2). The aim of the present study was to determine whether or not there might be an autoimmune reaction causing PPS. The background to the study was that data check details from previous studies indicate an inflammatory process in cerebrospinal fluid as well as peripheral blood in PPS patients [5], [6], [8], [9] and [11]. High levels of antibodies, and a positive clinical effect when the inflammation is dampened by immunological treatment, also indicate an active inflammatory process in PPS
[13], and it was speculated that the inflammation is secondary to an autoimmune process. As shown from the results in the present study there was no increase in IC in PPS patients when data of the patients
were compared with those Docetaxel of healthy controls. IC was measured both by biochemical means, as levels of IgG-containing IC binding to C1q, and by functional means, as levels of TNF-α induced in vitro by PEG-precipitated IC. In both these investigations, SLE sera known to contain elevated levels of IC yielded high responses. There is a possibility that PPS patients might have increased circulating IC containing mainly IgA or IgM. Although IC containing IgM (but not IgA) would bind to C1q, they would still not be detected by the IgG-specific secondary antibody in our ELISA. We also think that IC containing only non-IgG isotypes would show negative reactivity in our functional test, as our previous studies have shown IC to induce cytokines via the IgG-specific FcγRIIa receptor [24] and [26]. A weakness of the study is the different sex distribution in PPS patients and controls, but as the analysis did not show any difference in IC levels between the female and male controls, we believe that the comparison is still valid. Thus, further immunological
studies are needed in order to increase the knowledge of the immunological pathophysiology of PPS. EM contributed to the design of the study, recruited the patients, and wrote the BCKDHA manuscript. AZ performed PEG precipitations, cytokine analyses and statistical calculations. JR participated in the design of the study, recruited the controls, made the ELISAs, statistical calculations and helped to draft the manuscript. KB conceived of the study, and participated in its design and coordination and helped to draft the manuscript. All authors read and approved the final manuscript. “
“Mild and asymptomatic infections by the fungal pathogen Pneumocystis are of uncertain pathological significance. They are known as “Pneumocystis colonization” and are highly frequent in normal immunocompetent infants and adults [1].