Large spontaneous HBV DNA fluctuations and potential usefulness of a single-point measurement of combined HBV DNA and quantitative HBsAg for the exclusion of HBeAg-negative chronic hepatitis B: A prospective Tunisian cohort study

BACKGROUND AND STUDY AIM

During the natural course of HBeAg-negative chronic hepatitis B (CHB), fluctuations in hepatitis B virus (HBV) DNA and alanine aminotransferase (ALT) levels are often observed, making the classification of patients difficult. We aimed to describe spontaneous short-term HBV DNA level fluctuations and to assess the usefulness of qHBsAg in Tunisian patients with HBeAg-negative chronic HBV infection.

PATIENTS AND METHODS

We included 174 treatment-naive Tunisian patients with HBeAg-negative chronic HBeAg-negative HBV infection. A prospective 1-year follow-up was conducted with serial determinations of HBV DNA, ALT levels, and qHBsAg. The patients were classified into three groups: inactive carriers (G1), patients with negative HBeAg CHB (G2), and patients with an "indeterminate state" (G3). For the latter group, a liver biopsy was indicated.

RESULTS

Only genotype D was detected. During follow-up, 21.6% and 19.5% of patients with a low initial (<2,000 IU/ml) and intermediate viral load (2,000-20,000 IU/ml) experienced a subsequent increase in their HBV DNA levels above 2,000 and 20,000 IU/ml, respectively. Significant variations in viral load were observed in 61.1% of patients at 6-month intervals. Among the 174 patients, 89 (51.1%) belonged to G1, 33 (19%) to G2, and 52 (29.9%) to G3. Fourteen patients have undergone a liver biopsy, of whom seven showed moderate to severe liver disease. Combination of HBV DNA < 2,000 IU/ml and qHBsAg < 832 IU/ml excluded CHB in 98.4% of cases. A cutoff point for qHBsAg < 100 IU/ml associated with an annual decline of > 0.5 log 10 IU/ml is a good predictor marker of functional cure for hepatitis B.

CONCLUSIONS

This study highlights the large short-term fluctuations in HBV DNA in patients with HBeAg-negative chronic HBeAg-negative HBV infection with genotype D. Thus, using the cutoff value of 832 for qHBsAg combined with that of 2,000 for HBV DNA makes it possible to exclude CHB for most patients.

Significant impact of COVID-19 pandemic on the circulation of respiratory viruses in Tunisia, 2020-2021

Background

The COVID-19 pandemic changed the typical patterns of respiratory infections globally. While SARS-CoV-2 illness exhibited explosive growth since 2020, the activity of other respiratory viruses fell below historical seasonal norms. The objective of this study was to assess the prevalence of seasonal respiratory viruses during the COVID-19 pandemic in Tunisia.

Methods

This is a retrospective cross-sectional study including 284 nasopharyngeal samples tested negative for SARS-CoV-2 during the period October 2020-May 2021. All samples were screened for fifteen common respiratory viruses. Either a fast syndromic approach using Biofire FILM ARRAY respiratory 2.1 (RP2.1) Panel, or end-point multiplex RT-PCRs detecting RNA viruses and Real-Time PCR detecting Adenoviruses were used.

Results

Overall, 30.6% (87/284) of samples were positive for at least one virus. Mixed infections were detected in 3.4% of positive cases. Enterovirus/Rhinovirus (HEV/HRV) was the most detected virus throughout the study period, especially during December 2020 (33.3% of all HEV/HRV being detected). During the 2020-2021 winter season, neither Respiratory Syncytial Virus nor Influenza Viruses circulation was observed. Metapneumovirus and Parainfluenza Viruses infections were detected during the spring season. The highest rate of respiratory viruses detection was observed in children and adults aged [0-10] years (50%) and [31-40] years (40%). HEV/HRV was the most detected virus regardless of age group.

Conclusions

Public health measures used to prevent SARS-CoV-2 spread in Tunisia were also effective to reduce transmission of the other respiratory viruses, especially Influenza. The higher resistance of HEV/HRV in the environment could explain their predominance and continuous circulation during this period.

Development of a duplex q-PCR for the simultaneous detection of Parachlamydia acanthamoebae and Simkania negevensis in environmental and clinical samples

Parachlamydia acanthamoebae and Simkania negevensis, two Chlamydia-like bacteria, have been recently recognized as emerging human respiratory pathogens. The prevalence and frequency of these bacteria in the environment and among atypical pneumonia patients are still underestimated by classical cultures, immunohistochemistry and serology which are non-specific, long and tedious methods. This study aims to develop a new duplex probe-based q-PCR assay for the simultaneous detection and quantification of P. acanthamoebae and S. negevensis. The selected hydrolysis probes displayed no cross-reaction with the closely related Chlamydia or the other tested waterborne pathogens. The assay achieved a large dynamic range for quantification (from 5 × 10⁶ to 5 DNA copies/reaction). Efficiencies of FAM and JOE label probes weren't affected when they were combined. They were close to 100%, indicating the linear amplification. The application of this diagnostic tool resulted in 9/47 (19%) and 4/47 (8.5%) positive water samples for P. acanthamoebae and S. negevensis, respectively. P. acanthamoebae was also covered from 2/78 (2.5%) respiratory specimens and only one case (1/200 = 0.5%) of P. acanthamoebae and SARS-CoV-2 co-infection was noticed. While S. negevensis wasn't detected in clinical samples, the developed duplex q-PCR was shown to be an accurate, highly sensitive, and robust diagnostic tool for the detection and quantification of P. acanthamoebae and S. negevensis.

A new TaqMan real-time PCR assay to detect Parachlamydia acanthamoebae and to monitor its co-existence with SARS-COV-2 among COVID-19 patients

Human respiratory infections caused by a large variety of microbial pathogens are the most common diseases responsible for hospitalization, morbidity and mortality. Parachlamydia acanthamoebae, a Chlamydia-related bacterium, has been found to be potentially associated with these diseases. An early and accurate diagnosis of this pathogen could be useful to avoid the potential respiratory complications linked especially to COVID-19 patients and to set suitable outbreak control measures. A TaqMan-PCR assay was developed to detect and quantify Parachlamydia acanthamoebae in environmental and clinical samples from patients of all ages with COVID-19. The selected hydrolysis probe displayed no cross-reaction with the closely related Chlamydia or the other tested pathogens. This q-PCR achieved good reproducibility and repeatability with a detection limit of about 5 DNA copies per reaction. Using this q-PCR assay, Parachlamydia acanthamoebae was detected in 2/78 respiratory specimens and 9/47 water samples. Only one case (1.3%) of Parachlamydia acanthamoebae and SARS-COV-2 co-infection was noticed. To our knowledge, the combination of these two respiratory pathogens has not been described yet. This new TaqMan-PCR assay represents an efficient diagnostic tool to survey Parachlamydia acanthamoebae on a large-scale screening programs and also during outbreaks.

Prognostic Value of Serum Cholinesterase Activity in Severe SARS-CoV-2-Infected Patients Requiring Intensive Care Unit Admission

We evaluated the prognostic value of serum cholinesterase (SChE) levels in SARS-CoV-2-infected patients requiring intensive care unit (ICU) admission. This is a retrospective study of severe, critically ill, adult COVID-19 patients, all of whom had a confirmed SARS-CoV-2 infection and were admitted into the ICU of a university hospital. We included all patients admitted to our ICU and whose SChE levels were explored on ICU admission and during ICU stay. One hundred and thirty-seven patients were included. There were 100 male and 37 female patients. The mean of SChE activity on ICU admission was 5,656 ± 1,818 UI/L (range: 1926-11,192 IU/L). The SChE activity on ICU admission was significantly lower in nonsurvivors (P < 0.001). A significant association between the SChE activity on ICU admission and the need for invasive mechanical ventilation was found. We also found a significant correlation between the SChE activity and other biomarkers of sepsis (C-reactive protein, procalcitonin, and leukocytes) on ICU admission and during the ICU stay. A significant correlation among SChE nadir value activity recorded during ICU stay, the occurrence of nosocomial infection, and the outcome of studied patients was found. Our study shows that the low SChE activity value is associated with a severe outcome. It might be used as a biomarker to aid in prognostic risk stratification in SARS-CoV-2-infected patients. Further studies for external validation of our findings are needed on this subject.

Evidence of SARS-CoV-2 symptomatic reinfection in four healthcare professionals from the same hospital despite the presence of antibodies

OBJECTIVES

Since the onset of the COVID-19 pandemic, cases of reinfection with SARS-CoV-2 have been reported, raising additional public health concerns. SARS-CoV-2 reinfection was assessed in healthcare workers (HCWs) in Tunisia because they are at the greatest exposure to infection by different variants.

METHODS

We conducted whole-genome sequencing of the viral RNA from clinical specimens collected during the initial infection and the suspected reinfection from 4 HCWs, who were working at the Habib Bourguiba University Hospital (Sfax, Tunisia) and retested positive for SARS-CoV-2 through reverse transcriptase-polymerase chain reaction (RT-PCR) after recovery from a first infection. A total of 8 viral RNAs from the patients' respiratory specimens were obtained, which allowed us to characterize the differences between viral genomes from initial infection and positive retest. The serology status for total Ig, IgG, and IgM against SARS-CoV-2 was also determined and followed after the first infection.

RESULTS

We confirmed through whole-genome sequencing of the viral samples that all 4 cases experienced a reinfection event. The interval between the 2 infection events ranged between 45 and 141 days, and symptoms were milder in the second infection for 2 patients and more severe for the remaining 2 patients. Reinfection occurred in all 4 patients despite the presence of antibodies in 3 of them.

CONCLUSION

This study adds to the rapidly growing evidence of COVID-19 reinfection, where viral sequences were used to confirm infection by distinct isolates of SARS-CoV-2 in HCWs. These findings suggest that individuals who are exposed to different SARS-CoV-2 variants might not acquire sufficiently protective immunity through natural infection and emphasize the necessity of their vaccination and the regular follow-up of their immune status both in quantitative and qualitative terms.

A year of genomic surveillance reveals how the SARS-CoV-2 pandemic unfolded in Africa

The progression of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic in Africa has so far been heterogeneous, and the full impact is not yet well understood. In this study, we describe the genomic epidemiology using a dataset of 8746 genomes from 33 African countries and two overseas territories. We show that the epidemics in most countries were initiated by importations predominantly from Europe, which diminished after the early introduction of international travel restrictions. As the pandemic progressed, ongoing transmission in many countries and increasing mobility led to the emergence and spread within the continent of many variants of concern and interest, such as B.1.351, B.1.525, A.23.1, and C.1.1. Although distorted by low sampling numbers and blind spots, the findings highlight that Africa must not be left behind in the global pandemic response, otherwise it could become a source for new variants.

[Virus and Atypical Pathogens Detected in Community-Acquired Lower Respiratory Tract Infection in Infants and Children of Sfax Region, Tunisia]

Little is known about viral and atypical bacteria pathogen spectra of community-acquired lower respiratory tract infection in children in Tunisia. Thus, a prospective study was carried out between January 2009 and March 2010 in Sfax. Nasopharyngeal aspirates collected from 368 patients (78 with pneumonia and 290 with acute bronchiolitis) were analyzed by indirect immunofluorescence assay and PCR to detect influenza viruses, parainfluenza viruses, respiratory syncytial virus (RSV), human metapneumovirus, human rhinovirus, human enterovirus, adenovirus, coronavirus, Mycoplasma pneumonia (Mpn) and Chlamydia pneumonia (Cpn). One or more etiology was documented in 319 cases (86.7%). The most detected viruses were RSV (42.7%), rhinovirus (32.9%) and adenovirus (28.5%). Co-detection of two or three pathogens was found in 40% of positive samples. This study highlights the importance of respiratory viruses in lower respiratory tract infection in children of Sfax region as well as the high rate of co-detection of multiple viruses, resulting in challenges in clinical interpretation.

Nephrotoxicity of Kalach 360 SL: biochemical and histopathological findings

Kalach 360 SL (KL) is a commercial herbicide which contains 360 g/l of glyphosate used in both agricultural and urban areas throughout the world including Tunisia. We aimed to evaluate the effects of KL on rats' renal system. Female Wistar rats were divided into three groups: group 1 (n = 6) received a standard diet and served as control, groups 2 and 3 (n = 12 each) received 0.07 ml (D1: 126 mg/kg), and 0.175 ml (D2: 315 mg/kg) of KL, respectively, for 60 d. The chronic exposure to KL induced a significant increase in plasma creatinine, urea, and uric acid levels. Creatinine clearance decreased in KL-treated groups, compared with controls. Several urine parameters, such as urine-specific gravity and urine osmolality, significantly decreased, while dieresis and urinary Na/K + ratio increased in KL-treated groups. These findings suggested a distal tubular damage caused by tubular necrosis. Moreover, the chronic exposure to KL induced an increase in lipid peroxidation (LPO) and a decrease in antioxidant status, enzymatic activities (superoxide dismutase and catalase) and non-enzymatic levels (vitamin C), which led to an oxidative stress. Histopathological studies showed a peritubular inflammatory reaction, nephrose, fragmented glomeruli, necrotic epithelial cells, and tubular dilatation. These results could have significant health implications for animal and human populations. Further data are necessary to investigate the potential consequences of chronic dose exposure during life.

[Assessment of nutritional status in patients with primary lung cancer]

BACKGROUND

Lung cancer is the leading cause of cancer-related mortality worldwide. Malnutrition is a common problem among patients with cancer, affecting up to 85% of patients with certain cancers and represents a risk factor for poor prognosis. aim: evaluate nutritional status in patients with lung cancer before and during treatment using nutritional risk index.

METHODS

it's a prospective study conducted in pneumology IV department in Abderahman Mami hospital, from January to May 2011. 30 male patients with a lung cancer were included. Nutritional status was assessed before and during treatment based on anthropometric measures, biological markers and nutritional risk index (NRI).

RESULTS

Mean age of patients was 58 ± 12 years, ranging from 19 to 82 years. 29 patients had non small cell lung cancer and one patient had small cell cancer. Malnutrition was noted in 14 patients (47%) before treatment according to the NRI. It was noted in 23 patients (77%) after three cycles of chemotherapy with severe malnutrition in 8 patients. Relationship between body mass index (BMI) and the NRI was linear, but NRI tends to evaluate more objectively risk of malnutrition in patients with lung cancer.

CONCLUSION

Nutritional assessment in patient with lung cancer should be performed systematically, early and repeatedly. Several markers can be used such as BMI and NRI. Nutritional support will reduce morbidity and improve quality of life in patients with lung cancer.

[Sternal tuberculosis causing spontaneous fracture of the sternum]

Sternal tuberculosis is an uncommon condition. Few cases have been reported. We report the case of a 74-year-old man, presented with a swelling and pain of the anterior chest wall associated to worsening of general state. All routine investigations were normal. Chest radiograph in lateral view showed sternal and chest wall hypertrophy with spontaneous fracture of the sternum. Computed tomography (CT) scan demonstrated ring-enhancing hypodense soft tissue mass surrounding the sternum with sternal fracture. Tuberculosis diagnosis was confirmed by histological study of the mass biopsy. We noted clinical and radiological recovery with medical tuberculosis treatment.

[Pseudotumoral mediastinal amyloidosis]

PURPOSE

Amyloidosis involvement of mediastinal nodes is rare. Isolated pseudotumoral involvement without extra-thoracic disease is a diagnostic challenge and typically raises concern for underlying malignancy. We present 3 cases of pseudotumoral mediastinal amyloidosis.

METHODS

We report the cases of 3 patients presenting with recent onset of respiratory symptoms. Bronchoscopy showed mucosal infiltration suspicious for lymphangitic spread of tumor. The patients underwent chest radiography complemented by CT of the chest and abdomen, and laboratory and immunological work-up. A diagnosis of pseudotumoral mediastinal amyloidosis was confirmed by mediastinoscopic biopsy in all cases.

RESULTS

CT showed a pulmonary and mediastinal tumor process in 2 cases and pericarinal tumor in 1 case. Diffuse bronchial wall thickening was present in all cases. Review of biopsy material showed tracheobronchial amyloidosis in 1 case. Patient work-up showed no evidence of extra-thoracic amyloidosis. Rapid progression of bronchial obstruction was observed in 1 case.

CONCLUSION

The imaging features of mediastinal amyloidosis are non-specific. Pseudotumoral involvement of mediastinal nodes associated with pulmonary amyloidosis accelerates the degree of airway obstruction.

[Pulmonary tuberculosis and diabetes. A retrospective study of 60 patients in Tunisia]

BACKGROUND

Tuberculosis is a frequent infectious disease in Tunisia. The estimated case rate is 22.3 per 100,000 inhabitants. The risk of tuberculosis is 2 to 6 times greater in patients with diabetes. The purpose of this study was to analyze the particularities in the etiology, diagnosis and bacteriologic course of pulmonary tuberculosis in patients with diabetes and to evaluate the impact of tuberculosis on diabetes control.

METHOD

This retrospective case-control study of 142 patients with confirmed pulmonary tuberculosis seen from 2000-2006 compared the 60 patients with diabetes with the 82 without diabetes.

RESULTS

Diabetes was more frequent in older patients with tuberculosis and in women. 91.5% had type 2 diabetes. A history of contact with people with tuberculosis was significantly less frequent in the group with diabetes (13.3% vs 30.5%; p=0.01). Tuberculosis symptoms and their duration did not differ between the 2 groups. Basal lesions and cavitation occurred more frequently in the patients with diabetes, but this difference was not significant. The time for conversion to negative of sputum culture was longer in case patients (43+/-27 days) than in controls (28.2+/-20.5) (p=0.03). The proportion of patients with uncontrolled diabetes was elevated, and 50% required frequent insulin treatment.

CONCLUSION

Tuberculosis is frequently associated with diabetes, usually due to reactivation of Mycobacterium tuberculosis. It is characterized by a longer time to culture conversion to negative and a risk of uncontrolled diabetes that requires frequent treatment adjustment and insulin use.

[Association of IGg multiple myeloma with pulmonary amyloidosis: about one case]

Pulmonary amyloidosis is a rather rare complication of multiple myeloma particularily the rare Ig D myeloma. It is often generalized and is seen in a late stage of the disease. We report a case of an Ig G myeloma complicated of a pulmonary amyloidosis in a 66-year-old man hospitalised for infectious pulmonary disease with a radiologic interstitial syndrome. Discovery of the multiple myeloma and of the amyloidosis was fortuitous.

[Lung cancer and chondromatous hamartoma: a case report]

The association lung cancer with chondromatous hamartoma is frequent. We present a case of synchronous primary lung adenocarcinoma and chondromatous hamartoma. Although hamartoma is generally considered to be a benign tumor, there have been several reports of increased risk of lung cancer in patients with a chondromatous hamartoma. Therefore we recommend that patients with hamartoma should be submitted to a complete evaluation and to regular follow up, considering the risk of associated synchronous malignancy.

[Tracheobronchial foreign bodies. Diagnostic and therapeutic aspects in children]

In this retrospective study, the authors reviewed 31 cases of tracheobronchial foreign body in children ranging in age from one to 15 years, recruited in Ariana hospital since 1987. 74% of the patients were male, and only 26% were less than 3 years old. The foreign body is mostly revealed by a radio-clinical presentation of a feverish bronchopneumonia (32%); children were referred to the hospital within 15.4 months. Although penetration syndrome was reported in 61% of patients, it represented the reason of consultation in only 19% of cases, and children were referred within 4.5 days. The main radiographic findings were atelectasis (32%) and non specific foci of pneumonia (19%). Air trapping was noted in just 10% of cases. 55% of foreign bodies were vegetable in nature, with sunflower seeds at the head of the list (16%). They have been lodged preferentially in the right bronchial tree (58%) and 51% of them were found in the mainstem bronchus. 71% were removed by endoscopic procedures; a surgical operation was performed in 6 cases (19%): one case of pneumotomy to extract a metallic foreign body from distal respiratory tract, and five cases of parenchymal excision, including four for bronchiectasis. 77% of patients had symptoms that lasted at least 2 weeks before diagnosis; the long delay in diagnosis (average of 7.6 months) explains the high-level of bronchiectasis in our study (22%). The authors emphasize the necessity to promote preventive measures by information parents and physicians on risks of foreign body aspiration, which early diagnosis can save much trouble in children.

[Endobronchial pulmonary rhabdomyosarcoma. A case report]

We report a case of pleiomorphous pulmonary rhabdomyosarcoma observed in a 64-year-old patient with no history of soft tissue tumor. The tumor was found extending into the right lower and middle lobes. The intra-parenchymatous extension protruded into the middle lobular bronchus and was prolonged by a 4 cm polyp. The polyp extended up to the carina and reached the contralateral common bronchus. Outcome was fatal after surgery performed in an emergency setting due to asphyxia. Explorations could not be continued to determine the primary or secondary nature of the tumor. An intraparenchymatous endobronchial localization is uncommon. Primary rhabdomyosarcoma is generally a purely intra-parenchymatous tumor. The endobronchial localization has been described before but is very exceptional. This localization would also be exceptional for secondary rhabdomyosarcoma mimicking a primary malignant tumor. The histology study revealed an undifferentiated pleiomorphous tumor. Immunohistochemistry provided the final diagnosis.

Preparation and amino acid sequence of human kappa-casein

Human kappa-casein was prepared from whole casein by successive hydroxyapatite and thiol-Sepharose chromatographies. The primary structure of its 99-residue N-terminal fragment has been determined by sequencing peptides obtained by tryptic and chymotryptic digestions of the whole protein. This fragment overlaps the known sequence of the 65-residue C-terminal fragment. The 158-residue sequence of human kappa-casein was compared to those of goat, ewe, cow and rat kappa-caseins. Only 22% of the residues are identical in homologous positions. The rate of divergence of the 93-residue N-terminal segment (para-kappa-casein) appears to be higher than that of the rest of the molecule.

Quantification of beta-casein in human milk

A method is described for preparing immunologically homogeneous human milk beta-casein, against which monospecific rabbit antiserum was prepared. The antiserum was used to quantify beta-casein, the major human casein, by rocket immunoelectrophoresis in individual milk samples. However, it was found that in most samples beta-casein occurred together with degradation products originating from its proteolysis by plasmin. Immunological quantification of human beta-casein, treated with plasmin for various time periods, showed that rocket height was not affected by proteolysis up to degradation states clearly more advanced than those observed in all samples of fresh human milk tested. Assays of 150 individual milk samples from 80 women, covering a lactation period of up to 730 d, gave an average concentration of beta-casein (native + degraded) of 4.67 +/- 0.89 standard deviation (g/l); extremes at 2.1 and 7.3 g/l did not vary significantly during the period under study. Comparison of this average value with an accepted casein content of 4.4 g/l (Macy & Kelly, 1961) showed that the casein content of human milk is underestimated when obtained by N determinations on milk and on its supernatants at pH 4.6 (whey). Caseins other than beta-casein occurred only in minute amounts, if at all.

Does beta-lactoglobulin occur in human milk?

Although beta-lactoglobulin (beta-lg) has been considered to be absent from human milk, recent results of other workers, based on immunological reactions between human milk and rabbit antiserum to bovine beta-lg, suggest that this protein may be present. Although our results show similar immunological reactions, we consider that lactoferrin is responsible for these, as it was the only reactive protein species which could be prepared to homogeneity. Indeed two types of antibodies were found by ELISA test in the antisera to bovine beta-lg. One of them would be able to bind loosely to human lactoferrin, but its binding sites would not be antigenic in the rabbit.