Their mean age was 3.19 (1.0–11.9) months; all had died suddenly and unexpectedly (SUID) in the community without hospitalization [2]. One gram of deep lung tissue was extracted with all possible sterile precautions inside a MEK inhibitor laminar flow biosafety cabinet, flash-frozen pulverized in liquid nitrogen using a mortar and pestle, homogenized, and frozen

at −80 °C until nPCR was repeated to re-confirm their Pneumocystis jirovecii-status. Quantitative PCR (qPCR) for P. jirovecii was performed on all P. jirovecii-positive samples; Reverse Transcription PCR (RT-PCR) or PCR for respiratory viruses, and Western blot analyses of hCLCA1 were also performed. Pneumocystis status of samples was re-confirmed using a nested-PCR specific for P. jirovecii as described [2]. Total DNA extraction Lumacaftor was performed using QIAamp®DNA Minikit (Qiagen, Valencia, CA, USA). RNA was extracted using Trizol reagent (Invitrogen,

CA, USA) according to the manufacture’s instructions. P. jirovecii burden was quantified by qPCR amplifying the human Pneumocystis GpA/MSG gene with specific primers and probe (5′ d FAM-TGCAAACCAACCAAGTGTACGACAGG-BHQ-1 3′) as described [14] and [15]. These probe quantifications were compared with Pneumocystis SYBR green quantifications of the same specimens in our previous study [2]. cDNAs were synthesized to identify Respiratory Syncytial Virus (RSV), Influenza A and B, Parainfluenza virus 1, 2, and 3, and Metapneumovirus, by RT-PCR with specific primers [16], [17], [18] and [19]. Total DNA was used to evaluate Adenovirus by PCR as described [20]. Viral positive controls were additionally confirmed using standard diagnostic immunofluorescence microscopy. Bacterial cultures are not considered as part of the legal autopsy protocol, and were not done because the samples were received after 24 h post-mortem [2]. Samples for hCLCA1 determinations were processed as described, unless stated otherwise. Western blot were performed from 30 µg protein aliquots, using SDS-PAGE 12% polyacrylamide resolving gels. hCLCA1 was detected using

mouse anti-hCLCA1 IgG (1:500 sc-271156, Santa Cruz, USA). Measured values were normalized by human actin-gene expression Forskolin for inter-sample comparison. GraphPad Prism 5 software (San Diego, CA, USA) was used for analysis. Comparisons between normalized levels of hCLCA1 protein expression values according to the presence of Pneumocystis or of viruses were performed using Mann–Whitney. The correlation between hCLCA1 protein levels with Pneumocystis GpA/MSG copies was done using the Spearman test. A P value of <0.05 was considered significant. All selected infants were confirmed to have died suddenly and unexpectedly at home and without being hospitalized, indicating that Pneumocystis infection in them was mild. P.