A Nationwide Study of the Delayed Diagnosis and the Clinical Manifestations of Predominantly Antibody Deficiencies and CTLA4-Mediated Immune Dysregulation Syndrome in Greece.

Background and Objectives: Predominantly antibody deficiencies (PAD) represent the most common type of primary immunodeficiencies in humans, characterized by a wide variation in disease onset, clinical manifestations, and outcome. Considering that the prevalence of PAD in Greece is unknown, and there is limited knowledge on the clinical and laboratory characteristics of affected patients, we conducted a nationwide study. Materials and Methods: 153 patients (male/female: 66/87; median age: 43.0 years; range: 7.0-77.0) diagnosed, and followed-up between August 1979 to September 2023. Furthermore, we classified our cohort into five groups according to their medical history, immunoglobulin levels, and CTLA4-mutational status: 123 had common variable immunodeficiency (CVID), 12 patients with "secondary" hypogammaglobulinemia due to a previous B-cell depletion immunotherapy for autoimmune or malignant disease several years ago (median: 9 years, range 6-14) displaying a typical CVID phenotype, 7 with combined IgA and IgG subclass deficiencies, 5 patients with CVID-like disease due to CTLA4-mediated immune dysregulation syndrome, and 6 patients with unclassified hypogammaglobulinemia. Results: We demonstrated a remarkable delay in PAD diagnosis, several years after the onset of related symptoms (median: 9.0 years, range: 0-43.0). A family history of PAD was only present in 11.8%, with the majority of patients considered sporadic cases. Most patients were diagnosed in the context of a diagnostic work-up for recurrent infections, or recurrent/resistant autoimmune cytopenias. Interestingly, 10 patients (5.6%) had no history of infection, diagnosed due to either recurrent/resistant autoimmunity, or during a work-up of their medical/family history. Remarkable findings included an increased prevalence of lymphoproliferation (60.1%), while 39 patients (25.5%) developed bronchiectasis, and 16 (10.5%) granulomatous disease. Cancer was a common complication in our cohort (25 patients, 16.3%), with B-cell malignancies representing the most common neoplasms (56.7%). Conclusion: Our findings indicate the necessity of awareness about PAD and their complications, aiming for early diagnosis and the appropriate management of affected patients.

Predicting lymphoma in Sjögren's syndrome and the pathogenetic role of parotid microenvironment through precise parotid swelling recording.

OBJECTIVE: Parotid swelling (PSW) is a major predictor of non-Hodgkin's lymphoma (NHL) in primary SS (pSS). However, since detailed information on the time of onset and duration of PSW is scarce, this was investigated to verify whether it may lead to further improved prediction. NHL localization was concomitantly studied to evaluate the role of the parotid gland microenvironment in pSS-related lymphomagenesis. METHODS: A multicentre study was conducted among patients with pSS who developed B cell NHL during follow-up and matched controls that did not develop NHL. The study focused on the history of salivary gland and lachrymal gland swelling, evaluated in detail at different times and for different durations, and on the localization of NHL at onset. RESULTS: PSW was significantly more frequent among the cases: at the time of first referred pSS symptoms before diagnosis, at diagnosis and from pSS diagnosis to NHL. The duration of PSW was evaluated starting from pSS diagnosis, and the NHL risk increased from PSW of 2-12 months to >12 months. NHL was prevalently localized in the parotid glands of the cases. CONCLUSION: A more precise clinical recording of PSW can improve lymphoma prediction in pSS. PSW as a very early symptom is a predictor, and a longer duration of PSW is associated with a higher risk of NHL. Since lymphoma usually localizes in the parotid glands, and not in the other salivary or lachrymal glands, the parotid microenvironment appears to be involved in the whole history of pSS and related lymphomagenesis.

Clinical picture, outcome and predictive factors of lymphoma in primary Sjögren's syndrome: results from a harmonized dataset (1981-2021).

OBJECTIVES: Primary Sjögren's Syndrome (pSS) carries the highest risk for non-Hodgkin's lymphoma (NHL) development among systemic autoimmune diseases. However, the paucity of data on the long-term survival of those patients and the lack of established predictors for each lymphoma histologic subtype prompted our present study. METHODS: We retrospectively analysed 121 patients diagnosed with NHL according to the WHO classification criteria. All patients fulfilled the 2016 ACR-EULAR classification criteria for pSS. Cumulative clinical, laboratory, radiologic, treatment regimens and histologic data were recorded, harmonized and analysed. Overall survival (OS) and event-free survival (EFS) curves were calculated. A mucosa-associated lymphoid tissue lymphoma (MALTL) prediction model was developed by applying innovative data-driven analysis of clinical features present at the time of pSS diagnosis. RESULTS: MALTLs constituted the majority of lymphomas (92/121, 76.0%) followed by diffuse large B-cell lymphomas (DLBCL) (11/121, 9.0%) and nodal marginal zone lymphomas (NMZL) (8/121, 7%). MALTLs show salivary glands localization, limited disease and often bone marrow and nodal involvement. The 10-year OS and EFS rates were 79% and 45.5% for MALTLs, 40.9% and 24.2% for DLBCL and 46% and 31% for NMZL. Cryoglobulinemia, focus score and the total EULAR SS Disease Activity Index (ESSDAI) composite index at pSS diagnosis were proven independent MALTL predictors. Even though MALTLs have a comparatively good survival outlook, they are accompanied by frequent events throughout their clinical course. CONCLUSIONS: Common features of pSS, present at diagnosis, can predict future lymphomagenesis meriting a more intensive follow-up plan.

Interferon (IFN)-stimulated gene 15: A novel biomarker for lymphoma development in Sjögren's syndrome.

OBJECTIVE: We investigated whether interferon (IFN) induced genes could serve as biomarkers for the detection of lymphoma development among patients with Sjögren's syndrome (SS). METHODS: Total RNA was extracted from 98 labial minor salivary glands (LMSG) biopsies of SS patients [61 not complicated by lymphoma (SS-nL) and 37 complicated by Non-Hodgkin Lymphoma (NHL) (SS-L)] and 67 matched peripheral blood (PB) samples, as well as from 30 LMSG biopsies and 17 matched PB derived from sicca controls (SC). RNA sequencing was performed in LMSG biopsies of high and low risk SS patients for lymphoma development and SC. Expression analysis of type I (MX-1, IFIT-1, IFI44 and ISG-15) and type II IFN induced (CXCL9/MIG-1, GBP-1) genes was performed by real time PCR. RESULTS: ISG-15 transcript levels were significantly higher in SS-L patients compared to SS-nL patients in both LMSG tissues and PB specimens. Additionally, MIG-1 was found to display higher expression values in LMSG tissues, but not in PB derived from SS-L patients compared to the SS-nL group. A coordinate expression in PB/LMSG of type I IFN (ISG-15, MX-1 and IFI44), but not type II IFN induced genes was also observed. CONCLUSION: ISG-15 gene expression was able to distinguish SS-nL and SS-L at both periphery and tissue level and therefore could represent a novel biomarker for lymphoma development among SS patients. PB and LSMG seem to share a common transcriptional profile of type I IFN pathway.

From the (Epi)Genome to Metabolism and Vice Versa; Examples from Hematologic Malignancy.

Hematologic malignancies comprise a heterogeneous group of neoplasms arising from hematopoietic cells or their precursors and most commonly presenting as leukemias, lymphomas, and myelomas. Genetic analyses have uncovered recurrent mutations which initiate or accumulate in the course of malignant transformation, as they provide selective growth advantage to the cell. These include mutations in genes encoding transcription factors and epigenetic regulators of metabolic genes, as well as genes encoding key metabolic enzymes. The resulting alterations contribute to the extensive metabolic reprogramming characterizing the transformed cell, supporting its increased biosynthetic needs and allowing it to withstand the metabolic stress that arises as a consequence of increased metabolic rates and changes in its microenvironment. Interestingly, this cross-talk is bidirectional, as metabolites also signal back to the nucleus and, via their widespread effects on modulating epigenetic modifications, shape the chromatin landscape and the transcriptional programs of the cell. In this article, we provide an overview of the main metabolic changes and relevant genetic alterations that characterize malignant hematopoiesis and discuss how, in turn, metabolites regulate epigenetic events during this process. The aim is to illustrate the intricate interrelationship between the genome (and epigenome) and metabolism and its relevance to hematologic malignancy.

Akt Signaling Pathway Is Activated in the Minor Salivary Glands of Patients with Primary Sjögren's Syndrome.

Primary Sjögren's syndrome (pSS) is an autoimmune exocrinopathy of mainly the salivary and lacrimal glands associated with high prevalence of lymphoma. Akt is a phosphoinositide-dependent serine/threonine kinase, controlling numerous pathological processes, including oncogenesis and autoimmunity. Herein, we sought to examine its implication in pSS pathogenesis and related lymphomagenesis. The expression of the entire and activated forms of Akt (partially and fully activated: phosphorylated at threonine-308 (T308) and serine-473 (S473), respectively), and two of its substrates, the proline-rich Akt-substrate of 40 kDa (PRAS40) and FoxO1 transcription factor has been immunohistochemically examined in minor salivary glands (MSG) of pSS patients (n = 29; including 9 with pSS-associated lymphoma) and sicca-complaining controls (sicca-controls; n = 10). The entire and phosphorylated Akt, PRAS40, and FoxO1 molecules were strongly, uniformly expressed in the MSG epithelia and infiltrating mononuclear cells of pSS patients, but not sicca-controls. Morphometric analysis revealed that the staining intensity of the fully activated phospho-Akt-S473 in pSS patients (with or without lymphoma) was significantly higher than sicca-controls. Akt pathway activation was independent from the extent or proximity of infiltrates, as well as other disease features, including lymphoma. Our findings support that the Akt pathway is specifically activated in MSGs of pSS patients, revealing novel therapeutic targets.

Exploiting the Role of Hypoxia-Inducible Factor 1 and Pseudohypoxia in the Myelodysplastic Syndrome Pathophysiology.

Myelodysplastic syndromes (MDS) comprise a heterogeneous group of clonal hematopoietic stem (HSCs) and/or progenitor cells disorders. The established dependence of MDS progenitors on the hypoxic bone marrow (BM) microenvironment turned scientific interests to the transcription factor hypoxia-inducible factor 1 (HIF-1). HIF-1 facilitates quiescence maintenance and regulates differentiation by manipulating HSCs metabolism, being thus an appealing research target. Therefore, we examine the aberrant HIF-1 stabilization in BMs from MDS patients and controls (CTRLs). Using a nitroimidazole-indocyanine conjugate, we show that HIF-1 aberrant expression and transcription activity is oxygen independent, establishing the phenomenon of pseudohypoxia in MDS BM. Next, we examine mitochondrial quality and quantity along with levels of autophagy in the differentiating myeloid lineage isolated from fresh BM MDS and CTRL aspirates given that both phenomena are HIF-1 dependent. We show that the mitophagy of abnormal mitochondria and autophagic death are prominently featured in the MDS myeloid lineage, their severity increasing with intra-BM blast counts. Finally, we use in vitro cultured CD34+ HSCs isolated from fresh human BM aspirates to manipulate HIF-1 expression and examine its potential as a therapeutic target. We find that despite being cultured under 21% FiO2, HIF-1 remained aberrantly stable in all MDS cultures. Inhibition of the HIF-1α subunit had a variable beneficial effect in all <5%-intra-BM blasts-MDS, while it had no effect in CTRLs or in ≥5%-intra-BM blasts-MDS that uniformly died within 3 days of culture. We conclude that HIF-1 and pseudohypoxia are prominently featured in MDS pathobiology, and their manipulation has some potential in the therapeutics of benign MDS.

TREX1 variants in Sjogren's syndrome related lymphomagenesis.

Genetic variants of the three-prime repair exonuclease 1 (TREX1) -an exonuclease involved in DNA repair and degradation- have been previously found to increase susceptibility to Aicardi Goutieres syndrome, familial chilblain lupus and systemic lupus erythematosus. We aimed to explore whether TREX1 common variants could influence the risk of primary Sjogren's syndrome (SS) and SS-related lymphoma. Three single nucleotide polymorphisms (SNPs) of the TREX1 gene (rs11797, rs3135941 and rs3135945) were evaluated in 229 SS, 89 SS-lymphoma (70 SS-MALT and 19 SS non-MALT) and 240 healthy controls by PCR-based assays. In available 52 peripheral blood and 26 minor salivary gland tissues from our SS cohort, mRNA expression of type I interferon (IFN) related genes and TREX1 was determined by real-time PCR. Significantly decreased prevalence of rs11797 A minor allele was detected in SS patients complicated by non-MALT lymphoma compared to controls (ΟR [95% CI]: 0.4 [0.2-0.9], p-value: 0.02). SS patients carrying the rs11797 AA genotype had increased type I IFN related gene mRNA expression in minor salivary gland tissues. These data support genetically related dampened type I IFN production as an additional mechanism for SS-related lymphomagenesis.

Predictive markers of lymphomagenesis in Sjögren's syndrome: From clinical data to molecular stratification.

Sjögren's syndrome (SS) is a chronic systemic autoimmune disease, affecting predominantly the exocrine glands, a large array of systemic manifestations and high risk of lymphoma development. The latter constitutes the major adverse outcome of SS contributing in the increased morbidity and mortality of the disease. The vast majority of lymphomas in SS are B-cell non-Hodgkin's lymphomas (NHL), primarily indolent mucosa-associated lymphoid tissue (MALT) lymphomas, followed by nodal marginal zone lymphomas (NMZL) and diffuse large B cell lymphomas (DLBCL). In the last 3 decades and due to the adverse impact of NHL in disease outcome, an effort has been undertaken to identify markers and models predicting patients with SS at high risk for lymphoma development. Several epidemiological, clinical, laboratory and histological parameters, some of which are evident at the time of SS diagnosis, were proved to independently predict the development of NHL. These include salivary gland enlargement, skin vasculitis/purpura, glomerulonephritis, peripheral neuropathy, Raynaud's phenomenon, lymphadenopathy, splenomegaly, cytopenias, hypocomplementemia, cryoglobulinemia, rheumatoid factor, anti-Ro/La autoantibodies, hypergammaglobulinemia, serum monoclonal gammopathy, biopsy focus score and organization of lymphocytic infiltrates in the salivary glands into ectopic germinal centers. Prediction models combining some of the afore-mentioned predictors have also been described. However, the identification of specific and sensitive molecular biomarkers, related to the process of lymphomagenesis is still pending. Recently, we described a novel biomarker the miR200b-5p micro-RNA. Low levels of this miRNA in the minor salivary glands, appears to discriminate with high specificity and sensitivity the SS patients who have from those who do not have NHL. miR200b-5p, being expressed years before the clinical onset of NHL, independently predicts NHL development with a predictive value higher than the previously published multifactorial models and has a possible role in the monitoring of therapeutic response. Thus, it is a strong candidate for the identification and follow-up of patients at risk.

Low miR200b-5p levels in minor salivary glands: a novel molecular marker predicting lymphoma development in patients with Sjögren's syndrome.

OBJECTIVES: Development of non-Hodgkin's lymphoma (NHL) is the major adverse outcome of Sjögren's syndrome (SS) affecting both morbidity and mortality. Preliminary evidence suggested that, although not deregulated compared with sicca controls, miR200b-5p levels are decreased in the minor salivary glands (MSGs) of SS patients with NHL. The aim of the current study was to evaluate the MSG expression of miR200b-5p in SS-associated NHLs and its potential predictive value for the identification of patients with SS susceptible to develop NHL. METHODS: miR200b-5p expression was investigated in MSG tissues of patients with SS who were at: (A) low risk and did not develop NHL during follow-up (n=27; median follow-up time on biopsy performance, range: 8.9 years, 1.33-14 years), (B) high-risk and diagnosed with NHL during follow-up (prelymphoma; n=17; median follow-up to until lymphoma diagnosis, range: 3.67 years, 0.42-8.5 years) and (C) had NHL (n=35), as well as non-SS sialadenitis controls (sarcoidosis and hepatitis C virus (HCV) infection, four each). The differential miR200b-5p expression, correlations with disease features and its discriminative/predictive value, was evaluated by appropriate statistical approaches. RESULTS: The MSG levels of miR200b-5p were significantly downregulated in patients with SS who will develop or have NHL and strongly discriminated (p<0.0001) them from those without lymphoma or non-SS sialadenitis. Furthermore, they were reduced long before clinical onset of lymphoma, did not significantly change on transition to lymphoma and, importantly, were proved strong independent predictors of patients who will develop NHL (p<0.0001). CONCLUSIONS: These findings support that miR200b-5p levels in MSGs represent a novel predictive and possibly pathogenetic mechanism-related factor for the development of SS-associated NHL, since its expression is impaired years before lymphoma clinical onset.

Type I and II interferon signatures in Sjogren's syndrome pathogenesis: Contributions in distinct clinical phenotypes and Sjogren's related lymphomagenesis.

Both type I and II interferons (IFNs) have been implicated in the pathogenesis of Sjogren's syndrome (SS). We aimed to explore the contribution of type I and II IFN signatures in the generation of distinct SS clinical phenotypes including lymphoma development. Peripheral blood (PB) from SS patients (n = 31), SS patients complicated by lymphoma (n = 13) and healthy controls (HC, n = 30) were subjected to real-time PCR for 3 interferon inducible genes (IFIGs) preferentially induced by type I IFN, 2 IFIGs preferentially induced by IFNγ as well as for IFNα and IFNγ genes. The same analysis was performed in minor salivary gland tissues (MSG) derived from 31 SS patients, 10 SS-lymphoma patients and 17 sicca controls (SC). In PB and MSG tissues, overexpression of both type I and type II IFIGs was observed in SS patients versus HC and SC, respectively, with a predominance of type I IFN signature in PB and a type II IFN signature in MSG tissues. In SS-lymphoma MSG tissues, lower IFNα, but higher IFNγ and type II IFIG transcripts compared to both SS and SC were observed. In receiver operating characteristic curve analysis, IFNγ/IFNα mRNA ratio in MSG tissues showed the best discrimination for lymphoma development. Discrete expression patterns of type I and II IFN signatures might be related to distinct SS clinical phenotypes. Additionally, IFNγ/IFNα mRNA ratio in diagnostic salivary gland biopsies is proposed as a novel histopathological biomarker for the prediction of in situ lymphoma development in the setting of SS.

B-cell activating factor genetic variants in lymphomagenesis associated with primary Sjogren's syndrome.

Primary Sjogren's syndrome (pSS) is complicated by B-cell lymphoma in 5-10% of patients. Several clinical and serological features are proposed as adverse predictors for such complication and define a high risk pSS phenotype. We aimed to explore whether previously described polymorphisms of the B-cell activating factor (BAFF) could be related to pSS-related lymphomagenesis. Five single nucleotide polymorphisms (SNPs) of the BAFF gene (rs1224141, rs12583006, rs9514828, rs1041569 and the rs9514827) were evaluated in 111 low risk pSS patients (type II), 82 high risk/lymphoma patients (type I) and 137 healthy controls (HC) by PCR-based assays. The classification of pSS patients into types I and II was based on the presence or absence of risk factors or lymphoma development, respectively. Genotype and haplotype analysis was performed for all variants in the pSS groups. Since the rs1041569 SNP was not in Hardy-Weinberg equilibrium in the HC group (p < 0.001), haplotype analysis was performed in the remaining four out of the five SNPs tested when comparisons with HC individuals were performed. The high risk pSS group was characterized by higher frequency of the minor T allele of the rs9514828 BAFF polymorphism compared to HC. Compared to the low risk pSS patients but not the HC, the high risk pSS group exhibited lower frequencies of the AA genotype of the rs12583006 polymorphism as well as the TACAC and TACC haplotypes and higher frequency of the TTTC haplotype. The low risk pSS group exhibited higher frequency of the minor A allele and AA genotype of the rs12583006 variant compared to HC. Both pSS groups were characterized by increased frequency of the haplotype TATT and GTTC and decreased frequency of the TTCT when compared to HC. Taken together, these findings suggest the implication of the host's genetic background in pSS-related lymphomagenesis. The interaction of pSS-related BAFF gene haplotypes together with distinct BAFF genetic variants appears to contribute to this complication.

Validation of the classification criteria for cryoglobulinaemic vasculitis.

OBJECTIVE: The aim of this study was to validate the classification criteria for cryoglobulinaemic vasculitis (CV). METHODS: Twenty-three centres were involved. New patients with CV (group A) and controls, i.e. subjects with serum cryoglobulins but lacking CV based on the gold standard of clinical judgment (group B) and subjects without cryoglobulins but with clinical features that can be observed in the course of CV (group C), were studied. Positivity of serum cryoglobulins was necessary for CV classification. Sensitivity and specificity of the criteria were calculated by comparing group A vs group B. The group A vs group C comparison was done to demonstrate the possible diagnostic utility of the criteria. RESULTS: The study included 268 patients in group A, 182 controls in group B and 193 controls in group C (small vessel vasculitis, 51.8%). The questionnaire (at least 2/3 positive answers) showed 89.0% sensitivity and 93.4% specificity; the clinical item (at least 3/4 clinical involvement) showed 75.7% sensitivity and 89.0% specificity and the laboratory item (at least 2/3 laboratory data) showed 80.2% sensitivity and 62.4% specificity. The sensitivity and specificity of the classification criteria (at least 2/3 positive items) were 89.9% and 93.5%, respectively. The comparison of group A with group C demonstrated the clinical utility of the criteria in differentiating CV from CV mimickers. CONCLUSION: Classification criteria for CV were validated in a second, large, international study confirming good sensitivity and specificity in a complex systemic disease.

MDR1 mRNA expression and MDR1 gene variants as predictors of response to chemotherapy in patients with acute myeloid leukaemia: a meta-analysis.

Data from 30 pharmacogenomic studies that investigated MDR1 mRNA expression or gene variants (C3435T, G2677TA, C1236T) and response to therapy in acute myeloid leukaemia (AML) were synthesized. Anthracycline-based regimens were mainly used. MDR1 mRNA overexpression was associated with poor response to therapy [odds ratio (OR) = 2.49 95% confidence interval (CI) 1.38-4.50]. The gene variants were not associated with response to treatment; the generalized ORs, a genetic model-free approach, for the variants C3435T, G2677TA and C1236T were ORG = 0.86 (95% CI 0.55-1.37), ORG = 0.97 (95% CI 0.58-1.64) and ORG = 1.17 (95% CI 0.75--1.83), respectively. There is indication that MDR1 mRNA expression may be considered as a potential marker for response to chemotherapy in AML patients.

Indications for bone marrow examination in autoimmune disorders with concurrent haematologic alterations.

OBJECTIVES: The aim of this study was to evaluate the aetiology of 'unexplained' cytopenias in patients with autoimmune disorders, as well as to identify parameters that should alert clinicians to the need for bone marrow examination. METHODS: During the study period (2005-2010), 110 consecutive patients with an underlying systemic autoimmune disease, excluding Sjogren's syndrome, were referred for haematological consultation and bone marrow examination, due to cytopenias without evident cause including blood loss, haemolysis, nutritional deficiencies and haemoglobin disorders. RESULTS: Systemic lupus erythaematosus was the most frequent underlying condition (38/110, 34.5%), and anaemia (haemoglobin<12gr/dl) the most common haematologic abnormality (81/110, 74%). Prior to evaluation, more than half of the patients received cytotoxic or immunosuppressive drugs, with methotrexate being the most commonly administrated agent (29/110, 26.4%). Evaluation was informative in 31 (28.2%) of the cases. Twenty-four (21.8%) cases of haematologic clonal disease were diagnosed; 11 myelodysplastic syndromes, 6 lymphoproliferative disorders, 6 plasma cell dyscrasias and one myeloproliferative neoplasm. Seven cases (6.4%) with bone marrow toxicity were also noted. Male gender, serum iron >90 µg/dl, mean corpuscular volume (MCV) >90fl, and serum monoclonal band were significant predictors of specific diagnosis including clonal haematologic disorder or bone marrow toxicity. All other correlations were insignificant. CONCLUSIONS: Clonal haematologic disorders and toxicity are frequent findings in patients with autoimmunity referred for haematologic consultation, owing to otherwise unexplained cytopenias. Patients with high serum iron, high MCV and presence of serum monoclonal band should undergo bone marrow examination to exclude haematologic malignancy or bone marrow toxicity.

The Role of the Akt Signaling Pathway in Sjögren's Syndrome.

Primary Sjögren's syndrome (pSS) is a chronic autoimmune disorder with diverse clinical picture and high prevalence of B-cell non-Hodgkin lymphoma (NHL), that possibly raises from the chronic activation of B-cells. The mechanisms underlying the development of neoplasia in pSS remain elusive. Activated Akt/mTOR pathway is a uniform finding in cancer, whereas its significance in haematologic malignancies is highlighted by the plethora of inhibitors with promising therapeutic efficacy. PI3K-Akt activation has been involved in the TLR3-induced apoptosis of cultured salivary gland epithelial cells (SGECs), whereas upregulated expression of the phosphorylated ribosomal S6 protein (pS6), an end-result of PI3K signalling, has been detected in the infiltrating T and B lymphocytes at the MSG lesions of pSS patients; nevertheless, without specifying if this was mediated by the Akt/mTOR or Ras/ERK pathways. To this end, the role of Akt/mTOR pathway in pSS and associated lymphomagenesis, will be investigated by the immunohistochemical detection of the entire and phosphorylated protein forms of Akt kinase and two of its substrates, namely the FoxO1 transcription factor and the proline-rich Akt substrate of 40-kDa (PRAS40) in MSGs of pSS patients with variable histological and clinical phenotype, as well as sicca-complaining controls. Subsequently, the role of this pathway will be evaluated in in-vitro inhibition experiments, studying the effect of specific inhibitors in the phenotype, function, and interaction of SGECs and B cells. The current proposal is expected to promote the understanding of pSS pathogenesis, enlighten the mechanisms underlying related lymphomagenesis and possible therapeutic targets.

The Use of Low-Dose Chest Computed Tomography for the Diagnosis and Monitoring of Pulmonary Infections in Patients with Hematologic Malignancies.

The study aimed to assess the image quality and diagnostic performance of low-dose Chest Computed Tomography (LDCCT) in detecting pulmonary infections in patients with hematologic malignancies. A total of 164 neutropenic patients underwent 256 consecutive CT examinations, comparing 149 LDCCT and 107 Standard-Dose Chest CT (SDCCT) between May 2015 and June 2019. LDCCT demonstrated a 47% reduction in radiation dose while maintaining acceptable image noise and quality compared to SDCCT. However, LDCCT exhibited lower sensitivity in detecting consolidation (27.5%) and ground glass opacity (64.4%) compared to SDCCT (45.8% and 82.2%, respectively) with all the respective p-values from unadjusted and adjusted for sex, age, and BMI analyses being lower than 0.006 and the corresponding Odds Ratios of detection ranging from 0.30 to 0.34. Similar trends were observed for nodules ≥3 mm and ground glass halo in nodules but were not affected by sex, age and BMI. No significant differences were found for cavitation in nodules, diffuse interlobular septal thickening, pleural effusion, pericardial effusion, and lymphadenopathy. In conclusion, LDCCT achieved substantial dose reduction with satisfactory image quality but showed limitations in detecting specific radiologic findings associated with pulmonary infections in neutropenic patients compared to SDCCT.