Response to: regarding the significance of anti-COVID-IgA antibody response in COVID-19 breakthrough infection

In response to Chen et al.'s comments on our paper regarding the significance of anti-COVID-IgA antibody response in COVID-19 breakthrough infection in vaccinated patients, we have highlighted the role and the scope of this paper in this correspondence. The role of anti-COVID-19-IgA is already known. The objective of the previous study was to see its role in breakthrough-infected patients. To analyse this effect, we recruited patients with COVID-19 infection after they were fully vaccinated and compared them with the vaccinated group who did not get the infection. Both groups were equally exposed to the virus as all of them were health care workers. We also showed that the anti-COVID-19-NP-IgA was absent in the healthy cohort of our study groups, signifying the absence of natural infection in them during this period. The article also highlights the importance of vaccinating all individuals including those who are immunosuppressed, as it prevents severe COVID-19 infection in these individuals. The physicians should be aware of the fact that immunosuppressed patients are more likely to get COVID-19 breakthrough infection. However, proper vaccination with booster doses prevents severe infection in them.

Significance of Anti-COVID-IgA antibody response in COVID-19 breakthrough infection in vaccinated patients - a single-centered study from Pakistan

An increasing number of breakthrough-COVID-19-vaccinated individuals are being reported across the world. Humoral immunity has a crucial role in combating infection. In this study, we aimed to assess the importance of anti-COVID-S1-IgA and anti-COVID-NP-IgA in confirmed COVID-19 after vaccination (breakthrough infection group). Blood samples were collected from the breakthrough infection group within one week of breakthrough infections (n = 34). A second sample was also collected after 4 to 8 weeks (n = 27). Blood samples of healthy individuals (n = 29) were collected 4-8 weeks after the completion of vaccination. Anti-COVID-S1-IgA and anti-COVID-NP-IgA were detected by ELISA. Statistical analysis was performed using IBM SPSS version 24. In this study, we found a higher positivity rate for anti-COVID-S1-IgA in the breakthrough infection group (70% vs. 28% in healthy individuals). Anti-COVID-NP-IgA was not found in the control group (11% in the breakthrough infection group vs. 0 in healthy individuals). In the breakthrough-infected group, the positivity rate of anti-COVID-NP-IgA decreased significantly (median titers 16.9 IU/ml decreased to 4.2 IU/ml) p = 0.001), while anti-COVID-S1-IgA increased over a period of 4-8 weeks (9.35-16.35 IU/ml). Importantly, IgA response to both COVID-19 NP and S1 antigens was not found in 13 patients at initial testing. The findings of this study show that serum IgA may have a role both in breakthrough infections and also in the prevention of severe infection. Sluggish anti-COVID-19-IgA antibody response may be responsible for the occurrence of COVID-19 infection in breakthrough infection. On the other hand, more sustained anti-COVID-19-S1-IgA over a longer period of time may have a role in preventing these patients from severe infections and hospitalization. However, a study on a larger sample size including patients with severe disease after vaccination is required to prove this hypothesis. To the best of our knowledge, this is the first study reporting the importance of serum IgA in breakthrough-infected patients from our region.

Breakthrough COVID-19 infections - Analyzing our experience

Objective

There are many cases of post-vaccination COVID-19 globally. Also, literature on serum antibodies after vaccination is abundant. Our research focuses on breakthrough infections reported at our institution during the third wave of COVID-19.

Methods

A total of 177 people recruited at the Indus Hospital Karachi between May to September 2021 with COVID-19 infection were divided into vaccinated, partially vaccinated, and unvaccinated cohorts. Furthermore, a subset of the vaccinated cohort was tested for anti-NP and anti-S antibodies.

Results

There were 119 patients with breakthrough infection, however, 74% had mild symptoms. The antibodies against NP and S were found at a higher level in those who had a breakthrough infection in comparison to healthy vaccinated controls.

Conclusion

Vaccination does not prevent disease but does confer some immunity causing less severe infection.

Comparative effectiveness of adding delamanid to a multidrug-resistant tuberculosis regimen comprised of three drugs likely to be effective

Clarity about the role of delamanid in longer regimens for multidrug-resistant TB is needed after discordant Phase IIb and Phase III randomized controlled trial results. The Phase IIb trial found that the addition of delamanid to a background regimen hastened culture conversion; the results of the Phase III trial were equivocal. We evaluated the effect of adding delamanid for 24 weeks to three-drug MDR/RR-TB regimens on two- and six-month culture conversion in the endTB observational study. We used pooled logistic regression to estimate the observational analogue of the intention-to-treat effect (aITT) adjusting for baseline confounders and to estimate the observational analogue of the per-protocol effect (aPP) using inverse probability of censoring weighting to control for time-varying confounding. At treatment initiation, 362 patients received three likely effective drugs (delamanid-free) or three likely effective drugs plus delamanid (delamanid-containing). Over 80% of patients received two to three Group A drugs (bedaquiline, linezolid, moxifloxacin/levofloxacin) in their regimen. We found no evidence the addition of delamanid to a three-drug regimen increased two-month (aITT relative risk: 0.90 (95% CI: 0.73-1.11), aPP relative risk: 0.89 (95% CI: 0.66-1.21)) or six-month culture conversion (aITT relative risk: 0.94 (95% CI: 0.84, 1.02), aPP relative risk: 0.93 (95% CI: 0.83, 1.04)). In regimens containing combinations of three likely effective, highly active anti-TB drugs the addition of delamanid had no discernible effect on culture conversion at two or six months. As the standard of care for MDR/RR-TB treatment becomes more potent, it may become increasingly difficult to detect the benefit of adding a single agent to standard of care MDR/RR-TB regimens. Novel approaches like those implemented may help account for background regimens and establish effectiveness of new chemical entities.

Clinical, Socio-Demographic Characteristics and Gender Disparity in Patients with Tuberculosis Infection in Pakistan

Objectives: To assess the clinical, environmental, and socio-demographic characteristics leading to gender disparity in tuberculosis in Pakistan. Study Design: Prospective Comparative study. Study Setting and Duration: The Indus Hospital, Karachi Pakistan, from Jul 2020 to Dec 2020. Methodology: A sample of 200 patients with diagnosed tuberculosis (detected on an acid-fast bacillus (AFB) smear with radiographic abnormalities) irrespective of gender, sensitivity, or site of tuberculosis, were included in the study. Data of gender, personal history, substance abuse history, and dietary habits was documented. Results: Pulmonary tuberculosis was significantly more common in female patients than in males (p<0.001). The mean age of male patients was 30.16 ± 9.47 years. Male patients were significantly older than their female counterparts (p=0.003). The diabetes mellitus in male patients was significantly higher than in female patients with TB (p=0.01). Similarly, substance abuse history was more frequently positive in male patients as compared to female patients, 28 (40.60%) vs 9 (6.70%); p-value <0.001. There was no significant difference in the occurrence of drug-resistance tuberculosis between the two genders. However, pulmonary tuberculosis was significantly more common in female patients than in males (p<0.001). Conclusion: We reported some distinctive differences between male and female tuberculosis patients. Young females had more predilections toward tuberculosis as compared to men. Diabetes mellitus and substance abuse history were more common in male tuberculosis patients than in females.

Neutralizing Antibody Response to BBIBP-CorV in Comparison with COVID-19 Recovered, Unvaccinated Individuals in a Sample of the Pakistani Population

Fifty five percent of the Pakistani population is still unvaccinated with the two-dose protocol of COVID-19 vaccines. This study was undertaken to determine the seroconversion rate and antibody titers following the two-dose BBIBP-CorV protocol, and to compare these variables in unvaccinated, COVID-19 recovered individuals (total n = 180) at Indus Hospital and Health Network, Karachi. Pseudotyped lentivirus antibody neutralization assays and SARS-CoV-2 IgG Quant II (Abbott) immunoassays were performed 4-8 weeks following the second dose of the BBIBP-CorV or PCR positivity/onset of symptoms of COVID-19. Seroconversion rate, using neutralization assays, in vaccinated individuals was lower (78%) than that in unvaccinated, COVID-19-recovered individuals with moderate to severe infection (97%). Prior PCR positivity increased serocoversion rate to 98% in vaccinated individuals. Immunoassays did not, however, reveal significant inter-group differences in seroconversion rates (≥95% in all groups). Log10 mean antibody neutralizing titers following the two-dose BBIBP-CorV protocol (IC50 = 2.21) were found to be significantly less than those succeeding moderate to severe COVID-19 (IC50 = 2.94). Prior SARS-CoV-2 positivity significantly increased post-vaccination antibody titers (IC50 = 2.82). Similar inter-group titer differences were obtained using the immunoassay. BBIBP-CorV post-vaccination titers may, thus, be lower than those following natural, moderate to severe infection, while prior SARS-CoV-2 exposure increases these titers to more closely approximate the latter.

Effect of Remdesivir on mortality and length of stay in hospitalized COVID-19 patients: A single center study

Objectives: To see the difference in mortality among hospitalized COVID-19 patients given Remdesivir (RDV) with those who were not given RDV. Methods: A prospective cohort study was conducted on patients who were admitted to the COVID-19 isolation unit at The Indus Hospital, Korangi Campus Karachi between March and June 2020. Results: Groups were similar in age and gender distribution. RDV group was more hypoxic, had severe ARDS and needed higher Oxygen support compared to non-RDV group (p=0.000). Median SOFA score was 2 in RDV vs 5 in non-RDV (p=0.000). More than moderate COVID pneumonia was found in 92% of the RDV group while 89% of non-RDV group (p value=0.001). Median day of illness to administer Remdesivir was 10. There was no difference in mortality (45.5% in RDV vs 40.4% in non-RDV; p=0.4) between the two groups. Median length of hospital stay was 12 days (IQR=7.5-14.5) in RDV group compared to 10 days (IQR=6-14) in non-RDV group (p=0.009). Conclusion: RDV did not show any difference in in-hospital mortality in our patients. More patients had severe ARDS in the RDV group while patients in the non-RDV group had higher SOFA score and multi-organ failure. Length of stay was longer in patients receiving Remdesivir. doi: https://doi.org/10.12669/pjms.38.ICON-2022.5779 How to cite this:Shaikh Q, Sarfaraz S, Rahim A, Hussain M, Shah R, Soomro S. Effect of Remdesivir on mortality and length of stay in hospitalized COVID-19 patients: A single center study. Pak J Med Sci. 2022;38(2):405-410.  doi: https://doi.org/10.12669/pjms.38.ICON-2022.5779 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Clinical spectrum and outcomes of patients with different resistance patterns of Salmonella enterica

Background and Objective:

Unceasing rise in cases of enteric fever, in particular extensively drug resistant (XDR) strain of Salmonella enterica, has led to a growing threat, leaving only carbapenems and azithromycin as the precious option. In this regard, we determined the burden and clinical course of XDR salmonella in comparison to multidrug-resistant (MDR) and drug sensitive (DS) strains.

Methods:

A retrospective chart review of 1515 Salmonella Typhi (S.typhi) culture positive patients was conducted at Indus Hospital and Health Network, Karachi from July 2017 to December 2018.

Results:

During our study, we observed children at the age of 5-6 years and adults at the age of 20-22 years were the chief targets of S.typhi. Further, we witnessed a rapid shift of drug resistance from MDR to XDR over the one year of study. Almost all patients presented with fever. However other signs and symptoms like malaise, body aches, anorexia, diarrhea, vomiting and abdominal pain were more common in XDR Typhoid patients. Further, the need of hospitalization, total hospital stay and mortality was also greater for XDR typhoid patients.

Conclusion:

There is a crucial requirement for consolidated steps to curtail the spread of XDR Salmonella tyhi disease as its management is challenging, and it is associated with increased morbidity and mortality.

Determinants of in-hospital mortality in COVID-19; a prospective cohort study from Pakistan

A prospective cohort study was conducted at the Indus Hospital Karachi, Pakistan between March and June 2020 to estimate the in-hospital mortality among hospitalized COVID-19 patients and its determinants. A total of 170 adult patients were enrolled and all-cause mortality was found to be 39% (67/170). Most non-survivors were above 60 years of age (64%) while gender distribution was quite similar in both groups (males: 77% vs 78%). Most (80.6%) non-survivors came with peripheral oxygen saturation less than 93% while 95% of them had critical disease on arrival. Use of non-invasive ventilation in emergency room was higher among non-survivors (56.7%) versus survivors (26.2%). Median Interleukin-6 levels were higher among non-survivors (78.6: IQR = 33.8-49.0) compared to survivors (21.8: IQR = 12.6-36.3). Most patients in the non-survivor group (86.6%) required invasive ventilator support during hospital stay compared to 7.8% in the survivors. The median duration of ICU stay was longer for non-survivors (9: IQR = 6-12) compared to survivors (5: IQR = 3-7) days. Univariable binary logistic regression showed that age above 60 years, oxygen saturation below 93%, Neutrophil to lymphocyte ratio above 5, procalcitonin above 2ng/ml, unit increase in SOFA score and arterial lactate levels were associated with mortality. We also found that a unit decrease in Pao2/FiO2 ratio and serum albumin were associated with mortality in our patients. Multivariable regression showed that age above 60 years (aOR = 3.4: 95% CI = 1.6-6.9), peripheral oxygen saturation below 93% (aOR = 3.5:95% CI = 1.6-7.7) and serum pro-calcitonin above 2ng/ml (aOR = 4.8; 95% CI = 1.9-12.2) were associated with higher odds of mortality when adjusted by month of admission. Most common cause of death was multisystem organ failure in 35 (56.6%) non-survivors while 22 (35.5%) died due to respiratory failure. Larger prospective studies are needed to further strengthen these findings.

Frequency, clinical characteristics, risks, and outcomes of Paradoxical upgrading reactions during anti-tuberculosis treatment in tuberculous lymphadenitis

Objectives

To investigate the clinical characteristics, risks and outcomes of Paradoxical upgrading reactions (PUR) during anti-tuberculosis treatment (ATT) in superficial tuberculous lymphadenitis (TBLA).

Methods

In this nested case-control study, all patients diagnosed with TBLA based on combinations of histopathology, acid-fast bacilli (AFB) microscopy, AFB culture, and GeneXpert, between February 2013 and April 2016, were enrolled. Standard ATT was given. Demographics, clinical characteristics, occurrence of PUR and outcome were recorded.

Results

TBLA was diagnosed and treated in 189 patients. PUR developed in 33 (17%), of which 77% developed new inflamed glands, 20.6% had increased size and inflammation of pre-existing glands and 5.9% had superficial chest wall abscesses requiring aspiration. All responded to regular NSAIDs except one, where a steroid course was effective. No change in dose or duration of ATT was required. Presence of anorexia (OR; 95%CI: 2.6; 1.003-6.74), bilateral extensive lymphadenopathy (OR; 95%CI: 2.9; 1.1-7.5) and lymph node specimen positive for AFB (OR; 95%CI: 3.2; 1.04-10.1) were significantly associated with PUR.

Conclusion

PUR is common in TBLA. It responded to NSAIDS and does not need any modification in ATT.

Clinical manifestation and outcomes of multi-drug resistant (MDR) Raoultella terrigena infection - A case series at Indus Health Network, Karachi, Pakistan

Background and objectives

There is paucity of literature available on Raoultella terrigena infection. Microbiological identification of Raoultella terrigena is difficult and isolates are frequently misidentified as Klebsiella species. This series of 3 cases with Raoultella terrigena septicemia provides a description of the pitfalls and challenges in the diagnosis and management of the highly resistant strains isolated and to the best of our knowledge, is the first report from Pakistan.

Methods

The medical records of 3 cases of R. terrigena reported in the hospital over two months were reviewed retrospectively to record all relevant clinical information. Organism was identified by using Analytical profile index (API) 20 E with 90–95% successful identification and the sensitivity testing was performed by disc diffusion method.

Results

This organism caused fulminant sepsis in case 2 resulting in mortality and complicated urinary tract infection in the third, while in case 1 it preceded the fatal candidemia. All three patients were females who had multiple co-morbid and had a history of protracted hospital stay and antibiotic usage elsewhere before being shifted to our hospital. The isolates were resistant to all beta lactams and were even colistin resistant in two patients, creating challenges and suboptimal response for effective antibiotic therapy.

Conclusions

The purpose of this case series is to highlight the highly drug resistant profile of this organism and the fulminant infection it can cause, which if spreads in our hospitals due to breaches in infection control practices, can pose risk as a deadly and untreatable nosocomial infection.

An Unusual Case of Extensively Drug Resistant Typhoid Fever

Enteric fever is a potentially fatal multisystemic illness caused primarily by Salmonella typhi and, to a lesser extent, by Paratyphi A, B, and C. Emergence of resistance has depleted the antimicrobial arsenal overtime, making treatment challenging and costly. In 2016, a new extensively drug resistant (XDR) strain of Salmonella typhi emerged in Sindh, which only responds to two antibiotics--carbapenems and azithromycin. Its clinical spectrum is not yet clear but increased morbidity and mortality is being observed with it. We present a severe case of XDR Salmonella typhi where the clinical course was complicated by delayed defervescence, severe hepatitis, soft tissue infection, and profuse lower gastrointestinal bleeding, which responded to a combination of carbapenem and azithromycin and an invasive procedure to contain bleeding from the cecal artery. The purpose of this case report is to highlight the morbidity, cost, and therapeutic challenges associated with severe XDR Salmonella typhi infection.

LAMC2 enhances the metastatic potential of lung adenocarcinoma

Lung cancer is the number one cancer killer, and metastasis is the main cause of high mortality in lung cancer patients. However, mechanisms underlying the development of lung cancer metastasis remain unknown. Using genome-wide transcriptional analysis in an experimental metastasis model, we identified laminin γ2 (LAMC2), an epithelial basement membrane protein, to be significantly upregulated in lung adenocarcinoma metastatic cells. Elevated LAMC2 increased traction force, migration, and invasion of lung adenocarcinoma cells accompanied by the induction of epithelial-mesenchymal transition (EMT). LAMC2 knockdown decreased traction force, migration, and invasion accompanied by EMT reduction in vitro, and attenuated metastasis in mice. LAMC2 promoted migration and invasion via EMT that was integrin β1- and ZEB1-dependent. High LAMC2 was significantly correlated with the mesenchymal marker vimentin expression in lung adenocarcinomas, and with higher risk of recurrence or death in patients with lung adenocarcinoma. We suggest that LAMC2 promotes metastasis in lung adenocarcinoma via EMT and may be a potential therapeutic target.