Lower T Regulatory and Th17 Cell Populations Predicted by RT-PCR-Amplified FOXP3 and RORγt Genes Are Not Rare in Patients With Primary Immunodeficiency Diseases.

Deficiencies in T regulatory (Treg) and Th17 cells attenuate peripheral tolerance and the IL-17 family of cytokines, contributing to autoimmune disorders and opportunistic (fungal) infections, respectively. Because of limited blood samples from patients with primary immunodeficiency diseases (PIDs), a positive correlation/linear relationship between Treg and Th17 cells and their respective expressions of transcription factors forkhead box P3 (FOXP3) and retinoic acid-related orphan receptor γ (RORγt) by real-time PCR (RT-PCR) amplification, was used to predict the percentages of Treg and Th17 cells in peripheral blood. Compared to glyceraldehyde 3-phosphate dehydrogenase (GAPDH) expression, the percentages of Treg and Th17 cells were calculated as the linear relationship to the 2-ΔCT value (cycle threshold). Among 91 PIDs patients, 68 and 78 had predicted Treg and Th17 percentages below 5% of the normal ranges (0.859 and 0.734%, respectively), which expanded different categories beyond obvious T cell deficiency. Notably, FOXP3 was undetectable in one patient (CVID), RORγt was undetectable in six patients (one CVID, one CID, two neutropenia, one WAS, and one CMC), and both were undetectable in four patients (two SCID, one STAT1, and one periodic fever). In contrast, two patients with auto-IFNγ antibodies had increased susceptibility to intracellular mycobacterial infections, interrupted Th1 development and subsequent elevation in the Th17 cells. Both predicted Treg and Th17 percentages in the PIDs patients were more independent of age (months) than in the controls. The predicted Th17/Treg ratio in the PIDs patients, overall, was lower than that in the healthy controls (0.79 ± 0.075 vs. 1.16 ± 0.208; p = 0.038). In conclusion, lower predicted Treg and Th17 cell populations calculated by RT-PCR-amplified FOXP3 and RORγt in PIDs patients at diagnosis can explain the higher potential phenotypes of autoimmune disorders and opportunistic infections, although effective interventions in the early stage might have prevented such phenotypic development and caused a statistical bias in the comparisons.

Applying T-cell receptor excision circles and immunoglobulin κ-deleting recombination excision circles to patients with primary immunodeficiency diseases.

BACKGROUND: Biomarkers of T-cell receptor excision circles (TRECs) and immunoglobulin κ-deleting recombination excision circles (KRECs) reflect naïve T and B cell emigrants. This study assessed the biomarkers in patients with primary immunodeficiency diseases (PIDs) to determine the lymphocyte output disturbance and the correlation to lymphocytes. METHODS: A standard plasmid was constructed to calculate TRECs and KRECs in 250 ng genomic DNA from whole blood of PIDs patients. These were correlated to naïve and memory lymphocytes for further classification and adequate treatment. RESULTS: In 69 studied patients, the low TRECs mainly included those with severe combined T and B immunodeficiency (SCID, 7/8), combined immunodeficiency (CID, 4/4), and common variable immunodeficiency (CVID, 6/7). The diminished KRECs was in SCID (4/8), CID (4/4), CVID (7/7), Bruton's tyrosine kinase mutation (Btk, 3/4), anti-B cell deletion (by anti-CD20 antibody in 1), and Behçet syndrome under steroid treatment (1). The TRECs and KRECs positively correlated to absolute naïve T (CD4 + CD45RA+) and naïve B (CD19 + CD27-), and to memory B (CD19 + CD27+) numbers, respectively. CONCLUSION: This study validates that low TRECs and KRECs values reflect low naïve T and B lymphocytes in 'combined immunodeficiencies' and in some CVID patients with the potential to develop the CID phenotype.

Patients with inhibitory and neutralizing auto-antibodies to interferon-γ resemble the sporadic adult-onset phenotype of Mendelian Susceptibility to Mycobacterial Disease (MSMD) lacking Bacille Calmette-Guerin (BCG)-induced diseases.

To recognize patients with inhibitory and neutralizing auto-antibodies to interferon-γ (AutoAbs-IFN-γ) presenting with the sporadic phenotype of Mendelian Susceptibility to Mycobacterial Disease (MSMD) mainly characterized by recurrent intracellular mycobacterium or/and salmonella infections, we comprehensively investigated IL12/23-IFN-γ signaling, candidate genetic sequencings or/and protein expressions of IL12RB1, IFNRG1, IL12p40, IFNRG2, STAT1, IKKA, NEMO, CYBB and IRF8 in four patients. Their serum was further titrated to detect AutoAbs-IFN-γ, for which the biological activity was assessed in Jurkat T cells. The patients mainly presented with recurrent non-tuberculous mycobacterium osteomyelitis and lymphadenopathy (Mycobacterium abscessus, chelonae and avium intracellular complex), and salmonella sepsis (S. enterica serogroup B, C2 and D). Additionally, Penicillium marneffei, varicella-zoster virus, and herpes simplex virus infections occurred. Inhibitory and neutralizing IFN-γ downstream signaling was elucidated in Jurkat cell lines as decreased MHC class I and phosphorylated STAT1 expression. Together with 24 patients from the PubMed search, the majority of the AutoAbs-IFN-γ patients were Asian (25/28). The most common involvement was lymph nodes (in 22/28), lungs (19/28) and bones (12/28). Mycobacterium avium complex (in 14) and chelonae (7) were the most common pathogens from 40 isolations. In contrast to those with the mild form of MSMD phenotype, AutoAbs-IFN-γ patients, in the absence of BCG-induced diseases, had a more persistent course and poor response to IFN-γ treatment. In conclusion, AutoAbs-IFN-γ patients may have a sporadic adult-onset MSMD phenotype in Asian regions endemic for mycobacterial infections.

Distribution, clinical features and treatment in Taiwanese patients with symptomatic primary immunodeficiency diseases (PIDs) in a nationwide population-based study during 1985-2010.

Primary immunodeficiency diseases (PIDs) are a group of rare diseases with wide geographic and ethnic variations in incidence, prevalence, and distribution patterns. The aim of this study was to examine the distribution pattern and clinical spectrum of PIDs in Taiwan at a national referral institute. From 1985 to 2010, 215 patients from 183 families were diagnosed and grouped according to the updated classification of PIDs. Eighty-one (37.7%) patients had "other well-defined immunodeficiency syndromes", followed by "predominantly antibody deficiencies" (54 patients; 25.1%), "T- and B-cell immunodeficiencies" (34; 15.8%), "congenital defects of phagocytes" (25; 20.2%), "complement deficiencies" (15; 7.0%), and "disease in immune dysregulation" (5; 2.3%). The last category included two patients with Chediak-Higashi syndrome, and one each with familial hemophagocytosis, IPEX, and hypogammaglobulinemia and albinism. One female had cold-induced auto-inflammatory disease. There were no cases of "defects in innate immunity". Pseudomonas and Streptococcus pneumoniae were the two most identified microorganisms in septicemia (42.7%; 44/103 episodes). Stem cell transplantation was successful in 13 of 22 patients, while 34 patients (15.8%) died. Molecular defects were identified in 109 individuals (from 90 families). There were relatively fewer cases of "predominantly antibody deficiencies" due to there being only a few patients with adult-onset PIDs, implying certainty bias rather than ethnic variation. Awareness of under-diagnosis among physicians rather than pediatricians is vital for timely diagnosis and consequently adequate treatment.