Clinical and Laboratory Evaluations of Patients Diagnosed as Having Multisystem Inflammatory Syndrome Associated with Coronavirus Disease 2019 in Children: A Single Center Experience from Konya

Objective Multisystem inflammatory syndrome in children (MIS-C), characterized by fever, inflammation, and multiorgan dysfunction, was newly defined after severe acute respiratory syndrome coronavirus 2 infection. The clinical spectrum of MIS-C can be classified as mild, moderate, and severe. We aimed to evaluate demographics, clinical presentations, laboratory findings, and treatment modalities of patients with MIS-C according to clinical severity.

Methods We performed a retrospective study of patients who were diagnosed as having MIS-C between September 2020 and October 2021 in the Necmettin Erbakan University Meram Faculty of Medicine, Turkey.

Results A total of 48 patients (24 females and 24 males) with a median age at diagnosis of 10.3 years (range: 42 months–17 years) were enrolled, the most common clinical severity of MIS-C was moderate. The common presentations of patients were fever (97%), nonpurulent conjunctivitis (89.6%), rashes (81.3%), fatigue (81.3%), strawberry tongue (79.2%), and myalgia (68.8%). The most common laboratory findings were lymphopenia (81.2%), thrombocytopenia (54.1%), elevated D-dimer levels (89.5%), C-reactive protein (CRP; 100%), procalcitonin (97%), erythrocyte sedimentation rate (87.5%), ferritin (95.8%), interleukin 6 (IL-6) (86.1%), and probrain natriuretic peptide (pro-BNP) (97%). High levels of CRP, procalcitonin, pro-BNP, and urea were associated with the severity of MIS-C (p < 0.05). Fifteen of the patients were found to have pulmonary involvement. Ascites were the most common finding on abdominal ultrasonography (11 patients) and were not seen in a mild form of the disease. During the study period, two patients died.

Conclusion It is important to make patient-based decisions and apply a stepwise approach in treating patients with MIS-C due to the increased risk of complications and mortality.

Memory B cells and serum immunoglobulins are associated with disease severity and mortality in patients with COVID-19

PURPOSE OF THE STUDY

The aim of this study was to investigate the relationship of B cell-mediated immunity with disease severity and mortality in patients with COVID-19.

STUDY DESIGN

In this retrospective cohort and single-centre study, 208 patients with laboratory-confirmed COVID-19 were recruited. A COVID-19 severity score, ranging from 0 to 10, was used to evaluate associations between various factors. Serum immunoglobulin levels and the number of cells in B lymphocyte subsets were measured and their association with disease severity and mortality in patients with COVID-19 examined.

RESULTS

The median age of the patients was 50 (35-63) years and 88 (42%) were female. The number of deceased patients was 17. The median COVID-19 severity score was 8 (6-8) in deceased patients and 1 (0-2) in survivors. Deceased patients had significantly lower levels of total B lymphocytes, naive B cells, switched memory B cells, and serum IgA, IgG, IgG1 and IgG2 than recovered patients (all p<0.05). In addition, a significant negative correlation was found between the number of these parameters and COVID-19 severity scores. Decrease in the number of total B cells and switched memory B cells as well as lower serum IgA, IgG and IgG1 levels were independent risk factors for mortality in patients with COVID-19.

CONCLUSION

In the present study, the prognosis of patients with COVID-19 was shown to be associated with the B cell subset and serum immunoglobulin levels.

Seroprevalence of Toxoplasma gondii in Different Patient Groups in Our Hospital

OBJECTIVE

Toxoplasma gondii (T. gondii) is an obligate intracellular parasite. It is regarded as an important cause of morbidity and mortality in congenital contamination and immunosuppressive patients. This study aimed to determine the seropositivity of T. gondii in various ages and patient groups, as well as to reveal the current immune status, especially in risk groups.

METHODS

Results of T. gondii serology conducted between 2015 and 2019 in the medical microbiology laboratory in a university hospital were retrospectively analyzed. In the study, anti-T. gondii IgM, anti-T. gondii IgG antibodies, and anti-T. gondii IgG avidity test results were investigated by the enzyme-linked fluorescent assay method. Additionally, seropositivity rates among immunosuppressed patients and pregnant women, which are risk groups for toxoplasmosis, were revealed. In the identification of the immunosuppressed patients, groups with significant immunosuppression were retrospectively determined by examining their files.

RESULTS

The serology of T. gondii was investigated in serum samples of a total of 20.875 individuals, among which 6.220 (29.8%) are males and 14.655 (70.2%) are females. Anti-T. gondii IgM and IgG positivity rates were significantly higher in women than in men. When all years are evaluated, IgM positivity in 16.448 patients and IgG positivity in 4.427 patients were investigated. In the 5-year period, T. gondii IgM seropositivity and T. gondii IgG seropositivity was among all the patients was 2.4% and 24.1%, respectively. While the rate of T. gondii IgG seropositivity in women of childbearing age was 36.1%, it was 42.4% in pregnant women and 14.6% in immunosuppressed patients.

CONCLUSION

T. gondii serology follow-up of pregnant women and immunosuppressed patients in terms of reactivity of latent infection should be advised and toxoplasmosis should be considered in suspicious clinical cases.

Relationship between selective IgA deficiency and COVID-19 prognosis

The prevalence and mortality rates of coronavirus disease 2019 (COVID-19) vary widely among populations. Mucosal immunity is the first barrier to pathogens' entry into the body. Immunoglobulin A (IgA) is the main antibody of mucosal immunity. We explored the relationship between selective immunoglobulin A deficiency (SIgAD) and the severity of COVID-19. We included 424 patients (203 females) with COVID-19. Eleven patients had SIgAD. Laboratory data on patients with SIgAD and normal IgA levels were compared. The relationship between SIgAD and severe COVID-19 infection was explored by logistic regression analysis. In univariate logistic regression analysis, the risk of severe disease in COVID-19 patients with SIgAD was approximately 7.7-fold higher than in the other patients (odds ratio [OR], 7.789; 95% confidence interval [CI], 1.665-36.690, p = 0.008), while it was 4-fold (OR, 4.053; 95% CI, 1.182-13.903, p = 0.026) higher in multivariate logistic regression analysis. Serum IgA levels were positively correlated with total lymphocyte counts, and negatively correlated with C-reactive protein (CRP) levels, which were found as a risk factor for severe COVID-19.In SIgAD patients, the number of SARS-CoV-2 viruses that pass through mucosal membranes may be increased, leading to complications such as cytokine storm syndrome and acute respiratory distress syndrome.

Laboratory Diagnosis of Pediatric Herpesvirus Infections of the Central Nervous System by a Multiplex Polymerase Chain Reaction Assay and Intrathecal Antibodies

Introduction Central nervous system (CNS) viral infections are a serious problem requiring accurate diagnosis and treatment. Human herpesviruses (HHVs) are an important cause of these infections. Recent research has focused on new diagnostic methods allowing accurate and rapid identification of viral infections because there are still diagnostic difficulties for these infections. This study was done to determine the etiologic role of human herpes viruses and to obtain information that will contribute to the diagnostic algorithm in suspected cases of viral encephalitis or aseptic meningitis.

Materials and Methods In our study, herpes simplex virus (HSV)-1, HSV-2, varicella zoster virus (VZV), cytomegalovirus (CMV), Epstein–Barr virus (EBV), and HHV-6 DNA was detected in the cerebrospinal fluid (CSF) by multiplex polymerase chain reaction (PCR) and virus-specific immunoglobulin G (IgG) antibodies in CSF and serum by EIA in pediatric encephalitis/meningitis cases.

Results HSV-1 and VZV were detected in 5 and 3.3% of aseptic meningitis cases, respectively, but no encephalitis cases. Other viruses were not identified as etiologic agents. The seroprevalences were determined as 72.4, 34.3, 81.9, 93.3, 88.6, and 80.9%, respectively for HSV-1, HSV-2, VZV, CMV, EBV, and HHV-6. The performance of specific IgG CSF/serum antibody index (AI) was not satisfactory.

Conclusion Our study indicates that the multiplex PCR method is the most suitable for the diagnosis of CNS infections caused by HHVs. However, due to the high cost of the PCR method, the positive results of the specific AI may be significant, but the negative results are unreliable, especially in limited health care facilities.

Investigation of Parvovirus B19 IgM and IgG Positivity Rates in Pediatric Hematology Patients

Human parvovirus B19 is a frequent etiologic agent causing erythema infectiosum in children. It has recently been suggested that parvovirus B19 may be latent after infection and cause reactive infections especially in immunosuppressed patients with hematological problems. In this study, we aimed to investigate the parvovirus B19 immunoglobulin M (IgM) and immunoglobulin G (IgG) seropositivity rates of patients evaluated in a pediatric hematology clinic. We retrospectively screened the laboratory results of parvovirus B19 IgM and IgG antibody assays of children less than 18 years, who consulted pediatric in-and-outpatient clinics between 2013 and 2016. Parvovirus B19 IgM and IgG antibodies were investigated in serum samples by using enzyme-linked immunosorbent assay method in the Medical Microbiology Laboratory. Parvovirus B19 IgM antibodies were detected in 109 of 602 patients attending pediatric hematology clinics (18.1%). Parvovirus B19 IgG antibody was detected in 244 of 952 patients attending pediatric hematology clinics (25.6%). Parvovirus B19 IgM and IgG positivity in samples from pediatric in-and-outpatient clinics other than pediatric hematology were 2.8% and 35.7%, respectively. Parvovirus IgM and IgG positivity in serum samples sent from the pediatric hematology clinic and outpatients was statistically significant compared with those sent from pediatric clinics other than pediatric hematology (p = 0.0001 and p = 0.0008, respectively). The higher detection rate of serum parvovirus B19 IgM positivity in patients under the follow-up of pediatric hematology clinics suggests that immune suppression-related viral reinfection or persistence may occur in these patients.

The presence of Torque teno virus in chronic obstructive pulmonary disease

Torque Teno Virus (TTV) has been identified as transfusion-transmitted virus in humans, initially. Although TTV viremia is extremely common in the general population worldwide, there is no direct causal evidence linking TTV infection to specific clinical manifestations. Our hypothesis was that TTV might play a role in Chronic obstructive pulmonary disease (COPD) by inducing inflammatory mechanisms previously identified. The study was conducted on 57 COPD patients and 39 healthy control groups. COPD patient groups included: the patients (n:20) with exacerbation needed noninvasive ventilation, the patients (n:19) who received only medical treatment, and the invited patients (n:18) for outpatient control. Serum samples were collected from patients and voluntary blood donors. TTV DNA quantification was carried out with a real time PCR by the hybridization probe system and viral load was interpreted through the crossing point value. TTV DNA was detected in the majority of both patients and healthy control groups. The prevalence was 94.4% (17/18) in patients for outpatient control, 94.7% (18/19) in patients who received only medical treatment, 100% (20/20) in patients with exacerbation needed noninvasive ventilation and 84.6% (33/39) in healthy controls. This difference was not statistically significant. However, CP values was statistically different in all the patient groups from the control group. TTV DNA prevalence was higher in patients than healthy individuals. More interesting thing, viral load was highest in the patients with exacerbation needed noninvasive ventilation. As a result, TTV may be associated with COPD and the severity of it.

A comparison of immuncapture agglutination and ELISA methods in serological diagnosis of brucellosis

BACKGROUND

Different serological tests are used in serologic diagnosis of brucellosis. The most widely used of these are Standard Tube Agglutination and Coombs anti-brucella tests. Whereas ELISA Ig M and Ig G tests have been in use for a long time, immuncapture agglutination test has been recently introduced and used in serological diagnosis. The aim of this study was to compare diagnostic values of ELISA Ig M and Ig G and immuncapture agglutination tests with Coombs anti-brucella test.

METHODS

Sera from 200 patients with presumptive diagnosis of brucellosis were included into the study. Coombs anti-brucella test, ELISA Ig M and Ig G tests and Immuncapture test were investigated in these sera. Then, sensitivity, specificity, negative predictive and positive predictive values were calculated.

RESULTS

Sensitivity, specificity, negative predictive and positive predictive values were found to be 90.6%, 76.3%, 94.2%, and 65.9% respectively for the Immuncapture test, whereas they were found to be 73.7%, 58.9%, 84.2%, and 42.8% for Ig G and 72.2%, 67.8%, 85.2%, and 48.7% for Ig M. The Immuncapture test was found to be compatible with ELISA Ig M and Ig G tests but it was statistically incompatible with Coombs anti-brucella test.

CONCLUSIONS

Immuncapture agglutination test yields similar results to those of Coombs anti-brucella test. This test is a useful test by virtue of the fact that it determines blocking antibodies in the diagnosis and follow-up of brucellosis.

A rare cause of bacteremia in a pediatric patient with Down syndrome: Sphingomonas paucimobilis

Sphingomonas paucimobilis, is a yellow-pigmented, aerobic, non fermentative, gram negative motile bacillus. S. paucimobilis which is widely found in nature and hospital environments rarely cause serious or life threatening infections. In this report, a case of hospital acquired bloodstream infection due to S. paucimobilis in a patient with Down syndrome who was on treatment for presumed pneumonia is presented. A one year-old child patient who was a known case of Down syndrome and had previously experienced cardiac surgery was hospitalized and treated for pneumonia. On the 12th day of hospitalization, blood cultures were taken because of a high body temperature. One of the blood cultures was positive for gram-negative rods. After 48 hour of incubation, the sub-cultures on blood agar medium yielded pure growth of a yellow, non-fermentative, gram-negative, rod-shaped bacterium. The microorganism was positive for oxidase, and esculin hydrolysis, while negative for urea and nitrate reduction, citrate utilisation and motility. The isolate had been identified as S. paucimobilis by using Vitek 2 system. The antibiotic susceptibility test was also performed with the same system and the strain was found to be susceptible to piperacillin-tazobactam and other antibiotics. Treatment with intravenous piperacilin-tazobactam (150 mg/kg/day) was initiated. He responded well to the treatment and was discharged after 10 days. This case is reported to emphasize that S. paucimobilis should be kept in mind as a nosocomial infectious agent in patients with Down syndrome and immunosuppressive patients and the infections should be treated according to the sensitivity test results.