The development of cellular immunity to Epstein-Barr virus after allogeneic bone marrow transplantation

Epstein-Barr virus-induced lymphoproliferative disease (EBV-LPD) is a potentially lethal complication during the first 6 months after allogeneic bone marrow transplantation (BMT). To determine whether deficiencies of EBV-specific cellular immunity contribute to EBV-LPD susceptibility and distinguish patients at risk, we performed limiting dilution analysis to quantify anti-EBV cytotoxic T-lymphocyte precursor (CTLp) frequencies in 26 recipients of unmodified or T-cell-depleted (TCD) grafts from EBV-seropositive donors. At 3 months post-BMT (n = 26), only five patients had EBV CTLp frequencies in the range of seropositive normal controls, irrespective of the type of transplant administered. By 6 months post-BMT, 9 of 13 patients tested had EBV CTLp frequencies within the normal range. The time period in which these patients had deficient cellular immunity to EBV corresponds to the period in which we have observed EBV-LPD in most prior patients. One patient with a low EBV CTLp frequency at 4 months post-BMT developed an EBV-LPD. Within 2 weeks of receiving an infusion of donor peripheral blood mononuclear cells (PBMC) providing less than 1,200 EBV- specific cytotoxic T-cell precursors, populations of EBV-specific CTL in the circulation were restored to levels detected in normal seropositive adults. Concurrently, the patient achieved a regression of the EBV-LPD, which has been sustained without further therapy. These studies indicate that recipients of both unmodified and TCD marrow grafts have profound deficiencies of EBV-specific T cell-mediated immunity early posttransplant, and that the period of risk for EBV-LPD closely corresponds to this interval of severe deficiency. Treatment of one patient with EBV-LPD with marrow donor-derived PBMC induced a rapid expansion of EBV-specific cytotoxic T-cell populations that occurred contemporaneously with the clinical regression of disease.     

Organization of the gene for human platelet/endothelial cell adhesion molecule-1 shows alternatively spliced isoforms and a functionally complex cytoplasmic domain

Platelet endothelial cell adhesion molecule-1 (PECAM-1) is a cell-cell adhesion molecule that is expressed on circulating platelets, on leukocytes, and at the intercellular junctions of vascular endothelial cells and mediates the interactions of these cells during the process of transendothelial cell migration. The cDNA for PECAM-1 encodes an open reading frame of 738 amino acids (aa) that is organized into a 27- aa signal peptide, a 574-aa extracellular domain composed of 6 Ig homology units, and a relatively long cytoplasmic tail of 118 aa containing multiple sites for posttranslational modification and postreceptor signal transduction. To provide a molecular basis for the precise evaluation of the structure and function of this transmembrane glycoprotein, we have determined the organization of the human PECAM-1 gene. The PECAM-1 gene, which has been localized to human chromosome 17, is a single-copy gene of approximately 65 kb in length and is broken into 16 exons by introns ranging in size from 86 to greater than 12,000 bp in length. Typical of other members of the Ig superfamily, each of the extracellular Ig homology domains is encoded by a separate exon, consistent with PECAM-1 having arisen by gene duplication and exon shuffling of ancestral Ig superfamily genes. However, the cytoplasmic domain was found to be surprisingly complex, being encoded by seven short exons that may represent discrete functional entities. Alternative splicing of the cytoplasmic tail appears to generate multiple PECAM-1 isoforms that may regulate phosphorylation, cytoskeletal association, and affinity modulation of the mature protein. Finally, a processed pseudogene having 76% identity with PECAM- 1 cDNA was identified and localized to human chromosome 3. These findings should have important implications for structure/function analysis of PECAM-1 and its role in vascular adhesive interactions.     

Orofacial neuralgia associated with a middle cerebral artery aneurysm

Chronic orofacial pain of neuropathic origin can present diagnostic and management dilemmas to dental practitioners and also affects the patient's quality of life. Intracranial aneurysms are a potential cause of stroke (e.g. sub‐arachnoid haemorrhage) that is usually associated with, high rates of mortality and morbidity. A patient who had been previously managed for symptoms of temporomandibular joint disorder (TMD) presented with sharp, shooting pain of moderate intensity. It was precipitated by swallowing, and radiated to the right throat, posterior border of the mandible, ear and temporomandibular joint. Clinical and radiological investigations ruled out odontogenic pain, TMD and other more common types of facial pain. Magnetic resonance imaging revealed a 7 × 6 mm aneurysm in the right middle cerebral artery (MCA) which was subsequently surgically clipped. Interestingly, the facial pain resolved after this procedure. Compression of the insular region of the brain innervated by the trigeminal, glossopharyngeal and vagus nerves provides a plausible explanation for the pain reported. To our knowledge, this is the first case of facial neuralgia associated with an aneurysm in the MCA which emphasizes the importance of a multidisciplinary approach in the diagnosis and management of unusual cases of chronic orofacial pain.     

Hypoalbuminaemia and impaired renal function are associated with increased anticholinergic drug prescribing

Background: A higher anticholinergic risk score (ARS) is associated with an increased risk of anticholinergic adverse effects in elderly patients. It is unknown whether factors other than the use of anticholinergic drugs determine the ARS. Methods: A comprehensive medical record review was conducted in 155 consecutive hospitalised patients (median age 79.0 years, interquartile range 66.0–86.0). Information was collected on: demographics; clinical characteristics (including medications and their doses); history of anticholinergic‐induced adverse effects; and biochemical markers of hepatic and renal function (serum albumin concentrations and estimated glomerular filtration rate, eGFR). The ARS was calculated for each patient using a standard scoring approach and Poisson regression was used for identifying variables associated with the ARS. Results: Patients with an ARS ≥ 3 had a lower eGFR (p = 0.012) and were receiving more non‐anticholinergic drugs (p < 0.001) than patients with an ARS < 3. In addition to being prescribed more anticholinergic drugs, patients with ARS ≥ 3 were prescribed high doses of these drugs more often than patients with ARS < 3 (41.3% vs. 26.9%, p = 0.034). A higher number of non‐anticholinergic drugs (p < 0.001), a lower serum albumin concentration (p = 0.014), and a lower eGFR (p = 0.012) were independently associated with a higher ARS. Conclusions: Polypharmacy, hypoalbuminaemia and low eGFR are independently associated with the ARS. Patients with a higher ARS are also prescribed higher doses of anticholinergic medications than those with lower ARS.     

Low immunisation uptake: Is the process the problem?

OBJECTIVE: To examine mothers' satisfaction with the process of immunisation and its possible contribution to suboptimal immunisation uptake. DESIGN: In depth interviews with mothers. SETTING: Two Community Care Areas, Dublin city, Ireland. PARTICIPANTS: In depth interviews of 23 mothers of children 1-2 years old, recruited purposively from a birth cohort born in 1994. MAIN RESULTS: Mothers preferred general practice to Health Centre immunisation (11:5) for predominantly emotional compared with practical reasons (4:1). Health Centre immunisation was seen, at times, as unacceptably rough and inhuman. Many mothers experienced severe emotional distress at the prospect of inflicting the pain of immunisation on their babies. The non-empathic stance of some immunising doctors was unacceptable to mothers. They valued attempts by health professionals to acknowledge the pain of immunisation and to engage with their baby. Adverse experiences contributed to deferral of future visits and to defaulting behaviour. CONCLUSIONS: Low empathy mass immunisation in clinic type settings may be unacceptable to mothers in the 1990s, and may in part explain suboptimal uptake in health care systems that use such clinics.