Influenza virus strains with a fusion threshold of pH 5.5 or lower are inhibited by amantadine. Brief report

Nineteen influenza virus strains were examined for susceptibility to amantadine-HCl (AMT) and for pH-thresholds of haemagglutinin-induced haemolysis. Whereas pH-thresholds below 5.5 were not seen in AMT-resistant strains, AMT-sensitive strains showed pH-thresholds either below or above 5.5

Antibody induction by influenza vaccines in the elderly: a review of the literature

Conflicting results have been reported concerning the association between high age and response to influenza vaccines. Some authors have found a reduced response in aged subjects, others have found no difference or even better results as compared with younger control subjects. Seventeen papers were selected from international literature published in the period 1968-1988 for a review of the anti-haemagglutinin-IgG sero-response following vaccination: among 30 cases in which vaccine components could be studied independently, ten revealed a better immune response in young subjects than in the elderly, four found more favourable results in the elderly, and 16 could not detect any significant between-group-differences, the latter most probably because of a high type-2-error. Nine of these 16 cases tended to favour young subjects. These results were relativated by the finding that each paper had at least one of three methodological limitations: (1) the failure to exclude subjects with illnesses or using drugs influencing the immune system, (2) the failure to exclude subjects with previous vaccinations against influenza, (3) the failure to exclude subjects with high prevaccination antibody titres. The direction of these biases is such that failure to address any one issue will lead to an underestimate of the response of aged subjects. In view of the failure to control these biases, it was not surprising that the papers reviewed presented a heterogeneous picture. Thus, the association between high age per se and response to influenza vaccines, if any, has not yet been established. Suggestions are made for future studies in which admission criteria should control health state and previous exposure to influenza antigens

Trivalent influenza vaccine in patients on haemodialysis: impaired seroresponse with differences for A-H3N2 and A-H1N1 vaccine components

One hundred and one patients on haemodialysis, 21 patients on peritoneal dialysis and 30 healthy controls received a trivalent split vaccine containing 15 micrograms haemagglutinin of a recent influenza A-H3N2, influenza A-H1N1 and influenza B strain, respectively. Antibody production after four weeks was determined by the haemagglutination-inhibition test and expressed as response rate, protection rate and overall mean fold increase. The patients on haemodialysis revealed a diminished seroresponse, as compared to patients on peritoneal dialysis and controls. For influenza A-H3N2, this was less distinct than for the other two antigens. In patients on haemodialysis the protection rate was 66% against the A-H3N2 vaccine component (versus 85% in controls, not significant), but only 25% against A-H1N1 and 27% against B (versus 84 and 77% in controls, p less than 0.001). Duration of haemodialysis up to eight years did not affect seroresponse. Patients on haemodialysis who were primed for influenza A-H1N1 in the period 1947-1957, reacted markedly better to the A-H1N1 vaccine component than subjects of other priming periods. A booster injection of the same vaccine dosage four weeks after the first immunization, performed in 98 patients on haemodialysis, was of little value: it had virtually no effect with regard to influenza A-H1N1 and influenza B, and showed, though significantly better, still poor results for A-H3N2. The differences in seroresponse between the A-H3N2 and A-H1N1 vaccine component suggest a major defect of primary, and a minor defect of secondary humoral response in patients on haemodialysis. The consequences for vaccine policy in these patients are discussed

Gender differences in local and systemic reactions to inactivated influenza vaccine, established by a meta-analysis of fourteen independent studies

In order to determine whether there is a difference between genders in reported adverse reactions to inactivated influenza vaccine, a computerized database of serological studies was investigated. A standardized questionnaire was used to evaluate vaccine reactogenicity. A total of 1,800 vaccinees in 14 studies were analyzed separately for two age groups ( or = 60 years of age). Females reported significantly more local reactions than males. The pooled odds ratio for the outcome measure "any local reaction" was 0.32 (95% confidence interval, 0.26-0.40, significant) and 0.54 (95% Cl, 0.41-0.70, significant) for young and elderly adults, respectively. Similar results were obtained for the outcome measure "any systemic reaction." Previous exposure to influenza or influenza vaccine had no influence on reactogenicity. There were no gender differences in sero-responses. In conclusion, gender should be regarded as a predictor of reported reactions to influenza vaccine in both young and elderly adults and should be addressed in future study designs

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

Annually repeated influenza vaccination improves humoral responses to several influenza virus strains in healthy elderly

The benefit of annually repeated influenza vaccination on antibody formation is still under debate. In this study the effect of annually repeated influenza vaccination on haemagglutination inhibiting (HI) antibody formation in the elderly is investigated. Between 1990 and 1993 healthy young and elde

Nocturnal hypoglycaemia in type 1 diabetic patients, assessed with continuous glucose monitoring: frequency, duration and associations

WSTĘP. W niniejszej pracy określono ilościowo częstość występowania i czas trwania epizodów nocnej hipoglikemii u chorych na cukrzycę typu 1, leczonych ciągłym podskórnym wlewem insuliny (CSII) lub za pomocą wielokrotnych wstrzyknięć insuliny (MIT), wykorzystując ciągły podskórny pomiar glukozy z zastosowaniem czujnika. METODY. Czujnik mikrodializacyjny był noszony w warunkach domowych przez 24 pacjentów leczonych CSII (średnie stężenie HbA1c 7,8 ± 0,9%) oraz przez 33 pacjentów, u których stosowano MIT (średnie stężenie HbA1c 8,7 ± 1,3%) przez 48 godzin. Oceniano częstość występowania i czas trwania epizodów hipoglikemii oraz związek między stężeniem HbA1c, czasem trwania cukrzycy, sposobem jej leczenia (CSII vs. MIT), wartościami glikemii na czczo oraz przed spoczynkiem nocnym, całkowitą dobową dawką insuliny, a także średnimi wartościami glikemii w nocy a częstością występowania i czasem trwania epizodów hipoglikemii. WYNIKI. Epizody nocnej hipoglikemii z wartościami glikemii ≤ 3,9 mmol/l wystąpiły u 33,3% pacjentów w obu grupach - zarówno w grupie leczonej CSII (8/24), jak i stosującej MIT (11/33). średni czas trwania hipoglikemii (± SD; mediana, przedział międzykwartylowy) wynosił 78 min na noc (± 76; 57, 23-120) u chorych poddanych CSII oraz 98 min na noc (± 80; 81, 32-158) u pacjentów stosujących MIT. W analizie metodą regresji wieloczynnikowej wykazano, że glikemia przed spoczynkiem nocnym najsilniej wiąże się z częstoœcią (p = 0,026) oraz czasem trwania (p = 0,032) epizodów nocnej hipoglikemii. WNIOSKI. Ciągłe monitorowanie glikemii z wykorzystaniem metody mikrodializy umożliwiło bardziej precyzyjne określenie ilościowe częstoœci występowania i czasu trwania epizodów nocnej hipoglikemii u chorych na cukrzycę typu 1. Parametry te wiążą się głównie z wartościami glikemii przed spoczynkiem nocnym.AIMS. We quantified the occurrence and duration of nocturnal hypoglycaemia in individuals with type 1 diabetes treated with continuous subcutaneous insulin infusion (CSII) or multiple-injection therapy (MIT) using a continuous subcutaneous glucose sensor. METHODS. A microdialysis sensor was worn at home by 24 patients on CSII (mean HbA1c 7.8 ± 0.9%) and 33 patients on MIT (HbA1c 8.7 ± 1.3%) for 48 h. Occurrence and duration of nocturnal hypoglycaemia were assessed and using multivariate regression analysis, the association between HbA1c, diabetes duration, treatment type (CSII vs. MIT), fasting and bedtime blood glucose values, total daily insulin dose and mean nocturnal glucose concentrations, and hypoglycaemia occurrence and duration was investigated. RESULTS. Nocturnal hypoglycaemia ≤ 3.9 mmol/l occurred in 33.3% of both the CSII- (8/24) and MITtreated patients (11/33). Mean (± SD; median, interquartile range) duration of hypoglycaemia ≤ 3.9 mmol/l was 78 (± 76; 57, 23-120) min per night for the CSII- and 98 (± 80; 81, 32-158) min per night for the MIT-treated group. Multivariate regression analysis showed that bedtime glucose value had the strongest association with the occurrence (p = 0.026) and duration (p = 0.032) of nocturnal hypoglycaemia. CONCLUSIONS. Microdialysis continuous glucose monitoring has enabled more precise quantification of nocturnal hypoglycaemia occurrence and duration in type 1 diabetic patients. Occurrence and duration of nocturnal hypoglycaemia were mainly associated with bedtime glucose value

Humoral immune response to influenza vaccination in patients with primary immunoglobulin A nephropathy. An analysis of isotype distribution and size of the influenza-specific antibodies.

Primary IgA nephropathy (IgAN) is characterized by mesangial deposits of IgA1, increased serum IgA1 levels, and circulating immune complexes containing predominantly IgA1. It has previously been found that patients with IgAN have a higher than normal IgA response to vaccination, but the IgA subclasses have not been studied. To investigate whether the IgA hyperresponsiveness is limited to the subclass IgA1, which is involved in the pathogenesis of IgAN, we compared the immune responses of 18 patients with 22 healthy controls after intramuscular vaccination with inactivated influenza virus. Antibody titers were significantly higher (P less than 0.0001) for the IgA1 subclass in patients versus controls, but not for the other isotypes. A substantial portion of the IgA and IgA1 antiinfluenza immune response comprised polymers in both patients and controls. There was no preferential response of polymers in patients. Patients produced significantly more monomeric IgA1 antibodies than controls. These results show that patients with IgAN have a hyperresponsiveness limited to the subclass IgA1 and mainly expressed by an excess of monomers