Cytotoxic Epstein-Barr virus-positive large B cell lymphoma: a regulatory B cell-derived neoplasia?

AIMS: A new subtype of granzyme B (GrB)-producing regulatory B cells (Bregs ) has been described recently; these peculiar cytotoxic B cells are increased significantly in interleukin (IL)-21-rich settings, and in particular during HIV and Epstein-Barr virus (EBV) infection. Our aim is to report a unique case of an EBV-positive diffuse large B cell lymphoma (DLBCL) with cytotoxic features arisen in an HIV+ patient, and to understand if this lesion may represent a proliferation of neoplastic cytotoxic Bregs . METHODS AND RESULTS: We describe a 66-year-old male patient who presented with cervical lymph node enlargement and B symptoms; subsequently, HIV infection was diagnosed. Histopathological, immunohistochemical and molecular studies were performed, and revealed an EBV-positive DLBCL with cytotoxic features. Considering the immunological setting and unconventional phenotype observed, we tried to evaluate further the expression of GrB and IL-21 in another 150 aggressive B cell lymphomas (17 of 150 EBV+ , two of 150 EBV+ /HIV+ ). Minimal dot-like expression of GrB was found in seven lymphomas (in fewer than 1% of tumour cells), three of which were EBV-positive. CONCLUSIONS: Breg origin has never been reported in B cell lymphomas. We describe an exceptional case of EBV-positive DLBCL with aberrant expression of cytotoxic markers in a patient with a previously unknown HIV infection. We propose cytotoxic Bregs as a possible normal counterpart for this unusual tumour.

Antibodies are forever: a study using 12-26-year-old expired antibodies.

AIMS: The aim of this study was to investigate whether the shelf-life of diagnostic antibodies is longer than the expiry date on the label. METHODS AND RESULTS: Four independent laboratories tested a small number of diagnostic antibodies kept at +4°C for 12-26 years, and found them to work perfectly on routine histology sections. CONCLUSIONS: Diagnostic antibodies may have a workable half-life in excess of 10 years, and the emphasis on performance should shift to the preservation of antigenic targets in the tissue.

Human herpesvirus 8+ polyclonal IgMλ B-cell lymphocytosis mimicking plasmablastic leukemia/lymphoma in HIV-infected patients.

PURPOSE: Multicentric Castleman disease (MCD) is a distinct lymphoproliferative disorder characterized by inflammatory symptoms, lymphadenopathy, splenomegaly, and cytopenia. Kaposi's sarcoma-associated herpesvirus (KSHV), also called human herpesvirus-8 (HHV-8), is the cause of virtually all cases of MCD occurring in patients with HIV infection. MCD lesions characteristically contain HHV-8-infected polyclonal IgMλ plasmablasts. A high frequency of HHV-8-related non-Hodgkin lymphoma has been reported in these patients. PATIENTS AND METHODS: We now report on three patients who presented with severe symptoms of MCD, extreme splenomegaly, and rapid expansion of B-cell lymphocytosis (44-81%) attributable to circulating HHV-8 positive plasmablasts. RESULTS: The circulating plasmablastic cells shared the phenotype (IgMλ, CD19+, CD20- CD138-) of HHV-8-infected cells from MCD lesions, mimicking the leukemic phase of large B-cell lymphoma occurring in HHV-8-related MCD. These patients displayed a very high HHV-8 viral load in blood (>7 logs HHV-8 DNA copies/ml) and high levels of serum vIL-6, the viral homolog of human interleukin 6. Serum IL-6 and IL-10 were also abnormally elevated. HHV-8-infected cells were demonstrated by immunoglobulin gene rearrangement analysis, to be polyclonal and likely represent an expansion of HHV-8-infected cells similar to those found in MCD lesions. CONCLUSION: Thus, the spectrum of HHV-8-related plasmablastic lymphoproliferative disorders in patients with HIV infection is expanded to include HHV-8+ polyclonal IgMλ B-cell lymphocytosis. At onset, this lymphoproliferative disorder may mimic plasmablastic leukemia/lymphoma. Recognizing this unusual complication may have important implications in treatment decision avoiding unnecessary toxicity to the patients.

Non-human primate and human malaria: past, present and future.

BACKGROUND: Studies of the malaria parasites infecting various non-human primates (NHPs) have increased our understanding of the origin, biology and pathogenesis of human Plasmodium parasites.This review considers the major discoveries concerning NHP malaria parasites, highlights their relationships with human malaria and considers the impact that this may have on attempts to eradicate the disease. RESULTS: The first description of NHP malaria parasites dates back to the early 20th century. Subsequently, experimental and fortuitous findings indicating that some NHP malaria parasites can be transmitted to humans have raised concerns about the possible impact of a zoonotic malaria reservoir on efforts to control human malaria.Advances in molecular techniques over the last 15 years have contributed greatly to our knowledge of the existence and geographical distribution of numerous Plasmodium species infecting NHPs, and extended our understanding of their close phylogenetic relationships with human malaria parasites. The clinical application of such techniques has also made it possible to document ongoing spillovers of NHP malaria parasites (Plasmodium knowlesi, P. cynomolgi, P. simium, P. brasilianum) in humans living in or near the forests of Asia and South America, thus confirming that zoonotic malaria can undermine efforts to eradicate human malaria. CONCLUSIONS: Increasing molecular research supports the prophetic intuition of the pioneers of modern malariology who saw zoonotic malaria as a potential obstacle to the full success of malaria eradication programmes. It is, therefore, important to continue surveillance and research based on one-health approaches in order to improve our understanding of the complex interactions between NHPs, mosquito vectors and humans during a period of ongoing changes in the climate and the use of land, monitor the evolution of zoonotic malaria, identify the populations most at risk and implement appropriate preventive strategies.

Histoplasmosis Diagnosed in Europe and Israel: A Case Report and Systematic Review of the Literature from 2005 to 2020.

Human histoplasmosis is a mycosis caused by two distinct varieties of a dimorphic fungus: Histoplasma capsulatum var. capsulatum and H. capsulatum var. duboisii. In Europe, it is usually imported by migrants and travellers, although there have been some autochthonous cases, especially in Italy; however, most European physicians are unfamiliar with its clinical and pathological picture, particularly among immunocompromised patients without HIV infection. This systematic review of all the cases of histoplasmosis reported in Europe and Israel between 2005 and 2020 identified 728 cases diagnosed in 17 European countries and Israel described in 133 articles. The vast majority were imported (mainly from Central and South America), but there were also seven autochthonous cases (six in Europe and one in Israel). The patients were prevalently males (60.4%), and their ages ranged from 2 to 86 years. The time between leaving an endemic region and the diagnosis of histoplasmosis varied from a few weeks to more than 40 years. Progressive disseminated histoplasmosis was the most frequent clinical picture among people living with HIV infection (89.5%) or a different immunocompromising condition (57.1%), but it was also recorded in 6.2% of immunocompetent patients. Twenty-eight cases were caused by Histoplasma duboisii. Immunocompromised patients without HIV infection had the worst outcomes, with a mortality rate of 32%.

Surgery and topic cidofovir for nasal squamous papillomatosis in HIV+ patient.

Intranasal schneiderian exophytic squamous papillomatosis is rare and often secondary to human papilloma virus infection. Treatment usually consists of repeated surgical or endoscopic excisions due to recurrences. The use of intravenous or intralesional or topically applied cidofovir, a cytidine nucleotide analogue suppressing viral replication, alone or as adjuvant therapy has been proposed and described in the literature for the treatment of other human papillomavirus (HPV)-related lesions. We firstly describe a successful combined approach of surgery and topical cidofovir for recurrent nasal HPV-related exophytic squamous papillomatosis in a HIV-infected patient. As no untoward effects were encountered this therapeutical option should be considered in the management of recurrent nasal papillomatosis in HIV-infected patients.

Gastrointestinal basidiobolomycosis: An emerging mycosis difficult to diagnose but curable. Case report and review of the literature.

BACKGROUND: Gastrointestinal basidiobolomycosis (GIB) is a rare mycosis affecting almost exclusively immunocompetent subjects. METHODS: We describe a case of GIB caused by Basidiobolus ranarum in a 25-year-old Italian immunocompetent man resident in Ireland who presented a 2-month history of epigastric pain. Suspecting colon cancer he underwent a right hemicolectomy subsequently leading to a diagnosis of GIB by means of molecular biology. After surgery a 9-month therapy with itraconazole was employed with a good outcome. A review of medical literature regarding GIB cases published in the period 1964-2017 is presented. RESULTS: One-hundred and two cases of GIB were included in this analysis. The disease was observed predominantly in male gender (74.5%) and children (41.2%). Abdominal pain was the single most common complaint (86.3%) followed by fever (40.2%) and evidence of an abdominal mass (30.4%). Peripheral blood eosinophilia was detected in 85.7% of cases. Most of the patients were diagnosed in Saudi Arabia (37.2%) followed by USA (21.6%) and Iran (20.6%). Surgery plus antifungal therapy was employed in the majority of patients (77.5%). An unfavourable outcome was documented globally in 18.6% of patients. CONCLUSIONS: GIB seems to be an emerging intestinal mycosis among immunocompetent patients living in the Middle East and Arizona.

Leishmaniasis among organ transplant recipients.

Leishmaniasis is a rarely reported disease among transplant recipients; however, the number of published cases has quadrupled since the beginning of the 1990s. Most cases have been observed in patients living in countries of the Mediterranean basin. Leishmaniasis is most commonly associated with kidney transplantation (77%), and cases are also recorded among patients undergoing liver, heart, lung, pancreas, and bone marrow transplantation. Visceral leishmaniasis (VL) is the most frequently observed clinical presentation, followed by mucosal leishmaniasis and more rarely cutaneous leishmaniasis. Transplant recipients with VL develop the classic clinical form of the disease, which is a febrile hepatosplenic and pancytopenic syndrome. Immunodepression seems to predispose to development of mucosal leishmaniasis caused by viscerotropic strains. Early diagnosis of VL is crucial for patient therapy and outcome; however, this is frequently overlooked or delayed in transplant patients. Pentavalent antimonials are the most commom form of treatment for VL, but have a high incidence of toxicity (34%). Although used in fewer patients, liposomal amphotericin B seems to be better tolerated and should be considered as first-line therapy in transplant recipients.

Challenges in the Diagnosis of Invasive Fungal Infections in Immunocompromised Hosts.

PURPOSE OF REVIEW: The expanding population of immunocompromised patients coupled with the recognition of a growing number of different species of fungi responsible for diseases in such hosts makes the diagnosis of invasive fungal infection (IFI) a challenging task. The recent advances and challenges in the diagnosis of IFI in the setting of immunocompromised hosts are reviewed. The advantages and limitations of histopathology and the role of culture-independent methods, such as those based on the use of nucleic acids applied to fresh and formalin-fixed, paraffin-embedded sections, besides culture- and non-culture-based diagnostic methods, to obtain a timely and correct diagnosis of IFI are highlighted. RECENT FINDINGS: The therapeutic implications of identifying the genus and species of the fungus present in the specimen with the molecular diagnostics applied to tissue specimens are reviewed. No method alone is efficient in correctly identifying fungi and it is essential to combine the traditional histochemical staining with molecular methods to achieve a rapid and genus-/species-specific diagnosis of IFI. SUMMARY: We review the recent findings and challenges in the hystopathologic diagnosis of IFI in the setting of immunocompromised hosts. Non method alone is efficient in correctly identify fungi and pathologists should combine classic staining with molecular methods to achieve a rapid and genus/species fungal diagnosis.

Human parvovirus 4 in the bone marrow of Italian patients with AIDS.

Human parvovirus 4 (PARV4) is a recently discovered member of the Parvoviridae. We investigated the presence of this virus in bone-marrow aspirates of 35 Italian patients with AIDS. Viral DNA was detected by polymerase chain reaction in over 40% of patients (16/35). The infection was most prevalent in injection drug users (IDU; 12/18; 66.7%) as opposed to non-IDU (4/17; 23.5%). PARV4 infection is widespread in Italian patients with AIDS.

Clinical use of polymerase chain reaction performed on peripheral blood and bone marrow samples for the diagnosis and monitoring of visceral leishmaniasis in HIV-infected and HIV-uninfected patients: a single-center, 8-year experience in Italy and review of the literature.

BACKGROUND: To overcome some of the limitations of conventional microbiologic techniques, polymerase chain reaction (PCR)-based assays are proposed as useful tools for the diagnosis of visceral leishmaniasis. PATIENTS AND METHODS: A comparative study using conventional microbiologic techniques (i.e., serologic testing, microscopic examination, and culture) and a Leishmania species-specific PCR assay, using peripheral blood and bone marrow aspirate samples as templates, was conducted during an 8-year period. The study cohort consisted of 594 Italian immunocompetent (adult and pediatric) and immunocompromised (adult) patients experiencing febrile syndromes associated with hematologic alterations and/or hepatosplenomegaly. Identification of the infecting protozoa at the species level was directly obtained by PCR of peripheral blood samples, followed by restriction fragment-length polymorphism analysis of the amplified products, and the results were compared with those of isoenzyme typing of Leishmania species strains from patients, which were isolated in vitro. RESULTS: Sixty-eight patients (11.4%) had a confirmed diagnosis of visceral leishmaniasis. Eleven cases were observed in human immunodeficiency virus (HIV)-uninfected adults, 20 cases were observed in HIV-infected adults, and the remaining 37 cases were diagnosed in HIV-uninfected children. In the diagnosis of primary visceral leishmaniasis, the sensitivities of the Leishmania species-specific PCR were 95.7% for bone marrow aspirate samples and 98.5% for peripheral blood samples versus sensitivities of 76.2%, 85.5%, and 90.2% for bone marrow aspirate isolation, serologic testing, and microscopic examination of bone marrow biopsy specimens, respectively. None of 229 healthy blood donors or 25 patients with imported malaria who were used as negative control subjects had PCR results positive for Leishmania species in peripheral blood samples (i.e., specificity of Leishmania species-specific PCR, 100%). PCR and restriction fragment-length polymorphism analysis for Leishmania species identification revealed 100% concordance with isoenzyme typing in the 19 patients for whom the latter data were available. CONCLUSIONS: PCR assay is a highly sensitive and specific tool for the diagnosis of visceral leishmaniasis in both immunocompetent and immunocompromised patients and can be reliably used for rapid parasite identification at the species level.

Is imported onchocerciasis a truly rare entity? Case report and review of the literature.

BACKGROUND: Onchocerciasis is endemic in a number of tropical countries in Africa and South America, and it is occasionally diagnosed as an imported disease in non-endemic areas. METHODS: We describe the case of an African migrant with long-lasting pruritus and a cutaneous nodule who was diagnosed with onchocerciasis after nodulectomy, and review the medical literature regarding imported cases of onchocerciasis in the period 1994-2014. RESULTS: Twenty-nine cases of onchocerciasis diagnosed in migrants from endemic countries, and in expatriates and travellers from non-endemic areas were retrieved. They were predominantly males (73.3%), had a median age of 37 years (two were aged <15 years), and acquired the diseases in sub-Saharan Africa, most frequently in Cameroon (43.3%). Diagnosis of onchocercosis was proven in 73.3% of patients. The most frequent clinical manifestations in these and our own patient were pruritus (23/30, 76.7%), unilateral leg or forearm swelling (13/30, 43.3%) and rash (12/30, 40.0%), whereas only two (6.9%) complained of eye symptoms. Eosinophilia was observed in almost all of the patients (92.0%), with median counts of 2915/µL among migrants and 1960/µL among travellers/expatriates. Eighteen patients underwent a skin snip biopsy, which was positive in 10 cases (55.5%); in the other 13 patients the parasite was directly demonstrated by means of a skin or nodule biopsy (n = 5), nodulectomy (n = 5) or slit lamp examination (n = 3). Eighteen received ivermectin, alone, and seven ivermectin combined with diethylcarbamazine or doxycycline. Outcome details were available for only 14 patients, all of whom were asymptomatic after a median follow-up of 10 months (range 1-48). CONCLUSIONS: Onchocerciasis is a neglected tropical disease whose subtle and non-specific features may lead to under-diagnosis or underreporting in non-endemic areas. Physicians should consider this tropical disease when caring for migrants and travellers/expatriates with pruritus, skin lesions and eosinophilia.

Diagnosis of Louse-Borne Relapsing Fever despite Negative Microscopy in Two Asylum Seekers from Eastern Africa.

We report two cases of louse-borne relapsing fever observed at our Institution in June 2016. Both patients were young asylum seekers from Africa who had recently arrived in Milan, Italy. Notably, direct microscopic examination of peripheral blood smears was repeatedly negative for the presence of spirochetes and the diagnosis, supported by clinical and epidemiologic evidence, required molecular confirmation by polymerase chain reaction amplification of DNA extracted from blood and sequencing of the amplified products.

Histoplasmosis among human immunodeficiency virus-infected people in Europe: report of 4 cases and review of the literature.

We reviewed the clinical, microbiologic, and outcome characteristics of 72 patients with human immunodeficiency virus (HIV)-associated histoplasmosis (4 newly described) reported in Europe over 20 years (1984-2004). Seven cases (9.7%) were acquired in Europe (autochthonous), whereas the majority involved a history of travel or arrival from endemic areas. The diagnosis of progressive disseminated histoplasmosis (PDH) was made during life in 63 patients (87.5%) and was the acquired immunodeficiency syndrome (AIDS)-presenting illness in 44 (61.1%). Disease was widespread in 66 patients (91.7%) and localized in 6 (8.3%), with the skin being the most frequent site of localized infection. Overall skin involvement was reported in 47.2% of the patients regardless of whether histoplasmosis was acquired in Africa or South America. Reticulonodular or diffuse interstial infiltrates occurred in 52.8%. The diagnosis was made during life by histopathology plus culture in 44 patients (69.8%), histopathology alone in 18 (28.5%), and culture alone in 1 (1.5%). During the induction phase amphotericin B and itraconazole (74.6%) were the single most frequently used drugs. Both drugs were also used either in combination (10.2%) or in sequential therapy (11.8%). Cumulative mortality rate during the induction phase of treatment was 15.2%. Overall, 37 patients died (57.8%); death occurred early in the course in 18 (28.1%). Seven of 40 patients (17.5%) who responded to therapy subsequently relapsed. Autopsy data in 13 patients confirmed the widespread disseminated nature of histoplasmosis (85%) among AIDS patients with a median of 4.5 organs involved. The results of the present report highlight the need to consider the diagnosis of PDH among patients with AIDS in Europe presenting with a febrile illness who have traveled to or who originated from an endemic area.

Disseminated Penicillium marneffei infection in an HIV-positive Italian patient and a review of cases reported outside endemic regions.

We describe a case of disseminated Penicillium marneffei in a human immunodeficiency virus (HIV)-positive Italian man who stayed for 4 years in Chiang Ray province, northern Thailand. A review of the literature shows that penicilliosis, although unusual, may represent an emerging opportunistic infection among HIV-positive people traveling to endemic areas.

Can Drainage Using a Negative-Pressure Wound Therapy Device Replace Traditional Sample Collection Methods?

BACKGROUND: In 2015 a new device for the collection of mediastinal fluid from patients with deep sternal wound infection (DSWI) in the presence of negative-pressure wound therapy (NPWT) became available. The present study was designed to evaluate whether changing sample collection devices increased micro-organism detection in patients undergoing NPWT. METHODS: During 2013-2014, 207 samples were collected and cultured from NPWT patients (n = 23) to demonstrate the presence of DSWI using reticulated polyurethane sponge culture, a swab, and blood culture. In 2015, a new collection device was introduced for specimen collection. A total of 357 samples (n = 17) were collected using the ESwab(™) (Copan, Murrieta, CA) for deep and superficial wound sample collection. In addition, blood culture devices were used for collecting mediastinal fluid aspirated directly from the wound and biologic fluid obtained from the NPWT device. Fisher exact test was performed to test the rate of independence rate of micro-organism identification using the NPWT sponge device and taking blood culture results as a reference for micro-organism identification. RESULTS: After the introduction of the new collection device in our hospital, an overall increase in the detection of micro-organisms (46.7%) was reported. During 2013-2014 our traditional microbiologic collection method did not detect a pathogen in 30.4% of patients. During 2015, the new sample collection approach, direct from the NPWT device, improved micro-organism detection by 10.4% and reduced DSWIs with undetected pathogens to 17.6% (p < 0.01). CONCLUSIONS: As a result of proficiency gained in the last year, the most representative specimen in wound infection was represented by mediastinal fluid collected directly from the wound and the NPWT device. Given the correlation between the blood culture of micro-organisms detected using the ESwab device from the wound, mediastinal drainage, and drainage from the NPWT device, we can assume that the NPWT device may replace the other biologic sampling devices.

Thrombotic microangiopathy in patients with acquired immunodeficiency syndrome before and during the era of introduction of highly active antiretroviral therapy.

The incidence of thrombotic microangiopathy (TMA) was retrospectively evaluated in a cohort of 1223 patients with acquired immunodeficiency syndrome (AIDS) who were observed from January 1985 through December 1996 (before the era of highly active antiretroviral therapy [HAART]), and the incidence was prospectively assessed for 347 patients with AIDS during the period of January 1997 through December 2000 (during the HAART era). Seventeen cases were reported in the former cohort (1.4%). The increased risk of developing TMA was statistically significant in patients with cryptosporidiosis or AIDS-related cancer but not in those with other diseases. In the 1997-2000 cohort, no cases were observed during follow-up. TMA is associated with conditions observed in the advanced phases of human immunodeficiency virus infection. The disappearance of TMA during the HAART era may be explained by the lower percentage of patients with long-lasting CD4+ T cell depletion, advanced AIDS, or cryptosporidiosis or who have undergone multiple courses of chemotherapy for treatment of cancer.

Primary gastric Merkel cell carcinoma harboring DNA polyomavirus: first description of an unusual high-grade neuroendocrine carcinoma.

Merkel cell carcinoma (MCC) is a skin cancer that can also rarely arise in extracutaneous sites including mucosal surfaces. About 80% of MCCs harbor the Merkel cell polyomavirus (MCPyV). All cases of gastric MCCs so far reported were metastases from cutaneous sources. In the present article, we describe for the first time a primary gastric MCC harboring MCPyV. A 72-year-old man presented to clinical observation due to epigastric pain. Upper endoscopy revealed an ulcerated gastric tumor. The patient underwent total gastrectomy. The tumor was composed of mitotically active monomorphic small cells showing round nuclei with finely dispersed chromatin arranged in sheets and nests with large areas of necrosis. Tumor cells were positive for neuroendocrine markers and showed paranuclear dot immunoreactivity for cytokeratin 20. MCPyV was demonstrated with immunohistochemistry and electron microscopy, which showed intranuclear and intracytoplasmic viral particles. The MCPyV DNA in tumor cells was demonstrated with polymerase chain reaction analysis.

Gastrointestinal cancers reactive for the PAb416 antibody against JCV/SV40 T-Ag lack JCV DNA sequences while showing a distinctive pathologic profile.

AIM: Immunohistochemical and molecular studies have suggested an oncogenic role for JCV in gastrointestinal carcinomas, but at least in colorectal cancers, the data are far from being unambiguous. METHODS: Two large series of formalin-fixed paraffin-embedded gastric and colorectal cancers were analysed for the expression of JCV large T Antigen (T-Ag) with a panel of five antibodies, and for the presence of T-Ag DNA sequences using two PCR systems. RESULTS: Intense nuclear staining was observed in 54/116 (46%) colorectal, and in 92/234 (39%) gastric cancers, using the PAb416 monoclonal antibody against large T-Ag. In colorectal cancers, PAb416-positivity was directly related to the presence of chromosomal instability, lymph node metastases and a more advanced tumour stage, and inversely related to proximal tumour site and the presence of microsatellite instability (MSI). In gastric cancers, the glandular histotype, the presence of lymph node metastases, a low frequency of MSI and EBV infection, and a worse prognosis were significantly associated with PAb416 immunoreactivity. Moreover, at both these sites, PAb416 expression was significantly associated with p53 nuclear accumulation. No positivity was obtained with all the other four anti-T-Ag-antibodies, and molecular analysis failed to demonstrate the presence of JCV DNA sequences in tested cases. CONCLUSIONS: Our immunohistochemical and molecular results do not support the idea that JCV T-Ag has a role in gastrointestinal carcinogenesis. It is possible that PAb416, besides binding the viral protein, may cross-react with a hitherto undefined protein whose expression is associated with a distinct pathological profile and, at least in gastric cancers, with worse prognosis.