Activated phosphoinositide 3-kinase δ syndrome(APDS) is an autosomal dominant inherited primary immunodeficiency disease that is caused by mutations in PIK3CD or PIK3R1 genes leading to overactivation of the PI3Kδ signaling pathway, first reported by Angulo et al in 2013. The clinical manifestations of the disease are recurrent respiratory tract infections, benign lymph node hyperplasia, autoimmune diseases, lymphoma and so on. Although most patients develop the disease in childhood, there are also reports of adult onset and asymptomatic patients. In addition, the immunophenotype of activated phosphoinositide 3-kinase δ syndrome is changeable, usually the IgA levels are reduced, the IgM levels can be normal or elevated, and the IgG levels are variable, so it is easy to be misdiagnosed at first diagnosis. There is no unified diagnostic standard at present, and timely genetic testing is required to confirm the diagnosis.

The heparan sulfate proteoglycan(HSPG) is the major part of sulfated macromolecules synthesized by the cultured rat GECs, and plays an important role in maintaining the glomerular charge—selective function. We have investigated the effects of lipopolysaccharide (LPS, 6.25ng/ml), human recombinant interleukin—2, (HrI1—2, 2. 5u/ml), and protamine sulfate(PtS, 100?g/ml) on the proliferation of rat GEC and incorporation of 35 SO into cell layers in vitro. A method of 3 H—TdR and 35 S—Na_2SO_4 dual isotope labelling technique was used. Statistical analysis was done using analysis of variance for both 3 H—TdR uptake and 35 SO incorporation, and analysis of variance only for the latter. These results show that LPS, HrIL—2 and PtS inhibited the proliferation of rat GECs. HrIL—2 also directly inhibited the incorporation of 35 SO into cell layers, but the roles of LPS and PtS, which decreased 35 SO—content, only came from their inhibition effects on cell proliferation. We suppose that the decreased production of HSPG by GECs, may contribute to the development of proteinuria.