Management of Persistent SARS-CoV-2 Infection in Patients with Follicular Lymphoma

INTRODUCTION

There is no consensus on the management of the coronavirus disease (COVID-19) in patients with secondary immunosuppression due to either an underlying hematological disease or to the effects of immunochemotherapy (ICT). Some of them may present persistent infection with multiple relapses of COVID-19, requiring several admissions. This study evaluated the clinical characteristics and outcomes after treatment of 5 patients with follicular lymphoma (FL), previously treated with ICT, who developed several episodes of COVID-19.

METHODS

We analyzed the clinical evolution and response to treatment with antiviral agent, steroids, and convalescent plasma in 5 patients with FL and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) persistent infection. Reverse transcriptase polymerase chain reaction tests and peripheral blood immunophenotype were performed for all patients.

RESULTS

All patients required hospitalization due to pneumonia with severity criteria and were re-admitted after a median of 22 days (13-42) from the previous discharge. They all showed B-cell depletion by immunophenotyping, and no traces of immunoglobulin antibodies against SARS-CoV-2 were detected in any of the cases. The survival rate was 80%.

CONCLUSION

The combination therapy evidenced clinical benefits, demonstrating its capacity to control infection in immunosuppressed FL patients treated with ICT.

Prevalence of submicroscopic malaria infection in immigrants living in Spain

BACKGROUND

The importance of submicroscopic malaria infections in high-transmission areas could contribute to maintain the parasite cycle. Regarding non-endemic areas, its importance remains barely understood because parasitaemia in these afebrile patients is usually below the detection limits for microscopy, hence molecular techniques are often needed for its diagnosis. In addition to this, the lack of standardized protocols for the screening of submicroscopic malaria in immigrants from endemic areas may underestimate the infection with Plasmodium spp. The aim of this study was to assess the prevalence of submicroscopic malaria in afebrile immigrants living in a non-endemic area.

METHODS

A prospective, observational, multicentre study was conducted. Afebrile immigrants were included, microscopic observation of Giemsa-stained thin and thick blood smears, and two different molecular techniques detecting Plasmodium spp. were performed. Patients with submicroscopic malaria were defined as patients with negative blood smears and detection of DNA of Plasmodium spp. with one or both molecular techniques. Demographic, clinical, analytical and microbiological features were recorded and univariate analysis by subgroups was carried out with STATA v15.

RESULTS

A total of 244 afebrile immigrants were included in the study. Of them, 14 had a submicroscopic malaria infection, yielding a prevalence of 5.7% (95% confidence interval 3.45-9.40). In 71.4% of the positive PCR/negative microscopy cases, Plasmodium falciparum alone was the main detected species (10 out of the 14 patients) and in 4 cases (28.6%) Plasmodium vivax or Plasmodium ovale were detected. One patient had a mixed infection including three different species.

CONCLUSIONS

The prevalence of submicroscopic malaria in afebrile immigrants was similar to that previously described in Spain. Plasmodium vivax and P. ovale were detected in almost a third of the submicroscopic infections. Screening protocols for afebrile immigrants with molecular techniques could be useful for a proper management of these patients.

Study of the diagnostic accuracy of microbiological techniques in the diagnosis of malaria in the immigrant population in Madrid

Background

Malaria is currently the most important human parasitic disease in the world responsible for high morbidity and mortality. Appropriate diagnostic methods are essential for early detection. Microscopy examination remains the gold standard, although molecular techniques have higher sensitivity and are very useful in cases of low parasitaemia and mixed infections. The objective of this study was to evaluate a new commercial molecular diagnostic technique.

Methods

A prospective, observational, multicentre study was performed between January 2015 and April 2017. All participants were immigrants from malaria-endemic areas, who were divided into two groups: asymptomatic group and symptomatic. Samples from both groups were evaluated by a rapid diagnostic test (ImmunoQuick^® Malaria + 4 RDT), microscopy examination, and two commercial molecular malaria tests (FTD Malaria and FTD Malaria Differentiation), then compared against an in-house reference PCR technique.

Results

In all, 250 patients were included: 164 (65.6%) in the asymptomatic group, and 86 (34.4%) in the symptomatic group. There were seven cases of asymptomatic parasitaemia (prevalence = 2.8%) that were detected only by molecular methods. In the symptomatic group, there were seven cases of submicroscopic malaria. The main species detected was Plasmodium falciparum (96.6%). The commercial molecular technique had higher sensitivity than the other methods (S = 96%) and a high rate of concordance with the in-house reference PCR technique (Kappa score = 0.93).

Conclusions

The molecular techniques, although slower than microscopy, have adequate diagnostic accuracy and are very useful for the detection of P. falciparum in cases with low parasitaemia.

Meningitis due to mixed infection with penicillin-resistant and penicillin-susceptible strains of Streptococcus pneumoniae

Streptococcus pneumoniae is the major cause of bacterial meningitis. We report a case of meningitis due to a mixed infection with two distinct strains of S. pneumoniae: one penicillin-resistant strain of serotype 9V and one penicillin-susceptible strain of serotype 7. The two strains exhibited different pulsed-field gel electrophoresis profiles.

[Evaluation of mutations that confer resistance to nucleoside analogs and protease inhibitors in HIV-1-infected patients. Study Group on Resistance to Antiretroviral Agents]

Genotypes that confer drug resistance to reverse transcriptase inhibitors and protease inhibitors were evaluated in HIV-1 proviral DNA obtained from peripheral blood mononuclear cell samples. Fifty-three HIV-1-infected patients were studied, 19 of whom had not received antiretroviral treatment. In the other 34 patients, 9 had been treated with combinations of two reverse transcriptase inhibitors (AZT, ddI, d4T, 3TC) and 25 had been treated with triple antiretroviral therapy including a protease inhibitor (nelfinavir, indinavir, saquinavir, ritonavir). To determine the presence of mutations involved in the development of resistance to reverse transcriptase inhibitors a hybridization Microtiter assay was carried out. Mutations were detected in treated patients as well as in those without previous antiretroviral treatment, with the most frequent mutations being those that confer resistance to AZT, followed by those that develop cross-resistance to ddI/ddC and 3TC, which are the most commonly used drugs to date. No mutations were detected to any nucleoside analog in only 13 cases. To analyze the presence of mutations in the protease gene a dot-blot hybridization was carried out which included the mutations in codons 36, 82 and 90. Mutation 82 was detected in one case. Therefore, with the aim of determining the pattern of genotypic mutations in patients infected with HIV-1 and in order to make the best therapeutic choice, it would be recommended to consider carrying out genotypic resistance assays in clinical practice.

Association between HIV and other DNA viruses in vitro

To investigate the association of human immunodeficiency virus (HIV) with various DNA viruses, including hepatitis B virus (HBV), cytomegalovirus (CMV) and Epstein-Barr virus, (EBV), simultaneous detection of HIV p24 antigen, HBV surface antigen and DNA, CMV-DNA and EBV-DNA expression was performed in phytohemagglutinin-stimulated peripheral blood mononuclear (PBMC) culture supernatants obtained from 54 individuals at risk for HIV infection. HIV expression in PBMC culture supernatants never occurred alone; expression of other viruses was always detected in the 24 samples expressing HIV antigen in vitro. Furthermore, in 16 patients expression of other viruses was detected without HIV expression, and in 14 patients none of the tested viruses were detected. These results indicate a strong association between the presence of HIV antibody and expression of DNA viruses in vitro (p = 0.0001). The coexpression of these viruses could be related to the evolution of HIV infection and AIDS.

Detection of human immunodeficiency virus type 1 by PCR before seroconversion in high-risk individuals who remain seronegative for prolonged periods

HIV-1 seronegative patients at high risk for HIV infection were followed up. In 1990 PCR was positive for HIV DNA sequences in samples of 17 seronegative patients who continued to report for surveillance of HIV infection. There was clear evidence of seroconversion in four of these 17 seronegative patients, while in one patient an indeterminate result for HIV was repeatedly obtained in different samples. The other 12 patients continue to be seronegative without any evidence of HIV infection except the presence of provirus in peripheral blood mononuclear cells. It is important to apply the PCR technique together with tests to detect other virological and immunological markers, in order to identify seronegative carriers and thus avoid HIV transmission by them.

Detection of hepatitis B virus DNA and determination of surface antigen expression in peripheral blood mononuclear cells from patients with AIDS

The polymerase chain reaction (PCR) was used to analyze the presence of hepatitis B virus (HBV) DNA in serum and peripheral blood mononuclear cells (PBMCs) from 20 patients with AIDS with and without conventional HBV serological markers. DNA sequences of HBV were detected in PBMCs from 13 patients, nine of whom were positive for anti-HBc only and four of whom were also positive for anti-HBs. When PBMCs from patients were activated in culture with phytohemagglutinin, the presence of HBsAg could be detected in the culture supernatants from four of 13 patients with HBV DNA in their PBMCs; for two of the four, HBV DNA could also be detected in the culture supernatant after DNA amplification. It was observed that HBV DNA sequences found in PBMCs can be reactivated by mitogen stimulation in some HIV-1 infected patients.

[Detection of the HIV p24 antigen on lymphocyte membranes using flow cytometry]

The evaluation of the presence of p24 antigen on the membrane of peripheral blood mononuclear cells from 31 HIV infected individuals is presented. The study was performed by indirect immunofluorescence and flow cytometry and the data were analyzed by the Kolmogorov-Smirnov test. Values obtained [D/s(n)] result from the comparison of the fluorescence histograms of each sample with a control one. Cases showing p24 Ag on peripheral blood mononuclear cells also presented percentages of CD3, HLA-DR positive cells significantly higher than p24 negative ones. In addition, D/s(n) values were superior in symptomatic patients than in asymptomatic ones, which indicate the existence of a correlation between flow cytometry results, viral replication and clinical course. Nevertheless in this study, as well and in previous ones, a high degree of cross reactivity between the anti-p24 monoclonal antibody employed and normal lymphocytes has been observed. This reactivity is localized preferentially in the CD4 positive subset.

[Detection of HBV-DNA in peripheral blood mononuclear cells of anti-HIV-positive patients and its relation to other serological markers of HBV]

HBV infection has been investigated in 47 anti-human HIV positive patients in relation to a similar group of 33 anti-HIV negative patients. Serological HBV markers were found in 87% of anti-HIV positive patients. The difference in markers of viral replication (HBeAg, HBV-DNA) was not statistically significant between the two groups. It has been suggested that HBV infection of peripheral blood mononuclear cells could be a cofactor implicated in the development of immunodeficiency due to HIV. For this reason we have investigated the presence of HBV-DNA in peripheral blood mononuclear cells by in situ hybridization. Although its detection was more frequent in anti-HIV positive patients than in anti-HIV negative ones (p < 0.05), it was not related to clinical state of immunodeficiency. With regard to serological HBV markers, HBV-DNA was detected in peripheral blood mononuclear cells from antiHBc w/o antiHBs patients. This fact means the virus may persist in this cells after recovery and suggest they could serve as additional reservoirs of HBV. These cells, that contain the HBV genome, could be implicated in the perpetuation, reactivation of the infection and in its transmission.

Detection of hepatitis B virus DNA in chronic carriers by the polymerase chain reaction

The polymerase chain reaction (PCR) was used to detect hepatitis B virus DNA (HBV-DNA) in serum samples of 104 chronic HBV carriers. Of 22 patients positive for both HBV surface (HBsAg) and HBVe (HBeAg) antigens, seven were positive for HBV-DNA on dot blot hybridisation, and all 22 positive in the PCR. Of 41 HBsAg positive patients who had antibodies against HBeAg (anti-HBe), only three were positive for DNA-HBV on dot blot hybridisation, however DNA was detected in 30 of them with the PCR. Similarly, of 41 individuals with antibodies against HBsAg (anti-HBs), 23 yielded positive results in the PCR technique, although dot blot hybridisation detected HBV-DNA in only one patient. These results indicate that while serological and conventional DNA hybridisation assays are not sensitive enough to determine the infectivity of HBV chronic carriers, PCR is an accurate method for establishing the status and progression of disease in these patients.

Evidence of an in vitro association between human immunodeficiency virus antigen P24 and Epstein-Barr virus DNA

To investigate the association between human immunodeficiency virus (HIV) and Epstein-Barr virus (EBV), simultaneous determinations of HIV antigen (HIV Ag) p24 and EBV DNA were performed in lymphocyte culture supernatants from 63 individuals at risk of HIV infection. In vitro data, together with HIV immune status results, were subjected to a statistical analysis. HIV infection was identified in 49 patients (78%); of these, in vitro EBV DNA was found in 44 individuals (90%), while in only 3 of the 14 non-infected ones (21%). Statistical analysis demonstrated a close relationship between evidence of HIV infection and in vitro detection of EBV DNA (87.3% concordant with 95% confidence interval: 76.5%-94.5%). Furthermore, a strong dependence was revealed between the presence of EBV DNA and HIV Ag in culture (p less than 0.00001). These results indicate the existence of in vitro viral interactions, with likely in vivo implications in the pathogenesis and evolution of HIV infection.

[Detection of hepatitis B virus DNA in peripheral blood mononuclear cells from patients with various hepatopathies using in situ hybridization]

We have investigated, by "in situ" hibridisation, the presence of hepatitis B virus (HBV) DNA in peripheral blood mononuclear cells (PBMC) from 45 patients with acute and chronic hepatic disorders directly related with HBV or with some seric HBV marker. Results has been related with serological markers and the different types of hepatopaties. The HBV-DNA was detected in PBMC more frequently in patients with hepatic alterations more prolongated (chronic active hepatitis, chronic persistent hepatitis and cirrhosis) than in acute hepatitis patients. It was not detected in any asymptomatic patient with HBV serological markers. As regards HBV serological markers, HBV-DNA was detected in PBMC in 8/11 HBsAg positive patients and in 11/34 HBsAg negative patients: 3 antiHBc positive, 5 antiHBc and antiHBs positive and 3 without conventional seric markers. The detection of HBV-DNA in antiHBc and/or antiHBs positive subjects means the virus may persist after recovery of infection and suggests PMBC could serve as additional reservoirs for reinfection of hepatocytes leading to a reactivation of the liver disease. Our results suggest that HBV infection of PBMC is a frequent event during HBV infection and can have important consequences fundamentally with respect to pathogenic mechanisms of HBV induced liver disease and to the transmission of the virus.

[Detection and antigenic distribution of hepatitis B virus in liver tissue and its relation to other serological markers of viral replication]

The aim of this work has been the production of specific monoclonal antibodies against HBV-antigens and their utilisation in order to study their distribution on liver tissue. The monoclonal antibodies anti-HBc and anti-HBs were obtained by the modified hybridoma technique. This study was performed on 50 patients affected by several chronic hepatopathies. For the detection of the antigens, avidin-biotin-peroxidase complex immunostaining was used. Both cytoplasmic and membranous HBsAg were detected in 15 out of 16 HBsAg+ patients; 8 of 12 HBsAg-/anti-HBc+ patients and 1 HBsAg-/antiHBc- patient. Cytoplasmic and nuclear HBcAg was observed in 12 of 16 HBsAg+ patients and 4 of 20 HBsAg- patients. Although the presence of serum HBsAg is an index of liver infection, in some HBsAg-/antiHB+ patients (20%) with undetectable levels of HBsAg, hepatic injury may be disclosed by the detection of other markers of active viral replication.

[Hepatitis B virus (HBV) replication in patients with various types of chronic hepatopathy]

We study retrospectively the viral replication state (HBV) of 50 patients with chronic hepatic alterations. The seric DNA-HBV and/or intrahepatic (molecular hybridization), the intrahepatic distribution of HBV antigens (specific monoclonal antibodies labelled with immunoperoxidase), conventional seric HBV markers (commercial enzymoimmunoessay) and the different histopathologic features. We found a correlation between DNA-HBV "in situ" and HBcAg intrahepatic and the seric DNA-HBV production. 81% of the patients with HBsAg (+) had intrahepatic HBcAg and 85% (11/13) of them showed the antigen in their cytoplasms. Patients with HBcAg also had seric and liver DNA-HBV (+). The lack of seric HBsAg did not mean that non-active replication of HBV did not exist because 20% of the patients with HBsAg (-) showed seric and "in situ" DNA-HBV and cytoplasmic HBcAg. The detection of DNA-HBV in endothelial cells and vascular elements in hepatic tissue show that the rate of the HBV host cells is greater.

[The detection of the DNA of the hepatitis B virus in patients with probable non-A, non-B hepatitis]

We found the presence of hepatitis B virus in 17 cases of non-A-non-B hepatitis using the DNA detection technique in serum of patients with a type of chronic hepatopathy. This finding supports the needs to determine this seric marker in all patients afflicted with chronic hepatopathy before the diagnosis of hepatitis B is excluded.

[Presence of HBsAg in lymphocyte cultured from patients infected with human immunodeficiency virus (HIV)]

The behavior of the hepatitis B virus was investigated in mononuclear cell cultures in nine patients infected by the human immunodeficiency virus. Although only one of them was a carrier of HBsAg and four had anti-HBs in their sera, HBsAg was detected in the supernatant of the cultures from all patients. These results suggest that mononuclear cells might act as a reservoir for hepatitis B virus, and that the concomitant infection by this virus and human immunodeficiency virus may alter the natural evolution of any of both conditions.