Encephalopathy and Axonal Neuropathy Associated With Mycoplasma Pneumoniae Infection: Response to Intravenous Immunoglobulin Therapy

Mycoplasma pneumoniae infection frequently presents as a self-limited process, however, severe cases and even fatalities have been reported. The authors present a case of Mycoplasma pneumoniae infection associated with both encephalopathy and peripheral neuropathy that responded to intravenous immunoglobulin therapy. To our knowledge, this is the first documented case of Mycoplasma pneumoniae related to encephalitis and peripheral axonal neuropathy. To date, there is insufficient data on the effect of intravenous immunoglobulin on the course of mycoplasma-associated central nervous system/peripheral nervous system disease. While intravenous immunoglobulin has aided in a variety of autoimmune-mediated disorders, its efficacy in mycoplasma-mediated encephalitis treatment remains unclear. In this patient case, reversal of both central and peripheral nervous system symptoms after treatment with intravenous immunoglobulin suggested a possible therapeutic benefit.

Inherited IL-12p40 deficiency: genetic, immunologic, and clinical features of 49 patients from 30 kindreds

Autosomal recessive interleukin (IL)-12 p40 (IL-12p40) deficiency is a rare genetic etiology of mendelian susceptibility to mycobacterial disease (MSMD). We report the genetic, immunologic, and clinical features of 49 patients from 30 kindreds originating from 5 countries (India, Iran, Pakistan, Saudi Arabia, and Tunisia). There are only 9 different mutant alleles of the IL12B gene: 2 small insertions, 3 small deletions, 2 splice site mutations, and 1 large deletion, each causing a frameshift and leading to a premature stop codon, and 1 nonsense mutation. Four of these 9 variants are recurrent, affecting 25 of the 30 reported kindreds, due to founder effects in specific countries. All patients are homozygous and display complete IL-12p40 deficiency. As a result, the patients lack detectable IL-12p70 and IL-12p40 and have low levels of interferon gamma (IFN-γ). The clinical features are characterized by childhood onset of bacille Calmette-Guérin (attenuated Mycobacterium bovis strain) (BCG) and Salmonella infections, with recurrences of salmonellosis (36.4%) more common than recurrences of mycobacterial disease (25%). BCG vaccination led to BCG disease in 40 of the 41 patients vaccinated (97.5%). Multiple mycobacterial infections were rare, observed in only 3 patients, whereas the association of salmonellosis and mycobacteriosis was observed in 9 patients. A few other infections were diagnosed, including chronic mucocutaneous candidiasis (n = 3), nocardiosis (n = 2), and klebsiellosis (n = 1). IL-12p40 deficiency has a high but incomplete clinical penetrance, with 33.3% of genetically affected relatives of index cases showing no symptoms. However, the prognosis is poor, with mortality rates of up to 28.6%. Overall, the clinical phenotype of IL-12p40 deficiency closely resembles that of interleukin 12 receptor β1 (IL-12Rβ1) deficiency. In conclusion, IL-12p40 deficiency is more common than initially thought and should be considered worldwide in patients with MSMD and other intramacrophagic infectious diseases, salmonellosis in particular.

Antiretroviral resistance in HIV-infected Saudi children failing first-line highly active antiretroviral therapy

BACKGROUND AND OBJECTIVES

The use of a potent combination of antiretroviral (ARV) drugs, so-called highly active ARV therapy (HAART), has dramatically improved the quality of life and overall survival of children with human immunodeficiency virus (HIV) infection. However, these benefits can be compromised by the development of drug resistance. Our objectives were to analyze the prevalence and pattern of HIV-drug resistance among HIV-infected children failing first-line HAART.

DESIGN AND SETTING

Retrospective study based on data obtained from July 2006 through January 2009 of prevalence of genotypic resistance estimated in HAART-treated children who experienced virologic failure (HIV RNA > 1000 copies/mL) at a tertiary care center in Riyadh.

PATIENTS AND METHODS

The characteristics of the study population and genotype resistance data were analyzed in ARV-treated children who experience virologic failure.

RESULTS

Among 22 children who underwent resistance testing, the prevalence of resistance to any drug was 86.4%. Inadequate adherence to ARVs in children with drug resistance was 91%. Twenty-four mutations were detected within the protease coding region and 14 in the reverse transcriptase (RT) coding region. In 80% of isolates piM36I was detected, while rtM184V was detected in 70% of the isolates and was associated with cross-resistance to at least two nucleoside RT inhibitors (NRTI). Clinically significant non-nucleoside RT inhibitors (NNRTI) resistance was conferred by rtK103N. The best ARV susceptibility was to lopinavir in the PI class. ARV resistance was not associated with geographic regions or the CDC classification status. Study children responded satisfactorily to genotype-guided treatment and intensive family counseling.

CONCLUSION

ARVs resistance is common among HIV-infected Saudi children who experienced virologic failure to HAART. Inadequate adherence is a common cause for resistance to ARVs in children. Mutations M36I and M184V were more frequent for PIs, NRTIs and NNRTIs. Evaluation of genotype tests should be considered in all children with therapeutic failure to guide future selection of ARV regimens. These data will help improve clinical management of HIV-infected children in Saudi Arabia.

Impaired response to interferon-alpha/beta and lethal viral disease in human STAT1 deficiency

The receptors for interferon-alpha/beta (IFN-alpha/beta) and IFN-gamma activate components of the Janus kinase-signal transducer and activator of transcription (JAK-STAT) signaling pathway, leading to the formation of at least two transcription factor complexes. STAT1 interacts with STAT2 and p48/IRF-9 to form the transcription factor IFN-stimulated gene factor 3 (ISGF3). STAT1 dimers form gamma-activated factor (GAF). ISGF3 is induced mainly by IFN-alpha/beta, and GAF by IFN-gamma, although both factors can be activated by both types of IFN. Individuals with mutations in either chain of the IFN-gamma receptor (IFN-gammaR) are susceptible to infection with mycobacteria. A heterozygous STAT1 mutation that impairs GAF but not ISGF3 activation has been found in other individuals with mycobacterial disease. No individuals with deleterious mutations in the IFN-alpha/beta signaling pathway have been described. We report here two unrelated infants homozygous with respect to mutated STAT1 alleles. Neither IFN-alpha/beta nor IFN-gamma activated STAT1-containing transcription factors. Like individuals with IFN-gammaR deficiency, both infants suffered from mycobacterial disease, but unlike individuals with IFN-gammaR deficiency, both died of viral disease. Viral multiplication was not inhibited by recombinant IFN-alpha/beta in cell lines from the two individuals. Inherited impairment of the STAT1-dependent response to human IFN-alpha/beta thus results in susceptibility to viral disease.

Inherited interleukin-12 deficiency: IL12B genotype and clinical phenotype of 13 patients from six kindreds

Interleukin-12 (IL12) is a cytokine that is secreted by activated phagocytes and dendritic cells and that induces interferon-gamma production by natural-killer and T lymphocytes. It consists of two subunits, p35 and p40, which are encoded by IL12A and IL12B, respectively. The first reported patient with a genetic cytokine disorder was a Pakistani child, who was homozygous for a large loss-of-function deletion (g.482+82_856-854del) in IL12B. This IL12-deficient child suffered from infections caused by bacille Calmette-Guérin (BCG) and Salmonella enteritidis. We herein report 12 additional patients from five other kindreds. In one kindred from India, the same large deletion that was described elsewhere (g.482+82_856-854del) was identified. In four kindreds from Saudi Arabia, a recessive loss-of-function frameshift insertion (g.315_316insA) was found. A conserved haplotype encompassing the IL12B gene suggested that a founder effect accounted for the recurrence of each mutation. The two founder mutational events-g.482+82_856-854del and g.315_316insA-were estimated to have occurred approximately 700 and approximately 1,100 years ago, respectively. Among a total of 13 patients with IL12 deficiency, 1 child had salmonellosis only and 12 suffered from clinical disease due to BCG or environmental nontuberculous mycobacteria. One patient also had clinical disease caused by virulent Mycobacterium tuberculosis, five patients had clinical disease caused by Salmonella serotypes, and one patient had clinical disease caused by Nocardia asteroides. The clinical outcome varies from case to case, since five patients (aged 2-11 years) died of overwhelming infection, whereas eight patients (aged 3-12 years) are still in good health and are not currently taking antibiotics. In conclusion, IL12 deficiency is not limited to a single kindred, shows significant variability of outcome, and should be considered in the genetic diagnosis of patients with mycobacteriosis and/or salmonellosis. To date, two founder IL12B mutations have been identified, accounting for the recurrence of a large deletion and a small insertion within populations from the Indian subcontinent and from the Arabian Peninsula, respectively.

Acrophialophora fusispora brain abscess in a child with acute lymphoblastic leukemia: review of cases and taxonomy

A 12-year-old girl with acute lymphoblastic leukemia was referred to King Faisal Specialist Hospital and Research Center. The diagnosis without central nervous system (CNS) involvement was confirmed on admission, and chemotherapy was initiated according to the Children Cancer Group (CCG) 1882 protocol for high-risk-group leukemia. During neutropenia amphotericin B (AMB) (1 mg/kg of body weight/day) was initiated for presumed fungal infection when a computed tomography (CT) scan of the chest revealed multiple nodular densities. After 3 weeks of AMB therapy, a follow-up chest CT revealed progression of the pulmonary nodules. The patient subsequently suffered a seizure, and a CT scan of the brain was consistent with infarction or hemorrhage. Because of progression of pulmonary lesions while receiving AMB, antifungal therapy was changed to liposomal AMB (LAMB) (6 mg/kg/day). Despite 26 days of LAMB, the patient continued to have intermittent fever, and CT and magnetic resonance imaging of the brain demonstrated findings consistent with a brain abscess. Aspiration of brain abscess was performed and the Gomori methenamine silver stain was positive for hyphal elements. Culture of this material grew Acrophialophora fusispora. Lung biopsy showed necrotizing fungal pneumonia with negative culture. The dosage of LAMB was increased, and itraconazole (ITRA) was added; subsequently LAMB was discontinued and therapy was continued with ITRA alone. The patient demonstrated clinical and radiological improvement. In vitro, the isolate was susceptible to low concentrations of AMB and ITRA. A. fusispora is a thermotolerant, fast-growing fungus with neurotropic potential. We report the first case of human infection involving the CNS. Acrophialophora resembles Paecilomyces but differs in having colonies that become dark and in the development of phialides along the sides or at the tips of echinulate brown conidiophores. Conidia are borne in long chains and are smooth or ornamented with fine-to-coarse echinulations, sometimes in spiral bands. The taxonomy of the genus Acrophialophora is reviewed, and Acrophialophora nainiana and Acrophialophora levis are considered as synonyms of A. fusispora.

Simplified high-performance liquid chromatographic method for the determination of gentamicin sulfate in a microsample of plasma: comparison with fluorescence polarization immunoassay

The authors describe a simplified high-performance liquid chromatographic (HPLC) method for the determination of gentamicin sulfate (GEN) in microsamples of plasma using 9-fluorenylmethyl chloroformate (FMOC) as a derivatizing agent and neomycin sulfate as the internal standard (IS). The drug and IS were separated on a 4 microm (particle size), 8 x 100 mm Nova-Pak C18 radial compression cartridge using a mixture of 84.5% acetonitrile and 15.5% water at a flow rate of 2.5 mL/min. The compounds were detected fluorometrically in the effluent at excitation and emission wavelengths of 260 nm and 315 nm, respectively. Sample preparation was performed on 50 microL of plasma using a simple liquid-liquid extraction followed by a room-temperature derivatization procedure. No interference from any endogenous substance or concurrently used drug was observed, and the retention times of the IS and three major components of GEN were 12.4, 19.5, 23.6, and 27.6 min, respectively. The concentration of the GEN in plasma for the range of 0.2-20.0 microg/mL was linearly (r > .997) related to the peak height ratio of the sum of the three major GEN peaks to that of the IS, with CV value at 0.3, 7.5, and 15 microg/mL being <3.61%. A comparison of the results from this assay versus fluorescence polarization immunoassay (TDx) showed a close agreement between the two methods with r = 0.994. This assay is currently being used to monitor GEN and investigate its pharmacokinetics in pediatric patients.

Bone marrow morphologic findings in patients with human immunodeficiency virus (HIV) infection

The hematologic, histologic and morphologic bone marrow findings of 18 patients with human immunodeficiency virus (HIV) infection were reviewed. The mean age of the patients studied was 27 years; age range was six to 63 years. The main bone marrow morphologic finding was hypercellularity (72%), which was mainly due to megakaryocytic hyperplasia with or without granulocytic or erythrocytic hyperplasia. Naked (denuded) megakaryocytic nuclei, which are considered an indicator of HIV infection, were present in 72% of the bone marrows examined. Reticuloendothelial iron blockade was identified in 78% of cases. Other less frequent findings included erythrocytic dysplasia (44%), plasmacytosis (28%), nonspecific granulomas (17%), Hodgkin's and non-Hodgkin's lymphoma (17%), lymphocytic aggregates (11%) and histiocytosis (6%) . The bone marrow findings in this series of HIV patients appear to be similar to what has been previously reported from other countries.

Structured guidelines for the use of influenza vaccine among children with chronic pulmonary disorders

National committees recommend annual influenza vaccination for children > or = 6 months of age with chronic pulmonary diseases, but several studies have suggested that many high risk children do not receive the vaccine. The purpose of this pilot study was to determine whether the use of structured guidelines for which pulmonary disorders warrant influenza vaccination would increase agreement among physicians on whether specific children should be vaccinated. Hospital records of 73 children with an outpatient appointment during the previous month in the pulmonary, allergy or high risk neonatology clinics were reviewed independently by 4 pediatricians. Two reviewers used a set of specific guidelines in deciding whether influenza vaccination was indicated, whereas the other 2 used unspecified clinical judgment. Interrater agreement concerning the advisability of vaccination was higher between the reviewers using the guidelines (overall agreement, 0.89; kappa = 0.73) than between the reviewers using clinical judgment (overall agreement, 0.68; kappa = 0.31). Even among the 34 children for whom all 4 reviewers thought the vaccine advisable, only 13 (38%) had been vaccinated. Studies to define the risk of severe influenza among children with specific lung disorders are needed, but these guidelines can serve as a starting point for the identification of children who deserve individual consideration for annual influenza vaccination.

Chorea as a presentation of herpes simplex encephalitis relapse

Three infants, ages 3 months to 3 years, presented with chorea as the initial manifestation of herpes simplex encephalitis (HSE) relapse. Patient 2, treated with repeated 10 day courses of 30 mg/kg/day of acyclovir, had no clear improvement in neurological status. Patient 1, treated with a repeated 10-day course, improved only to have another HSE relapse 4 years later. Patient 3 clearly improved soon after a 3-week course of acyclovir at conventional dosages. A fourth patient (Patient 4) who relapsed with chorea after what was thought to be HSE, and who did not respond to repeated acyclovir treatment, was negative for herpes simplex virus indicators on brain biopsy and DNA testing. We recommend treating all patients suffering from HSE with a minimum 3-week course of acyclovir at 30-35 mg/kg/day in 3 divided doses.

Nasopharyngeal swabs and nasopharyngeal aspirates equally effective for the diagnosis of viral respiratory disease in hospitalized children

Paired nasopharyngeal swab and nasopharyngeal aspirate specimens from 125 patients were compared for viral diagnosis. The viral isolation rates were comparable for the two types of specimens. There was a high level of agreement between the two specimens in overall positivity rate by immunofluorescence and positivity in culture-confirmed patients.

Role of Ureaplasma urealyticum and other pathogens in the development of chronic lung disease of prematurity

A prospective cohort study enrolling 107 infants weighing less than 1250 g was conducted between September 1, 1986, and November 15, 1987 in order to determine the role of microorganisms on the development of chronic lung disease (CLD). Ureaplasma urealyticum was isolated significantly more frequently from gastric aspirates and nasopharyngeal or endotracheal aspirates from 43 infants developing CLD than from 56 who did not (51% vs. 16%; P less than 0.005). Infants developing CLD, defined by radiographic and blood gas abnormalities, were significantly younger (26 vs. 29 weeks; P less than 0.0001), weighed significantly less (830 vs. 1050 g; P less than 0.0001) and required more ventilatory support (37 vs. 10 were being ventilated and 42 vs. 26 received oxygen supplementation on Day 7) compared with those who did not develop CLD. Viruses were isolated in association with U. urealyticum in two infants developing CLD and in one infant who did not develop CLD. Mycoplasma hominis was isolated from three infants who were colonized with U. urealyticum and developed CLD. Chlamydia trachomatis was not recovered from any patients. From a discriminant analysis it was found that U. urealyticum contributed to the development of CLD along with the effect of ventilatory support, gestational age and severity of initial respiratory disease. The effect of interventions directed against U. urealyticum on the development of CLD deserves further study.

Immunologic responses of children to serious infections with Streptococcus pneumoniae

Antibody responses (as measured by radioimmunoassay), alterations in serum levels of complement, and the presence of circulating immune complexes (as measured by the fluid-phase C1Q-binding assay, the fluid-phase conglutinin assay, and the activation of C1 were evaluated in 15 children after meningitis and/or bacteremia caused by Streptococcus pneumoniae. The ages of the children ranged from two months to 16 years; the duration of follow-up ranged from 18 to 189 days (mean, 78 days). Increases in levels of homotypic antibody were found in only three (25%) of the 12 children in whom this response could be assessed, and all of these responses were transient. Eight (53%) of the 15 children had evidence of a heterotypic antibody response to S pneumoniae serotypes other than those causing their infections. The activation of C1 and C1q-binding activity were detected at the early stage of disease and were generally transient. The result of the fluid-phase conglutinin assay was positive for 14 (93%) of the 15 children later in the course of disease; this result was consistently positive throughout the follow-up period in the majority of children. Depressed concentrations of C4 were noted in nine children, depressed levels of C3 in four, and depressed levels of factor B in two.