Obstructive jaundice, early satiety and xerostomia in an 82-year-old woman.

Amyloid light-chain (AL) amyloidosis is a multisystem disease with obstructive jaundice and gastrointestinal (GI) involvement being uncommon initial presentations. Patients with AL amyloidosis seldom have jaundice and advanced GI tract involvement as their presenting symptoms. This case report describes an 82-year-old lady who presented with a 6-month history of early satiety, weight loss, xerostomia and progressive jaundice. Imaging did not suggest a biliary cause but demonstrated hepatomegaly and ascites. Oesophagogastroduodenoscopy revealed a duodenal stricture. Duodenal and liver biopsies were consistent with amyloid deposition. Multiple myeloma was confirmed to be the underlying cause. Significant cholestatic liver dysfunction and a duodenal stricture have not been previously described as simultaneous manifestations of amyloidosis. This case also highlights the difficulty in treating multiple myeloma as the cause of AL amyloidosis in the context of liver dysfunction, given that many chemotherapy agents undergo hepatic metabolism.

Recurrent Campylobacter jejuni Infection in an Immunodeficient Patient Treated with Repeated Faecal Microbiota Transplant (FMT)-A Case Report.

There is limited evidence to guide successful treatment of recurrent Campylobacter infection in patients with common variable immunodeficiency (CVID) already managed on regular immunoglobulin therapy. The role of faecal microbiota transplant (FMT) is uncertain. We report a case of recurrent Campylobacter jejuni infection in a patient with CVID treated with repeated FMT with 18 months of symptom resolution prior to relapse.

A case report of Adult-onset Still's disease presenting with acute fibrinous and organising pneumonia.

Adult-onset Still's disease is a rare inflammatory disorder characterised by fever, arthritis and rash. It can present in a number of ways and is associated in 5% of cases with parenchymal lung involvement. We present the case of a 37-year-old man who initially presented with fever, weight loss and pancytopaenia. He gradually deteriorated requiring non-invasive ventilation with a Computerised tomography of his chest showing bilateral nodular infiltrates. An open lung biopsy showed acute fibrinous organising pneumonia, which responded well to corticosteroid treatment. He then re-presented over three years later with a similar systemic illness although with less severe lung involvement. Following extensive further investigations, he was diagnosed with Adult-onset Still's disease fulfilling the Yamaguchi criteria. We feel this case is important due to the rare association of Adult-onset Still's disease and interstitial lung disease. More specifically, we are not aware of any published cases of Adult-onset Still's disease with acute fibrinous organising pneumonia.

Navigating the benefits and burdens of life-saving treatment in severely decompensated cirrhosis: an illustrative, multisourced narrative.

Severely decompensated cirrhosis presents major challenges in terms of balancing the benefits and burdens of life-extending treatment. Using accounts and interviews with a patient, her mother, consultant hepatologists and a consultant intensivist, this article explores the decision making around a 43-year-old woman with alcoholic liver disease who died after 100 days in a hospital. Particular focus is given to decisions on escalation, recognition of futility, distress associated with therapy and how messages given during end-of-life discussions are processed. Without suggesting that the case is an example of ideal practice, the importance of frequent multidisciplinary discussion, clinical re-evaluation and continuity of care is emphasised.

Effects of Peptide on NK cell-mediated MHC I recognition.

The inhibitory receptors for MHC class I have a central role in controlling natural killer (NK) cell activity. Soon after their discovery, it was found that these receptors have a degree of peptide selectivity. Such peptide selectivity has been demonstrated for all inhibitory killer cell immunoglobulin-like receptor (KIR) tested to date, certain activating KIR, and also members of the C-type lectin-like family of receptors. This selectivity is much broader than the peptide specificity of T cell receptors, with NK cell receptors recognizing peptide motifs, rather than individual peptides. Inhibitory receptors on NK cells can survey the peptide:MHC complexes expressed on the surface of target cells, therefore subsequent transduction of an inhibitory signal depends on the overall peptide content of these MHC class I complexes. Functionally, KIR-expressing NK cells have been shown to be unexpectedly sensitive to changes in the peptide content of MHC class I, as peptide:MHC class I complexes that weakly engage KIR can antagonize the inhibitory signals generated by engagement of stronger KIR-binding peptide:MHC class I complexes. This property provides KIR-expressing NK cells with the potential to recognize changes in the peptide:MHC class I repertoire, which may occur during viral infections and tumorigenesis. By contrast, in the presence of HLA class I leader peptides, virus-derived peptides can induce a synergistic inhibition of CD94:NKG2A-expressing NK cells through recruitment of CD94 in the absence of NKG2A. On the other hand, CD94:NKG2A-positive NK cells can be exquisitely sensitive to changes in the levels of MHC class I. Peptide antagonism and sensitivity to changes in MHC class I levels are properties that distinguish KIR and CD94:NKG2A. The subtle difference in the properties of NK cells expressing these receptors provides a rationale for having complementary inhibitory receptor systems for MHC class I.

Synergistic inhibition of natural killer cells by the nonsignaling molecule CD94.

Peptide selectivity is a feature of inhibitory receptors for MHC class I expressed by natural killer (NK) cells. CD94-NKG2A operates in tandem with the polymorphic killer cell Ig-like receptors (KIR) and Ly49 systems to inhibit NK cells. However, the benefits of having two distinct inhibitory receptor-ligand systems are not clear. We show that noninhibitory peptides presented by HLA-E can augment the inhibition of NKG2A(+) NK cells mediated by MHC class I signal peptides through the engagement of CD94 without a signaling partner. Thus, CD94 is a peptide-selective NK cell receptor, and NK cells can be regulated by nonsignaling interactions. We also show that KIR(+) and NKG2A(+) NK cells respond with differing stoichiometries to MHC class I down-regulation. MHC-I-bound peptide functions as a molecular rheostat controlling NK cell function. Selected peptides which in isolation do not inhibit NK cells can have different effects on KIR and NKG2A receptors. Thus, these two inhibitory systems may complement each other by having distinct responses to bound peptide and surface levels of MHC class I.

Natural killer cells and hepatitis C: action and reaction.

In 1989, hepatitis C virus (HCV) was first identified as the infectious agent responsible for human non-A, non-B hepatitis. Two decades later, HCV remains a global public health problem with a suboptimal response rate to treatment and the absence of a protective vaccine. Recent work has highlighted the influence of the innate immune system, and in particular natural killer cells, on the outcome and pathology of HCV infection. These cells are considerably more complex than was originally thought and their role in viral infections is currently being unravelled. This review summarises our emerging understanding of natural killer cells in HCV infection.

Case Report: Fatal case of disseminated BCG infection in an infant born to a mother taking infliximab for Crohn's disease.

We present the case of a 28 year old lady with refractory Crohn's Disease treated with infliximab throughout her pregnancy. Her baby was born healthy and received a Bacillus Calmette-Guérin (BCG) vaccine aged 3 months. Soon after this the infant became unwell and died aged 4.5 months. At post-mortem the cause of death was attributed to an unusual complication of the BCG vaccine, known as disseminated BCG. BCG vaccination is contraindicated in individuals who are receiving immunosuppressive drugs. We recommend physicians should exercise caution before such vaccines are used in infants born to mothers taking anti-TNF therapies or other potentially immunosuppressive IgG1 antibodies.

Peptide antagonism as a mechanism for NK cell activation.

Inhibition of natural killer (NK) cells is mediated by MHC class I receptors including the killer cell Ig-like receptor (KIR). We demonstrate that HLA-C binding peptides can function as altered peptide ligands for KIR and antagonize the inhibition mediated by KIR2DL2/KIR2DL3. Antagonistic peptides promote clustering of KIR at the interface of effector and target cells, but do not result in inhibition of NK cells. Our data show that, as for T cells, small changes in the peptide content of MHC class I can regulate NK cell activity.

Natural killer cells: integrating diversity with function.

The key role of natural killer cells in many aspects of the immune response is now being recognized. The last decade has seen an exponential increase in our understanding of the workings of these cells. Receptor diversity is crucial in allowing natural killer cells to respond effectively to a variety of different pathogens. This article reviews aspects of natural killer cell diversity that combine to generate populations of functional natural killer cells that exist within both the individual and throughout the population at large.