Bacillus Calmette-Guerin polysaccharide nucleic acid vs Bacillus Calmette-Guerin vaccine in the treatment of warts: A comparative, double-blind, controlled study

Research progress in the off-target effects of Bacille Calmette-Guérin vaccine

ABSTRACT

Bacille Calmette-Guérin (BCG) vaccine is designed to provide protection against tuberculosis (TB). However, numerous epidemiological, clinical, and immunological studies have shown that BCG vaccination affects neonatal and infant mortality, which may be related to the reduction of TB-unrelated infections and diseases by BCG vaccine. We aimed to discuss the off-target effects of BCG vaccine on un-TB infections and diseases, as well as the potential mechanism and influencing factors. Literature was retrieved mainly from PubMed using medical subject headings "BCG, variations, and non-specific, heterologous or off-target". Studies have showed that BCG vaccination can prevent various heterologous infections, including respiratory tract infections, leprosy, and malaria, treat viral infections including human papillomavirus and herpes simplex virus infection as immunotherapy, and improve the immune responses as vaccine adjuvant. Besides, BCG vaccine can reduce the recurrence rate of non-muscle-invasive bladder cancer, and may provide protection against autoimmune diseases. These off-target effects of BCG vaccine are thought to be achieved by modulating heterologous lymphocyte responses or inducing trained immunity, which were found to be sex-differentiated and affected by the BCG vaccine strains, sequence or time of vaccination.

Systematic Review of Intralesional Therapies for Cutaneous Warts

Intralesional therapies are used for recalcitrant warts, but no Food and Drug Administration-approved treatment exists nor is there consensus regarding the most efficacious therapy. Therefore, this systematic review aims to summarize efficacy and adverse events reported in 62 randomized controlled trials (RCTs) of intralesional therapies for cutaneous warts. The most studied intralesional therapies included measles, mumps, rubella (MMR) vaccine (n = 24 studies), purified protein derivative (PPD) (n = 19 studies), vitamin D3 (n = 15 studies), and Candida antigen (n = 14 studies). Most studies included adult and pediatric patients or adults alone, with only 4 studies on pediatric patients alone. MMR vaccine was the most studied treatment (n = 853 patients). MMR had a complete response rate of 27-90%. The next most common treatment, PPD, had a complete response rate of 45-87%. Other treatments included Candida antigen and vitamin D3, with complete response rates of 25-84% and 40-96%, respectively. The most frequent side effects were injection-site reactions and flu-like symptoms. This systematic review represents a useful summary of intralesional therapy RCTs for clinician reference. This study also highlights the lack of large multi-institutional RCTs, despite many patients being treated for this widespread problem.

Influenza Virus Infection Increases Host Susceptibility To Secondary Infection with Pseudomonas aeruginosa, and This Is Attributed To Neutrophil Dysfunction through Reduced Myeloperoxidase Activity

Secondary bacterial infection greatly increased the morbidity and mortality of influenza virus infection. To investigate the underlying mechanism by which influenza impairs the pulmonary defense against secondary Pseudomonas aeruginosa (P. aeruginosa) infection, we established a lethal mouse model in which to study secondary P. aeruginosa infection after influenza virus infection. We found a significant increase in host susceptibility to a secondary infection with P. aeruginosa in mice after an influenza virus infection, and this was accompanied by severe immunopathology and pulmonary inflammation. Importantly, we demonstrated that neutrophils were essential for P. aeruginosa clearance in secondarily infected mice. Further, we revealed that influenza impaired the phagocytosis and digestion functions of pulmonary neutrophils for P. aeruginosa clearance. We identified that the activity of reactive oxygen species (ROS) and the myeloperoxidase (MPO) activity of neutrophils in the lungs played an important role in antibacterial host defense in influenza-infected lungs. Hereby, influenza virus infection causes deficient MPO activity in neutrophils, and this contributes to the increased susceptibility to secondary P. aeruginosa infection. Treatment with Bacillus Calmette-Guerin polysaccharide nucleic acid (BCG-PSN) prior to secondary P. aeruginosa infection may improve the function of neutrophils, resulting in significantly reduced lethality during secondary P. aeruginosa infection. We also demonstrated that treatment with anti-influenza immune serum during the early stage of an influenza virus infection could decrease the disease severity of secondary P. aeruginosa infection. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.

IMPORTANCE A secondary bacterial infection, such as that of P. aeruginosa, often occurs after a pulmonary virus infection and contributes to severe disease. However, the underlying mechanisms responsible for viral-bacterial synergy in the lung remain largely unknown. In this study, we reported that influenza virus infection increases a host’s susceptibility to secondary infection by P. aeruginosa by reducing the MPO activity of neutrophils. We also demonstrated that treatment with BCG-PSN or anti-influenza immune serum prior to secondary P. aeruginosa infection can reduce the disease severity. Our findings suggest that improving the MPO activity of neutrophils may provide a therapeutic strategy for viral-bacterial coinfection.

Clinical guideline for the diagnosis and treatment of cutaneous warts (2022)

AIM

Cutaneous warts caused by human papillomavirus are benign proliferative lesions that occur at any ages in human lives. Updated, comprehensive and systematic evidence-based guidelines to guide clinical practice are urgently needed.

METHODS

We collaborated with multidisciplinary experts to formulate this guideline based on evidences of already published literature, focusing on 13 clinical questions elected by a panel of experts. We adopted Grading of Recommendations Assessment, Development and Evaluation (GRADE) system to form classification of recommendations as well as the improved Delphi method to retain respective recommendations with a consensus degree of over 80%.

RESULTS

Our guideline covered aspects of the diagnosis and treatment of cutaneous warts such as diagnostic gold standard, transmission routes, laboratory tests, treatment principle, clinical cure criterion, definitions, and treatments of common warts, flat warts, plantar warts, condyloma acuminatum, and epidermodysplasia verruciformis. Recommendations about special population such as children and pregnant women are also listed. In total, 49 recommendations have been obtained.

CONCLUSIONS

It is a comprehensive and systematic evidence-based guideline and we hope this guideline could systematically and effectively guide the clinical practice of cutaneous warts and improve the overall levels of medical services.

Comparative study between intralesional injection of MMR, BCG, and candida albicans antigen in treatment of multiple recalcitrant warts

BACKGROUND

Cutaneous warts represent a challenging condition to treat.

OBJECTIVE

To evaluate the safety and efficacy of intralesional injection of MMR (mumps, measles, and rubella) antigen, BCG (bacillus Calmette-Guerin) vaccine, and candida antigen for the treatment of multiple warts.

METHODS

A total of ninety (90) clinically confirmed adult patients complaining of recalcitrant extragenital warts of various sizes and durations were recruited in this randomized clinical trial. They were divided into three groups (A, B, and C). Each group consisted of (30) patients. Group (A) subjects received intralesional MMR injections. Group (B) subjects received intralesional BCG injection and Group (C) received intralesional candida antigen injection.

RESULTS

Full clearance of warts was observed in (73.33%, 70%, and 43.33%) in groups A, B, and C, respectively. Infrequent side effects including pain, erythema, and minimal induration were reported in all groups but did not necessitate termination of treatment.

CONCLUSION

All the three modalities used demonstrated a simple, safe modality with low adverse events, and with no recurrence. To achieve an optimal response with an ideal immunotherapeutic agent and ideal dose, further comparative studies are warranted and on different populations and larger sample sizes.