Primer İmmün Yetmezlikler-İşlevsel Çözümleme

Abstract

Primary immunodeficiency diseases are rare diseases with a wide spectrum due to the increasing the number of new mutations defined to cause these diseases. Besides the clinical and laboratory manifestations, the genetic analysis is performed for definitive diagnosis. Delay of genetic testing makes the diagnosis and treatment challenging and changes the disease course. In this thesis, pathway characterization, protein expression, and proliferation analyses were performed using flow cytometry to evaluate the pathogenicity of the variant and to help diagnose relevant diseases with clinical and laboratory suspicion. Flow cytometry studies were performed with a total of 31 patients having suspicion of or with DOCK8, BTK, PIK3RI-PIK3CD, and LRBA/CTLA-4 deficiency and 27 healthy control individuals in the Immunology Department of Hacettepe University Ihsan Dogramaci Children's Hospital. We observed that protein expression is low in patients with DOCK8, BTK, LRBA gene mutations. We determined that protein expression in patients with suspected disease is low in some patients and normal in some similar to healthy controls. When the patient group with a DOCK8 gene mutation was compared with the healthy control group, DOCK8 protein expression was found to be statistically significantly low (p<0.05). The statical test could not be done for other patient groups’ protein analysis results as there was not adequate patient number. In the akt/mTOR pathway study, increased phosphorylation and proliferation were observed in the patients with PIK3CD gain of function mutation. In this study, DOCK8 and LRBA protein expression after transplantation was also examined by flow cytometry in two patients who underwent bone marrow transplantation, and we observed that the expression results indicated similar value for clinical conclusion with the chimerism results of the patients. The results of this study showed the effectiveness of flow cytometric evaluation of low protein expression in patients with definitive or a suspicion of having a specific mutation to understand the pathogenicity of the genetic defect and for early diagnosis timely. In addition, the data showed that flow cytometry provides valuable information about the engraftment and the success of the transplantation, and that it might be possible to use with a chimerism test in clinical follow-up.