Comparative Analysis of FCGR Gene Polymorphism in Pulmonary Sarcoidosis and Tuberculosis

Insights on immune profile, pathogenesis and differential diagnosis of hypersensitivity pneumonitis and pulmonary sarcoidosis-A holistic review and bibliometric analysis

Hypersensitivity pneumonitis (HP) and sarcoidosis are granulomatous interstitial lung diseases with overlapping clinical and immunological features, posing diagnostic and therapeutic challenges. This review offers a comprehensive assessment of their immune mechanisms, etiology, and pathogenesis. HP is predominantly triggered by exposure to environmental antigens, while sarcoidosis involves an exaggerated immune response to elusive antigens. Both diseases are driven by Th1 and Th17 pathways, regulatory T-cell dysfunction, and cytokine-mediated granuloma formation. Emerging diagnostic and prognostic biomarkers, such as KL-6, GDF15, PD-1, TIGIT, and genetic regulators including m6A and m5C modifications, provide valuable insights for disease stratification. Incorporating findings from a total of 38 studies (HP: n = 13; sarcoidosis: n = 25) published in the last 5 years, this review highlights key immune regulatory mechanisms, identifies critical research gaps, and provides directions for improving differential diagnosis. Addressing these gaps through multi-omics integration, computational tools, and interdisciplinary collaboration holds significant potential for refining diagnostic accuracy, advancing therapeutic strategies, and improving patient outcomes in both HP and sarcoidosis.

Immunoglobulin genes and severity of COVID-19

There is tremendous interindividual and interracial variability in the outcome of SARS-CoV-2 infection, suggesting the involvement of host genetic factors. Here, we investigated whether IgG allotypes GM (γ marker) 3 and GM 17, genetic markers of IgG1, contributed to the severity of COVID-19. IgG1 plays a pivotal role in response against SARS-CoV-2 infection. We also investigated whether these GM alleles synergistically/epistatically with IGHG3 and FCGR2A alleles-which have been previously implicated in COVID-19-modulated the extent of COVID-19 severity. The study population consisted of 316 COVID-19 patients who needed treatment in the intensive care unit of Hospital Universitario Central de Asturias. All individuals were genotyped for GM 3/17, IGHG3 hinge length, and FCGR2A rs1801274 A/G polymorphisms. Among the 316 critical patients, there were 86 deaths. The risk of death among critical patients was significantly higher in subjects with GM 17 (IgG1) and short hinge length (IgG3). GM 17-carriers were at almost three-fold higher risk of death than non-carriers (p < 0.001; OR = 2.86, CI 1.58-5.16). Subjects with short hinge length of IgG3 had a two-fold higher risk of death than those with medium hinge length (p = 0.01; OR = 2.16, CI 1.19-3.90). GM 3/3 and IGHG3 (MM) genotypes were less frequent among death vs. survivors (9% vs 36%, p < 0.001) and associated with protective effect (OR = 0.18, 95% CI = 0.08-0.39). This is the first report implicating IgG1 allotypes in COVID-19-spurred death. It needs to be replicated in an independent study population.

Identification of Potential Ferroptosis Biomarkers and Analysis of Immune Cell Infiltration in Psoriasis Using Machine Learning

Background

Ferroptosis is a type of cell death characterized by the accumulation of iron-dependent lethal lipid peroxides, which is associated with various pathophysiological processes. Psoriasis is a chronic autoimmune skin disease accompanied by abnormal immune cell infiltration and excessive production of lipid reactive oxygen species (ROS). Currently, its pathogenesis remains elusive, especially the potential role of ferroptosis in its pathophysiological process.

Methods

The microarrays GSE13355 (58 psoriatic skin specimens versus 122 healthy skin specimens) and the ferroptosis database were employed to identify the common differentially expressed genes (DEGs) associated with psoriasis and ferroptosis. The functions of common DEGs were investigated through functional enrichment analysis and protein-protein interaction analysis. The potential diagnostic markers for psoriasis among the common DEGs were identified using four machine-learning algorithms. DGIdb was utilized to explore potential therapeutic agents for psoriasis. Additionally, CIBERSORT was employed to investigate immune infiltration in psoriasis.

Results

A total of 8 common DEGs associated with psoriasis and ferroptosis were identified, which are involved in intercellular signaling and affect pathways of cell response to stress and stimulation. Four machine-learning algorithms were employed to identify poly (ADP-ribose) polymerase 12 (PARP12), frizzled homolog 7 (FZD7), and arachidonate 15-lipoxygenase (ALOX15B) among the eight common DEGs as potential diagnostic markers for psoriasis. A total of 18 drugs targeting the five common DEGs were identified as potential candidates for treating psoriasis. Additionally, significant changes were observed in the immune microenvironment of patients with psoriasis.

Conclusion

This study has contributed to our enhanced comprehension of ferroptosis-related genes as potential biomarkers for psoriasis diagnosis, as well as the alterations in the immune microenvironment associated with psoriasis. Our findings offer valuable insights into the diagnosis and treatment of psoriasis.

Comparative Analysis of Fcγ and Complement Receptors Presence on Monocytes in Pulmonary Sarcoidosis and Tuberculosis

Sarcoidosis (SA) is a granulomatous disorder, which mostly affects the lungs. Its clinical characteristics resemble tuberculosis (TB), but its treatment is different. The etiology of SA is unknown; however, mycobacterial antigens were proposed as environmental factors in its development. Due to previously revealed immunocomplexemia with mycobacterial antigens in the blood of our SA but not TB patients, and in the search for biomarkers for differential diagnosis of the two disorders, we studied the phagocytic activity of monocytes from both patients' groups with flow cytometry. With the use of this method, we also analyzed the occurrence of receptors for IgG (FcγR) and complement components (CR) at the surface of these monocytes, responsible for phagocytosis of immunocomplexes. We revealed a higher phagocytic activity of monocytes in both disorders, but an increased frequency of monocytes with FcγRIII (CD16) and decreased with CR1 (CD35) receptor in the blood of SA vs. TB patients. With regard to our other genetic study on FcγRIII variants in SA and TB, this may account for the decreased clearance of immunocomplexes and different immune responses in the two diseases. Thus, the presented analysis not only sheds light on the pathomechanisms of SA and TB but may also support their differential diagnosis.