Syphilis-related rapidly progressive glomerulonephritis: a case presentation.

BACKGROUND: Syphilis is a multisystemic infection that causes a wide variety of symptoms and thus has been dubbed one of the great medical mimickers. Due to recent global re-emergence of syphilis, it has become important to recognize its various presentations. Relative to the kidney, syphilitic infections generally present themselves with nephrotic range proteinuria, and are most often associated with pathological features of a membranous glomerulonephritis with subepithelial immune complex deposition. However, other rare renal presentations have been reported. One of these includes a rapidly progressive glomerulonephritis picture. All described cases have been successfully resolved with the treatment of the underlying syphilis infection. CASE PRESENTATION: The patient was an elderly woman of Caribbean descent who presented with lower extremity weakness, anasarca and proteinuria, hematuria with progressive renal failure. On kidney biopsy, she was found to have a pauci-immune crescentic glomerulonephritis pattern and a concomitant acute tubulointerstitial nephritis. She had a positive Treponema pallidum particle agglutination test and a negative syphilis rapid plasma reagin test with clinical evidence of polyneuropathy suggestive chronic syphilis infection. CONCLUSION AND DISCUSSION: It is important in the context of pauci-immune crescentic glomerulonephritis to explore all differential diagnoses. Given the positive syphilis serologies, clinical context and presence of tubulointerstitial nephritis, she was determined to have syphilitic glomerulonephritis that resolved with a course of both penicillin and steroids.

The metastatic site does not influence PD-L1 expression in advanced non-small cell lung carcinoma.

INTRODUCTION: PD-L1 expression by immunohistochemistry (IHC) testing with Tumor Proportion Score (TPS) ≥50% and ≥1% is required to be eligible for first- and second-line Pembrolizumab treatment for metastatic non-small cell lung cancer (NSCLC) respectively. Stage IV NSCLC often presents with metastasis to multiple distant sites which are easily accessible for biopsy. Knowing whether PD-L1 IHC TPS can be indifferently measured from different metastatic site is therefore an important clinical question. In this study, we evaluated PD-L1 expression in NSCLC from varied distant metastatic sites. METHODS: A total of 580 NSCLC specimens of distant metastases were retrieved for study, including 35 paired samples from two different metastatic sites. The metastatic sites included brain, bone, remote lymph nodes, serous membranes (pleura, pericardium and peritoneum), extra-thoracic solid organs and skin/soft tissues. The samples were cytology cell blocks, small biopsies or surgical resections. IHC was performed using Dako PD-L1 IHC 22C3 pharmDx. A total of 100 viable tumor cells was required for adequacy. TPS ≥ 50% and 1-49% were defined as high and low PD-L1 expression respectively. RESULTS: PD-L1 TPS scores were not significantly different across a range of distant metastatic sites nor between metastases in paired samples. CONCLUSION: Our results suggest that the PD-L1 TPS scoring is similar across different metastatic sites and any site biopsied will yield necessary information for guiding clinical management.

Cytology cell blocks are suitable for immunohistochemical testing for PD-L1 in lung cancer.

Background: PD-L1 immunohistochemistry (IHC) testing is usually carried out on tissue blocks from core needle biopsy or surgical resections. In this study, we assessed the feasibility of using cytology cell blocks for PD-L1 IHC assay. Methods: A total of 1419 consecutive cases of non-small-cell lung cancer (NSCLC), including 371 cytology cell blocks, 809 small biopsies, and 239 surgical specimens, were included in the study. The cytology cell blocks were prepared with formalin only, methanol/alcohol only or both. PD-L1 expression was examined by staining with Dako PD-L1 IHC 22C3 pharmDx kit. A Tumor Proportion Score (TPS) was categorized as <1%, 1%-49% and ≥50% tumor cells. A total of 100 viable tumor cells were required for adequacy. Results: Of the cytology cell blocks, 92% of the specimens had an adequate number of tumor cells, not significantly different from small biopsies. The rate of TPS ≥50% differed between sample types and was observed in 42% of cytology cell blocks versus 36% of small biopsies (P = 0.04), and 29% of surgical resections (P = 0.001). The fixative methods did not affect the immunostaining, with overall PD-L1 high expression (TPS ≥50%) rates of 42% in formalin-fixed specimens versus 40% in specimens with combined fixation by methanol/alcohol and formalin (NS). The PD-L1 high expression rate was not associated with EGFR, ALK or KRAS molecular alterations. Higher stage (IV) was associated with higher PD-L1 TPS (P= 0.001). Conclusion: Our results show that when the TPS ≥50% is used as the end point, PD-L1 IHC performs well with cytology cell blocks. Cell blocks should be considered as a valuable resource for PD-L1 testing in advanced NSCLC. The clinical significance of higher PD-L1 IHC scores in cytology specimens needs to be evaluated prospectively.

Children with atopic histories exhibit impaired lipopolysaccharide-induced Toll-like receptor-4 signalling in peripheral monocytes.

BACKGROUND: The hygiene hypothesis states that early exposure to bacterial products such as lipopolysaccharide (LPS) may be protective against the development of allergic diseases. Whether atopic disease affects the ability of immune cells to respond to LPS is unclear. Our laboratory has demonstrated previously that children express high levels of Toll-like receptor (TLR)-4 on CD4(+) cells in nasal mucosa. OBJECTIVE: To determine if children with a history of allergic disease have impaired responses to LPS on circulating CD4(+) leucocytes. METHODS: Peripheral blood mononuclear cells from children (aged 2-18) and adults with or without a history of atopic conditions were cultured with/without IL-4 or LPS for up to 24 h. Expression of surface TLR-4, CD14, CD4, CD3, as well as of intracellular phosphorylated (p42/p44) ERK and p38 mitogen-activated protein kinase (MAPK) were assessed by flow cytometry. RESULTS: A history of atopy in children was associated with impaired LPS-induced TLR-4-dependent phosphorylation of (p42/44) ERK and p38 MAPK by CD4(+) monocytes. Decreased LPS signalling was reproduced by pre-incubation of control cells with recombinant IL-4. LPS stimulation also decreased TLR-4 expression on monocytes from children without atopic histories but not from atopic subjects. CD4(+) T lymphocytes showed limited LPS responsiveness, regardless of atopic status. In contrast with non-atopic children, TLR-4 expression on monocytes of children with atopic histories decreased as a function of age. CONCLUSIONS: This study provides evidence for defective LPS recognition on circulating CD4(+) leucocytes of subjects with atopic histories compared with those from non-atopic children. CD4(+) TLR4(+) monocytes from children with atopic histories failed to phosphorylate MAPKs. Our results suggest that a history of atopic disease is associated with impaired TLR-4-mediated innate immune function compared with non-atopic children.

Signal transducer and activator of transcription 6 down-regulates toll-like receptor-4 expression of a monocytic cell line.

BACKGROUND: Toll-like receptor 4 (TLR4), part of the bacterial lipopolysaccharide (LPS) receptor, is an important bridge between innate and adaptive immunity. Our previous studies have indicated reduced expression of TLR4 and reduced responsiveness to LPS in nasal mucosa of atopic adults compared with non-atopic adults. IL-4 and signal transducer and activator of transcription 6 (STAT6), which are increased in atopic patients, may have a role in modulating TLR4. OBJECTIVE: To examine direct effects of IL-4 and STAT6 on TLR4 expression of U-937 monocytic cells. METHODS: LPS responsiveness, under different conditions of U-937 cells was measured by nuclear factor (NF)-kappaB activation of transcription. TLR4 mRNA was quantified by real-time PCR and TLR4 surface expression was measured by flow cytometry. The promoter and 4.3 kb of the upstream region of TLR4 were cloned into a plasmid vector and transiently transfected into U-937 cells. Transfected cells were incubated with IL-4 and transcriptional activity was assayed by the luciferase assay. STAT6 was transfected to evaluate overexpression of this transcription factor. Cells were also incubated with Tyrphostin AG490 to inhibit tyrosine kinases. RESULTS: NF-kappaB activation by LPS was inhibited by IL-4 pre-incubation but not when IL-4 was added at the same time as LPS. TLR4 mRNA expression was inhibited by IL-4 as early as 6 h but the effect was lost by 24 h. Surface expression of TLR4 was inhibited by IL-4 at 12 and 24 h, but returned to baseline at 48 h. IL-4 inhibited activity of the TLR4 promoter as early as 6 h, but, like the mRNA, these effects were transient. STAT6 overexpression enhanced the inhibition of the TLR4 promoter and prolonged it. Inhibition of TLR4 by IL-4 was abolished by pre-incubation with the tyrosine kinase inhibitor Tyrphostin AG490. CONCLUSION: Our findings demonstrate that IL-4, through STAT6, can modulate TLR4 expression and suggests that Th2 cytokines can impact on the LPS responsiveness of cells.