Utility of Liver Biopsy in the Diagnosis and Management of Possible Drug-Induced Liver Injury in Patients Receiving Antituberculosis Therapy: A Retrospective Study

BACKGROUND

Drug-induced liver injury (DILI) secondary to ATT treatment (TB-DILI) is reported in 2-28% of patients. We present here a series of clinical cases of suspected DILI arising during antituberculosis treatment, studied with the aid of liver biopsy.

METHODS

this was a retrospective descriptive study including 10 tuberculosis patients who underwent liver biopsy for suspected TB-DILI at the "Lazzaro Spallanzani" Institute from 2017 to 2022.

RESULTS

Ten patients who underwent LB were extracted from the database and included in the retrospective study cohort. According to the clinical classification, eight patients had hepatocellular liver injury, one patient had cholestatic injury, and another had mixed-type injury. Histopathological diagnosis revealed liver damage due to DILI in 5/10 (50%) cases. In one case, liver biopsy showed necrotizing granulomatous hepatitis.

CONCLUSIONS

Severe and persistent elevation of hepatic transaminases, hepatic cholestasis despite discontinuation of therapy, and other suspected hepatic conditions are indications for liver biopsy, which remains a valuable tool in the evaluation of selected tuberculosis patients with suspected DILI for many reasons. However, the decision to perform a liver biopsy should be based on clinical judgment, considering the benefits and risks of the procedure.

Diagnosis of Tuberculosis in a Case of Chronic Urticaria following Omalizumab Therapy

In Italy, tuberculosis (TB) incidence in the last decade has remained constant at under 10 cases/100,000 inhabitants. In the Philippines, TB annual incidence is greater than 500 cases/100,000 inhabitants. Omalizumab is a humanized anti-IgE monoclonal antibody approved for the treatment of chronic spontaneous urticaria. We report the case of a 32-year-old Filipino woman who suffered from chronic urticaria, treated with topic steroids since June 2022 and systemic steroids for 2 weeks. In November 2022, she started omalizumab therapy at a monthly dose of 300 mg; she was not screened for TB infection. In the same month, a left laterocervical lymphadenopathy arose, which worsened in February 2023 (diameter: 3 cm). The patient recovered in April 2023 in INMI "Lazzaro Spallanzani" in Rome for suspected TB. Chest CT showed a "tree in bud" pattern at the upper-right pulmonary lobe. The patient tested positive for lymph node biopsy molecular tuberculosis. The patient started standard antituberculosis therapy. She discontinued omalizumab. To our knowledge, this is the second diagnosed TB case during omalizumab treatment, which suggests that attention should be paid to the known risk of TB during biotechnological treatments. Even if current guidelines do not recommend screening for TB before starting anti-IgE therapy, further data should be sought to assess the relationship between omalizumab treatment and active TB. Our experience suggests that screening for TB should be carried out in patients from highly tuberculosis-endemic countries before starting omalizumab therapy.

Recovery from Triple Infection with SARS-CoV-2, RSV and Influenza virus: A case report

The overall probability of infection with RSV, influenza virus, or SARS-CoV-2 in the general population is assessed as high by the ECDC. A high level of respiratory virus circulation increases hospitalizations and places significant pressure on healthcare systems. Here we describe the case of a 52-year-old woman who recovered from pneumonia with a triple infection with SARS-CoV-2, RSV, and Influenza virus. We suggest searching for antigenic or molecular detection of VSR and influenza viruses, together with SARS-CoV-2, in patients with respiratory symptoms during this epidemic period, whereas all three viruses are present right now.

What is the impact of post-COVID-19 syndrome on health-related quality of life and associated factors: a cross-sectional analysis

BACKGROUND

After the acute phase, symptoms or sequelae related to post-COVID-19 syndrome may persist for months. In a population of patients, previously hospitalized and not, followed up to 12 months after the acute infection, we aim to assess whether and to what extent post-COVID-19 syndrome may have an impact on health-related quality of life (HRQoL) and to investigate influencing factors.

METHODS

We present the cross-sectional analysis of a prospective study, including patients referred to the post-COVID-19 service. Questionnaires and scales administered at 3, 6, 12 months were: Short-Form 36-item questionnaire (SF-36); Visual Analogue Scale of the EQ5D (EQ-VAS); in a subgroup, Beck Anxiety Inventory (BAI), Beck Depression Inventory (BDI-II) and Pittsburgh Sleep Quality Index (PSQI). Linear regression models were fitted to identify factors associated with HRQoL.

RESULTS

We considered the first assessment of each participant (n = 572). The mean scores in SF-36 and in EQ-VAS were significantly lower than the Italian normative values and remained stable over time, except the mental components score (MCS) of the SF-36 and EQ-VAS which resulted in lower ratings at the last observations. Female gender, presence of comorbidities, and corticosteroids treatment during acute COVID-19, were associated with lower scores in SF-36 and EQ-VAS; patients previously hospitalized (54%) reported higher MCS. Alterations in BAI, BDI-II, and PSQI (n = 265)were associated with lower ratings in SF-36 and EQ-VAS.

CONCLUSIONS

This study provides evidence of a significantly bad perception of health status among persons with post-COVID-19 syndrome, associated with female gender and, indirectly, with disease severity. In case of anxious-depressive symptoms and sleep disorders, a worse HRQoL was also reported. A systematic monitoring of these aspects is recommended to properly manage the post-COVID-19 period.

Risk and predictive factors of prolonged viral RNA shedding in upper respiratory specimens in a large cohort of COVID-19 patients admitted to an Italian reference hospital

Background

Limited data are available about the predictors and outcomes associated with prolonged SARS-CoV-2 RNA shedding (VS).

Methods

A retrospective study including COVID-19 patients admitted to an Italian hospital between March 1 and July 1, 2020. Predictors of viral clearance (VC) and prolonged VS from the upper respiratory tract were assessed by Poisson regression and logistic regression analyses. The causal relation between VS and clinical outcomes was evaluated through an inverse probability weighted Cox model.

Results

The study included 536 subjects. The median duration of VS from symptoms onset was 18 days. The estimated 30-day probability of VC was 70.2%. Patients with comorbidities, lymphopenia at hospital admission, or moderate/severe respiratory disease had a lower chance of VC. The development of moderate/severe respiratory failure, delayed hospital admission after symptoms onset, baseline comorbidities, or D-dimer >1000 ng/mL at admission independently predicted prolonged VS. The achievement of VC doubled the chance of clinical recovery and reduced the probability of death/mechanical ventilation.

Conclusions

Respiratory disease severity, comorbidities, delayed hospital admission and inflammatory markers negatively predicted VC, which resulted to be associated with better clinical outcomes. These findings highlight the importance of prompt hospitalization of symptomatic patients, especially where signs of severity or comorbidities are present.

Dermatological manifestations during COVID-19 and histological picture: Description of two clinical cases

It is not yet entirely clear what is the relevance of skin symptoms and what clinical implications are related to their appearance in COVID-19 patients. We describe two cases of COVID-19-associated pneumonia, which presented skin manifestations in advanced stage of illness, when nasopharyngeal swabs became negative for SARS-CoV-2. The first case presented erythematous, maculopapular lesions; the second developed petechial, vesicular and blood-encrusted lesions on the limbs. Histopathology documented perivascular lymphocytic infiltrates, with prevalent CD4+ T-cells in both patients. The research of SARS-CoV-2 in tissues with real time RT-PCR was negative. Basal keratinocytes displayed C4d deposits in one case, who developed laboratory signs indicative of a procoagulative condition at the same time as the skin rash. Skin manifestations during SARS-CoV-2 infection seem to be clinically relevant and further studies are necessary to assess if they are linked to systemic complications, lack of viral clearance or cascades of immune responses induced by the virus, even in patients affected by mild pneumonia.

Active Pulmonary Tuberculosis in Elderly Patients: A 2016-2019 Retrospective Analysis from an Italian Referral Hospital

Tuberculosis (TB) in the elderly (>65 years old) has increasingly become a global health problem. It has long been recognized that older people are vulnerable to developing tuberculosis. We retrospectively evaluated data from patients older than 65 years diagnosed with pulmonary TB admitted to the National Institute for Infectious Diseases L. Spallanzani, Rome, Italy, from 1 January 2016 to 31 December 2019. One hundred and six consecutive patients were diagnosed with pulmonary TB and 68% reported at least one comorbidity and 44% at least one of the TB risk-factors. Out of the 26 elderly patients who reported an adverse event, having risk factors for TB (O.R. (Odds Ratios) = 1.45; 95% CI 1.12-3.65) and the presence of cavities on Chest X-rays (O.R. = 1.42; 95% CI 1.08-2.73) resulted in being more likely to be associated with adverse events in elderly patients. Having weight loss (O.R. = 1.31; 95% CI 1.08-1.55) and dyspnea (O.R. = 1.23; 95% CI 1.13-1.41) resulted in being significant predictors of unsuccessful treatment outcome in elderly patients. Older people with TB represent a vulnerable group, with high mortality rate, with a challenging diagnosis. Hospitalizations in tertiary referral hospital with clinical expertise in TB management can be useful to improve the outcome of these fragile patients.

Usefulness of bronchoalveolar lavage in the management of patients presenting with lung infiltrates and suspect COVID-19-associated pneumonia: A case report

OBJECTIVE

To report a clinical case of a patient with a compatible HRCT scan and two negative SARS-CoV-2 RNA upper respiratory tract specimens but with a confirmed viral infection by BAL (19 days after symptom onset).

METHODS

Revision of a patient's clinical charts with COVID-19 admitted at INMI L. Spallanzani Hospital RESULTS: Two oropharyngeal swab tests of SARS-CoV-2 by qualitative real-time reverse-transcriptase-polymerase-chain-reaction (RT-PCR) assay were performed at admission (17 days from symptoms onset) and a day apart and were found negative. BAL fluid collected 19 days after symptoms onset was positive for SARS-CoV-2.

CONCLUSION

This case highlights importance of clinical suspicion of SARS-CoV-2 infection in diagnosis and infectivity assessment. We suggest collection of BAL fluid when consecutive nasopharyngeal swabs are negative, to confirm or exclude the diagnosis of COVID-19-associated pneumonia. Healthcare workers should perform aerosol-generating procedures in an adequately ventilated room and should wear adequate PPE.

Implementing a combined infection prevention and control with antimicrobial stewardship joint program to prevent caesarean section surgical site infections and antimicrobial resistance: a Tanzanian tertiary hospital experience

Background

Surgical site infections are a leading cause of morbidity and mortality after caesarean section, especially in Low and Middle Income Countries. We hypothesized that a combined infection prevention and control with antimicrobial stewardship joint program would decrease the rate of post- caesarean section surgical site infections at the Obstetrics & Gynaecology Department of a Tanzanian tertiary hospital.

Methods

The intervention included: 1. formal and on-job trainings on infection prevention and control; 2. evidence-based education on antimicrobial resistance and good antimicrobial prescribing practice. A second survey was performed to determine the impact of the intervention. The primary outcome of the study was post-caesarean section surgical site infections prevalence and secondary outcome the determinant factors of surgical site infections before/after the intervention and overall. The microbiological characteristics and patterns of antimicrobial resistance were ascertained.

Results

Total 464 and 573 women were surveyed before and after the intervention, respectively. After the intervention, the antibiotic prophylaxis was administered to a significantly higher number of patients (98% vs 2%, p < 0.001), caesarean sections were performed by more qualified operators (40% vs 28%, p = 0.001), with higher rates of Pfannenstiel skin incisions (29% vs 18%, p < 0.001) and of absorbable continuous intradermic sutures (30% vs 19%, p < 0.001). The total number of post-caesarean section surgical site infections was 225 (48%) in the pre-intervention and 95 (17%) in the post intervention group (p < 0.001). A low prevalence of gram-positive isolates and of methicillin-resistant Staphylococus aureus was detected in the post-intervention survey.

Conclusions

Further researches are needed to better understand the potential of a hospital-based multidisciplinary approach to surgical site infections and antimicrobial resistance prevention in resource-constrained settings.

Hepatitis C virus infection: a challenge in the complex management of two cases of multidrug-resistant tuberculosis

Background

Multidrug-resistant tuberculosis (MDR-TB) requires lengthy use of second-line drugs, burdened by many side effects. Hepatitis C virus (HCV) chronic infection increases risk of drug-induced liver injury (DILI) in these patients. Data on MDR-TB patients with concurrent HCV chronic infection treated at the same time with second-line antitubercular drugs and new direct-acting antivirals (DAAs) are lacking. We evaluate if treating at the same time HCV infection and pulmonary MDR-TB is feasible and effective.

Cases presentation

In this study, we described two cases of patients with pulmonary MDR-TB and concurrent HCV chronic infection cured with DAAs at a Tertiary Infectious Diseases Hospital in Italy. During antitubercular treatment, both patients experienced a DILI before treating HCV infection.

After DAAs liver enzymes normalized and HCV RNA was undetectable. Then antitubercular regimen was started according to the institutional protocol, drawn up following WHO MDR-TB guidelines. It was completed without further liver side effects and patients were declared cured from both HCV infection and MDR-TB.

Conclusions

We suggest to consider treatment of chronic hepatitis C with DAAs as a useful intervention for reintroduction of second-line antitubercular agents in those patients who developed DILI, reducing the risk of treatment interruption when re-exposed to these drugs.

Unexpected human cases of cutaneous anthrax in Latium region, Italy, August 2017: integrated human-animal investigation of epidemiological, clinical, microbiological and ecological factors

On 31 August, a veterinarian and a farmworker were hospitalised for skin lesions. Both had been exposed to a dead cow on 19 August on a farm near Rome, where eight further cattle died of confirmed anthrax later the same month. At admission, the first case showed a black depressed eschar and another smaller lesion on one hand. The second case presented deep infection of the skin, with involvement of both arms. Anthrax diagnosis was confirmed by detection of B. anthracis DNA in eschar fragments from both patients. T-cell specific immunity was studied by flow cytometry and Elispot assay after stimulation with B. anthracis secretome in blood samples collected from Case 1. Immunoglobulin production was detected by complement fixation assay. In Case 1, specific CD4+ T-cell activation was detected, without antibody production. Specific antibodies were detected only in the second patient with severe cutaneous illness. Both patients recovered. The two human anthrax cases were epidemiologically linked, but anthrax was not suspected at admission in either case. The veterinarian had initially unrecognised professional exposure and the exposed farmworker did initially not report exposure to affected animals. A One Health strategy integrating human and animal investigations was essential to confirm the diagnosis.

Putting in harm to cure: Drug related adverse events do not affect outcome of patients receiving treatment for multidrug-resistant Tuberculosis. Experience from a tertiary hospital in Italy

Rationale

Treatment of multi-drug resistant Tuberculosis (MDR-TB) is challenging because it mostly relies on drugs with lower efficacy and greater toxicity than those used for drug-susceptible TB.

Objectives

Aim of the study was to describe the frequency and type of adverse drug reactions in a cohort of MDR-TB patients and their potential impact on treatment outcome.

Methods

We conducted a retrospective study in a cohort of MDR-TB patients enrolled at a tertiary referral hospital in Italy from January 2008 to December 2016. The records of patients were reviewed for epidemiological, clinical, microbiological and adverse drug reactions data.

Results

Seventy-four MDR-TB patients (mean age 32 years, 58.1% males, 2 XDR, 12 pre-XDR TB) were extracted from the Institute data base and included in the retrospective study cohort in the evaluation period (January 2008—December 2016). Median length of treatment duration was 20 months (IQR 14–24). Treatment outcome was successful in 57 patients (77%; 51 cured, 6 treatment completed); one patient died and one failed (2.7% overall); 15 patients were lost to follow-up (20.3%). Sixty-six (89.2%) presented adverse drug reactions during the whole treatment period. Total number of adverse drug reactions registered was 409. Three hundred forty-six (84.6%) were classified as adverse events (AEs) and 63 (15.4%) were serious AEs (SAEs). One third of the total adverse drug reactions (134/409; 32.8%) was of gastrointestinal origin, followed by 47/409 (11.5%) ototoxic drug reactions, thirty-five (8.6%) regarded central nervous system and 33 (8.1%) affected the liver. All 63 SAEs required treatment suspension with 61 SAEs out of 63 (96.8%) occurring during the first six months of treatment. Factors associated with unsuccessful treatment outcome were smoking (p = 0.039), alcohol abuse (p = 0.005) and homeless condition (p = 0.044). Neither the number of antitubercular drugs used in different combinations nor the number of AEs showed significant impact on outcome. Patients who completed the treatment experienced a greater number of AEs and SAEs (p < 0.001) if compared to lost to follow-up patients.

Conclusions

Our data demonstrate that, despite the high frequency of adverse drug reactions and long term therapy, the clinical management of MDR-TB patients in a referral center could reach successful treatment according to WHO target, by implementing active and systematic clinical and laboratory assessment to detect, report and manage suspected and confirmed adverse drug reactions.

Five cases of Plasmodium vivax malaria treated with artemisinin derivatives: the advantages of a unified approach to treatment

OBJECTIVES

In endemic countries with a high level of chloroquine resistance, Plasmodium vivax malaria is associated with high morbidity and mortality. In these areas, the dihydroartemisinin-piperaquine combination resulted in clinical response, a more rapid clearance of parasitaemia, compared to chloroquine therapies, and reduction of recrudescence or reinfection.

METHODS

We describe five cases of Plasmodium vivax malaria in returning travelers treated with dihydroartemisinin-piperaquine.

RESULTS

All patients showed the early parasite clearance and no side effects. Our preliminary results suggest that the dihydroartemisinin-piperaquine combination is effective and safe even in imported cases.

CONCLUSIONS

A unified treatment policy using the artemisinin combination therapy should be adopted even in non-endemic countries and larger studies are underway to support this strategy.

Tuberculin skin test - Outdated or still useful for Latent TB infection screening?

OBJECTIVE

To make an informed viewpoint on the usefulness of Tuberculin Skin test (TST) compared to Interferon Gamma Release Assays (IGRAs) for diagnosis of Latent TB Infection (LTBI) in different geographical settings.

METHODS

We reviewed the current literature on TST compared to IGRA, including national implementation of WHO LTBI recommendations and retrospective data over the past 7 years at the National Institute for Infectious Diseases "L. Spallanzani" as indirect indicator of usage of both tests under actual programmatic conditions.

RESULTS

Current national guidelines vary considerably, reflecting the uncertainty and rapidly evolving evidence about the potential use of these tests. Data from Institute "L. Spallanzani" showed IGRA concordance in TST positive subjects only in 54.74% of subjects, while there was strong concordance between two tests in TST negative subjects (93.78%).

CONCLUSION

Neither IGRAs nor TST can distinguish active TB from LTBI. TST will continue to be clinically useful in low and high TB endemic areas until more accurate and predictive tests will become available. Clinical judgment remains fundamental in choosing between IGRA/TST tests and interpreting their results.

Febrile rhabdomyolysis of unknown origin in refugees coming from West Africa through the Mediterranean

OBJECTIVES

Cases of undiagnosed severe febrile rhabdomyolysis in refugees coming from West Africa, mainly from Nigeria, has been observed since May 2014. The aim of this study was to describe this phenomenon.

METHODS

This was a multicentre retrospective observational study of cases of febrile rhabdomyolysis reported from May 2014 to December 2016 in 12 Italian centres.

RESULTS

A total of 48 cases were observed, mainly in young males. The mean time interval between the day of departure from Libya and symptom onset was 26.2 days. An average 8.3 further days elapsed before medical care was sought. All patients were hospitalized with fever and very intense muscle aches. Creatine phosphokinase, aspartate aminotransferase, and lactate dehydrogenase values were abnormal in all cases. The rhabdomyolysis was ascribed to an infective agent in 16 (33.3%) cases. In the remaining cases, the aetiology was undefined. Four out of seven patients tested had sickle cell trait. No alcohol abuse or drug intake was reported, apart from a single reported case of khat ingestion.

CONCLUSIONS

The long incubation period does not support a mechanical cause of rhabdomyolysis. Furthermore, viral infections such as those caused by coxsackievirus are rarely associated with such a severe clinical presentation. It is hypothesized that other predisposing conditions like genetic factors, unknown infections, or unreported non-conventional remedies may be involved. Targeted surveillance of rhabdomyolysis cases is warranted.

Reliability and validity of using telephone calls for post-discharge surveillance of surgical site infection following caesarean section at a tertiary hospital in Tanzania

Background

Surgical site infection (SSI) is a common post-operative complication causing significant morbidity and mortality. Many SSI occur after discharge from hospital. Post-discharge SSI surveillance in low and middle income countries needs to be improved.

Methodology

We conducted an observational cohort study in Dodoma, Tanzania to examine the sensitivity and specificity of telephone calls to detect SSI after discharge from hospital in comparison to a gold standard of clinician review. Women undergoing caesarean section were enrolled and followed up for 30 days. Women providing a telephone number were interviewed using a structured questionnaire at approximately days 5, 12 and 28 post-surgery. Women were then invited for out-patient review by a clinician blinded to the findings of telephone interview.

Results

A total of 374 women were enrolled and an overall SSI rate of 12% (n = 45) was observed. Three hundred and sixteen (84%) women provided a telephone number, of which 202 had at least one telephone interview followed by a clinical review within 48 h, generating a total of 484 paired observations. From the clinical reviews, 25 SSI were diagnosed, of which telephone interview had correctly identified 18 infections; telephone calls did not incorrectly identify SSI in any patients. The overall sensitivity and specificity of telephone interviews as compared to clinician evaluation was 72 and 100%, respectively.

Conclusion

The use of telephone interview as a diagnostic tool for post-discharge surveillance of SSI had moderate sensitivity and high specificity in Tanzania. Telephone-based detection may be a useful method for SSI surveillance in low-income settings with high penetration of mobile telephones.

Pulmonary tuberculosis followed by sarcoidosis in an HIV-infected patient: A case report and a simplified diagnostic flowchart for diagnosis and treatment of sarcoidosis

The diagnosis of sarcoidosis in a patient living with HIV infection is an uncommon event and a challenge for clinicians. Clinical manifestations are variable and fluctuating depending to adherence to ARV therapy and to the level of CD4 count. We analyze here one chronic case in which sarcoidosis appeared clinically two years after pulmonary tuberculosis. The course of the disease was influenced and prolonged by frequent interruptions of antiretroviral therapy. Moreover the diagnosis and the decision to treat have been delayed by the need of exclusion of other pathologies, principally tuberculosis reactivation/reinfection, other mycobacterial diseases, hematologic malignancies. We propose a simplified flowchart for diagnosis and follow up of sarcoidosis, which may also be applied to patients with HIV infection. Diagnosis of latent tuberculosis infection (LTBI) may be difficult in these patients, because the immunological paradox of sarcoidosis. For this reason, following exclusion of active tuberculosis, we advise to submit all sarcoidosis patients to IPT (isoniazid preventive therapy), when immunosuppressive therapy is started.

Haemolytic anaemia after oral artemether-lumefantrine treatment in a patient affected by severe imported falciparum malaria

Artemisinin and its derivatives are essential components of artemisinin-based combination therapies for treating severe falciparum malaria. In this paper, we describe the occurrence of haemolysis after oral artemether-lumefantrine treatment. To the best of our knowledge, this is the second reported case of a patient affected by severe falciparum malaria with haemolytic anaemia that is likely associated with oral artemether-lumefantrine treatment.

Mutations in dihydropteroate synthase gene of Pneumocystis carinii in HIV patients with Pneumocystis carinii pneumonia

The purpose of this study was to determine whether dihydropteroate synthase gene (DHPS) mutations were associated with the failure of sulpha/sulphone drugs used as prophylaxis agents in HIV infected patients. Results suggested that DHPS mutations were significantly associated with failure of anti-Pneumocystis carinii sulphone prophylaxis (P=0.031). An increasing number of mutant P. carinii strains have been isolated from patients no longer having prophylaxis. There was no statistically significant difference in severity or outcome of the pneumonia caused by wild-type or mutant DHPS. Moreover, two of the three patients with mutant P. carinii pneumonia (PCP) were successfully treated with sulpha drugs. We think that P. carinii drug-resistance could be an emerging problem for immunocompromised patients including those with HIV infection.

Pneumocystis carinii infection in young non-immunosuppressed rabbits. Kinetics of infection and of the primary specific immune response

The aim of this study was to determine the kinetics, the dissemination of the infection and the immunological response to Pneumocystis carinii primary infection in a non-immunosuppressed rabbit model. For this purpose, we developed a nested PCR that amplified a portion of the mitochondrial large-subunit rRNA gene of rabbit-derived P. carinii. The PCR detected P. carinii DNA in lung and bronchoalveolar lavage fluids from 14- to 45-day-old rabbits but not in their serum. No P. carinii DNA was detected in extrapulmonary organs from 28-day-old rabbits with P. carinii pneumonia. ELISA and immunoblotting analysis showed that 5-day-old pups had elevated specific IgG. The IgG concentration sharply decreased, reaching a trough on day 21, and from then onwards progressively increased as the infection cleared. Conversely, the specific IgM concentration increased during the infection and peaked on day 28. IgG mainly recognized a 50-kDa subunit of P. carinii organisms; IgM recognized first a 45-kDa subunit on day 21, whereas from day 28 onwards it also recognized the 50-kDa subunit. A P. carinii-specific splenocyte proliferative response was observed on day 45. These findings suggest that P. carinii primary infection is a time-limited and a lung-limited event and contribute new information on the relationship between the kinetics of primary P. carinii infection and the immunological response in a model that mimics the primary infections in humans.

Potential impact of Pneumocystis genetic diversity on the molecular detection of the parasite in human host

Our aim was to evaluate if genetic diversity of Pneumocystis carinii could influence the detection by molecular techniques in bronchoalveolar lavage (BAL) fluids and in non-invasive specimens (induced sputum, oropharyngeal washing and serum/blood). P. carinii is morphologically similar in different hosts although several strains have been identified by biomolecular techniques. Variations of mt-LSU and ITSs sequences could determine a lack of hybridization of some clinical samples and could have diagnostic consequences with loss in sensitivity and specificity of available molecular tests, but at the moment no data support a significant impact of genetic diversity in these sequences on molecular detection of P. carinii for clinical purposes.

Typing with ITS regions of P.carinii from AIDS patients with recurrent pneumonia

To understand the way of reinfection of Pneumocystis carinii we have analyzed the genetic variation at the internal transcribed spacer (ITS) in DNA samples from bronchoalveolar lavage fluid of Italian HIV patients who had multiple episodes of P.carinii pneumonia. The presence of the same and/or a new type in both episodes suggest the possible occurrence of both reactivation of a previously acquired infection and reinfection from an exogenous source. Furthermore the occurrence of two different types in the same episode indicate that a mixed infection is common.

Detection of Pneumocystis carinii in oropharyngeal washings by PCR-SHELA and nested PCR

Oropharyngeal washings (Ophs) from 27 HIV infected patients (18 with P. carinii pneumonia, PCP, and 9 without PCP) were examined for P. carinii using morphological staining and DNA amplification with PCR-SHELA and nested PCR methods. The comparison of these techniques shows that 1. the amplification of P. carinii DNA is more sensitive than (and as specific as) morphological staining; 2. PCR-SHELA is less sensitive than (and as specific as) nested PCR.

Detection of Pneumocystis carinii in respiratory specimens by PCR-solution hybridization enzyme-linked immunoassay

By using a recently developed PCR-solution hybridization enzyme-linked assay (PCR-SHELA), we investigated Pneumocystis carinii in bronchoalveolar lavage fluid samples and induced sputa of patients with pneumocystosis. In detecting P. carinii, PCR-SHELA proved more sensitive than immunofluorescence staining or a single PCR and significantly more diagnostically specific than a nested PCR. Our data suggest that PCR-SHELA could be used to detect P. carinii organisms in respiratory samples, particularly in patients with uncertain diagnoses.

Imbalance between Pneumocystis carinii cysts and trophozoites in bronchoalveolar lavage fluid from patients with pneumocystosis receiving prophylaxis

Detection and quantification of different Pneumocystis carinii (PC) life cycle forms were performed by polymerase chain reaction (PCR) and by morphological stains on bronchoalveolar lavage fluids (BALF) from HIV-infected patients with P. carinii pneumonia (PCP). The number of PC trophozoites was higher in patients with PCP who were receiving prophylaxis than in those not receiving prophylaxis. Also the cyst: trophozoite ratio was lower in the first group. No difference was observed between patients receiving different prophylactic medications. The imbalance between PC forms in BALF from patients with PCP receiving anti-PC prophylaxis may hamper the sensitivity of cyst stains. Multiple stains or PCR examination should be performed on BALF from patients with clinically suspected PCP who are receiving prophylaxis.

Detection of Pneumocystis carinii DNA in blood by PCR is not of value for diagnosis of P. carinii pneumonia

A nested PCR which amplified a portion of the mitochondrial large-subunit rRNA gene of Pneumocystis carinii was used to detect P. carinii DNA in blood from patients with P. carinii pneumonia. P. carinii DNA was not detected in serum and was detected at low levels of blood cells.

Non specific PCR products using rat-derived Pneumocystis carinii dihydrofolate reductase gene-specific primers in DNA amplification of human respiratory samples

DNA amplification using dihydrofolate reductase (DHFR) primers in bronchoalveolar lavage fluids (BALFs) from patients with Pneumocystis carinii (PC) pneumonia yielded low sensitivity and specificity. Amplified products of BALFs from an AIDS patient without PC pneumonia and five patients with PC pneumonia were cloned and sequenced. All samples showed the same sequence without any homology with DHFR cDNA of rat PC, or with any DHFR sequences in databases at the DNA or amino acid level. The data demonstrate that these DHFR primers amplify a non-specific region of DNA with a sequence unrelated to the human PC DHFR gene both in PC positive and in PC negative samples. This finding precludes the use of these DHFR primers for the diagnosis of PC pneumonia in respiratory specimens.

Variable efficiency of three primer pairs for the diagnosis of Pneumocystis carinii pneumonia by the polymerase chain reaction

The efficiency of three different primer pairs, complementary to different Pneumocystis carinii DNA regions, was compared in the polymerase chain reaction (PCR) for the diagnosis of Pneumocystis carinii pneumonia (PCP) on bronchoalveolar fluid (BALF) from patients with AIDS. PCR coupled with dot-blot hybridization (BLOT) using primers and probe from the mitochondrial 23SrDNA region showed the highest sensitivity, with a lower detection limit of 0.5-1 organisms microliter-1. When testing 47 BALF, PCR plus BLOT of the mitochondrial 23SrDNA region showed also the best diagnostic efficiency (97% sensitivity, 100% specificity). Sensitivity was significantly higher than with PCR and BLOT of the 5SrDNA region (81.5% sensitivity; P = 0.025, McNemar test); and of the dehydrofolate reductase (DHFR) gene region (75.6% sensitivity; P = 0.019). Sensitivity was also significantly higher than indirect immunofluorescence (75.8% sensitivity; P = 0.008). Using DHFR primers and probe, specificity was also reduced. The diagnostic sensitivity in clinical specimens paralleled the detection limit in the standard dilutions. The use of repeated DNA sequences of proven specificity as target of PCR amplification favourably influences sensitivity and specificity. This comparative study demonstrates that primer selection plays a significant role in the diagnosis of PCP by PCR.

Simple and rapid two-step polymerase chain reaction for diagnosis of Pneumocystis carinii infection

Two amplification steps were made to detect Pneumocystis carinii DNA by polymerase chain reaction (PCR). pAZ102-E and pAZ102-H (standard PCR), pAZ102-L2 (sense), and pAZ102-E (antisense) (two-step PCR) were used as primers. The amplification products were analyzed by ethidium bromide. After the two-step PCR, ethidium bromide detected all samples positive by oligohybridization after one amplification step. Our two-step PCR is a rapid, cost-effective, and clinically suitable method for the detection of P. carinii infection.

Haemopoietic CD34+ progenitor cells are not infected by HIV-1 in vivo but show impaired clonogenesis

We evaluated the role of CD34+ bone marrow progenitor cells in vivo, in the pathogenesis of AIDS-related haematological abnormalities. The clonogenic activity of CD34+ cells from seven patients with HIV-1 infection, without bone marrow involving opportunistic infections or neoplasms, was assessed in semisolid cultures. The number of CFU-GM was significantly reduced as compared to the controls (P = 0.017), independently from myelotoxic therapy, while the number of BFU-E was not. The presence of retroviral sequences in CFU-GM colonies from four patients and in the total population of CD34+ cells from six patients with advanced stage HIV infection was investigated using the polymerase chain reaction. The presence of HIV-1 sequences was also searched for in a purified suspension of CD34+ cells after 3 weeks liquid culture. All these cells were always HIV-1 negative, while viral sequences were always detected in bone marrow mononuclear cells from these and other patients. The number of HIV-1 DNA copies decreased with increasing enrichment. At most 1:10,000 CD34+ cells are infected in vivo. Other mechanisms than direct viral infection of progenitor cells must account for the defective haemopoiesis in HIV-1 infected patients.

Diagnosis of Pneumocystis carinii pneumonia: specificity and sensitivity of polymerase chain reaction in comparison with immunofluorescence in bronchoalveolar lavage specimens

DNA amplification by the polymerase chain reaction (PCR) is a promising method for the detection of Pneumocystis carinii in immunosuppressed patients. The sensitivity and specificity of the PCR technique has been assessed in comparison with the immunofluorescence method (IF) on bronchoalveolar lavage fluid (BALF). Results correlated in 43 (78.8%) of 52 cases studied. P. carinii PCR gave positive results with BALF from all 32 patients found to have P. carinii pneumonia (PCP); IF gave positive results with 26 of them. PCR was more sensitive and as specific as IF. However, at the present time, we do not believe that it is clinically useful for detection of P. carinii in BALF samples. P. carinii DNA amplification by PCR should be reserved for testing IF-negative BALF samples from patients judged clinically to have PCP.

Human immunodeficiency virus type 1 infection in a community of southern Mozambique

We report the results of a study held between 1986 and 1988 on a population constituted by 493 subjects (425 of Mozambican nationality) all living in the camp organized for the building of the dam in Corumana (Sabiè district, Maputo). We found five subjects, all of them from Mozambique, seropositive for HIV-1 antibodies (ELISA and WB) with a prevalence of 1.2%. Four of the positive samples came from female subjects (1.7% of 239 females tested); one positive sample came from a male subject (0.5% of 186 tested).