Enrichment of variations in KIR3DL1/S1 and KIR2DL2/L3 among H1N1/09 ICU patients: an exploratory study.

BACKGROUND: Infection by the pandemic influenza A (H1N1/09) virus resulted in significant pathology among specific ethnic groups worldwide. Natural Killer (NK) cells are important in early innate immune responses to viral infections. Activation of NK cells, in part, depend on killer-cell immunoglobulin-like receptors (KIR) and HLA class I ligand interactions. To study factors involved in NK cell dysfunction in overactive immune responses to H1N1 infection, KIR3DL1/S1 and KIR2DL2/L3 allotypes and cognate HLA ligands of H1N1/09 intensive-care unit (ICU) patients were determined. METHODOLOGY AND FINDINGS: KIR3DL1/S1, KIR2DL2/L3, and HLA -B and -C of 51 H1N1/09 ICU patients and 105 H1N1-negative subjects (St. Theresa Point, Manitoba) were characterized. We detected an increase of 3DL1 ligand-negative pairs (3DL1/S1(+) Bw6(+) Bw4(-)), and a lack of 2DL1 HLA-C2 ligands, among ICU patients. They were also significantly enriched for 2DL2/L3 ligand-positive pairs (P<0.001, Pc<0.001; Odds Ratio:6.3158, CI95%:2.481-16.078). Relative to St. Theresa aboriginals (STh) and Venezuelan Amerindians (VA), allotypes enriched among aboriginal ICU patients (Ab) were: 2DL3 (Ab>VA, P=0.024, Pc=0.047; Odds Ratio:2.563, CI95%:1.109-5.923), 3DL1*00101 (Ab>VA, P<0.001, Pc<0.001), 3DL1*01502 (Ab>STh, P=0.034, Pc=0.268), and 3DL1*029 (Ab>STh, P=0.039, Pc=0.301). Aboriginal patients ligand-positive for 3DL1/S1 and 2DL1 had the lowest probabilities of death (R(d)) (R(d)=28%), compared to patients that were 3DL1/S1 ligand-negative (R(d)=52%) or carried 3DL1*029 (R(d)=52%). Relative to Caucasoids (CA), two allotypes were enriched among non-aboriginal ICU patients (NAb): 3DL1*00401 (NAb>CA, P<0.001, Pc<0.001) and 3DL1*01502 (CA

Influenza pathogenesis: lessons learned from animal studies with H5N1, H1N1 Spanish, and pandemic H1N1 2009 influenza.

Because cases of highly pathogenic influenza are rare, no systematic clinical studies have evaluated different therapeutic approaches. Instead, treatment recommendations are aimed at the alleviation of clinical signs and symptoms, especially the restoration of respiratory function, and at the inhibition of virus replication, assuming viral load is responsible for disease phenotype. Studies of highly pathogenic influenza in different animal models, especially nonhuman primates and ferrets, reproduce many of the key observations from clinical cases. Host-response kinetics reveal a delayed but broad activation of genes involved in the innate and acquired immune responses (innate responses produce inflammatory responses), which continue after the virus has been cleared and may contribute importantly to the clinical signs observed. Experimental animal models point to an important role for immune dysregulation in the pathogenesis of highly pathogenic influenza. The use of these models to develop and validate therapeutic approaches is just beginning, but published studies reveal the importance of early treatment with antivirals and show the potential and limitations of approaches aimed at the host response.

A common CD4 gene variant is associated with an increased risk of HIV-1 infection in Kenyan female commercial sex workers.

BACKGROUND: It has been predicted that CD4 C868T, a novel CD4 single-nucleotide polymorphism (SNP) that has been found to be highly prevalent among Africans, changes the tertiary structure of CD4, which may alter susceptibility to human immunodeficiency virus (HIV) infection. METHODS: Participants were from a Kenyan cohort and included 87 uninfected and 277 HIV-1-infected individuals. DNA sequencing was used to determine CD4 genotype. A2.01 cells expressing similar levels of either wild-type CD4 or CD4-Trp240 as well as peripheral blood mononuclear cells from uninfected donors were infected with HIV-1(IIIB) or a Kenyan primary HIV-1 isolate. HIV-1 p24 enzyme-linked immunosorbent assay was used to determine the outcome of infection. RESULTS: CD4 C868T was found to be significantly more prevalent among HIV-1-infected participants than among HIV-1-uninfected participants (P = .002), and C868T was associated with an increased incidence of HIV-1 infection as well (P = .005, log-rank test; P = .009, Wilcoxon test), with an odds ratio of 2.49 (P = .009). Both in vitro and ex vivo models demonstrated a significant association between CD4 C868T and susceptibility to HIV-1 infection (P < .001 and P = .003, respectively). CONCLUSION: Overall, the present study found a strong correlation between CD4 C868T and increased susceptibility to HIV-1 infection. Given the high prevalence of both HIV infection and CD4 C868T in African populations, the effect of this SNP on the epidemic in Africa could be dramatic.

Multidisciplinary treatment of diabetic foot ulcers in Canadian Aboriginal and non-Aboriginal people.

BACKGROUND: Diabetic foot ulcers are a major cause of morbidity and mortality. This study evaluated the clinical outcomes in Canadian non-Aboriginal and Aboriginal diabetic patients with foot ulcers managed at a multidisciplinary, tertiary care diabetic foot clinic. METHODS: A retrospective review of medical records was done for 325 patients receiving care during a 2-year period. All patients were followed at least 1 year after the initial visit. RESULTS: There were 224 (69%) non-Aboriginal and 101 (31%) Aboriginal patients with 697 foot ulcers. At the initial office visit, 204 (63%) patients had lesions in Wagner grades 2-4. At the most recent evaluation (average, 79+/-73 weeks after initial clinic visit), 190 (58%) patients were rated as having a good outcome (either healed or healing), but a poor outcome (static, progression, amputation, or death) was noted in 135 (42%) patients. At the most recent evaluation, the majority of the 697 ulcers that were noted at the initial or subsequent clinic visits were healed. Aboriginal patients had a shorter average time from initial clinic visit to major lower extremity amputation (Aboriginal, 50+/-64 weeks; non-Aboriginal, 62+/-56 weeks; P<0.01). Residence in a rural or reserve community also correlated with shorter average time from initial clinic visit to major lower extremity amputation (rural or reserve, 45+/-56 weeks; urban, 66+/-61 weeks; P<0.002). When controlled for non-urban residence, Aboriginal ethnicity was not associated with poorer clinical outcome. Earlier major lower extremity amputation was significantly associated with non-urban residence, Aboriginal ethnicity, and arterial insufficiency. Poor clinical outcome was significantly associated with being referred with a lesion present, age greater than 60 years, prior lower extremity amputation or revascularization, arterial insufficiency, more than one lesion on initial presentation, longer duration of type 2 diabetes, and a higher initial Wagner grade for the most advanced lesion. CONCLUSIONS: A multidisciplinary diabetic foot clinic may be successful in treating diabetic foot ulcers in Aboriginal and non-Aboriginal people. However, the frequency of poor outcome is high, consistent with the high prevalence of associated significant risk factors in this population.

Oral antimicrobial therapy for diabetic foot osteomyelitis.

BACKGROUND: Osteomyelitis in the foot of a diabetic individual is a common complication of peripheral neuropathy, peripheral vascular disease, and infection. Operative facilities and home intravenous antibiotic therapy programs may not be available in remote or rural communities. Limited data are available regarding the treatment results of oral antimicrobial therapy, with or without limited office debridement for diabetic foot osteomyelitis. METHODS: This retrospective medical record review of 325 consecutive diabetic patients who were evaluated at a multidisciplinary foot clinic identified 94 (29%) patients with 117 episodes of osteomyelitis. The most common group of organisms isolated were aerobic gram-positive cocci, and the single most frequent organism was Staphylococcus aureus. A mean of 1.6 +/- 0.8 (range 1 to 4) pathogens were recovered per episode of osteomyelitis. Therapy was guided by culture results. There were 93 episodes of osteomyelitis (79 patients) that were treated with a mean of 3 +/- 1 oral antimicrobial agents (with or without an initial short course of intravenous antimicrobial agents) and had adequate followup to evaluate outcome of treatment; office treatment included bone debridement in 26 (28%) and toe amputation in nine (10%) of the 93 episodes (79 patients). RESULTS: Of the 93 episodes treated with oral antimicrobial agents (with or without an initial short course of intravenous antimicrobial agents), 75 (80.5%) episodes were put into remission. Mean duration of oral antimicrobial therapy was 40 +/- 30 weeks. Mean relapse-free followup duration was 50 +/- 50 weeks. CONCLUSIONS: Diabetic foot osteomyelitis was effectively managed with oral antimicrobial therapy with or without limited office debridement in most patients. This regimen may be especially useful in communities where infectious disease specialists and operative resources are limited.

Revascularization for peripheral vascular disease in Aboriginal and non-Aboriginal patients.

BACKGROUND: Canadian Aboriginal subjects have a higher prevalence of diabetes, renal disease, and lower extremity amputation than non-Aboriginal subjects. However, limited information is available about patient outcomes for arterial bypass surgery in Canadian Aboriginal compared with non-Aboriginal subjects. METHODS: A retrospective study of all patients undergoing revascularization for peripheral vascular disease at a tertiary care referral center was performed. RESULTS: A total of 828 procedures were performed on 678 patients between 1995 and 2002: 108 (13%) procedures on 84 (12%) Aboriginal patients and 720 (87%) procedures on 594 (88%) non-Aboriginal patients. Aboriginal patients had a higher prevalence of diabetes, chronic renal failure, and end-stage renal disease than non-Aboriginal patients. Aboriginal patients presented with more serious complications (gangrene [Aboriginal, 63 [58%] of 108 patients; non-Aboriginal, 112 [16%] of 720 patients; P < .0001] and nonhealing ulcer [Aboriginal, 29 [27%] of 108 patients; non-Aboriginal, 131 [18%] of 720 patients; P < .05]) and required urgent or emergency revascularization (Aboriginal, 47 [49%] of 95 patients; non-Aboriginal, 228 [36%] of 634 patients; P < .02) more frequently than non-Aboriginal patients. The 60-month patient mortality was similar for both groups (Aboriginal, 20 [24%] of 84 patients; non-Aboriginal, 160 [27%] of 594 patients; not significant), but Aboriginal patients had loss of limb more frequently (Aboriginal, 19 [18%] of 108 patients; non-Aboriginal, 62 [9%] of 720 patients; P < .0001) and had loss of primary graft patency more frequently (Aboriginal, 39 [36%] of 108 patients; non-Aboriginal, 155 [22%] of 720 patients; P < .0001) than non-Aboriginal patients. CONCLUSIONS: Canadian Aboriginal subjects had worse outcomes with revascularization than non-Aboriginal subjects, but ethnicity and diabetes were not independent risk factors for poor outcome. Multivariate analysis showed that the poor outcomes in mortality, limb salvage, and primary graft patency among Aboriginal patients undergoing revascularization may be attributed to renal disease and a more advanced mode of presentation of peripheral vascular disease complications at the time of intervention.

Diabetic foot complications in a northern Canadian Aboriginal community.

BACKGROUND: Limited access to basic foot care and protective footwear may contribute to diabetic foot complications. The purpose of this study was to determine the prevalence of foot complications, ongoing foot care, and footwear use in diabetic subjects in a remote northern Canadian Aboriginal community. METHODS: This was a cross-sectional cohort study of 169 diabetic people, including interview, physical examination, and retrospective chart review. RESULTS: The mean age of the 169 diabetic individuals in the study was 56 +/- 12 years and their duration of diabetes 10 +/- 7 years. There were 139 (82%) individuals who had 418 diabetic foot complications (average, 3.0 complications per subject with complications), including toenail pathology, foot and ankle deformities, calluses, impaired pulses, neuropathy, past or present ulcer, amputation, and Charcot arthropathy. Risk classification showed that 69 (41%) individuals were at risk for future ulceration. Fifty-five (33%) individuals had inadequate footwear for their foot risk category, and only 11 (17%) of 66 individuals in the higher risk categories (categories 2 and 3) had suitable footwear. In a 7-year period, only 0.7 screening foot examinations per diabetic subject per year were documented. However, during this period, foot problems accounted for 498 (18%) local emergency room visits, 359 (16%) hospitalization days, 109 (11%) nonemergency transfers, and 4 (6%) emergency transfers to a tertiary care hospital. CONCLUSIONS: Foot and ankle complications of diabetes in this remote Aboriginal community were common and associated with substantial morbidity. Preventive diabetic foot screening examinations and footwear were inadequate. The results suggest that programs for prevention and early detection of complications are needed, including foot screening, provision of appropriate footwear, and foot care.

Disability and quality of life in Canadian aboriginal and non-aboriginal diabetic lower-extremity amputees.

OBJECTIVE: To compare and contrast disability and quality of life (QOL) in Aboriginal and non-Aboriginal subjects with diabetes who had lower-extremity amputation (LEA) and were living in urban and rural communities in Canada. DESIGN: Descriptive study using an interviewer-administered questionnaire and hospital medical record review. SETTING: Tertiary care center. PARTICIPANTS: Forty-four diabetic subjects (minimum age, 18 y) not receiving dialysis, including 21 Aboriginal (8 urban, 13 rural) and 23 non-Aboriginal (16 urban, 7 rural) subjects. Subjects were living in their current residence and had undergone LEA above the level of the ankle 6 months or more before interview. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Qualitative and quantitative data about symptoms, impairment, and QOL. RESULTS: Aboriginal subjects were younger than non-Aboriginal subjects at the time of diabetes diagnosis (Aboriginal, 42+/-10 y; non-Aboriginal, 52+/-14 y; P<.005) and first major LEA (Aboriginal, 57+/-7 y; non-Aboriginal, 64+/-11 y; P<.015). All subjects received rehabilitation after amputation. More rural non-Aboriginal subjects (83%) used their prosthesis both in and outside the home for all movements than other subjects (P<.048). Rural non-Aboriginal subjects had the lowest and urban non-Aboriginal subjects had the highest frequency of walking-aid use outside the home. Assistance with personal care was required by a minority of subjects, but assistance with daily housework was required by the majority of subjects. Qualitative analysis revealed that participants were, in most cases, comfortable with their postamputation life. CONCLUSIONS: Although the majority of participants in this study generally felt satisfied with their current status, major functional changes were noted after LEA that had a large negative impact on QOL.

Mass spectrometric characterization of proteins from the SARS virus: a preliminary report.

A new coronavirus has been implicated as the causative agent of severe acute respiratory syndrome (SARS). We have used convalescent sera from several SARS patients to detect proteins in the culture supernatants from cells exposed to lavage another SARS patient. The most prominent protein in the supernatant was identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) as a approximately 46-kDa species. This was found to be a novel nucleocapsid protein that matched almost exactly one predicted by an open reading frame in the recently published nucleotide sequence of the same virus isolate (>96% coverage). A second viral protein corresponding to the predicted approximately 139-kDa spike glycoprotein has also been examined by MALDI-TOF MS (42% coverage). After peptide N-glycosidase F digestion, 12 glycosylation sites in this protein were confirmed. The sugars attached to four of the sites were also identified. These results suggest that the nucleocapsid protein is a major immunogen that may be useful for early diagnostics, and that the spike glycoprotein may present a particularly attractive target for prophylactic intervention in combating SARS.

Gonococcal cervicitis is associated with reduced systemic CD8+ T cell responses in human immunodeficiency virus type 1-infected and exposed, uninfected sex workers.

Neisseria gonorrhoeae cervicitis and human immunodeficiency virus (HIV) type 1 frequently coinfect core transmitter populations, such as female sex workers. Gonococcal cervicitis is associated with increased viral shedding and plasma viremia in HIV-1-infected women and increased HIV-1 susceptibility in uninfected women. We studied the influence of gonococcal cervicitis on CD8(+) interferon (IFN)-gamma responses to HIV-1 and cytomegalovirus (CMV) epitopes in HIV-1-infected and in highly-exposed, persistently seronegative (HEPS) female sex workers. In HIV-1-infected women, gonococcal cervicitis was associated with reduced IFN-gamma responses in bulk CD8(+) lymphocyte populations, and intracellular cytokine staining, combined with class I major histocompatibility complex (MHC)-peptide tetramer studies, demonstrated reduced IFN-gamma production by HIV-1 epitope-specific CD8(+) lymphocytes. In HEPS sex workers, cervicitis was associated with the transient loss of systemic HIV-1-specific CD8(+) responses and with reduced function of CMV-specific CD8(+) lymphocytes. Impaired function of virus-specific CD8(+) lymphocytes may partly explain the deleterious effects of gonococcal cervicitis on HIV-1 immune control and susceptibility.