Jean-Luc Iniguez

Measurement of Procalcitonin Levels in Children with Bacterial or Viral Meningitis

We measured the plasma procalcitonin levels in 59 children who were admitted to the hospital because of bacterial or viral meningitis. Eighteen children with acute bacterial meningitis had elevated procalcitonin levels (mean level, 54.5 micrograms/L; range, 4.8-110 micrograms/L). The procalcitonin levels in 41 children with viral meningitis were low (mean level, 0.32 micrograms/L; range, 0-1.7 micrograms/L; P < .0001). Assay of cerebrospinal fluid (CSF) cells and proteins and serum C-reactive protein showed a zone of overlapping values between the two groups. Procalcitonin was not produced in CSF. Plasma procalcitonin levels decreased rapidly during antibiotic therapy. These data suggest that the measurement of plasma procalcitonin might be of value in the differential diagnosis of meningitis due to either bacteria or viruses.

Mycoplasma pneumoniae and Asthma in Children

The aim of this prospective study of a population of children (age, 2-15 years) hospitalized for severe asthma was to test them for acute infection due to Mycoplasma pneumoniae and acute infection due to Chlamydia pneumoniae. Of 119 patients with previously diagnosed asthma, acute M. pneumoniae infection was found in 24 (20%) and C. pneumoniae infection was found in 4 (3.4%) of the patients during the current exacerbation. Of 51 patients experiencing their first asthma attack, acute M. pneumoniae infection was proven in 26 (50%) of the patients (P<.01) and C. pneumoniae in 4 (8.3%). In the control group of 152 children with stable asthma or rhinitis, 8 (5.2%) had M. pneumoniae infection (P<.005). Of the 29 patients experiencing their first asthma attack and infected with M. pneumoniae or C. pneumoniae, 18 (62%) had asthma recurrences but only 6 (27%) of the 22 patients who did not have such infections had asthma recurrences (P<.05). M. pneumoniae may play a role in the onset of asthma in predisposed children and could be a trigger for recurrent wheezing.

Procalcitonin in children admitted to hospital with community acquired pneumonia

AIMS To assess the sensitivity, specificity, and predictive value of procalcitonin (PCT) in differentiating bacterial and viral causes of pneumonia. METHODS A total of 72 children with community acquired pneumonia were studied. Ten had positive blood culture for Streptococcus pneumoniae and 15 had bacterial pneumonia according to sputum analysis (S pneumoniae in 15,Haemophilus influenzae b in one). Ten patients had Mycoplasma pneumoniae infection and 37 were infected with viruses, eight of whom had viral infection plus bacterial coinfection. PCT concentration was compared to C reactive protein (CRP) concentration and leucocyte count, and, if samples were available, interleukin 6 (IL-6) concentration. RESULTS PCT concentration was greater than 2 μg/l in all 10 patients with blood culture positive for S pneumoniae; in eight of these, CRP concentration was above 60 mg/l. PCT concentration was greater than 1 μg/l in 86% of patients with bacterial infection (includingMycoplasma and bacterial superinfection of viral pneumonia). A CRP concentration of 20 mg/l had a similar sensitivity but a much lower specificity than PCT (40%v 86%) for discriminating between bacterial and viral causes of pneumonia. PCT concentration was significantly higher in cases of bacterial pneumonia with positive blood culture whereas CRP concentration was not. Specificity and sensitivity were lower for leucocyte count and IL-6 concentration. CONCLUSIONS PCT concentration, with a threshold of 1 μg/l is more sensitive and specific and has greater positive and negative predictive values than CRP, IL-6, or white blood cell count for differentiating bacterial and viral causes of community pneumonia in untreated children admitted to hospital as emergency cases.

Reduced lung diffusion capacity after Mycoplasma pneumoniae pneumonia

Background. Mycoplasma pneumoniae is a frequent but underdiagnosed cause of community-acquired pneumonia (CAP) in children, and appropriate macrolide treatment is often given late. The aim of this work was to estimate the frequency of pulmonary involvement in children 6 months after a clinical episode of Mycoplasma CAP. Methods. We measured carbon monoxide diffusion capacity (TLCO) and conducted spirometric tests in 35 children without asthma or chronic lung disease (ages 4.5 to 15 years), 6 months and 1 year after acute CAP caused by M. pneumoniae (23 children), pneumococci (5 children) or viruses (7 children). Only 11 of 23 patients with M. pneumoniae CAP required hospitalization, whereas all the patients with pneumococcal or viral pneumonia were admitted to hospital. Results. Lung volumes and spirometric tests were normal for all children. TLCO was normal 6 months after pneumococcal or viral pneumonia (87 to 112% of expected values for height and sex). After acute M. pneumoniae CAP, 11 of 23 patients (48%) had TLCO values <80% of the expected value. The extent of change in lung diffusion capacity was correlated with the delay to diagnosis and treatment: TLCO was low in 8 of 11 patients given macrolide treatment 10 days or more after the onset of acute symptoms vs. only 3 of 10 patients given appropriate treatment in the first 10 days. TLCO was low in 7 of 7 who received macrolide therapy for <2 weeks. TLCO had increased slightly after 1 year in the 5 patients retested after a new course of macrolide treatment. TLCO reached the lower normal range in 2 patients controlled after 3 years. Conclusions. The abnormal TLCO values suggest that some children with Mycoplasma pneumonia have reduced pulmonary gas diffusion after recovery from the illness. The reduction is related to delay and short macrolide therapy.

Serum alpha-interferon in lower respiratory tract infections of children

BACKGROUND Serum alpha-interferon (IFN-alpha) concentrations are high in some children with viral meningitis and other viral infections. We have tried to assess the utility of determining serum IFN-alpha concentrations as a marker of acute viral respiratory infections. METHODS Measurement of IFN-alpha via a biologic assay on Madin-Darby bovine kidney cells was performed in 138 patients with lower respiratory tract infection in whom a pathogen was identified. RESULTS Serum IFN-alpha was detectable at the early stage of respiratory infections in the era of 59 of 75 (78.7%) of patients with a viral infection and in 4 of 63 (6.3%) of those with bacterial infection (P < 0.001). In the 4 patients with positive IFN-alpha and bacterial infection, a concomitant viral infection was found. The production of IFN-alpha is independent of age, and detectable levels are found in young infants, including the first 3 months of life, and in children with an acute viral disease. CONCLUSION This test could be useful in distinguishing between bacterial and viral origins in lower respiratory tract infection (the specificity was 94% and the sensitivity was 79%) and could help guide the use of antibiotics, but more rapid techniques, available in a matter of hours, are required.

Échees du traitement antibiotique des salmonelloses sévères de l'enfant et utilisation des quinolones

BACKGROUND: Quinolone antibiotics are effective in the treatment of Salmonella infections in adults. Their use in children is limited by their side-effects. POPULATION AND METHODS: Forty-two patients (21 girls and 21 boys), aged 1 month to 12 years (mean 3.3 yrs) were admitted from September 1991 to June 1993 for severe Salmonella infections. Criteria of severity were persistent diarrhea and fever for more than 3 days. Thirty-one of these patients were less than 5 years of age. Blood culture was positive in 7 out of 35 patients: culture of the stools was positive in all patients. Five of the 42 patients had presented an acute episode of Salmonella infection a few weeks earlier and had remained asymptomatic carriers until the new acute and severe episode of diarrhea. All patients were given usual antibiotics, mainly ampicillin, amoxicillin, trimethoprime-sulfamethoxazole. Twenty-five of these patients were then given pefloxacin, 12 mg/kg/day, since the 5th day, for 7 days, because persistence of diarrhea and fever. RESULTS: Diarrhea and fever disappeared within less than 2 days in the group of patients given pefloxacin, even though in 6 patients the infecting Salmonella was in vitro resistant to beta-lactamins. Twenty % of patients remained asymptomatic carriers of Salmonella in the group treated by pefloxacin vs 47% in the group without it. There was no difference in species of Salmonella between both groups. None of the patients treated by pefloxacin developed side-effects during the six months following its administration. CONCLUSIONS: Short treatment by pefloxacin may be an alternative choice for treating severe Salmonella infections in children.

Alteration of lung diffusion capacity in IgA nephropathy.

OBJECTIVE: To establish whether changes of lung transfer for carbon monoxide (TLCO) are related to the phase of IgA nephropathy. METHODS: Respiratory function was tested in 12 children with IgA nephropathy assessed by percutaneous renal biopsy. This was done during acute exacerbations or haematuria-free phases of the disease. RESULTS: TLCO was low in 12/13 measurements made in the haematuric phase of IgA nephropathy or during the month following gross haematuria (mean TLCO 64% of expected values). Lung volumes and blood gas values were normal and only minor radiological signs of interstial lung involvement were observed in 11/12 patients. When respiratory tests were performed more than three months after gross haematuria, TLCO was low in 4/9 patients, with no relation to the significance of residual proteinuria or severity of findings at renal biopsy. There was a significant difference between tests performed when haematuria was present or recent and those performed more than three months after an episode of gross haematuria (p < 0.01). CONCLUSIONS: The decrease of TLCO in the acute phases of the disease is probably related to alterations of the lung alveolarcapillary membrane by immune complexes containing IgA. This non-invasive technique, easy to perform and repeat, could be of value in the diagnosis of IgA nephropathy in haematuric children.