IL-6 and other biomarkers as predictors of severity in COVID-19

OBJECTIVE

Cytokine release syndrome is suggested to be the most important mechanism triggering acute respiratory distress syndrome and end organ damage in COVID-19. The severity of disease may be measured by different biomarkers.

METHODS

We studied markers of inflammation and coagulation as recorded in 29 patients on admission to the hospital in order to identify markers of severe COVID-19 and need of ICU.

RESULTS

Patients who were eventually admitted to ICU displayed significantly higher serum levels of interleukin-6 (IL-6), C-reactive protein (CRP), and procalcitonin. No statistical differences were found between the groups in median levels of lymphocytes, D-dimer or ferritin.

CONCLUSIONS

IL-6 and CRP were the strongest predictors of severity in hospitalized patients with COVID-19.

Interleukin-10 gene promoter region polymorphisms are not associated with BCG osteitis in vaccinated infants

SETTING

Complications arising from bacille Calmette-Guérin (BCG) vaccination were recorded in a national register in Finland until 1988. In the period 1960-1988, 222 patients suffered from BCG osteitis.

OBJECTIVE

To evaluate whether single nucleotide polymorphisms (SNPs) in the promoter region of the gene encoding interleukin 10 (IL-10) are associated with BCG osteitis after vaccination in neonates.

DESIGN

Blood samples of 132 former BCG osteitis patients now aged 21-49 years were analysed in a controlled study for IL10 rs1800896 (-1082G/A), rs1800871 (-819C/T), rs1800872 (-592C/A) and rs1800890 (-3575T/A) polymorphisms.

RESULTS

The frequencies of genotypes of IL10 rs1800896, rs1800871, rs1800872 and rs1800890, the frequencies of variant genotypes and the frequencies of major or minor alleles did not differ between patients and controls. Furthermore, the frequencies of the eight possible combinations of the three IL10 alleles located close to each other (IL10 rs1800896, IL10 rs1800871 and IL10 rs1800872) were surprisingly similar.

CONCLUSION

Our results suggest that polymorphisms of the IL-10 encoding gene do not play a central role in the development of complications due to BCG vaccination, although the IL10 gene, especially IL10 rs1800896 (-1082G/A) polymorphism, is known to be associated with tuberculosis risk in Europeans and North Americans.

Interference between respiratory syncytial virus and rhinovirus in respiratory tract infections in children

An acute viral respiratory tract infection might prevent infections by other viruses because of the antiviral innate immune response. However, with the use of PCR methods, simultaneous detection of two or more respiratory viruses is frequent. We analysed the effect of respiratory syncytial virus (RSV) infection on the occurrence of simultaneous rhinovirus (RV) infection in children within a birth cohort study setting. We used PCR for virus detection in nasal swabs collected from children with an acute respiratory tract infection at the age of 0-24 months and from healthy control children, who were matched for age and date of sample collection. Of 226 children with RSV infections, 18 (8.0%) had co-infections with RV, whereas RV was detected in 31 (14%) of 226 control children (p 0.049 by chi-square test). Adjustment for sex, number of siblings and socio-economic status strengthened the negative association between RSV and RV (OR 0.46, 95% CI 0.24-0.90; p 0.02). The median durations of symptoms (cough, rhinorrhoea, or fever) were 11 days in children with single RSV infections and 14 days in children with RSV-RV co-infections (p 0.02). Our results suggest that the presence of RSV reduces the probability of RV infection, but that, if a co-infection occurs, both viruses cause clinical symptoms.

Normal behavior of plasma procalcitonin in adolescents undergoing surgery for scoliosis

Background and Aims:

Surgical site infections are relatively common after spinal deformity surgery. Early detection of deep wound infections is important, since it may allow retention of spinal instrumentation. However, serum C-reactive protein and erythrocyte sedimentation rate may remain elevated for almost 6 weeks, making differential diagnosis of systemic inflammatory response and acute deep bacterial wound infection difficult. Plasma procalcitonin has been suggested to be a useful indicator for bacterial infection. However, there are no studies evaluating behavior of procalcitonin in patients undergoing major spine surgery with instrumentation.

Materials and Methods:

A total of 50 consecutive adolescents (37 idiopathic scoliosis and 13 neuromuscular scoliosis, mean age = 15 years at surgery and follow-up time = 21 months (range = 12–29 months)) undergoing scoliosis surgery participated in this prospective follow-up study. White blood cell count, serum C-reactive protein, and plasma procalcitonin levels were measured on the day before surgery, on the day of surgery, and daily thereafter for 1 week. None of the patients developed signs of acute or delayed wound infection during the follow-up period; however, two neuromuscular scoliosis patients developed severe postoperative pneumonia, and their inflammatory parameter data will be reported separately.

Results:

Plasma procalcitonin levels peaked on the first postoperative day (mean = 0.19 ng/mL, range = 0.04–1.29 ng/mL), and mean values were less than 0.5 ng/mL during the whole first postoperative week, while C-reactive protein remained elevated during the whole first postoperative week (highest mean value = 63.8 mg/L (range = 5–248 mg/L) on third postoperative day). Patients with idiopathic scoliosis had lower C-reactive protein levels (p < 0.05 from first to sixth postoperative day) and lower procalcitonin levels (p < 0.05 from third to seventh postoperative day) than neuromuscular scoliosis patients. Two patients with postoperative pneumonia showed elevated procalcitonin values over the whole postoperative week (22.34 ng/mL and 0.72 ng/mL highest values, respectively).

Conclusions:

Elevated plasma procalcitonin levels seem useful when excluding acute deep wound infection from systemic inflammatory response.

Virus shedding after human rhinovirus infection in children, adults and patients with hypogammaglobulinaemia

The shedding of human rhinovirus (HRV) after an acute, naturally acquired infection has not been described in detail. We determined the duration of HRV shedding in immunocompetent children and adults, and in patients with primary hypogammaglobulinaemia. Subjects with symptoms of respiratory tract infection, and their household contacts, were screened for HRV by reverse transcription PCR. They were followed by serial, self-collected nasal swab specimens until negative for HRV or infected by another HRV type. We followed 62 HRV infections in 54 subjects. The mean (95% CI) duration of HRV shedding was 11.4 (8.2-14.7) days in children, 10.1 (7.4-12.9) days in adults, and 40.9 (26.4-55.4) days in patients with hypogammaglobulinaemia (p <0.001). The duration of respiratory tract symptoms correlated with the duration of virus shedding (p 0.002). A new infection by another HRV type soon after the first episode was common. We conclude that the shedding times of HRV are relatively short in otherwise healthy individuals. In contrast, prolonged shedding over 28 days is frequent in patients with hypogammaglobulinaemia despite immunoglobulin replacement therapy.

Admission diagnoses of children 0-16 years of age hospitalized with influenza

The prompt diagnosis of influenza enables the institution of antiviral therapy and adequate cohorting of patients, but scarce data are available to help clinicians correctly suspect influenza in children at the time of admission. This 16-year retrospective study assessed the main admission diagnoses of 401 children aged ≤16 years hospitalized with virologically confirmed influenza. The clinical data were derived from a systematic review of the medical records of the children. Sepsis-like illness was the main reason for admission in 52% of infants aged <6 months and in 7-16% of the older children. Respiratory symptoms accounted for 38% of admissions, and 15% of children were hospitalized due to acute neurologic conditions, primarily febrile convulsions. Wheezing or exacerbation of asthma was the primary reason for admission in 14% of children aged <3 years. No differences were observed in the admission diagnoses between children with influenza A and B infections. The main admission diagnoses vary widely in different age groups of children with influenza, and only a minority of children are hospitalized for respiratory symptoms. The leading role of sepsis-like illness in infants aged <6 months calls for increased efforts to find protective measures against influenza in this age group.

Induced sputum in the diagnosis of childhood community-acquired pneumonia

BACKGROUND

The usefulness of induced sputum in searching for causative agents of pneumonia in children has not been studied.

METHODS

The study involved 101 children, aged 6 months to 15 years, treated for community-acquired pneumonia at Turku University Hospital (Turku, Finland) from January 2006 to April 2007. Nasopharyngeal aspirate samples were first collected through both nostrils. Sputum production was then induced by inhalation of 5.0% hypertonic saline for 5-10 min and a sputum sample was either aspirated or expectorated. The presence and amount of bacteria and viruses in paired nasopharyngeal aspirate and sputum specimens was analysed and compared using semiquantitative bacterial culture and quantitative PCR techniques.

RESULTS

A good quality sputum specimen was obtained from 76 children. The possible causative agent was found in 90% of cases. Streptococcus pneumoniae (46%) and rhinovirus (29%) were the most common microbes detected. Newly discovered viruses human bocavirus and human metapneumovirus were detected in 18% and 13% of the children, respectively. One-quarter of all bacterial findings were only detected in sputum, and the amount of bacteria in the remainder of the sputum specimens compared with nasopharyngeal aspirate was higher in 14% and equal in 70%. The amount of rhinovirus in sputum was higher than in nasopharyngeal aspirate in 82%.

CONCLUSIONS

Sputum induction provides good quality sputum specimens with high microbiological yield in children with community-acquired pneumonia. Induced sputum analysis can be useful in the microbiological diagnosis of childhood community-acquired pneumonia.

Bacterial coinfections in children with viral wheezing

Bacterial coinfections occur in respiratory viral infections, but the attack rates and the clinical profile are not clear. The aim of this study was to determine bacterial coinfections in children hospitalized for acute expiratory wheezing with defined viral etiology. A total of 220 children aged 3 months to 16 years were investigated. The viral etiology of wheezing was confirmed by viral culture, antigen detection, serologic investigation, and/or PCR. Specific antibodies to common respiratory bacteria were measured from acute and convalescent serum samples. All children were examined clinically for acute otitis media, and subgroups of children were examined radiologically for sinusitis and pneumonia. Rhinovirus (32%), respiratory syncytial virus (31%), and enteroviruses (31%) were the most common causative viruses. Serologic evidence of bacterial coinfection was found in 18% of the children. Streptococcus pneumoniae (8%) and Mycoplasma pneumoniae (5%) were the most common causative bacteria. Acute otitis media was diagnosed in 44% of the children. Chest radiographs showed alveolar infiltrates in 10%, and paranasal radiographs and clinical signs showed sinusitis in 17% of the older children studied. Leukocyte counts and serum C-reactive protein levels were low in a great majority of patients. Viral lower respiratory tract infection in children is often associated with bacterial-type upper respiratory tract infections. However, coexisting bacterial lower respiratory tract infections that induce systemic inflammatory response are seldom detected.

Regulation of copper/zinc and manganese superoxide dismutase by UVB irradiation, oxidative stress and cytokines

We have examined the effects of UVB irradiation, oxidative stress and cytokines on the antioxidant enzymes copper/zinc and manganese superoxide dismutase (CuZnSOD and MnSOD) in HeLa cells. A single dose of UVB irradiation regulated dose-dependently the expression of the 4 kb transcript of MnSOD although it did not have any significant effect on MnSOD enzymatic activity. In contrast, UVB irradiation reduced both the enzymatic activity and the expression of the 0.7 and 0.9 kb mRNA transcripts of CuZnSOD. The cytokines TNF-alpha (1 ng ml-1 and 10 ng ml-1) and IL-6 (100 U ml-1) induced MnSOD activity, and TNF-alpha also upregulated MnSOD mRNA expression. Interestingly, genistein, a soy isoflavone and a tyrosine kinase inhibitor, was able to inhibit the induction of Mn-SOD activity and mRNA expression by TNF-alpha. Enzymatic CuZnSOD activity was depressed by a high dose of H2O2 while IL-6 or TNF-alpha had no effect on CuZnSOD activity. Our results demonstrate that, in addition to enzyme activity level, UVB irradiation can regulate the superoxide dismutases at the mRNA level. We also suggest that UVB irradiation, oxidative stress and cytokines regulate differentially CuZnSOD and MnSOD, and that the activities and expression of these antioxidant enzymes are controlled by distinct mechanisms.

Induction of lipid peroxidation during steroidogenesis in the rat testis

Free radical production and lipid peroxidation are potentially important mediators in testicular physiology and toxicology. The cytochrome P450 enzymes of the steroidogenic pathway are known to produce free radicals. The present study was conducted to elucidate in vivo the gonadotropin regulation of free radical-mediated lipid peroxidation and the antioxidative defense system in the rat testis. GnRH antagonist (Org 30276; 1 mg/kg BW) and testosterone [40-mm SILASTIC brand (Dow-Corning) capsules] treatments were used to suppress serum gonadotropin levels. As expected, serum LH decreased to a very low level, whereas serum FSH decreased only slightly. Testosterone treatment for 8 days decreased the levels of the peroxide-metabolizing enzymes, catalase, glutathione peroxidase (GSH-Px), and glutathione transferase (-44%, -24%, and -31%, respectively; P < 0.01 for all). These changes predominately reflect the interstitial tissue, in which catalase and GSH-Px activities were much higher than in the seminiferous tubules. Testicular CuZn or Mn superoxide dismutase activities, which were high in the seminiferous tubules, were not affected by gonadotropin suppression. The total peroxyl radical-trapping capacity of the testis, or its components, vitamin E and ubiquinol 9, were not affected either. Lipid peroxidation was decreased after 8-day treatment, as detected by diminished formation of conjugated dienes and fluorescent chromolipids (-30% and -19%, respectively; P < 0.05 for both). Similar results of decreasing catalase and GSH-Px activities were found after gonadotropin suppression with GnRH antagonist treatment for 2 days or testosterone treatment for 5 days. Substitution with hCG, alone or in combination with recombinant human FSH, reversed the changes in enzyme activities, whereas FSH alone had no effect. After 5-day testosterone treatment, catalase messenger RNA expression was studied by Northern hybridization, and it was observed to parallel the changes in enzyme activity. The site of free radical production was studied by separating interstitial tissue and seminiferous tubules 5 h after hCG injection. GSH-Px was induced by hCG only in the interstitial tissue (+28%; P< 0.01), supporting the hypothesis of free radical production during steroidogenesis. Aminoglutethimide, an inhibitor of the P450 cholesterol side-chain cleavage enzyme, induced extensive lipid peroxidation in the testis. Presumably, aminoglutethimide leads to leakage of free radicals from the P450 enzyme when substrate oxygenation is prevented. In conclusion, the present study suggests that physiological LH action in the rat testis causes lipid peroxidation and maintains high activities of peroxide-metabolizing enzymes in the interstitial tissue.(ABSTRACT TRUNCATED AT 400 WORDS)

Abdominal position of the rat testis is associated with high level of lipid peroxidation

Experimental cryptorchidism in the adult rat induces lipid peroxidation as a sign of oxidative stress. To further elucidate the role of free radicals and antioxidant enzymes in the degeneration of testis in cryptorchidism, we first studied testes of untreated rats before and after the normal testicular descent. In the second experiment, primary unilateral cryptorchidism was induced by surgically attaching one testis of each rat to the abdomen before testicular descent. The level of lipid peroxidation was detected by formation of fluorescent chromolipids and diene conjugates. At the age of testicular descent (18-21 days), the level of fluorescent chromolipids dropped to one third (p < 0.05). Correspondingly, the level of diene conjugates was 69% (p < 0.05) higher at 18 than at 30 days of age. The antioxidant enzyme activities did not change at the time of testicular descent. Primary unilateral cryptorchidism was induced at the age of 13 days. At 25 or 35 days of age, the level of diene conjugates was higher in the cryptorchid testes than in the contralateral scrotal testes (+39%, p < 0.01, and +51%, p < 0.001, respectively). In the abdominal testes, the mRNA of CuZn superoxide dismutase (SOD) was increased by 69% (p < 0.05) at 25 days, whereas by 35 days of age enzymatic CuZn SOD activity was slightly decreased and catalase activity increased. The present results show that the abdominal position of the testis, either before normal testicular descent or in experimental cryptorchidism, is associated with a high level of lipid peroxidation. The data provide evidence that increased production of reactive oxygen species could contribute to degeneration of the cryptorchid testis. The oxidative testis. The oxidative stress in the cryptorchid testis is not explained by inactivation of antioxidant enzymes.

Lipid peroxidation and antioxidant enzyme activities in the rat testis after cigarette smoke inhalation or administration of polychlorinated biphenyls or polychlorinated naphthalenes

Lipid peroxidation products and antioxidant enzyme activities were studied in the rat testis following exposures to cigarette smoke, polychlorinated biphenyls (PCBs), or polychlorinated naphthalenes (PCNs). Three hours after a single 1-hour period of smoke inhalation, the levels of fluorescent chromolipids and thiobarbituric acid-reactive species (TBARS) were markedly increased in the testis (+49%, P < 0.01, and +43%, P < 0.05, respectively). Twelve hours after daily smoking for 1 hour, for 1, 5, or 10 days, such an increase was not found. Activities of the antioxidant enzymes superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), or hexose monophosphate shunt (HMS) were not affected immediately, 3 hours, or 12 hours after a single smoking session. Twelve hours after smoking for 5 days, the activity of catalase was decreased (-16%, P < 0.05). Smoking exposures had no consistent effects on serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), or testosterone concentrations. Single i.p. injections of PCB or PCN mixtures resulted in decreases in testicular SOD activity 1 day after the exposures (-14%, P < 0.05, and -51%, P < 0.01, respectively). Catalase activity also decreased after both exposures (-30 to -42%, P < 0.05, at days 1-7 after PCB exposure, and -37 to -43%, P < 0.05, at days 3-7 after PCN exposure). Ninety days after the PCN exposure, activities of GSH-Px and GSH-Tr were decreased in the testis (-20%, P < 0.05, and -26%, P < 0.05, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)

Superoxide dismutase activity along rat seminiferous epithelial wave: effects of ethane dimethanesulphonate and 3.0 Gy of X-irradiation

Changes in generation of reactive oxygen species and antioxidant enzyme activities are associated with differentiation processes. The authors have studied the activity of superoxide dismutase (SOD) in sequentially cut stage-defined segments of rat seminiferous tubules. Great variation was observed in SOD activity along the seminiferous epithelial wave. At its highest, four-fold increases were observed in individual tubules. However, these changes showed no clear correlation to the stages of the cycle. To determine the effect of testosterone withdrawal, rats treated with ethane dimethanesulphonate (EDS) were studied. This treatment had no effect on the pattern of SOD activity along the seminiferous epithelial wave. Testes of other rats were exposed to local 3.0 Gy X-irradiation to cause selective loss of germ-cell populations. SOD activity in the seminiferous epithelium was not affected at 30 min or 7 d after X-irradiation. On day 31 post-irradiation, SOD activity increased at stages XIV-VI, peaking at stage III (P < 0.01 for comparison of stages XIV-VI with the other stages). The data presented here suggest that the activity of SOD in seminiferous epithelium is regulated over a wide range during spermatogenesis. Testosterone plays no major role in the control of seminiferous tubule SOD activity. The loss of spermatocytes and early spermatids by day 31 after X-irradiation revealed a stage-specific increase in SOD activity, which may be associated with the differentiation of elongated spermatids.

Comparison of effects of 0.5 and 3.0 Gy X-irradiation on lipid peroxidation and antioxidant enzyme function in rat testis and liver

The prooxidant effect of X-irradiation on rat testis and liver tissue was studied with doses of 0.5 and 3.0 Gy; the latter dose kills the proliferating spermatogonia and causes a maturation-depletion process in the germ cells. The level of lipid peroxidation, measured by the formation of diene conjugates and thiobarbituric acid-reactive substances (TBARS) and the activities of the antioxidant enzymes were determined 0.5 hours, 1 day, 7 days, and 31 days after the exposure. In the liver, increased levels of diene conjugation (+36%, P < 0.05) in the group of 3.0 Gy at 0.5 hours indicated increased lipid peroxidation. At the same time, TBARS were increased (+25%, P < 0.05) in the group of 0.5 Gy, but not in the 3.0-Gy group. In the testis, diene conjugation was not determined at 0.5 hours postirradiation, and at day 1 it was at the control level. The level of TBARS in the testis was below control (-11%, P < 0.01) in the 3.0-Gy group at day 1. At day 31 after 3.0 Gy in the testis, an increase in the amount of conjugated dienes (+24%, P < 0.01) was observed in parallel with a decreased level of TBARS (-15%, P < 0.01). The activity of superoxide dismutase (SOD) was decreased in the testis at 0.5 hours postirradiation (-28%, P < 0.05, and -29%, P < 0.05, in the groups of 0.5 and 3.0 Gy), whereafter it returned to normal by day 7. In the liver, such inactivation of SOD was not observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Antioxidant enzyme activity in the maturing rat testis

Developmental profiles of the activity of the antioxidant enzymes superoxide dismutase (SOD), catalase, glutathione peroxidase (GSH-Px), glutathione transferase (GSH-Tr), and hexose monophosphate shunt (HMS) were measured in the rat testis and liver. The level of SOD in the testis was high at the age of 6 to 10 days, after which it dropped to approximately one third of that level by 20 days of age, and remained there up to 8 months of age. In the liver, SOD activity steadily increased from the neonatal to adult stage of life, reaching the same level as detected in the testis. The testicular activity of catalase was only 2% to 7% of that found in liver at all ages. It increased in both organs up to 6 weeks of age, whereafter the hepatic activity gradually decreased and no further changes were seen in the testis. The GSH-Px activity was low in the testis and declined slightly with age, whereas activity in the liver increased four-fold between birth and adulthood. The activity of GSH-Tr was similar in both organs studied: it increased after birth, showing a maximum in the liver at 1.5 months (ten-fold increase) and in the testis at 5 months of age (four-fold increase). The HMS activity was two to three times higher in the liver than in the testis, and decreased slightly with age in both organs. Thus, the basal levels and developmental profiles of antioxidant enzymes in the testis differ greatly from those in the liver.(ABSTRACT TRUNCATED AT 250 WORDS)

Pro-oxidant effects of normobaric hyperoxia in rat tissues

Rats were exposed to 100% O2 atmosphere for 12, 36 or 48 h, and their lungs, brain, liver and kidneys were studied for signs of oxidative damage. Oxidative damage at molecular level was estimated by: (1) the appearance of conjugated diene double bonds and (2) the amount of fluorescent chromolipids in lipids extracted from tissues. As important intracellular regulators of oxidative stress, the response of enzymes detoxifying reactive oxygen species was also studied. Macroscopically, the brain and the lungs were most susceptible to oxygen-induced effects. As an indication of oxidative tissue damage, hyperoxia caused accumulation of fluorescent chromolipids in brain and lung tissues, whereas diene conjugation did not reveal any signs of lipid peroxidation. Accumulation of fluorescent chromolipids was most prominent in the brain, where 99 and 138% increases over the control were detected after 36 and 48 h hyperoxia, respectively. Fluorescent chromolipids appeared in urine already before their concentrations were elevated in tissues. The activity of superoxide dismutase in the brain was initially decreased, followed then by a slight induction of activity at the later time-points. Pulmonary and hepatic catalase activities were markedly decreased after prolonged (36 and 48 h) hyperoxia. In conclusion, fluorescent chromolipid formation seems to be a sensitive indicator of hyperoxia-induced oxidative damage in rat tissues. The lipid peroxidation-derived fluorescent chromolipids are eliminated from the body via urinary excretion. Moreover, impaired detoxication of reactive oxygen may be implicated in tissue damage due to hyperoxia.