Correlation between levels of anti-cytokine antibodies, recombination activity of the mutant RAG proteins and clinical phenotype in patients with RAG deficiency

RAG mutations cause various phenotypes: SCID, Omenn syndrome (OS), leaky SCID (LS) and combined immunodeficiency (CID). We had previously reported autoantibodies targeting IFN-alpha, IFN-omega in patients with RAG deficiency. However, how the presence of such antibodies correlated with the severity of the clinical phenotype and with the recombination activity of the mutant proteins was unknown. To address this, we have studied anti-cytokine antibodies in 118 patients with RAG defects (SCID, n = 28;OS, n = 29;LS, n = 29;CID, n = 32), and in 42 controls (protocols NCT03394053 and NCT03610802). RAG mutant proteins associated with CID and LS retained 35.6 +/- 4.3 (mean +/- SE) and 29.8 +/- 5.1% recombination activity respectively, compared to wildtype protein, which was significantly higher than the recombination activity of the mutant RAG proteins associated with OS (4.1 +/- 1.5%) and SCID (5.7 +/- 2.1%) (p < 0.0001). Among 32 CID patients, 24 tested positive for anti-IFN-alpha and 21 for anti-IFN-omega antibodies. Among 29 LS patients, 15 had high levels of anti-IFN-alpha and 13 of anti-IFN-omega antibodies. A minority of the CID and LS patients had also high levels of anti-IFN-beta and anti-IL-22 antibodies. By contrast, none of the OS patients tested positive for anti-cytokine antibodies. High levels of anti-IFN-alpha and anti-IFN-omega antibodies correlated with their neutralizing activity as demonstrated in vitro by analysis of STAT1 phosphorylation upon stimulation of healthy donor monocytes in the presence of the appropriate cytokine and patient's or control plasma. Severe viral infections were recorded in 26/41 patients with CID and LS who tested positive and in 7/20 who tested negative for anti-IFN-alpha and/or anti-IFN-omega antibodies (p <0.05). Among those with anti-IFN antibodies, EBV (n = 8), CMV (n = 6), HSV (n = 5), VZV (n = 4) and adenovirus (n = 4) infections were more common. Two patients had COVID-19, which was fatal in one. Presence of the rubella virus was documented in 5 patients with anti-type I IFN antibodies. These results demonstrate that high levels of neutralizing anti-IFN-alpha and anti-IFN-omega antibodies are common in patients with RAG mutations manifesting as CID and LS, but not in those with OS, and that their presence is associated with a high risk of serious viral infections.Copyright © 2023 Elsevier Inc.

Secondary immunodeficiencies related to the presence of anti-cytokine autoantibodies / Inmunodeficiencias secundarias relacionadas con la presencia de autoanticuerpos anticitocinas

Resumen Los autoanticuerpos anticitocinas (ACAA) han sido reportados como causa importante de inmunodeficiencias secundarias. Altos títulos de autoanticuerpos neutralizantes pueden causar susceptibilidad a diferentes enfermedades infecciosas potencialmente mortales. Por ejemplo, se ha informado que autoanticuerpos neutralizantes contra IFNγ se correlacionan con susceptibilidad a infecciones micobacterianas y patógenos fúngicos intracelulares. Autoanticuerpos contra IL-6 se detectaron en pacientes con abscesos subcutáneos y celulitis estafilocócica recurrente; asimismo, pacientes con criptococosis, nocardiosis y proteinosis alveolar pulmonar fueron positivos a autoanticuerpos contra GM-CSF. También se ha establecido una relación entre los autoanticuerpos contra IL-17 e IL-22 y las infecciones crónicas por Candida en mucosas, que se han identificado en pacientes con poliendocrinopatía autoinmune tipo 1 o timoma. Recientemente se han reportado autoanticuerpos contra interferón tipo I durante el inicio de COVID-19 aguda. Estos ACAA se asemejan a defectos genéticos en citocinas o en sus rutas de señalización. Por ello, pueden considerarse fenocopias de inmunodeficiencias primarias. De esta forma, la detección de ACAA podría ser importante en el diagnóstico, particularmente en pacientes con enfermedades de aparición tardía, para decidir los tratamientos apropiados. Esta revisión presenta una descripción general de la comprensión actual de las inmunodeficiencias secundarias asociadas a ACAA.

Abstract Anti-cytokine autoantibodies (ACAA) have been reported to be an important cause of secondary immunodeficiencies. High titers of neutralizing autoantibodies may cause susceptibility to different life-threatening infectious diseases. For example, neutralizing autoantibodies against IFNγ have been reported to be correlated with susceptibility to mycobacterial infections and intracellular fungal pathogens. Autoantibodies against IL-6 were detected in patients with subcutaneous abscesses and recurrent staphylococcal cellulitis; on the other hand, patients with cryptococcosis, nocardiosis, and pulmonary alveolar proteinosis were positive for autoantibodies to GM-CSF. A relationship has also been established between autoantibodies against IL-17 and IL-22 and chronic mucosal Candida infections, which have been identified in patients with APECED or thymoma. Autoantibodies against type-I IFN have been recently reported during the onset of acute COVID-19. These ACAAs resemble genetic defects in cytokines or their signaling pathways. Therefore, they may be considered to be primary immunodeficiencies phenocopies. Consequently, the detection of ACAA could be important in the diagnosis of patients, particularly in the case of late-onset diseases, in order to decide appropriate treatments. This review presents an overview of current understanding of ACAA-associated secondary immunodeficiencies.

Secondary immunodeficiencies related to the presence of anti-cytokine autoantibodies.

Anti-cytokine autoantibodies (ACAA) have been reported to be an important cause of secondary immunodeficiencies. High titers of neutralizing autoantibodies may cause susceptibility to different life-threatening infectious diseases. For example, neutralizing autoantibodies against IFNg have been reported to be correlated with susceptibility to mycobacterial infections and intracellular fungal pathogens. Autoantibodies against IL-6 were detected in patients with subcutaneous abscesses and recurrent staphylococcal cellulitis; on the other hand, patients with cryptococcosis, nocardiosis, and pulmonary alveolar proteinosis were positive for autoantibodies to GM-CSF. A relationship has also been established between autoantibodies against IL-17 and IL-22 and chronic mucosal Candida infections, which have been identified in patients with APECED or thymoma. Autoantibodies against type-I IFN have been recently reported during the onset of acute COVID-19. These ACAAs resemble genetic defects in cytokines or their signaling pathways. Therefore, they may be considered to be primary immunodeficiencies phenocopies. Consequently, the detection of ACAA could be important in the diagnosis of patients, particularly in the case of late-onset diseases, in order to decide appropriate treatments. This review presents an overview of current understanding of ACAA-associated secondary immunodeficiencies.

Los autoanticuerpos anticitocinas (ACAA) han sido reportados como causa importante de inmunodeficiencias secundarias. Altos títulos de autoanticuerpos neutralizantes pueden causar susceptibilidad a diferentes enfermedades infecciosas potencialmente mortales. Por ejemplo, se ha informado que autoanticuerpos neutralizantes contra IFNg se correlacionan con susceptibilidad a infecciones micobacterianas y patógenos fúngicos intracelulares. Autoanticuerpos contra IL-6 se detectaron en pacientes con abscesos subcutáneos y celulitis estafilocócica recurrente; asimismo, pacientes con criptococosis, nocardiosis y proteinosis alveolar pulmonar fueron positivos a autoanticuerpos contra GM-CSF. También se ha establecido una relación entre los autoanticuerpos contra IL-17 e IL-22 y las infecciones crónicas por Candida en mucosas, que se han identificado en pacientes con poliendocrinopatía autoinmune tipo 1 o timoma. Recientemente se han reportado autoanticuerpos contra interferón tipo I durante el inicio de COVID-19 aguda. Estos ACAA se asemejan a defectos genéticos en citocinas o en sus rutas de señalización. Por ello, pueden considerarse fenocopias de inmunodeficiencias primarias. De esta forma, la detección de ACAA podría ser importante en el diagnóstico, particularmente en pacientes con enfermedades de aparición tardía, para decidir los tratamientos apropiados. Esta revisión presenta una descripción general de la comprensión actual de las inmunodeficiencias secundarias asociadas a ACAA.

SARS-CoV-2 Inflammatory Syndrome. Clinical Features and Rationale for Immunological Treatment.

The current pandemic coronavirus, SARS-CoV-2, is a global health emergency because of its highly contagious nature, the great number of patients requiring intensive care therapy, and the high fatality rate. In the absence of specific antiviral drugs, passive prophylaxis, or a vaccine, the treatment aim in these patients is to prevent the potent virus-induced inflammatory stimuli from leading to the acute respiratory distress syndrome (ARDS), which has a severe prognosis. Here, the mechanism of action and the rationale for employing immunological strategies, which range from traditional chemically synthesized drugs, anti-cytokine antibodies, human immunoglobulin for intravenous use, to vaccines, are reviewed.