Infection-induced inflammatory response of adipocytes in vitro

BACKGROUND

Abdominal obesity plays an important role in the development of insulin resistance, diabetes mellitus and atherosclerosis. The exact pathophysiological mechanisms are unclear but adipocyte dysfunction is thought to be crucial. Infections are associated with the development of atherosclerosis as well as diabetes. In this study we investigated whether adipocytes can be infected and whether this results in production of inflammatory cytokines relevant for the development of atherosclerosis and diabetes.

METHODS

Pre-adipocytes were cultured and differentiated into mature adipocytes in vitro. Adipocytes and pre-adipocytes were incubated with infective and heat-inactivated Chlamydia pneumoniae, cytomegalovirus (CMV), adenovirus (Ad) subtypes 2 and 36, influenza A and respiratory syncitial virus (RSV). After 48 h, adiponectin, interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha) and plasminogen activator inhibitor-1 (PAI-1) were measured in supernatants.

RESULTS

Infection of adipocytes with Ad-36, CMV and RSV resulted in increased IL-6 production from 192+/-22 pg ml(-1) (uninfected) to 1030+/-86 pg ml(-1), 838+/-59 pg ml(-1) and 1241+/-191 pg ml(-1), respectively (all P<0.01 vs control). In addition, Ad-36 infection slightly reduced PAI production in adipocytes (285+/-26.8 ng ml(-1) vs uninfected: 477+/-71.2 ng ml(-1); P=0.05) and pre-adipocytes (709+/-43.3 ng ml(-1) vs uninfected: 1071+/-71.8 ng ml(-1); P<0.01). In contrast, human Ad type 2 did not exert any effect on IL-6 or PAI production. None of the microorganisms induced significant changes in adiponectin and/or TNF-alpha production.

CONCLUSIONS

Adipocytes can be infected with several microorganisms in vitro. Infection of adipocytes with Ad-36, but not Ad-2 leads to increased production of IL-6 which might contribute to chronic low-grade inflammation, a process known to be involved in the development of cardiovascular diseases and type 2 diabetes.

Infection induced inflammation is associated with erectile dysfunction in men with diabetes

BACKGROUND

In diabetic patients with erectile dysfunction, endothelial dysfunction is a major underlying cause. Infection-induced inflammation may be associated with endothelial dysfunction. The goal of this study was to determine whether erectile dysfunction in patients with diabetes is associated with infections of Chlamydia pneumoniae or cytomegalovirus and/or with low-grade inflammation.

MATERIALS AND METHODS

Diabetic patients, 57 with and 33 without erectile dysfunction, were enrolled in a case-control study. Both groups of patients consists of type 1 and type 2 diabetics. Serum antibodies against cytomegalovirus and C. pneumoniae and markers of inflammation, including high-sensitivity C-reactive protein and fibrinogen, were measured.

RESULTS

Adjusted odds ratios for erectile dysfunction in cytomegalovirus IgG, C. pneumoniae IgG and C. pneumoniae IgA seropositive men were 2.4 (95%CI; 1.0-6.0), 3.0 (95%CI; 1.2-8.1) and 1.8 (95%CI; 0.7-4.6), respectively. Odds ratios for the highest tertiles of high-sensitivity C-reactive protein and fibrinogen concentrations compared to the lowest tertile were 4.3 (95%CI; 1.4-13.1) and 6.6 (95%CI; 2.1-21.2), respectively.

CONCLUSION

Elevated high-sensitivity C-reactive protein or fibrinogen serum levels and infection with cytomegalovirus or C. pneumoniae were associated with erectile dysfunction in diabetes. The relation between cytomegalovirus and erectile dysfunction is markedly present in patients with elevated high-sensitivity C-reactive protein and fibrinogen levels, suggesting a modifying effect by the inflammation.

Comparison of the effects of continuous subcutaneous insulin infusion (CSII) and NPH-based multiple daily insulin injections (MDI) on glycaemic control and quality of life: results of the 5-nations trial

AIMS

The goal of the study was to determine whether continuous subcutaneous insulin infusion (CSII) differs from a multiple daily injection (MDI) regimen based on neutral protamine hagedorn (NPH) as basal insulin with respect to glycaemic control and quality of life in people with Type 1 diabetes.

METHODS

The 5-Nations trial was a randomized, controlled, crossover trial conducted in 11 European centres. Two hundred and seventy-two patients were treated with CSII or MDI during a 2-month run-in period followed by a 6-month treatment period, respectively. The quality of glycaemic control was assessed by HbA(1c), blood glucose values, and the frequency of hypoglycaemic events. For the evaluation of the quality of life, three different self-report questionnaires have been assessed.

RESULTS

CSII treatment resulted in lower HbA(1c) (7.45 vs. 7.67%, P < 0.001), mean blood glucose level (8.6 vs. 9.4 mmol/l, P < 0.001) and less fluctuation in blood glucose levels than MDI (+/- 3.9 vs. +/- 4.3 mmol/l, P < 0.001). There was a marked reduction in the frequency of hypoglycaemic events using CSII compared with MDI, with an incidence ratio of 1.12 [95% confidence interval (CI): 1.08-1.17] and 2.61 (95% CI: 1.59-4.29) for mild and severe hypoglycaemia, respectively. The overall score of the diabetes quality of life questionnaire was higher for CSII (P < 0.001), and an improvement in pump users' perception of mental health was detected when using the SF-12 questionnaire (P < 0.05).

CONCLUSION

CSII usage offers significant benefits over NPH-based MDI for individuals with Type 1 diabetes, with improvement in all significant metabolic parameters as well as in patients' quality of life. Additional studies are needed to compare CSII with glargine- and detemir-based MDI.

Azithromycin reduces Chlamydia pneumoniae-induced attenuation of eNOS and cGMP production by endothelial cells

BACKGROUND

Intracellular infections with cytomegalovirus (CMV) or Chlamydia pneumoniae (Cp) may play a role in the aetiology of atherosclerosis. Nitric oxide (NO) is a key regulator of endothelial function. Under pathological conditions uncoupling of endothelial nitric oxide synthase (eNOS) leads to vessel damage as a result of production of oxygen radicals instead of NO. We hypothesized that infection-induced atherosclerosis is initiated by changes in NO metabolism and may be reversed by azithromycin treatment.

METHODS

Confluent human umbilical vein endothelial cells (HUVECs) were infected with Cp or CMV. After 48 h of infection, production of eNOS, cyclic guanosine monophosphate (cGMP) and reactive oxygen species (ROS) was measured. Detection of cGMP was used as a reporter assay for the bioavailability of NO. Subsequently, Cp- and CMV-infected HUVECs were coincubated with 0.016 mg L(-1) and 1 mg L(-1) azithromycin.

RESULTS

Infection with Cp (MOI 1 and MOI 0.1) and CMV (MOI 1) caused a dose- and time-dependent reduction of eNOS production in the HUVECs: Cp MOI 1: 1141 +/- 74 pg mL(-1) (P < 0.01); Cp MOI 0.1: 3189 +/- 30 pg mL(-1) (P < 0.01); CMV: 3213 +/- 11 pg mL(-1) (P < 0.01) vs. 3868 +/- 83 pg mL(-1) for uninfected HUVECs. Chlamydia pneumoniae- but not CMV-infection also reduced cGMP-production (Cp: 0.195 +/- 0.030 pmol mL(-1) (P < 0.01); CMV: 0.371 +/- 27 pmol mL(-1) (P > 0.05) vs. 0.378 +/- 0.019 pmol mL(-1) for uninfected HUVECs). CMV-infection did not affect ROS production either, but Cp-infection reduced ROS-production by 21% (P > 0.05; Cp MOI 0.1) to 68% (P < 0.01; Cp MOI 1). Azithromycin treatment restored Cp-induced eNOS, cGMP and ROS production in a dose-dependent manner.

CONCLUSIONS

Infection with Cp in endothelial cells in vitro attenuates eNOS, cGMP and ROS production in HUVECs and azithromycin reverses Cp-induced effects on eNOS, cGMP and ROS-production. The results from our in vitro research support the role of antibiotic therapy for infection-induced atherosclerosis by indicating that azithromycin does actually improve endothelial function.

Procoagulant and inflammatory response of virus-infected monocytes

BACKGROUND

Monocytes play a prominent role in inflammation, coagulation and atherosclerosis by their ability to produce tissue factor (TF) and cytokines. The aim of the present study was to establish whether virus-infected monocytes initiate coagulation. In addition, the production of cytokines by monocytes may accelerate the chronic process of atherosclerosis and may contribute to coronary syndromes by eliciting plaque instability.

MATERIALS AND METHODS

Monocytes were isolated by Vacutainer(R), BD Biosciences, Alphen aan den Rijn, Netherlands and subsequent magnetic cell sorting (MACS(R), Milteny Biotec, Bergish Gladbach, Germany). Coagulation times in normal pooled plasma and Factor VII-deficient plasma were measured after infection with cytomegalovirus (CMV), Chlamydia pneumoniae (Cp) and influenza A\H1N1. Anti-TF antibodies were added to neutralize TF expressed on monocytes. Interleukins (IL) 6, 8 and 10 were measured in the supernatants.

RESULTS

Chlamydia pneumoniae- and CMV-infected monocytes decreased the clotting time by 60%, and influenza-infected monocytes by 19%, as compared to uninfected monocytes. Procoagulant activity was absent when Factor VII-deficient plasma or anti-TF antibodies were used. Monocytes produced both IL-6 and IL-8 after infection with CMV (317 pg mL-1 and 250 pg mL-1) or Cp (733 pg mL-1 and 268 pg mL-1). Similar results were obtained for influenza virus-infected monocytes, but the levels of both cytokines were 3-5-fold higher (1797 pg mL-1 and 725 pg mL-1). Interleukin-10 was not produced by infected monocytes.

CONCLUSION

The procoagulant activity of virus-infected monocytes is TF-dependent. Although influenza infection did not generate a significant reduction in clotting time, the pronounced expression of IL-6 and IL-8 may induce local and/or systemic inflammatory reactions, which may be associated with plaque rupture and atherosclerosis. The lack of production of the anti-inflammatory cytokine IL-10 may even accelerate these processes.

Procoagulant activity of endothelial cells after infection with respiratory viruses

Influenza virus epidemics are associated with excess mortality due to cardiovascular diseases. There are several case reports of excessive coagulation during generalised influenza virus infection. In this study, we demonstrate the ability of respiratory viruses (influenza A, influenza B, parainfluenza-1, respiratory syncytial virus, adenovirus, cytomegalovirus) to infect lung fibroblasts and human umbilical vein endothelial cells in culture. All viral pathogens induced procoagulant activity in infected endothelial cells, as determined in a one-stage clotting assay, by causing an average 55% reduction in the clotting time. When factor VII deficient plasma was used clotting time was not reduced. The induction of procoagulant activity was associated with a 4- to 5-fold increase in the expression of tissue factor, as measured by the generation of factor Xa. Both experiments indicate that the procoagulant activity of endothelial cells in response to infection with respiratory viruses is caused by upregulation of the extrinsic pathway. Although both enveloped viruses and a non-enveloped virus (adenovirus) induced procoagulant activity in endothelial cells by stimulating tissue factor expression, the role of the viral envelope in the assembly of the prothrombinase complex remains uncertain. We conclude that both enveloped and non-enveloped respiratory viruses are capable of infecting cultured human endothelial cells and causing a shift from anticoagulant to procoagulant activity associated with the induction of tissue factor expression.

Asymptomatic bacteriuria may be considered a complication in women with diabetes. Diabetes Mellitus Women Asymptomatic Bacteriuria Utrecht Study Group

OBJECTIVE

To study the prevalence of and risk factors for asymptomatic bacteriuria (ASB) in women with and without diabetes.

RESEARCH DESIGN AND METHODS

A total of 636 nonpregnant women with diabetes (type 1 and type 2) who were 18-75 years of age and had no abnormalities of the urinary tract, and 153 women without diabetes who were visiting the eye and trauma outpatient clinic (control subjects) were included. We defined ASB as the presence of at least 10(5) colony-forming units/ml of 1 or 2 bacterial species in a culture of clean-voided midstream urine from an individual without symptoms of a urinary tract infection (UTI).

RESULTS

The prevalence of ASB was 26% in the diabetic women and 6% in the control subjects (P < 0.001). The prevalence of ASB in women with type 1 diabetes was 21%. Risk factors for ASB in type 1 diabetic women included a longer duration of diabetes, peripheral neuropathy, and macroalbuminuria. The prevalence of ASB was 29% in women with type 2 diabetes. Risk factors for ASB in type 2 diabetic women included age, macroalbuminuria, a lower BMI, and a UTI during the previous year. No association was evident between current HbA1c level and the presence of ASB.

CONCLUSIONS

The prevalence of ASB is increased in women with diabetes and might be added to the list of diabetic complications in these women.

Rapid and short-acting mealtime insulin secretion with nateglinide controls both prandial and mean glycemia

OBJECTIVE

The objective of the study was to assess the efficacy and safety of four fixed doses of nateglinide compared with placebo in the treatment of patients with type 2 diabetes with focus on the prandial state.

RESEARCH DESIGN AND METHODS

This randomized double-blind placebo-controlled multicenter study was conducted in 289 patients who received either nateglinide at doses of 30 mg (n = 51), 60 mg (n = 58), 120 mg (n = 63), or 180 mg (n = 57) or placebo (n = 60) before three main meals for 12 weeks. Levels of HbA1c, fasting plasma glucose (FPG), fructosamine, and plasma lipids were measured at predetermined intervals, and the effects of nateglinide on prandial glucose insulin, C-peptide, and triglyceride levels were measured after a liquid standard meal (Sustacal; Mead Johnson, Evansville, IN). Adverse events and hypoglycemic episodes were recorded.

RESULTS

After a liquid meal challenge, nateglinide rapidly increased mealtime insulin levels within 30 min of drug intake and reduced mealtime glucose excursions without affecting triglyceride levels. At study end point, reduction of HbA1c levels was statistically significantly greater with nateglinide at doses of 60, 120, and 180 mg than placebo (-0.45, -0.62, and -0.64%, respectively; P<0.05). The mean level of FPG was significantly reduced versus placebo in the nateglinide 120-mg group only (-1.14 mmol/l P<0.01). Overall, nateglinide was well tolerated.

CONCLUSIONS

This study demonstrated that nateglinide improves mealtime and mean glycemic control in a dose-dependent manner by restoring early insulin secretion phase. Nateglinide was well tolerated and is suitable for the treatment of patients with type 2 diabetes.

Interleukin-6 production by endothelial cells after infection with influenza virus and cytomegalovirus

Inflammation plays a role in the pathogenesis of cardiovascular diseases. Viruses may be a cause of chronic inflammation, and both influenza virus and CMV have been associated with cardiovascular diseases. IL-6, a proinflammatory cytokine with antiviral effects, has a pivotal role in the immune response, and under pathologic conditions, prohemostatic effects of IL-6 could lead to pathologic thrombosis and vascular plaque instability. To investigate this role of IL-6, we measured the production of IL-6 by human endothelial cells after infection with influenza virus and CMV. After infection with influenza virus or CMV, IL-6 release into the medium increased (1756.5+/-156.9 pg/mL vs 284.4+/-55.3 pg/mL; P < .001) for influenza-Infected compared with uninfected cells after 36 hours' incubation. Ultracentrifuged influenza virus supernatants, heat-inactivated virus, and purified hemagglutinin were not able to elicit IL-6 synthesis by human endothelial cells. These findings show that CMV and influenza virus are capable of modulating the in vitro production of IL-6, a cytokine involved in vascular inflammation, by human endothelial cells.

[Factitious insulinoma]

A 32-year-old woman was admitted with signs of recurrent hypoglycaemia. Within 72 hours hypoglycaemia was successfully provoked by prolonged fasting. Also, blood samples demonstrated high levels of serum insulin and C-peptide and the insulin-glucose ratio was abnormally high. An insulinoma was strongly suspected. However, extensive imaging displayed no tumour in the pancreas. The patient also had extensive psychological and social problems. The psychiatrist suggested a factitious disorder. High serum concentrations of insulin and C-peptide in combination with the psychiatric disorder led to the suspicion of abuse of sulfonylurea derivatives by the patient. This was confirmed by toxicological screening. A patient with unexplained hypoglycaemia, especially if an insulinoma cannot be detected, should be suspected of abusing sulfonylurea derivatives.

Tissue concentrations after a single-dose, orally administered ofloxacin in patients with diabetic foot infections

We studied the penetration of orally administered ofloxacin at the site of diabetes-related foot infections in patients with a planned debridement of the lesion. A total of nine patients received 800 mg of oral ofloxacin 120 to 150 minutes before surgery. During surgery, vital margin tissue and a serum sample were obtained. Serum and tissue concentrations of ofloxacin were measured. From seven patients sufficient amounts of tissue were obtained. Mean serum concentration was 7.0+/-3.5 mg/liter; mean tissue concentrations was 11.5+/-8.4 mg/kg. Mean serum and tissue concentrations exceed the minimal inhibitory concentration90 (MIC90) of commonly involved pathogens. This indicates that orally administered ofloxacin can be an effective treatment for infected diabetic foot lesions.

Patients with diabetes mellitus and atherosclerosis; a role for cytomegalovirus?

Diabetic patients are known to have an impaired immune response to viral antigens and a high incidence of atherosclerosis. This study was initiated to evaluate the association between cytomegalovirus infection and atherosclerosis in patients with diabetes mellitus. Patients with diabetes mellitus type 1 and 2 (> 5 years) with (group A) and without (group B) clinical signs of atherosclerosis were included. Cytomegalovirus cultures were obtained, serum was screened for CMV-antibodies and CMV-IgG and CMV-IgM titers were determined. Cytomegalovirus antibodies were detected more often in diabetic patients with atherosclerosis compared to patients without atherosclerosis (70.7 vs. 45.2%, P = 0.018. In female patients the prevalence of CMV-antibodies was 89.5 vs. 40.0% (P = 0.0037). CMV IgG titers were twice as high in group A compared to group B. Cytomegalovirus was cultured from four urine samples and two throat swabs in group B and in one urine and one throat swab in group A. The prevalence of cytomegalovirus antibodies was higher in diabetic patients with atherosclerosis compared to diabetic patients without atherosclerosis. This difference was most striking in the female population. CMV-IgG titers were twice as high in the atherosclerosis group. These data suggest that cytomegalovirus may play a role in the development of clinical atherosclerosis in patients with diabetes mellitus.

[Large variation in the treatment of foot infections in diabetic patients in The Netherlands]

OBJECTIVE

To determine the treatment of foot infections in patients with diabetes mellitus and the implementation of the Dutch consensus guidelines.

DESIGN

Questionnaire.

SETTING

Nationwide.

METHOD

To 180 internists and paediatricians were sent a letter explaining the objective of the survey and a questionnaire. After two months an identical questionnaire was sent, with the request to return it when the first questionnaire had not been returned yet.

RESULTS

Seventy-three questionnaires (40%) were returned of which 63 were evaluable. The main reason for hospitalisation was the threat of limb loss (90%). Most patients presenting with superficial wound infections were treated with local surgical procedures (90%); however, 16% of the responders considered hospitalisation indicated. If osteomyelitis was present 81% of the responders would hospitalize the patient. Antibiotic treatment was instituted by 93%. In all, 11 different antibiotics were used. Of antibiotic combinations the combination of penicillin and lincomycin was used most frequently and the recommended combination of aminoglycoside and lincomycin least. The main reason for using a combination of antibiotics was presence of polymicrobial flora (93%).

CONCLUSION

We conclude that treatment of diabetic foot is still very diverse in spite of the consensus guidelines.

The diabetic foot in Dutch hospitals: epidemiological features and clinical outcome

OBJECTIVE

To assess the impact of the diabetic foot on the hospitalization of patients with diabetes mellitus in The Netherlands.

METHODS

Data on hospitalizations of patients with diabetes mellitus for the years 1988 and 1989 were obtained from the Dutch Information System on Hospital Care. Analysis of the data was performed if in the discharge summary a code number for chronic ulcer of the lower extremity, osteomyelitis or gangrene was reported.

RESULTS

In 1988 20.4% of all hospitalized diabetics were reported to have foot problems. The men age of the study population was 71.3 +/- 12.1 years for 1988 and 71.2 +/- 11.9 for 1989. In patients who underwent (partial) limb amputation the M/F ratio was higher than in patients without amputation for all patient groups studied (p < 0.001). In 1988, 3707 and in 1989, 3790 patients were hospitalized for diabetic foot problems. The cumulative costs were calculated to be 38,556,960 ECU for 1988 and 37,720,020 ECU for 1989. The mean duration of hospitalization was 40.0 days in 1988 and 38.3 days in 1989. Patients with limb amputation stayed significantly longer in the hospital than patients without amputation (p < 0.001). Overall in-hospital mortality was 10%. Mortality was highest in patients staged Wagner 4 + 5. Mortality among patients staged Wagner 1 and 2 was higher than in patients with osteomyelitis (p < 0.001). Of all patients, approximately 10% were discharged to a rehabilitation centre or nursing home.

CONCLUSION

Both the mean age of the patients hospitalized and the total amount of costs involved are higher than put forward previously in studies from the US Diabetic foot problems put a heavy burden on the health status of elderly diabetic patients. Financial resources should be reallocated in the direction of preventive health care.

Influence of blood glucose levels on peripheral lymphocytes in patients with diabetes mellitus

Abnormalities in lymphocyte subpopulations in patients with type 1 diabetes have been reported previously. To evaluate the effect of blood glucose levels on peripheral lymphocyte concentrations we studied the proportion and phenotypic composition of the T-cell population in 7 patients with type 1 and in 12 patients with type 2 diabetes at hospitalization because of metabolic dysregulation and in a period of restored control. Both the number of CD-4 and CD-8 positive cells increased significantly (p < 0.05), although no change in the CD-4:CD-8 ratio was observed. After restoring metabolic control there was a significant rise in the mean number of total lymphocytes (1760 +/- 759 x 10(6)/ml vs 2385 +/- 889 x 10(6)/ml, p < 0.05). The number of total lymphocytes increased in all patients but one. It is concluded that metabolic control can influence immunological parameters such as numbers of peripheral lymphocytes of various phenotypes.

Humoral immune response to a yeast-derived hepatitis B vaccine in patients with type 1 diabetes mellitus

The immune response following vaccination with a recombinant hepatitis B vaccine was investigated in 32 patients with Type 1 diabetes mellitus and compared with the outcome in 32 healthy age- and sex-matched volunteers. Participants were vaccinated at 0, 30, and 180 days and in vivo immune response was determined at 30, 60, 90, 180, and 210 days. The number of responders (anti-HBs greater than 1 IU l-1) was significantly lower (p less than 0.05) among patients at 30 (2 vs 11), 60 (17 vs 26), 90 (20 vs 28) and 180 (22 vs 29) days. The number of patients protected (anti-HBs greater than 10 IU l-1) was lower (p less than 0.05) than the number of protected volunteers at 60 (5 vs 14), 90 (10 vs 19), 180 (15 vs 24), and 210 days (24 vs 31). After the complete course of vaccination 8 out of 32 patients were still unprotected against hepatitis B (p less than 0.05). The anti-HBs titre of responders at 210 days was 251 (20, 3162) (geometric mean (-SD, +SD] IU l-1 in patients and 1259 (126, 12589) IU l-1 in control subjects (p less than 0.05). The HLA-antigen DQw1 frequency in the diabetic low responders (anti-HBs less than 100 IU l-1) was 0.27 compared with 0.86 in diabetic adequate responders. No relation between anti-HBs production and concentration of HbA1c could be demonstrated.

A prospective study of in vitro anti-HBs producing B cells (spot-ELISA) following primary and supplementary vaccination with a recombinant hepatitis B vaccine in insulin dependent diabetic patients and matched controls

A prospective study of the immune response after hepatitis B vaccination was carried out in 32 insulin dependent diabetes mellitus (IDDM) patients and their age and sex matched healthy controls. A sensitive, immunoenzymatic technique was used, able to detect in vitro specific antibody production by mitogen stimulated individual B cells. In-vivo serologic response after vaccination with a standard scheme (0, 1 and 6 months) of 20 micrograms recombinant hepatitis B (HB) vaccine was significantly impaired in the IDDM patients both with respect to the number of nonresponders (25 versus 3%, P less than 0.05) and antibody titers reached (1,377 vs. 9,060 IU/L, P less than 0.05). The total number of in vitro IgM- and IgG-class immunoglobulin producing B cells as detected by the spot-ELISA, was found to be comparable in both groups. Specific IgG anti-HBs (and to a lesser extent IgM anti-HBs) showed impairment in the diabetic population as a whole. The number of IgG anti-HBs producing B cells was markedly depressed one month following vaccination, which is probably a reflection of homing of B cells outside the circulation. Responding subjects were identified early during their vaccination by the detection of in vitro anti-HBs production using the spot-ELISA. Non-responding healthy subjects and IDDM patients as a group showed a low number of IgG anti-HBs spots, suggesting a reduced specific memory B cell frequency. In 13 of 15 hypo- and nonresponders with positive IgG anti-HBs spots supplementary vaccination(s) resulted in improved anti-HBs levels.

Effect of epidemic influenza on ketoacidosis, pneumonia and death in diabetes mellitus: a hospital register survey of 1976-1979 in The Netherlands

The influence of epidemic influenza on hospitalizations because of influenza, pneumonia and diabetic acidosis in patients with diabetes mellitus was investigated. Data on the weekly incidence of influenza-like illness were obtained from the Continuous Morbidity Registration and the cumulative data on hospitalizations in short-stay hospitals were obtained from the National Medical Registration. Patients with duodenal ulcer were used as a control population. Epidemic elevations of influenza infections were observed in 1976 and 1978. The estimated relative risk for hospitalization because of influenza infection was 1.1 and 1.0 for the two non-epidemic years 1977 and 1979, respectively. For the epidemic years 1976 and 1978 this risk was calculated to be 5.7 and 6.2, respectively. An increased relative risk was also noted for pneumonia; being 25.6 for both epidemic years. The estimated relative risk of dying during hospitalization rose from 30.9 in 1977 to 91.8 in 1978. The number of hospitalizations for ketoacidosis was 50% higher in 1978 than in the other three years. During the epidemic years, 25.7% of patients hospitalized for pneumonia died, while this percentage was 14.6% in the non-epidemic years (P less than 0.05). Differences in mortality due to diabetic acidosis were similar: 25.4% in epidemic and 14.7% in non-epidemic years (P less than 0.01). During the 1978 epidemic, one out of every 1300 patients with diabetes mellitus was hospitalized because of pneumonia. It is estimated that 1 of every 260 patients with IDDM was hospitalized for diabetic acidosis. It is concluded that patients with diabetes mellitus have indeed a very high influenza-associated morbidity.

No evidence for the enhanced production of insulin autoantibodies after confrontation with common viral antigens in insulin dependent diabetes mellitus

The production of insulin autoantibodies (IAA) was studied after common viral infections in 12 children with type 1 diabetes mellitus and in their 18 healthy siblings. In addition, the production of IAA was measured after influenza vaccination with booster in 39 patients with type 1 diabetes mellitus and in 39 healthy controls. In 7 of the 12 diabetic children 13 viral infections were serologically confirmed. Among the siblings 14 periods of infection were noted in 9 individuals. A significant rise in IAA antibody titre was demonstrated in patients twice (IgG both times) and in siblings 11 times (IgM 5x, IgG 6x, difference significant P less than 0.05). In only three cases the rise in antibody titres occurred 6-12 wk after documented infection. There was a significant inverse correlation with age in both patients (r = 0.89, P less than 0.0001) and siblings (r = 0.67, P less than 0.001) for IgM IAA. After influenza vaccination a significant increase in IAA was noted twice: IgM IAA in a patient with diabetes and IgG IAA in a healthy volunteer. A four-fold decrease in IgG IAA was demonstrated in one diabetic patient. From these results it is concluded that IAA formation is not a direct sequela of viral infection or vaccination.

Influenza infection and diabetes mellitus. Case for annual vaccination

Herein, epidemiological data on influenza pneumonia and mortality, results of clinical studies, and the outcome of influenza vaccination trials are reviewed. All excess mortality studies that specify for underlying disease list diabetes as one of the major risk factors. During influenza epidemics, death rates among patients with diabetes mellitus may increase by 5-15%. Diabetes mellitus is also mentioned as a risk factor in most clinical studies, making up 3-14% of the patients studied. Even in recent studies, diabetes mellitus is only preceded as a risk factor by cardiovascular disease and chronic pulmonary disorders. To what extent cardiovascular disease and old age contribute to the increased influenza mortality and morbidity in diabetic patients remains unclear. The influence of epidemic influenza on the incidence of diabetic acidosis in combination with an impaired immune response to both Staphylococcus aureus and the influenza virus suggests that diabetes mellitus itself is the main risk factor. It is concluded that all patients with diabetes mellitus should receive annual vaccinations and that, in official recommendations, patients with diabetes mellitus should be mentioned as a separate risk group. Whole-virus vaccines are preferred over subunit vaccines.

Once-daily dosing regimen for aminoglycoside plus beta-lactam combination therapy of serious bacterial infections: comparative trial with netilmicin plus ceftriaxone

PURPOSE

Once-daily dosing of aminoglycosides has been suggested to improve their efficacy and reduce their toxicity. To test the clinical validity of this suggestion, we conducted a prospective, randomized trial comparing a conventional multiple-daily-dosing regimen of netilmicin with once-daily administration of the same total daily dose of this aminoglycoside.

PATIENTS AND METHODS

We enrolled 141 predominantly elderly patients with severe bacterial infections. All patients received once-daily doses of 2 g ceftriaxone, in addition to netilmicin.

RESULTS

Patients randomized to either of the two dosing strategies were comparable regarding age, APACHE II score, concomitant diseases, infection site, and rate of culture-proven bacteremia. Netilmicin treatment did not differ significantly in mean daily dose per kg body weight and days of therapy between the two treatment arms. Compared to patients receiving conventional doses, patients treated with a once-daily dose had higher serum peak netilmicin levels and lower trough levels. Outcome of infection and mortality were not influenced by dosing strategy. Although the overall incidence of nephrotoxicity was similar in both groups (16%), the occurrence of nephrotoxicity in patients treated with once-daily doses of netilmicin was significantly shifted to those given prolonged treatment, i.e., beyond 9 days. Auditory toxicity was documented in one patient treated with conventional doses and two patients treated with once-daily doses.

CONCLUSION

Once-daily dosing of an aminoglycoside plus a long-acting cephalosporin in these patients constituted cost-effective and safe treatment for severe bacterial infections. Netilmicin-induced toxicity may be reduced by using once-daily dosing regimens and limiting the duration of treatment.

Cytotoxic T-cell response to influenza A subunit vaccine in patients with type 1 diabetes mellitus

The cytotoxic T-cell and humoral immune response to a commercially available influenza A-H1N1 subunit vaccine in 14 patients with type 1 diabetes mellitus was compared with the response in 13 healthy volunteers. Cytotoxic T-cell response to vaccination was poor in both patients and controls. At a calculated 50: 1 effector-target cell ratio, however, significantly more controls than patients showed an increase of over 5% cytotoxic T-cell mediated lysis after vaccination (P less than 0.05). In patients the cytotoxic T-cell response decreased with higher percentages of glycosylated haemoglobin (regression coefficient not equal to 0 with P less than 0.05). No significant difference was found between diabetic patients and control subjects with respect to antibody response after vaccination. Implications for vaccination strategy are discussed.

Humoral immune response and delayed type hypersensitivity to influenza vaccine in patients with diabetes mellitus

The antibody response and delayed type hypersensitivity reaction to commercially available trivalent influenza vaccine in 159 patients with diabetes mellitus was compared with response and reaction in 28 healthy volunteers. A correction for prevaccination titres was made. No differences were found between diabetic patients and control subjects with respect to antibody response to the three vaccine strains as measured by the difference between geometric mean titres of post- and prevaccination sera. In Type 1 (insulin-dependent) diabetic patients the incidence of non-responders to two vaccine components was significantly increased (p less than 0.05). The delayed type hypersensitivity reaction to influenza antigen was significantly decreased in patients with high concentrations of glycosylated haemoglobin (p less than 0.01). These findings suggest a role for impaired immune response in the increased influenza morbidity and mortality in patients with diabetes mellitus. Implications for therapy and vaccination strategy are discussed.