[Update on collaborative autopsy-based research in German pathology, neuropathology, and forensic medicine]

BACKGROUND

Autopsies are a valuable tool for understanding disease, including COVID-19.

MATERIALS AND METHODS

The German Registry of COVID-19 Autopsies (DeRegCOVID), established in April 2020, serves as the electronic backbone of the National Autopsy Network (NATON), launched in early 2022 following DEFEAT PANDEMIcs.

RESULTS

The NATON consortium's interconnected, collaborative autopsy research is enabled by an unprecedented collaboration of 138 individuals at more than 35 German university and non-university autopsy centers through which pathology, neuropathology, and forensic medicine autopsy data including data on biomaterials are collected in DeRegCOVID and tissue-based research and methods development are conducted. More than 145 publications have now emerged from participating autopsy centers, highlighting various basic science and clinical aspects of COVID-19, such as thromboembolic events, organ tropism, SARS-CoV‑2 detection methods, and infectivity of SARS-CoV-2 at autopsy.

CONCLUSIONS

Participating centers have demonstrated the high value of autopsy and autopsy-derived data and biomaterials to modern medicine. The planned long-term continuation and further development of the registry and network, as well as the open and participatory design, will allow the involvement of all interested partners.

[SARS-CoV-2-associated deaths in adult persons up to 50 years of age]

INTRODUCTION

Several evaluations of deaths in persons of advanced age associated with SARS-CoV‑2 can be found in the international literature. The aim of this work was the evaluation of deaths associated with SARS-CoV‑2 of persons of younger or middle age (up to 50 years) at the Institute of Legal Medicine in Hamburg, Germany, with presentation of frequency, comorbidities and disease courses.

MATERIAL AND METHODS

A total of 735 SARS-CoV-2-associated cases of decedents with registered addresses in Hamburg were evaluated in 2020 at the Institute of Legal Medicine in Hamburg, Germany, using various examination methods. The selection and performance of the respective methods was based on the consent given by the relatives. In addition, more autopsies of decedents with a registered address outside Hamburg and positive SARS-CoV‑2 detection were performed.

RESULTS AND CONCLUSION

Of the 735 decedents 9 with a registered Hamburg address and 3 of the deaths studied with an external registered address (n = 12; 7 men and 5 women) were aged 50 years or younger, with an average age of 39.8 years. Essentially, there were cardiovascular, neurological, and malignant pre-existing diseases, as well as obesity. The SARS-CoV‑2 was detected post-mortem for the first time in two cases; these were found to have a virus-independent cause of death. Of the individuals 7 died from COVID-19 pneumonia, 3 individuals from the consequences of the necessary intensive medical treatment.Several studies have demonstrated an association between obesity and severe SARS-CoV-2-related disease progression, particularly in younger patients and this was confirmed in the legal medicine study population.

COVID-19 lungs in post-mortem computed tomography

Post-mortem computed tomography (PMCT) is a rapid and noninvasive diagnostic tool for important contributions to the identification of pulmonary findings in the deceased with pneumonia, including cases of coronavirus disease 2019 (COVID-19). Although computed tomography (CT) shows a high sensitivity for pneumonia in living persons, it is relatively unspecific for COVID-19 pneumonia clinically. Typical CT findings for viral pneumonia therefore require confirmation by PCR tests (polymerase chain reaction tests), even if lung infections with severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) show characteristic patterns, most frequently ground glass opacities (GGO) and a combination of GGO and air space consolidations.

In the consecutive autopsy series of SARS-CoV‑2 deaths from Hamburg, Germany, the most frequent cause of death was and still is COVID-19 pneumonia. Typical findings were frequently found in the PMCT in SARS-CoV-2-associated deaths, which were taken into account when classifying the death as COVID-19.

[Postmortem imaging of the lung in cases of COVID-19 deaths]

CLINICAL/METHODOLOGICAL ISSUE

COVID-19 is a new viral disease that is associated with inflammatory pulmonary changes which can be detected in computed tomography (CT). So far postmortem CT (PMCT) has not been used as a screening instrument for the evaluation of deaths with and without autopsy. In this respect, its validity has to be proved in comparison to clinical-radiological experiences.

STANDARD RADIOLOGICAL METHODS

Postmortem CT METHODICAL INNOVATIONS: So far, PMCT can be regarded as a methodological innovation that has not yet been sufficiently evaluated for pneumonia.

PERFORMANCE

CT in clinical routine has a high sensitivity for pneumonia. However, to what extent postmortem artifacts are relevant to PMCT still has to be determined.

ACHIEVEMENTS

There is still no standard procedure for the postmortem radiological diagnosis of COVID-19 disease. Despite postmortem artifacts, PMCT can provide valuable information about the presence of pneumonia with interstitial character, especially without autopsy.

PRACTICAL RECOMMENDATIONS

PMCT is particularly useful in the assessment of suspected cases of COVID-19 pneumonia for morphological assessment in the context of monitoring deaths in the current pandemic situation.

[The first COVID-19 hotspot in a retirement home in Hamburg]

Background

Coronavirus disease 2019 (COVID-19), a disease caused by the new coronavirus (SARS-CoV-2), is a particular threat to old people. At the end of March 2020, the first and so far largest outbreak of the disease occurred in a retirement home in Hamburg.

Methods

Analysis of procedures in dealing with a residential unit affected by SARS-CoV‑2, accommodating a risk group of 60 seniors with dementia is presented as well as a detailed presentation of post-mortem examination results of all 8 deceased tested positive for SARS-CoV‑2.

Results

Out of 60 residents, 39 were infected by SARS-CoV‑2. Due to preventive procedures it was possible to stop further spreading of the infection to other residential areas. In all 8 fatal cases, the autopsy diagnosis was death due to COVID-19. Autopsies revealed all COVID-19 patients to have a fatal (broncho)pneumonia and signs of relevant pre-existing cardiac, renal and pulmonary conditions in all cases. In 75% (n = 6) of the cases a fresh venous thrombosis was found. In 66.7% (n = 4) of the cases thrombotic events were combined with peripheral pulmonary artery thromboembolisms.

Conclusion

The cohort of SARS-CoV‑2 infected residents of a nursing home is characteristic for clinical and epidemiological features of the new coronavirus disease. Due to a centralized evaluation of all fatalities at the Institute of Legal Medicine in Hamburg, a detailed examination of all deceased positive for SARS-CoV‑2 was possible. Thereby, increased case fatality rates of approximately 20% could in all cases be assigned to a relevant number of pre-existing comorbidities of multiple organ systems, which was consistent with the clinical data available.

Evidence for systematic autopsies in COVID-19 positive deceased: Case report of the first German investigated COVID-19 death

Forensic medicine and pathology involve specific health risks, whereby health workers are dealing with microorganisms, cells or parasites, which are referred to as biological agents. Biological agents are divided into four categories according to § 3 of the Biological Agents Ordinance. The newly identified coronavirus, severe acute respiratory syndrome, coronavirus 2 (SARS-CoV-2) that has spread rapidly around the world is placed into category 3 of the Biological Agents Ordinance, meaning pathogens that can cause serious illnesses in humans and may pose a risk to workers. The Robert Koch Institute, the German government’s central scientific institution in the field of biomedicine issued the announcement, that aerosol-producing measures (including autopsies) of SARS-CoV‑2 infected bodies should be avoided, despite the fact that autopsies are an important source of understanding the pathomorphological course of new diseases. The first German case of death due to a proven SARS-CoV‑2 infection is presented with global multifocal reticular consolidation in the post-mortem computed tomography (CT) scan, a macroscopic and microscopic viral pneumonia and viral RNA of SARS-CoV‑2 in pharyngeal mucosa and lung tissue.

The effect of bleaching agents on the DNA analysis of bloodstains on different floor coverings

Blood at crime scenes is one of the most significant traces of evidence in investigation proceedings. Cleaning up these traces with household cleaning products, often containing bleaching agents, inhibits or complicates the detection of DNA. In this study, human blood was applied onto different floor coverings (carpet, laminate, parquet, PVC, tile) and subsequently cleaned with water and bleaching agents (hydrogen peroxide, sodium hypochlorite, DanKlorix®, Vanish Oxi Action®) at different times. Samples have been collected afterwards from the floors. The samples underwent a quantitative and qualitative DNA analysis. Cleaning smooth surfaces with water is usually sufficed to prohibit retrieving a DNA profile in most of the cases. Cleaning carpets was more difficult due to their absorbent surface whereas the use of bleaching agents caused an additional reduction of verifiable DNA concentrations. Retrieving partial or complete profiles after the use of bleaching agents was only possible when cleaning with low concentrations of 3% hydrogen peroxide.

Ovarian hormones and binge eating: exploring associations in community samples

BACKGROUND

Significant associations between changes in ovarian hormones and binge eating are present across the menstrual cycle in women with bulimia nervosa. However, no study has examined these relationships in a non-clinical sample, despite the need for these data for designing risk-factor studies.

METHOD

In study 1, we modified several continuous measures of binge eating and identified those that were most sensitive to menstrual-cycle fluctuations in a non-clinical sample of 10 women who completed measures for 35 days. In study 2, we explored associations between ovarian hormones and binge-eating scores in nine women who completed these same measures for 65 days and provided daily saliva samples for assays of estradiol and progesterone concentrations.

RESULTS

In study 1, the Emotional Eating subscale of the Dutch Eating Behavior Questionnaire exhibited superior reliability and was most sensitive to predicted menstrual-cycle changes in binge eating (i.e. increased scores in the mid-luteal/premenstrual compared with follicular/ovulatory phases). In study 2, this scale showed predicted inverse associations with estradiol and positive associations with progesterone across the menstrual cycle that could not be accounted for by changes in negative affect.

CONCLUSION

Associations between ovarian hormones and binge eating are robust and present in clinical and non-clinical samples. Findings support the ability to examine the role of ovarian hormones as risk factors for binge eating in large-scale prospective studies and twin studies.

XmAb Fc engineered anti-CD19 monoclonal antibodies with enhanced in vitro efficacy against multiple lymphoma cell lines

3021

Background: CD19 is a pan-B cell surface receptor that is expressed from early stages of pre-B cell development through terminal differentiation into plasma cells. It is an attractive immunotherapy target for cancers of lymphoid origin since it is also expressed on the vast majority of Non-Hodgkin Lymphoma (NHL) cells as well as some leukemias. Despite major improvements in response rates and progression free survival the majority of NHL patients will relapse under the current combination chemotherapy with anti-CD20. Thus salvage regimens with new non-cross resistant antibody therapies are warranted. Methods: We employ our XmAb antibody engineering technology to increase the affinity of IgG antibodies for Fc gamma receptors (FcγR), improve the effector function of antibodies, and significantly increases their antitumor potency; we also we humanize and affinity mature such antibodies. Results: The XmAb technology was applied to a humanized anti-CD19 antibody to engineer a variant with significantly enhanced (10- to 100-fold) antibody-dependent cell-mediated cytotoxicity (ADCC). The resulting XmAb CD19 variant was assayed for ADCC against multiple cell lines representative of follicular lymphoma (FL), chronic lymphocytic leukemia (CLL), B-cell acute lymphoblastic leukemia (B-ALL), mantle cell lymphoma (MCL), hairy cell leukemia (HCL), chronic myelogenous leukemia (CML), and Burkitt’s lymphoma (BL). The ADCC activity of the XmAb CD19 was in striking contrast to a wild type IgG1 version of the antibody that mediates little ADCC. Moreover, ADCC potency and efficacy of the anti-CD19 Fc variant antibody were superior to that of rituximab: CLL - 10- and 1.5-fold higher, ALL - 10- and 100-fold higher, and HCL - 6- and 1.2-fold higher, respectively. Further, we observed no correlation between ADCC and antigen expression based on the measured cell surface density of CD19 for these cell lines. Conclusions: The increased affinity for FcγRs exhibited by the anti-CD19 Fc variant antibody overcomes much of the dependence of cytotoxicity on surface antigen density. Our data suggest that the anti-CD19 Fc variant antibody engineered for increased effector function could be a promising next-generation NHL immunotherapeutic.

No significant financial relationships to disclose.

Microbial Decomposition of Elm and Oak Leaves in a Karst Aquifer

Dry Chinquapin oak ( Quercus macrocarpa ) and American elm ( Ulmus americana ) leaves were placed in four microcosms fed by groundwater springs to monitor changes in dry mass, ash-free dry mass, and microbial activity over a 35-day period. Oxygen microelectrodes were used to measure microbial activity and to estimate millimeter-scale heterogeneity in that activity. Oak leaves lost mass more slowly than elm leaves. Generally, there was a decrease in total dry weight over the first 14 days, after which total dry weight began to increase. However, there were consistent decreases in ash-free dry mass over the entire incubation period, suggesting that the material remaining after initial leaf decomposition trapped inorganic particles. Microbial activity was higher on elm leaves than on oak leaves, with peak activity occurring at 6 and 27 days, respectively. The level of oxygen saturation on the bottom surface of an elm leaf ranged between 0 and 75% within a 30-mm 2 area. This spatial heterogeneity in O 2 saturation disappeared when the water velocity increased from 0 to 6 cm s -1 . Our results suggest that as leaves enter the groundwater, they decompose and provide substrate for microorganisms. The rate of decomposition depends on leaf type, small-scale variations in microbial activity, water velocity, and the length of submersion time. During the initial stages of decomposition, anoxic microzones are formed that could potentially be important to the biogeochemistry of the otherwise oxic aquifer.