Clinical and molecular practice of European thoracic pathology laboratories during the COVID-19 pandemic. The past and the near future

Background

This study evaluated the consequences in Europe of the COVID-19 outbreak on pathology laboratories orientated toward the diagnosis of thoracic diseases.

Materials and methods

A survey was sent to 71 pathology laboratories from 21 European countries. The questionnaire requested information concerning the organization of biosafety, the clinical and molecular pathology, the biobanking, the workload, the associated research into COVID-19, and the organization of education and training during the COVID-19 crisis, from 15 March to 31 May 2020, compared with the same period in 2019.

Results

Questionnaires were returned from 53/71 (75%) laboratories from 18 European countries. The biosafety procedures were heterogeneous. The workload in clinical and molecular pathology decreased dramatically by 31% (range, 3%-55%) and 26% (range, 7%-62%), respectively. According to the professional category, between 28% and 41% of the staff members were not present in the laboratories but did teleworking. A total of 70% of the laboratories developed virtual meetings for the training of residents and junior pathologists. During the period of study, none of the staff members with confirmed COVID-19 became infected as a result of handling samples.

Conclusions

The COVID-19 pandemic has had a strong impact on most of the European pathology laboratories included in this study. Urgent implementation of several changes to the organization of most of these laboratories, notably to better harmonize biosafety procedures, was noted at the onset of the pandemic and maintained in the event of a new wave of infection occurring in Europe.

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Biosafety measures used in the first wave of the COVID-19 crisis were heterogeneous in 53 European pathology laboratories.

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A dramatic decrease of the workload in pathology laboratories was noted.

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No case of healthcare workers contaminated with SARS-CoV-2 associated with samples handling was identified.

Infection with Toxoplasma gondii RH and Prugniaud strains in mice, rats and nude rats: kinetics of infection in blood and tissues related to pathology in acute and chronic infection

Since mice and rats are the most studied models of experimental toxoplasmosis, the aim of this work was to analyze the outcome of Toxoplasma infection in mice, rats and congenitally athymic nude rats; for this purpose, the parasitic load in different organs and the anatomic-pathological characteristics of infection were investigated in these animals. The data obtained after infection with two different strains and stages of Toxoplasma gondii (RH tachyzoites and Prugniaud cysts) concerned the following organs: brain, mesenteric lymph nodes, blood, spleen, heart, lungs, diaphragm and liver. In Fischer rats, the infection with either the Prugniaud or the RH strains displayed similar characteristics: after a peak in the parasite load, a complete disappearance of parasites was observed, except in the brain of Prugniaud strain-infected rats where toxoplasmas were evidenced throughout the experiment. In OF1 mice, where infection by the RH tachyzoites was lethal, infection with the Prugniaud strain led to survival; the parasitic burden peaked in the different organs and was then undetectable, except in the brain where toxoplasmas were still present during the chronic phase. Like mice, nude rats did not survive to the RH infection. Interestingly, for all the animals the observed histopathological changes in the infected organs, although more or less obvious in the acute phase, were not very severe in almost all cases. For instance, mice, although more susceptible to infection than rats, did not present more severe lesions. They consisted in a discrete inflammation with some focal areas of necrosis in some organs such as brain, liver and heart. Our results support the assumption that rats and nude rats constitute interesting experimental models relevant to either human acute toxoplasmosis, chronic toxoplasmosis, or disseminated toxoplasmosis in AIDS patients.

[Pulmonary malacoplakia caused by Rhodococcus equi in AIDS: a case report]

We describe the observation of a right upper lobe consolidation with cavitation produced by Rhodococcus equi in a patient suffering from AIDS. The inefficacy of a prolonged antimicrobial therapy adapted against R. equi led to a right upper lobectomy. The histopathology showed a pseudotumoral mass, with dense infiltration of macrophages containing Michaelis-Gutmann bodies, which was positive for the culture of R. equi. Pulmonary malacoplakia with Rhodococcus equi was diagnosed. This pathology should be evoked when a R. equi pneumonia persists despite a right management of treatment for several months. The features of pneumonia with Rhodococcus equi and of pulmonary malacoplakia are taken from a literature review.

[Association of celiac disease and esophageal small cell carcinoma]

BACKGROUND

Coeliac disease is known to favor the development of neoplasia. Coeliac disease associated with small-cell carcinoma of the esophagus has not been reported to date.

CASE REPORT

A 51-year-old man with coeliac disease known for several years was hospitalized for epigastric pain. Work-up led to the diagnosis of small-cell carcinoma of the lower esophagus. The patient was treated with 6 cycles of chemotherapy using an etoposide-ciplatinum protocol associated with 60 Gy radiotherapy starting at the third cycle. The patient has remained in complete remission 2 years after diagnosis.

DISCUSSION

Small-cell carcinoma of the esophagus is an exceptional finding in a patient with coeliac disease. Chemotherapy associated with radiotherapy has been successful in our patient.

[Pulmonary infection from Rhodococcus equi after renal transplantation. Review of the literature]

Rhodococcus Equi, a strictly aerobic Gram positive coco-bacillus, is a pathogen for horses and foals. It may induce opportunistic infections and is described in AIDS infected patients. We report the case of a 47-year old man, breeder of horses, with kidney transplant who has presented, 8 years after his graft, an impairment of health, a fever and evidence of pulmonary disease. The pulmonary biopsy under scanner guidance and microbiology study, has displayed the diagnosis of Rhodococcus equi infection. The evolution has been favorable with double antibiotherapy (follow-up 27 months). Ten comparable observations have been published after organ transplantation: (kidney: 8; heart: 1; liver: 1). Pulmonary locations are widely predominant. The animal contact is found only in 30% of cases. The presentation of the sickness has been compared to pulmonary tuberculosis or to nocardiosis, pathologies often observed in this context of immunosuppression. The antibiotic treatment is difficult and should required two bactericidal antibiotics. A surgical lobectomy can be envisaged in case of relapse. The mortality is 30%.

[Multivisceral Kaposi's disease and encrusted pyelitis in a renal transplantation recipient]

Immunosuppression therapy carries inherent risks involving the occurrence of infections and neoplasms. Whereas therapeutic advancement have reduced its frequency, encrusted pyelitis reappears in kidney-transplanted patients and may lead to detransplantation. It is related to chronic urological infections and not inevitably favored by endoscopic explorations. Kaposi's sarcoma is the third cause of tumor in renal-transplanted patients. It is rarely multivisceral and develops exceptionally in the transplant. We report the case of a 60 year-old woman who developed an encrusted pyelitis and a Kaposi's sarcoma in a kidney which was transplanted 14 months earlier.

Labial salivary gland biopsy assessment in rheumatoid vasculitis

OBJECTIVES

To assess the vascular involvement in labial salivary gland (LSG) from patients with rheumatoid vasculitis (RV).

METHODS

Forty seven patients with rheumatoid arthritis (RA) took part in a prospective study. Among them, 12 had proven RV. LSG biopsy was performed after local anaesthesia.

RESULTS

Histological appearance of inflammatory vascular damage was observed in all but one patient with proven RV (92%). Inflammatory vascular involvement was also identified in LSG biopsy of seven patients with RA (20%) and only one patient in the control group (8%). A second specimen of LSG was studied after a mean treatment period of six months and failed to show any feature of inflammatory vascular involvement in three of the five cases that were analysed.

CONCLUSIONS

The study emphasises the high incidence of immunopathological features of microvascular damage in patients with RV. LSG biopsy is minimally invasive and may be a potential useful tool for the diagnosis of RV especially when skin lesions are absent or impossible to biopsy. The assessment of the predictive value of positive LSG biopsy in RA requires a long term prospective study.

Pathology of Toxoplasma gondii infection in the nude rat. An experimental model of toxoplasmosis in the immunocompromised host?

Genetically athymic nu/nu (nude) rats, deficient in T cells, die from infection with various Toxoplasma gondii strains, including RH and Prugniaud strains. In contrast, these strains cause chronic infections without apparent symptoms in immunocompetent non-nude rats. We show here that nude rats die in two to three weeks after RH infection and three to four weeks after Prugniaud infection. Histological examination of brains from nude rats at different time points after infection, revealed an absence of lesions after RH strain infection and cysts with usually no inflammation after Prugniaud infection. Lungs from nude rats developed a fibrin alveolitis using either strain, whereas myocarditis with focal areas of necrosis were observed only after Prugniaud infection. Cysts and, in some cases, tachyzoites in the necrotic lesions were easily identifiable. The two strains of T. gondii elicited in nude rats a granulomatous hepatitis that only differed in intensity. Spleen and mesenteric lymph nodes appeared totally non reactive in both cases. This model allows immunological and parasitological studies by comparison with immunocompetent rat infection. Published data concerning toxoplasma pathology in AIDS, therefore, suggest that acute toxoplasma infection in nude rats may be a useful model for studying disseminated forms of toxoplasma infection found in AIDS patients.

[Is the expression of TNF-alpha and cell adhesion molecules a marker of development of rheumatoid vasculitis?]

TNF-alpha, ICAM1, VCAM1, ELAM, CD44 and DR expression were studied (indirect immunoperoxydase methods) on labial salivary gland sections in 5 patients with proven rheumatoid vasculitis (before and after treatment), 5 patients with RA and 5 normal controls. TNF-alpha and cell adhesion molecules were particularly expressed in vasculitic areas of patients with systemic vasculitis and only before the onset of the treatment.

Report of a primary lymphoma of the conjunctiva. A lymphoma of MALT origin?

A case of primary conjunctival lymphoma is reported herein. A 47-year-old woman presented with an indolent salmon-coloured tumour of the lower epibulbar conjunctiva. Histologically, we found a lymphoid infiltrate in the epithelium and subepithelium consisting of two components. One component was characterized by centrocytic-like cells and the other by lymphocytic, plasmacytoid and plasma cells. An immunohistological study demonstrated a light chain restricted immunoglobulin expression of the tumour cells as well as some residual polytypic follicles exhibiting reticular dendritic cells. Tumour cell proliferation was associated with a T cell reactive population. A comprehensive investigation (in particular an orbital scan) did not demonstrate any other localization of this lymphoma. Such a lesion raised the question of a possible MALT origin, by analog with MALT-lymphomas of the gastrointestinal tract described by Isaacson and colleagues.