of OLPDs in children. Case presentation: A 3-year-old female with orbital mass was admitted to the hospital and proceeded to have a CT orbit which showed an orbital mass. The orbital mass was removed after operation and pathologic diagnosis was identified. Pathological diagnosis with histopathological features and immunohistochemical markers was lymphoproliferative lesion in the left orbit. The diagnosis was consistent with OLPDs. There was no recurrence after one-year follow-up. Conclusions: OLPDs are rare in children. The clinical manifestations and imaging have no specificity; pathological diagnosis with histopathological features and immunohistochemical markers is the main basis for the diagnosis and treatment.

Hyaline Vascular Variant of Castleman Disease of the Tonsil in an Adolescent: A case Report.

Castleman disease (CD) is a lymphoproliferative disorder classified into two categories as unicentric Castleman disease (UCD) or localized type and multicentric Castleman disease (MCD). A rare case of hyaline vascular variant of tonsil has been presented in which a 14 years old male presented with symptomatic unilateral hypertrophy of right tonsil. A right tonsillectomy was done and surgical pathology report was concluded as hyaline vascular variant of Castleman's disease.Castleman disease (CD) is a rare lymphoproliferative disorder also called as giant lymph node hyperplasia, angiofollicular lymph node hyperplasia (AFH), angiomatous lymphoid hematoma and follicular lymphoreticuloma. The treatment of symptomatic patients with UCD is complete surgical excision (as in present case). In cases with incomplete resection, adjuvant radiotherapy can be given.

Etiological Profile of Lower Gastrointestinal Bleeding in Children and Adolescents from Kashmir; A Tale of 5 Years.

Background: Lower gut bleeding is an alarming sign among caregivers. Determining the etiology is of utmost importance for further management. This is the first study conducted in northernmost India. Methods: This cross-sectional study was conducted at the Department of Pediatrics, Government Medical College, Srinagar. This study aimed to describe the etiology of lower gastrointestinal bleeding in the age group of 1-18 years over the past 5 years from June 2017 to June 2022. Results: A total of 310 children presented with hematochezia (53.5%), blood mixed with loose stools for > 2 weeks (39.3%), melena (1.9%), and occult blood in stools (0.3%). The mean age was 5.12 years. The age group of 1-6 years was 73.5 %. The most common findings were rectosigmoid polyps n=104 (33.5%), anal fissure n=47 (15.1%), lymphoid nodular hyperplasia (LNH) n=38 (12.2%), trichuris dysentery syndrome n=30(9.7%), cow's milk protein allergy n=27(8.7%), non-specific colitis n=18(5.8%), solitary rectal ulcer syndrome n=14(4.5%), inflammatory bowel disease n=6 (1.9%),intestinal tuberculosis n=3(0.9%), duodenal dieulafoy lesion 1(0.3%), and blue bleb nevus rubber syndrome n=1(0.3%). 21 patients had a normal colonoscopy. The colonoscopy yield was 93.3 %. Among the colonoscopy-negative patients, 6(1.6%) had Meckel's diverticulum, and 1(0.3%) had a duodenal dieulafoy lesion. Conclusion: Lower GI bleeding most commonly presents as hematochezia, and the most common cause is a rectosigmoid polyp. Colonoscopy is the procedure of choice to evaluate the etiology of lower GI bleeding. Anal fissures, LNH, Trichuris trichiura, and cow's milk protein allergy are other common causes of lower gut bleeding in Kashmir, northernmost India.

DIFFICULTIES OF DIFFERENTIAL SEARCH FOR NODULAR LYMPHOID HYPERPLASIA OF THE GASTROINTESTINAL TRACT

Nodular lymphoid hyperplasia of the gastrointestinal tract is characterized by the presence of many small nodules, usually 2 to 10 mm in diameter, located more frequently in the small intestine, stomach, colon, or rectum. The pathogenesis is largely unknown, and the occurrence is possible in all age groups, quite common in children, and may affect adults with or without immunodeficiency. In some cases, patients may have comorbidities, namely common variable immunodeficiency, selective IgA deficiency, Giardia intestinalis, celiac disease, Helicobacter pylori, and less often human immunodeficiency virus. Recently, data have appeared on the detection of nodular lymphoid hyperplasia in patients who have undergone COVID-19. Nodular lymphoid hyperplasia is usually asymptomatic but can cause a variety of gastrointestinal symptoms such as abdominal pain, chronic diarrhea, bleeding, or ileus. Diagnosis is by endoscopy or barium contrast and must be confirmed by pathological findings. Nodular lymphoid hyperplasia is a risk factor for both intestinal and, very rarely, extraintestinal lymphoma.

B-cell Follicular Lymphoid Hyperplasia (Pseudolymphoma) of the Oral Cavity: A Diagnostic Quandary.

Pseudolymphoma is a reactive process involving lymphadenopathy, polyclonal proliferation of B or T-cells, simulating oral lymphoma. With its incidence being very rare, only four cases have been reported in oral cavity with the detailed immunocytochemical examination, which can be due to this entity's unawareness, underdiagnosis or overdiagnosis. It is prerogative to perform immunocytochemical investigations to prevent overdiagnosis as lymphoma, which can be debilitating to the patient. Wherein the treatment of pseudolymphoma initially includes topical or intralesional corticosteroid, antibiotics to surgical and radiotherapy based on its etiology. Herein, we discuss B-cell follicular lymphoid hyperplasia previously diagnosed as small round cell tumor.

TACI and endogenous APRIL in B cell maturation

While many of the genes and molecular pathways in the germinal center B cell response which initiate protective antibody production are known, the contributions of individual molecular players in terminal B cell differentiation remain unclear. We have previously investigated how mutations in TACI gene, noted in about 10% of patients with common variable immunodeficiency, impair B cell differentiation and often, lead to lymphoid hyperplasia and autoimmunity. Unlike mouse B cells, human B cells express TACI-L (Long) and TACI-S (Short) isoforms, but only TACI-S promotes terminal B cell differentiation into plasma cells. Here we show that the expression of intracellular TACI-S increases with B cell activation, and colocalizes with BCMA and their ligand, APRIL. We show that the loss of APRIL impairs isotype class switch and leads to distinct metabolic and transcriptional changes. Our studies suggest that intracellular TACI-S and APRIL along with BCMA direct long-term PC differentiation and survival.

What is the margin of error of surgeons and radiological imaging in diagnosing acute appendicitis?

Acute appendicitis is the most common emergency requiring surgical intervention in general surgery. Negative appendectomy is defined as the removal of a pathologically normal appendix. In this study, we aimed to show our negative appendectomy rate. This study was carried out among 2990 patients who were operated on for appendicitis between 2015-2020 at the Health Sciences University, İstanbul Kanuni Sultan Suleyman Training, and Research Hospital. Accrual and historical records of the patients were analyzed using NCSS (Number Cruncher Statistical System) 2007 Statistical Software (Utah, USA) package program. The results were evaluated at the significance level of P < 0.05. The mean age of all patients was 33. Of the patients, 1011 were women and 1979 were men. 27 of the women patients were pregnant. We requested a blood test (WBC count) and an abdominal ultrasound for all our patients who came with the complaint of abdominal pain in the right lower quadrant. Negative appendectomy was performed with ultrasonography in 622 patients with pathological diagnoses of lymphoid hyperplasia and fibrous obliteration (20.8%). We had abdominal computerized tomography (CT) for 285 patients and abdominal magnetic resonance imaging (MRI) for 16 of 27 pregnant women (59.25%) due to unclear clinical picture. Diagnostic laparoscopy was performed in 36 of the patients who underwent CT and 4 of the patients who underwent MRI since the diagnosis could not be made. We performed unnecessary appendectomy in 21.2% of the patients. With the increasing clinical follow-up experience of surgeons and developing technology in radiology, our aim is to minimize the negative appendectomy rate as much as possible.