Statins did not reduce the frequency of exacerbations in individuals with COPD and cardiovascular comorbidities in the COSYCONET cohort.

BACKGROUND: The evidence regarding effects of statins on exacerbation risk in COPD remains controversial. Previous studies often excluded patients with cardiovascular comorbidities despite their high prevalence in COPD and role for exacerbations. Based on the cardioprotective properties of statins, we hypothesised that statins may reduce the risk of exacerbations especially in patients with cardiovascular comorbidities. METHODS: One thousand eight hundred eighty seven patients of the German COPD cohort COSYCONET (COPD and Systemic Consequences Comorbidities Network) of GOLD grades 1-4 (37.8% female, mean age 64.78 ± 8.3) were examined at baseline and over a period of 4.5 years for the occurrence of at least one exacerbation or severe exacerbation per year in cross-sectional and longitudinal analyses adjusted for age, gender, BMI, GOLD grade and pack-years. Due to their collinearity, various cardiovascular diseases were tested in separate analyses, whereby the potential effect of statins in the presence of a specific comorbidity was tested as interaction between statins and comorbidity. We also identified patients who never took statins, always took statins, or initiated statin intake during the follow-up. RESULTS: One thousand three hundred six patients never took statins, 31.6% were statin user, and 12.9% initiated statins during the follow-up. Most cardiovascular diseases were significantly (p < 0.05)may associated with an increased risk of COPD exacerbations, but in none of them the intake of statins was a significant attenuating factor, neither overall nor in modulating the increased risk linked to the specific comorbidities. The results of the cross-sectional and longitudinal analyses were consistent with each other, also those regarding at least 1 exacerbation or at least 1 severe exacerbation per year. CONCLUSION: These findings complement the existing literature and may suggest that even in patients with COPD, cardiovascular comorbidities and a statin therapy that targets these comorbidities, the effects of statins on exacerbation risk are either negligible or more subtle than a reduction in exacerbation frequency. TRIAL REGISTRATION: Trial registration ClinicalTrials.gov, Identifier: NCT01245933. Other Study ID (BMBF grant): 01GI0881, registered 18 November 2010, study start 2010-11, primary completion 2013-12, study completion 2023-09. https://clinicaltrials.gov/study/NCT01245933?cond=COPD&term=COSYCONET&rank=3.

Midregional proatrial naturetic peptide (MRproANP) and copeptin (COPAVP) as predictors of all-cause mortality in recently diagnosed mild to moderate COPD-results from COSYCONET.

BACKGROUND: MRproANP and COPAVP are prognostic markers for mortality in chronic obstructive pulmonary disease (COPD). Furthermore, these biomarkers predict mortality due to cardiovascular diseases, which are important prognostically determining comorbidities in patients with COPD. However, less is known about these biomarkers in recently diagnosed mild to moderate COPD. Therefore, we analyzed these biomarkers as potential predictors of mortality in recently diagnosed mild to moderate COPD. METHODS: The blood biomarkers considered were copeptin (COPAVP), midregional adrenomedullin (MRproADM), midregional proatrial naturetic peptide (MRproANP), and fibrinogen. Analyses were performed in patients with stable "recently diagnosed mild to moderate COPD" defined by GOLD grades 0-2 and diagnosis of COPD ≤ 5 years prior to inclusion into the COSYCONET cohort (COPD and Systemic Consequences-Comorbidities Network), using Cox regression analysis with stepwise adjustment for multiple COPD characteristics, comorbidities, troponin and NT-proBNP. RESULTS: 655 patients with recently diagnosed mild to moderate COPD were included. In the initial regression model, 43 of 655 patients died during the 6-year follow-up, in the final model 27 of 487. Regression analyses with adjustment for confounders identified COPAVP and MRproANP as statistically robust biomarkers (p < 0.05 each) of all-cause mortality, while MRproADM and fibrinogen were not. The fourth quartile of MRproANP (97 pmol/L) was associated with a hazard ratio of 4.5 (95%CI: 1.6; 12.8), and the fourth quartile of COPAVP (9.2 pmol/L) with 3.0 (1.1; 8.0). The results for MRproANP were confirmed in the total cohort of grade 0-4 (n = 1470 finally). CONCLUSION: In patients with recently diagnosed mild to moderate COPD, elevated values of COPVP and in particular MRproANP were robust, independent biomarkers for all-cause mortality risk after adjustment for multiple other factors. This suggests that these markers might be considered in the risk assessment of early COPD.

Maternal Fever Associated With Continuous Spinal Versus Epidural Labor Analgesia: A Single-Center Retrospective Study.

BACKGROUND: Neuraxial labor analgesia is associated with elevations in maternal temperature; the mechanism responsible is unknown. Proposed mechanisms have included infection, altered thermoregulation, and inflammation, potentially triggered by local anesthetics. Studies of the association between neuraxial labor analgesia and maternal fever have focused on epidural analgesia, and there have been no comparisons of the rate of maternal fever between continuous spinal and epidural labor analgesia. METHODS: We performed a retrospective study to compare the rate of maternal fever between patients who received continuous spinal versus epidural labor analgesia between June 2012 and March 2020. Each patient who received continuous spinal analgesia was matched to 2 patients who received epidural analgesia and had the same nulliparous status. The primary outcome of our study was the incidence of intrapartum maternal fever, which we defined as any temperature ≥38 °C before delivery and compared between the continuous spinal and epidural groups using Fisher exact test. RESULTS: We identified 81 patients who received continuous spinal analgesia and 162 matched controls who received epidural analgesia. Demographic and obstetric characteristics of the patients were similar between groups. While the duration of analgesia did not significantly differ, there was markedly increased bupivacaine consumption in women with epidural analgesia. Eight of 81 (9.9%; 95% confidence interval [CI], 5.1-18.3) women with continuous spinal analgesia developed an intrapartum fever compared to 18 of 162 (11.1%; 95% CI, 7.1-16.9) of women with epidural analgesia ( P = .83; Fisher exact test). CONCLUSIONS: There was no significant difference in the rate of maternal fever between women with continuous spinal compared to epidural labor analgesia. While the route of administration and dose of bupivacaine differs between epidural and spinal labor analgesia, they are titrated to produce similar levels of neuraxial blockade. Our results are consistent with a model in which epidural related maternal fever is due to altered thermoregulation from a central neuraxial block and argue against a direct effect of bupivacaine or fentanyl, although we cannot rule out a concentration-independent effect of bupivacaine or fentanyl or an inflammatory effect of the catheter itself. These retrospective results highlight the importance of prospective and mechanistic study of neuraxial analgesia-related maternal fever.

Parallel substrate supply and pH stabilization for optimal screening of E. coli with the membrane-based fed-batch shake flask.

BACKGROUND: Screening in the fed-batch operation mode is essential for biological cultivations facing challenges as oxygen limitation, osmotic inhibition, catabolite repression, substrate inhibition or overflow metabolism. As a screening tool on shake flask level, the membrane-based fed-batch shake flask was developed. While a controlled supply of a substrate was realized with the in-built membrane tip, the possibilities for replenishing nutrients and stabilizing pH values was not yet exploited. High buffer concentrations were initially used, shifting the medium osmolality out of the biological optimum. As the growth rate is predefined by the glucose release kinetics from the reservoir, the resulting medium acidification can be compensated with a controlled continuous supply of an alkaline compound. The focus of this research is to establish a simultaneous multi-component release of glucose and an alkaline compound from the reservoir to enable cultivations within the optimal physiological range of Escherichia coli. RESULTS: In combination with the Respiratory Activity MOnitoring System, the membrane-based fed-batch shake flask enabled the detection of an ammonium limitation. The multi-component release of ammonium carbonate along with glucose from the reservoir resulted not only in the replenishment of the nitrogen source but also in the stabilization of the pH value in the culture medium. A biomass concentration up to 25 g/L was achieved, which is one of the highest values obtained so far to the best of the author's knowledge with the utilization of a shake flask and a defined synthetic medium. Going a step further, the pH stabilization allowed the decrease of the required buffer amount to one-fourth establishing an optimal osmolality range for cultivation. As optimal physiological conditions were implemented with the multi-component release fed-batch cultivation, the supply of 0.2 g glucose in a 10 mL initial culture medium volume with 50 mM MOPS buffer resulted in a twofold higher biomass concentration than in a comparable batch cultivation. CONCLUSIONS: The newly introduced multi-component release with the membrane-based fed-batch shake flask serves a threefold purpose of replenishing depleted substrates in the culture medium, stabilizing the pH throughout the entire cultivation time and minimizing the necessary amount of buffer to maintain an optimal osmolality range. In comparison to a batch cultivation, these settings enable to achieve higher biomass and product concentrations.

Aqueductal stenosis presenting as isolated tremor: case report and review of the literature.

Essential tremor is rare in children, particularly in the absence of a significant family history. We report the case of a child with compensated hydrocephalus secondary to aqueductal stenosis whose sole presenting symptom was tremor. An otherwise healthy 6-year-old male developed a fine hand tremor, which over the course of 4 years both increased in intensity and spread to involve the lower limbs and head. After an MRI had confirmed hydrocephalus due to aqueductal stenosis, the patient underwent an endoscopic third ventriculostomy. His tremor improved markedly, but did not completely resolve. Occult hydrocephalus should be considered in the differential diagnosis of new-onset tremor. Progression of the tremor should halt with treatment of the hydrocephalus, and clinical improvement may be seen.

[Update: acute hypercapnic respiratory failure]. / Update: akute hyperkapnische respiratorische Insuffizienz.

BACKGROUND: Hypercapnic respiratory failure is a frequent problem in critical care and mainly affects patients with acute exacerbation of COPD (AECOPD) and acute respiratory distress syndrome (ARDS). In recent years, the usage of extracorporeal CO2 removal (ECCO2R) has been increasing. OBJECTIVE: Summarizing the state of the art in the management of hypercapnic respiratory failure with special regard to the role of ECCO2R. METHODS: Review based on a selective literature search and the clinical and scientific experience of the authors. RESULTS: Noninvasive ventilation (NIV) is the therapy of choice in hypercapnic respiratory failure due to AECOPD, enabling stabilization in the majority of cases and generally improving prognosis. Patients in whom NIV fails have an increased mortality. In these patients, ECCO2R may be sufficient to avoid intubation or to shorten time on invasive ventilation; however, corresponding evidence is sparse or even missing when it comes to hard endpoints. Lung-protective ventilation according to the ARDS network is the standard therapy of ARDS. In severe ARDS, low tidal volume ventilation may result in critical hypercapnia. ECCO2R facilitates compensation of respiratory acidosis even under "ultra-protective" ventilator settings. Yet, no positive prognostic effects could be demonstrated so far. CONCLUSION: Optimized use of NIV and lung-protective ventilation remains standard of care in the management of hypercapnic respiratory failure. Currently, ECCO2R has to be considered an experimental approach, which should only be provided by experienced centers or in the context of clinical trials.

Combined effects of lung function, blood gases and kidney function on the exacerbation risk in stable COPD: Results from the COSYCONET cohort.

RATIONALE: Alterations of acid-base metabolism are an important outcome predictor in acute exacerbations of COPD, whereas sufficient metabolic compensation and adequate renal function are associated with decreased mortality. In stable COPD there is, however, only limited information on the combined role of acid-base balance, blood gases, renal and respiratory function on exacerbation risk grading. METHODS: We used baseline data of the COPD cohort COSYCONET, applying linear and logistic regression analyses, the results of which were implemented into a comprehensive structural equation model. As most informative parameters it comprised the estimated glomerular filtration rate (eGFR), lung function defined via forced expiratory volume in 1 s (FEV1), intrathoracic gas volume (ITGV) and (diffusing capacity for carbon monoxide (DLCO), moreover arterial oxygen content (CaO2), partial pressure of oxygen (PaCO2), base exess (BE) and exacerbation risk according to GOLD criteria. All measures were adjusted for age, gender, body-mass index, the current smoking status and pack years. RESULTS: 1506 patients with stable COPD (GOLD grade 1-4; mean age 64.5 ±â€¯8.1 y; mean FEV1 54 ±â€¯18 %predicted, mean eGFR 82.3 ±â€¯16.9 mL/min/1.73 m2) were included. BE was linked to eGFR, lung function and PaCO2 and played a role as indirect predictor of exacerbation risk via these measures; moreover, eGFR was directly linked to exacerbation risk. These associations remained significant after taking into account medication (diuretics, oral and inhaled corticosteroids), whereby corticosteroids had effects on exacerbation risk and lung function, diuretics on eGFR, BE and lung function. CONCLUSION: Even in stable COPD acid-base metabolism plays a key integrative role in COPD risk assessment despite rather small deviations from normality. It partially mediates the effects of impairments in kidney function, which are also directly linked to exacerbation risk.

Capacity of individual chronic lymphatic leukemia lymphocytes and leukemic blast cells for repair of O6-ethylguanine in DNA: relation to chemosensitivity in vitro and treatment outcome.

The elimination kinetics of the alkylation product O6-ethylguanine (O6eGua) from nuclear DNA were determined in individual lymphocytes or blast cells isolated from 27 patients with chronic lymphatic leukemia (CLL) and 26 patients with de novo acute myeloid leukemia (AML). A monoclonal antibody-based immunocytological assay was used for quantification of O6eGua in DNA of individual cells after pulse exposure of cells to N-ethyl-N-nitrosourea (EtNU). In cell specimens from a given patient, no major subpopulations with significantly different capacities for repair of O6eGua were observed. The time required to remove 50% of induced O6eGua residues varied interindividually between 0.5 and 8.4 h in CLL lymphocytes and between 0.8 and 6.3 h in leukemic blast cells. An inverse relationship was found between the rate of removal of O6eGua from DNA and the chemosensitivity of cells to EtNU, 1,3-bis(2-chloroethyl)-1-nitrosourea or mafosfamide in vitro. High rates of O6eGua repair and pronounced resistance to mafosfamide, 1,3-bis(2-chloroethyl)-1-nitrosourea, and EtNU in vitro were found in samples from 8 CLL patients nonresponsive to chemotherapy with alkylating agents. In AML patients treated with anthracyclines and 1-beta-D-arabinofuranosylcytosine, no relation was found between DNA repair capacity and treatment outcome. However, increased P-glycoprotein expression was observed between specimens derived from AML patients who had failed to reach complete remission (n = 12) after chemotherapy versus responsive patients (n = 14). DNA repair rate was not related to chemosensitivity to Adriamycin and 1-beta-D-arabinofuranosylcytosine in vitro, nor were cellular glutathione content, glutathione S-transferases activity, or P-glycoprotein expression.

Modulation of functions of granulocytes by recombinant human GM-CSF and possible complications of GM-CSF therapy.

Besides its effect on bone marrow progenitors, GM-CSF is able to modulate functions of mature cells such as neutrophils. It inhibits random migration and chemotaxis through action on both cells and chemotactic factors, and stimulates oxidative metabolism as well as elastase release. Furthermore, it strongly enhances the response of the cells to the usual stimulants such as f-Met-Leu-Phe and phorbol esters. The role of neutral proteinases and activated oxygen species in different diseases such as ARDS, emphysema, coagulation defects, arthritis, and inflammation, is recognized. The remarkable in vitro release of neutral proteinases and activated oxygen species from granulocytes after GM-CSF stimulation may be of importance in vivo. This should be considered in clinical application of GM-CSF, particularly with high-dose therapy.

Neutrophils cause oxidative DNA damage in alveolar epithelial cells.

Inflammation has been recognized as a contributing factor in the pathogenesis of some cancers. In the lung, inflammation is characterized by an influx of polymorphonuclear leukocytes (PMN) that release a variety of reactive oxygen species (ROS). The aim of the present study was to investigate the direct effect of PMN on oxidative DNA damage in lung target cells. Therefore, rat alveolar epithelial cells (RLE) were coincubated with PMN or hydrogen peroxide. Known to be correlated with the incidence of cancer, 7-hydro-8-oxo-2'deoxyguanosine (8-oxodG) was used as an effect marker for oxidative damage. Viability of the RLE, when coincubated with PMN, decreased to 43%, dependent on the ratio between PMN and RLE. After washing off PMN, 8-oxodG levels were significantly increased in RLE, but the highest levels were observed in the washed off PMN fraction. In addition, to avoid washing off procedures, immunohistochemical analysis was used to measure the 8-oxodG levels specifically in the RLE and similar results were obtained. In addition, inhibitor experiments showed that antioxidants ameliorated oxidative DNA damage. Our data provide evidence that ROS released by PMN as well as H2O2, cause oxidative DNA damage in epithelial cells.

A new method for fluorescence immunoassay using plane surface solid phases (FIAPS).

A method distinguished by high sensitivity, low non-specific binding, easy handling, and broad applicability with respect to various antigens is described. Films of polymethyl-methacrylate with plane surfaces were selected as solid phase for adhesive or covalent binding of different antigens (DNA, histone, human, rabbit or goat immunoglobulins). Proteins were covalently bound to the films by the azide method (Orth and Brummer, 1972). Polymethylmethacrylate films thus coated had a negligible autofluorescence and gave minimal non-specific binding of protein. Coated films were used for specificity control of FITC-labeled antibody preparations and in the double antibody and sandwich techniques for detection of antibodies or antigens in sera from man, rabbit and goat. FITC-conjugated hyperimmune antibody, in some cases purified by immunoadsorption was used as second antibody in indirect techniques. The amount of fluorescent-labeled antibody bound per unit of surface area of film was measured by incident light with a Zeiss-Axiomat fluorescence microscope equipped for fluorescence photometry and an uranyl acetate glass plate was used as a standard. The technique appears superior to present methods of quantitative immunofluorescence analysis.

Effect of granulocyte-macrophage colony-stimulating factor on the induction of unresponsiveness by lymphoid cells.

Skin grafts can be significantly prolonged in ALS-treated mice by the injection of 25 x 10(6) donor bone marrow cells or 50 x 10(6) spleen cells. Lymph node cells and thymocytes are only minimally effective in prolonging grafts. The effect of a hematopoietic growth factor, granulocyte-macrophage colony stimulating factor (GM-CSF) was studied in this model of unresponsiveness. C3H/He lymphoid cell donors were treated with GM-CSF. Either normal or GM-CSF-treated cells were injected into ALS-treated B6AF1 mice grafted with C3H/He skin. GM-CSF treatment significantly augmented the effect of marrow in prolonging graft survival at doses of 1 to 25 x 10(6) cells. In contrast, GM-CSF had no effect on the graft-prolonging effect of spleen cells when 50 x 10(6) cells were given. When the dose of cells was reduced to 25 x 10(6), graft survival in the group given GM-CSF-treated cells was prolonged compared with survival in the group given normal cells. Grafts in the group given GM-CSF-treated lymph node cells were rejected in sensitized fashion. When marrow and spleen are separated on a Percoll gradient, the cell active in promoting graft survival is recovered primarily in the 52.5% fraction. The graft-prolonging effect of the 52.5% marrow fraction was not affected by GM-CSF treatment. In contrast, GM-CSF-treated marrow cells in the 60% fraction significantly prolonged graft survival, while normal marrow cells in this fraction had no effect on graft survival. GM-CSF-treated spleen cells in the 52.5% and 60% fractions significantly decreased graft survival compared with normal cells when given at a dose equal to the number of cells recovered from 50 x 10(6) cells. When the dose of fractionated spleen cells was reduced, GM-CSF-treated spleen cells were more effective than normal cells in prolonging graft survival. These results indicate that GM-CSF activates a cell in marrow that promotes graft survival. This cell is recovered in the 60% Percoll fraction. In contrast, GM-CSF appears to affect two cell populations in spleen, one beneficial and one detrimental to graft survival. The predominant effect depends on the dose of spleen cells that is given.

Formation and persistence of 8-oxoguanine in rat lung cells as an important determinant for tumor formation following particle exposure.

Exposure of rats to quartz (or various other particles) can lead to the development of lung tumors. At the moment, the mechanisms involved in particle-induced tumor formation are not clarified. However, it is suggested that inflammation, in conjunction with the production of reactive oxygen species (ROS) and an enhancement of epithelial cell proliferation, may play a key role in the development of lung tumors. ROS induces 8-oxoguanine (8-oxoGua) and other mutagenic DNA oxidation products, which can be converted to mutations in proliferating cells. Mutation formation in cancer-related genes is a critical event with respect to tumor formation. In this study we investigated the effects of quartz (DQ12) and of the nontumorigenic dust corundum on the induction of 8-oxoGua in the DNA of rat lung cells, as well as on cell proliferation and pulmonary inflammation. Wistar rats were exposed by intratracheal instillation to quartz (2.5 mg/rat) or corundum (2.5 mg/rat) suspended in physiological saline; control animals exposed to physiological saline or left untreated. Measurements were carried out 7, 21, and 90 days after the exposures. 8-oxoGua levels were determined in lung tissue sections at the single cell level by immunocytological assay using a rabbit anti-8-oxoGua antibody. After exposure to quartz, 8-oxoGua levels were significantly increased at all time points of investigation. Additionally, we observed inflammation and an enhanced cell proliferation. Exposure to corundum had no adverse effects on the lung; neither increased 8-oxoGua levels nor enhanced cell proliferation or inflammation were detected. These observations support the suggestion that inflammation associated with increased 8-oxoGua levels in lung cells and increased cell proliferation is an important determinant for particle-induced development of lung tumors in the rat.

In-vivo phagocytosis: enhancement of bacterial clearance by native and enzyme-treated immunoglobulins.

The enhancement of bacterial blood clearance in mice by native and enzymatically derived fractions of rabbit anti-E. coli hyperimmune serum was tested. Native immune serum, the corresponding IgG, F(ab')2 and Facb fractions strongly augmented the phagocytosis rate of bacteria, whereas Fab/Fc, Fab, Fc fragments, corresponding preparations from normal serum, and E. coli-absorbed preparations showed no marked enhancing capacity. In one experiment opsonization by IgM was demonstrable. Mice that were injected with fatal doses of bacteria could be protected by subsequent treatment with IgG or F(ab')2 preparations of rabbit anti-E. coli serum. Conclusion is drawn that the Fc region of the IgG molecule is not predominantly responsible for opsonized clearance while the intact divalent antigen cross-linking F(ab')2 fragment - presumably by virtue of complement activation via the alternate pathway - could mediate enhanced bacterial clearance.

Mouse spleen cells are sensitized sheep red blood cells: an Fc-rosette-forming system allowing the detection of "activated" Fc structures.

From a variety of Fc receptor-bearing cell/sensitized red blood cell combinations, mouse spleen cells, and sensitized SRBC were selected as an Fc-specific EA rosette assay system because only this mixture combined a high percentage (about 50%) of rosette-forming cells with complete absence of spontaneous rosettes and showed no influence of complement on the rosette formation. From studies on the minimal structural requirement of IgG both for mediation and inhibition of EA rosettes using IgG and several well-defined fragments, it appeared that both the CH2 and the CH3 domain of Fc are needed for optimal interaction with the lymphocyte Fc receptor. Finally, it was demonstrated that the assay system is able to detect "activated" Fc structures (here: heat-aggregated IgG) and to differentiate between varying amounts of such structures.

The modulation of immune complex aggregation by classical pathway-mediated reactions.

Classical pathway (CP)-triggered reactions of complement-modulated immune complex (IC) aggregation (tetanus toxoid/human anti-tetanus toxoid-IgG; ICs of equivalence) were investigated turbidimetrically during the early stages of reaction. Monospecific Fab'- or Fab-fragments (rabbit) directed against certain complement components were used to block the complement function in normal human serum (NHS). Additionally, parts of the reactions were studied using purified complement components. C1q in serum generated by the addition of EDTA as well as purified C1q were found to increase the IC aggregation. In contrast to C1q, macromolecular C1 is able to inhibit IC aggregation, whereas additional participation of C-1 INH reversed this process. The cooperation of the remaining CP proteins (C4, C2, C4bp, and I) reconstituted the inhibition capacity of the complement. Whereas C3 supported significantly inhibition, a significant influence of other effector pathway (EP) components (C5-C9) was not detectable turbidimetrically.

The functional inhibition of activated C1 inhibitor in normal human serum causes spontaneous consumption of the complement components C2, C3, C4, and factor B.

The human complement components C1r, C1s, C4, C3, factor B, and/or activated C1INH were functionally blocked in normal human serum (NHS) and EGTA- or EDTA-treated NHS by polyclonal monospecific Fab'-fragments to the individual components. The results of inhibition experiments are compatible with the formation of a classical pathway fluid-phase C3 convertase (C4b2a) spontaneously generated by the inhibition of activated C1INH. This process in both NHS and EGTA-NHS was accompanied by the consumption of C2, C4, C3, and factor B but only by poor enhancement of C5 conversion. Blocking subcomponent C1r, completely inhibited spontaneous activation of the complement components, indicating that the control of C1r hydrolysis is the essential role of activated C1INH as a regulator of C1 activation in NHS. Non-complement serum proteases were inactive during the initiation of the activation process. The presence of blood cells during functional inhibition of activated C1INH in NHS slightly decreased the consumption of C3 but not of C2 and C4.

Combined antiviral effects of acyclovir or bromovinyldeoxyuridine and human immunoglobulin in herpes simplex virus-infected mice.

Suboptimal dosage regimens of antivirals (acyclovir or bromovinyldeoxyuridine) and human immunoglobulin have been combined in the treatment of hairless mice infected with herpes simplex virus type 1. The aim of this study was to establish how late after infection human immunoglobulin could be given to still be effective and for how long would the protective effect last. The combination of acyclovir or bromovinyldeoxyuridine with passive immunization proved additive or even synergistic depending on the time of immunoglobulin administration and the observation period after infection. When the survival rate of the mice was followed for up to 20 days postinfection, synergistic action seemed to occur with immunoglobulin given as late as 2 or 3 days after infection. When the mice were followed for up to 100 days after infection, however, it turned out that only the immunoglobulin given 4 h after infection led to a synergistic effect with the antivirals. Most of the mice subjected to combined treatment, in contrast to mice treated with the antivirals only, did not develop anti-HSV antibodies. This lack of a specific humoral immune response possibly reflects the rapid inhibition of virus replication early after challenge by the combined treatment, thus preventing the production of a sufficient amount of viral antigen in the body needed for a measurable antibody induction.