A fast method for processing biologic material for electron microscopic diagnosis in infectious disease

Understanding Sabiá virus infections (Brazilian mammarenavirus)

BACKGROUND

Only two naturally occurring human Sabiá virus (SABV) infections have been reported, and those occurred over 20 years ago.

METHODS

We diagnosed two new cases of SABV infection using metagenomics in patients thought to have severe yellow fever and described new features of histopathological findings.

RESULTS

We characterized clinical manifestations, histopathology and analyzed possible nosocomial transmission. Patients presented with hepatitis, bleeding, neurological alterations and died. We traced twenty-nine hospital contacts and evaluated them clinically and by RT-PCR and neutralizing antibodies. Autopsies uncovered unique features on electron microscopy, such as hepatocyte "pinewood knot" lesions. Although previous reports with similar New-World arenavirus had nosocomial transmission, our data did not find any case in contact tracing.

CONCLUSIONS

Although an apparent by rare, Brazilian mammarenavirus infection is an etiology for acute hemorrhagic fever syndrome. The two fatal cases had peculiar histopathological findings not previously described. The virological diagnosis was possible only by contemporary techniques such as metagenomic assays. We found no subsequent infections when we used serological and molecular tests to evaluate close contacts.

Distinct Microbial Communities in Dilated Cardiomyopathy Explanted Hearts Are Associated With Different Myocardial Rejection Outcomes

Background

Idiopathic dilated cardiomyopathy (IDCM) myocardial inflammation may be associated with external triggering factors such as infectious agents. Here, we searched if moderate/severe heart transplantation rejection is related to the presence of myocardial inflammation in IDCM explanted hearts, associated with microbial communities.

Method

Receptor myocardial samples from 18 explanted hearts were separated into groups according to post-transplant outcome: persistent moderate rejection (PMR; n = 6), moderate rejection (MR; n = 7) that regressed after pulse therapy, and no rejection (NR; n = 5)/light intensity rejection. Inflammation was quantified through immunohistochemistry (IHC), and infectious agents were evaluated by IHC, molecular biology, in situ hybridization technique, and transmission electron microscopy (TEM).

Results

NR presented lower numbers of macrophages, as well as B cells (p = 0.0001), and higher HLA class II expression (p ≤ 0.0001). PMR and MR showed higher levels of Mycoplasma pneumoniae (p = 0.003) and hepatitis B core (p = 0.0009) antigens. NR presented higher levels of parvovirus B19 (PVB19) and human herpes virus 6 (HHV6) and a positive correlation between Borrelia burgdorferi (Bb) and enterovirus genes. Molecular biology demonstrated the presence of M. pneumoniae, Bb, HHV6, and PVB19 genes in all studied groups. TEM revealed structures compatible with the cited microorganisms.

Conclusions

This initial study investigating on infectious agents and inflammation in the IDCM explanted hearts showed that the association between M. pneumoniae and hepatitis B core was associated with a worse outcome after HT, represented by MR and PMR, suggesting that different IDCM microbial communities may be contributing to post-transplant myocardial rejection.

Morphomolecular Characterization of Serum Nanovesicles From Microbiomes Differentiates Stable and Infarcted Atherosclerotic Patients

Microbial communities are considered decisive for maintaining a healthy situation or for determining diseases. Acute myocardial infarction (AMI) is an important complication of atherosclerosis caused by the rupture of atheroma plaques containing proinflammatory cytokines, reactive oxygen species, oxidized low-density lipoproteins (oxLDL), damaged proteins, lipids, and DNA, a microenvironment compatible with a pathogenic microbial community. Previously, we found that archaeal DNA-positive infectious microvesicles (iMVs) were detected in vulnerable plaques and in the sera of Chagas disease patients with heart failure. Now, we characterize and quantify the levels of serum microbiome extracellular vesicles through their size and content using morphomolecular techniques to differentiate clinical outcomes in coronary artery disease (CAD). We detected increased numbers of large iMVs (0.8–1.34 nm) with highly negative surface charge that were positive for archaeal DNA, Mycoplasma pneumoniae antigens and MMP9 in the sera of severe AMI patients, strongly favoring our hypothesis that pathogenic archaea may play a role in the worst outcomes of atherosclerosis. The highest numbers of EVs <100 nm (exosomes) and MVs from 100 to 200 nm in the stable atherosclerotic and control healthy groups compared with the AMI groups were indicative that these EVs are protective, entrapping and degrading infectious antigens and active MMP9 and protect against the development of plaque rupture.

Conclusion: A microbiome with pathogenic archaea is associated with high numbers of serum iMVs in AMI with the worst prognosis. This pioneering work demonstrates that the morphomolecular characterization and quantification of iEVs in serum may constitute a promising serum prognostic biomarker in CAD.

Repurposing topical triclosan for cutaneous leishmaniasis: Preclinical efficacy in a murine Leishmania (L.) amazonensis model

Leishmaniasis remains an important neglected tropical infection caused by the protozoan Leishmania and affects 12 million people in 98 countries. The treatment is limited with severe adverse effects. In the search for new therapies, the drug repositioning and combination therapy have been successfully applied to neglected diseases. The aim of the present study was to evaluate the in vitro and in vivo anti-Leishmania (Leishmania) amazonensis potential of triclosan, an approved topical antimicrobial agent used for surgical procedures. in vitro phenotypic studies of drug-treated parasites were performed to evaluate the lethal action of triclosan, accompanied by an isobolographic ex-vivo analysis with the association of triclosan and miltefosine. The results showed that triclosan has activity against L. (L.) amazonensis intracellular amastigotes, with a 50% inhibitory concentration of 16 μM. By using fluorescent probes and transmission electron microscopy, a pore-forming activity of triclosan toward the parasite plasma membrane was demonstrated, leading to depolarization of the mitochondrial membrane potential and reduction of the reactive oxygen species levels in the extracellular promastigotes. The in vitro interaction between triclosan and miltefosine in the combination therapy assay was classified as additive against intracellular amastigotes. Leishmania-infected mice were treated with topical triclosan (1% base cream for 14 consecutive days), and showed 89% reduction in the parasite burden. The obtained results contribute to the investigation of new alternatives for the treatment of cutaneous leishmaniasis and suggest that the coadministration of triclosan and miltefosine should be investigated in animal models.

A semi-synthetic neolignan derivative from dihydrodieugenol B selectively affects the bioenergetic system of Leishmania infantum and inhibits cell division

Leishmaniasis is a neglected disease that affects more than 12 million people, with a limited therapy. Plant-derived natural products represent a useful source of anti-protozoan prototypes. In this work, four derivatives were prepared from neolignans isolated from the Brazilian plant Nectandra leucantha, and their effects against intracellular amastigotes of Leishmania (L.) infantum evaluated in vitro. IC₅₀ values between 6 and 35 µM were observed and in silico predictions suggested good oral bioavailability, no PAINS similarities, and ADMET risks typical of lipophilic compounds. The most selective (SI > 32) compound was chosen for lethal action and immunomodulatory studies. This compound caused a transient depolarization of the plasma membrane potential and induced an imbalance of intracellular Ca²⁺, possibly resulting in a mitochondrial impairment and leading to a strong depolarization of the membrane potential and decrease of ATP levels. The derivative also interfered with the cell cycle of Leishmania, inducing a programmed cell death-like mechanism and affecting DNA replication. Further immunomodulatory studies demonstrated that the compound eliminates amastigotes via an independent activation of the host cell, with decrease levels of IL-10, TNF and MCP-1. Additionally, this derivative caused no hemolytic effects in murine erythrocytes and could be considered promising for future lead studies.

Archaea Symbiont of T. cruzi Infection May Explain Heart Failure in Chagas Disease

Background: Archaeal genes present in Trypanosoma cruzi may represent symbionts that would explain development of heart failure in 30% of Chagas disease patients. Extracellular vesicles in peripheral blood, called exosomes (< 0.1 μm) or microvesicles (>0.1 μm), present in larger numbers in heart failure, were analyzed to determine whether they are derived from archaea in heart failure Chagas disease. Methods: Exosomes and microvesicles in serum supernatant from 3 groups were analyzed: heart failure Chagas disease (N = 26), asymptomatic indeterminate form (N = 21) and healthy non-chagasic control (N = 16). Samples were quantified with transmission electron microscopy, flow cytometer immunolabeled with anti-archaemetzincin-1 antibody (AMZ 1, archaea collagenase) and probe anti-archaeal DNA and zymography to determine AMZ1 (Archaeal metalloproteinase) activity. Results: Indeterminate form patients had higher median numbers of exosomes/case vs. heart failure patients (58.5 vs. 25.5, P < 0.001), higher exosome content of AMZ1 antigens (2.0 vs. 0.0; P < 0.001), and lower archaeal DNA content (0.2 vs. 1.5, P = 0.02). A positive correlation between exosomes and AMZ1 content was seen in indeterminate form (r = 0.5, P < 0.001), but not in heart failure patients (r = 0.002, P = 0.98). Higher free archaeal DNA (63.0 vs. 11.1, P < 0.001) in correlation with exosome numbers (r = 0.66, P = 0.01) was seen in heart failure but not in indeterminate form (r = 0.29, P = 0.10). Flow cytometer showed higher numbers of AMZ1 microvesicles in indeterminate form (64 vs. 36, P = 0.02) and higher archaeal DNA microvesicles in heart failure (8.1 vs. 0.9, P < 0.001). Zymography showed strong% collagenase activity in HF group, mild activity in IF compared to non-chagasic healthy group (121 ± 14, 106 ± 13 and 100; P < 0.001). Conclusions: Numerous exosomes, possibly removing and degrading abnormal AMZ1 collagenase, are associated with indeterminate form. Archaeal microvesicles and their exosomes, possibly associated with release of archaeal AMZ1 in heart failure, are future candidates of heart failure biomarkers if confirmed in larger series, and the therapeutic focus in the treatment of Chagas disease.

Investigation of the Anti-Leishmania (Leishmania) infantum Activity of Some Natural Sesquiterpene Lactones

Leishmaniases are neglected infectious diseases caused by parasites of the ‘protozoan’ genus Leishmania. Depending on the parasite species, different clinical forms are known as cutaneous, muco-cutaneous, and the visceral leishmaniasis (VL). VL is particularly fatal and the therapy presents limitations. In the search for new anti-leishmanial hit compounds, seven natural sesquiterpene lactones were evaluated against promastigotes and intracellular amastigotes of Leishmania (Leishmania) infantum, a pathogen causing VL. The pseudoguaianolides mexicanin I and helenalin acetate demonstrated the highest selectivity and potency against intracellular amastigotes. In addition, promastigotes treated with helenalin acetate were subject to an ultrastructural and biochemical investigation. The lethal action of the compound was investigated by fluorescence-activated cell sorting and related techniques to detect alterations in reactive oxygen species (ROS) content, plasma membrane permeability, and mitochondrial membrane potential. Helenalin acetate significantly reduced the mitochondrial membrane potential and the mitochondrial structural damage was also confirmed by transmission electron microscopy, displaying an intense organelle swelling. No alteration of plasma membrane permeability or ROS content could be detected. Additionally, helenalin acetate significantly increased the production of nitric oxide in peritoneal macrophages, probably potentiating the activity against the intracellular amastigotes. Helenalin acetate could hence be a useful anti-leishmanial scaffold for further optimization studies.

Lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide via induction of oxidative stress in Leishmania (L.) infantum

Studying the cellular death pathways in Leishmania is an important aspect of discovering new antileishmanials. While using a drug repositioning approach, the lethal action of the nitrothiazolyl-salicylamide derivative nitazoxanide (NTZ) was investigated against Leishmania (L.) infantum. The in vitro antileishmanial activity and cytotoxicity were assessed using both parasite stages and mammalian NCTC cells, respectively. The lethal action of NTZ was investigated by detecting the phosphatidylserine (PS) exposure, reactive oxygen species (ROS) regulation, plasma membrane permeability, mitochondrial membrane potential and ultrastructural modifications by transmission electron microscopy. NTZ's activity against L. infantum was confirmed, producing IC50 values of 42.71μg/mL against promastigotes and 6.78μg/mL against intracellular amastigotes. NTZ rapidly altered the cellular metabolism of promastigotes by depolarising the mitochondrial membrane and up-regulating the reactive oxygen species (ROS). In addition, the flow cytometry data revealed an intense and time-dependent exposure of PS in promastigotes. When using SYTOX(®) Green as a fluorescent probe, NTZ demonstrated no interference in plasma membrane permeability. The ultrastructural alterations in promastigotes were time-dependent and caused chromatin condensation, plasma membrane blebbing and mitochondrial swelling. These data suggest that NTZ induced oxidative stress in L. (L.) infantum and might be a useful compound for investigating new therapeutic targets.

Respiratory syncytial virus (RSV) pneumonia in a southern muriqui (Brachyteles arachnoides)

BACKGROUND

An adult male Brachyteles arachanoides, kept in captivity since 1990, was found dead without apparent clinical evidence.

METHODS

Necropsy report, histopathology, immunohistochemistry, and ultrastructural examination were conducted.

RESULTS

Pulmonary syncytial cells were positive for respiratory syncytial virus (RSV), and ultrastructural examination revealed viral particles inside macrophages compatible with the Paramyxoviridae family.

CONCLUSIONS

Muriquis are susceptible to RSV pneumonia followed by respiratory distress syndrome and death.

Anti-leishmanial and anti-trypanosomal potential of polygodial isolated from stem barks of Drimys brasiliensis Miers (Winteraceae)

Parasitic protozoan diseases affect the poorest population in developing countries. Leishmaniasis and Chagas disease have been included among the most important threats for public health in Central and South American continent, with few therapeutic alternatives and highly toxic drugs. In the course of selection of novel drug candidates, we studied the anti-protozoal potential of Drimys brasiliensis. Thus, the crude hexane extract from stem bark as well as its main derivative, the sesquiterpene polygodial, were tested using in vitro assays. The crude hexane extract and polygodial showed activity against Leishmania spp. in the range between 22 and 62 μg/mL, but polygodial demonstrated high parasite selectivity towards Trypanosoma cruzi trypomastigotes (2 μg/mL), with a selectivity index of 19. Finally, polygodial showed a leishmanicidal effect, inducing intense ultrastructural damages in Leishmania in short-time incubation. The obtained results suggested that polygodial could be used as a tool for drug design studies against protozoan diseases and as a candidate molecule for further in vivo studies against T. cruzi.

Hepatic ultrastructural mitochondrial changes prior to antiretroviral therapy in HIV-infected patients in Brazil

The use of antiretroviral (ARV) medications has been linked to the emergence of severe adverse effects, including mitochondrial toxicity. The liver also appears to be among the affected organs. Nevertheless, different studies suggest that these patients' mitochondrial alterations could be associated to other etiological factors. The goal of this study was to analyze hepatic mitochondria ultrastructural changes in HIV-infected patients under investigation for hepatopathy. Semiquantitative analysis of mitochondria was performed in liver biopsies from 10 patients divided into 2 groups: Group 1 consisted of 5 patients who had never used ARV medications; group 2 consisted of 5 patients who reported previous use of either zidovudine or didanosine. Significant mitochondrial alterations were found in both groups. The summation of the mitochondrial alterations was higher in group 1 (P < .05) when compared with those who had previously used ARV medications. Therefore, the authors conclude that severe mitochondrial alterations occur in HIV-infected patients who have never been submitted to antiretroviral therapy.

Antiparasitic, antineuroinflammatory, and cytotoxic polyketides from the marine sponge Plakortis angulospiculatus collected in Brazil

Investigation of the bioactive crude extract from the sponge Plakortis angulospiculatus from Brazil led to the isolation of plakortenone ( 1) as a new polyketide, along with five known polyketides ( 2- 6) previously isolated from other Plakortis sponges. The known polyketides were tested in antileishmanial, antitrypanosomal, antineuroinflammatory, and cytotoxicity assays. The results show that plakortide P ( 3) is a potent antiparasitic compound, against both Leishmania chagasi and Trypanosona cruzi, and exhibited antineuroinflammatory activity. The known polyketides 2- 6 were tested for cytotoxicity against four human cancer cell lines, but displayed only moderate cytotoxic activity.

Diffuse-regressive alterations and apoptosis of myocytes: possible causes of myocardial dysfunction in HIV-related cardiomyopathy

OBJECTIVE

To determine the frequency of cardiac alterations in necropsies of AIDS patients in pre-HAART era and better understand the pathogenesis of HIV-related cardiomyopathy.

DESIGN

Retrospective study of 94 complete necropsies.

METHOD

Macroscopic, histopathologic (histochemical, immunohistochemical and in situ hybridization techniques) and ultra structural myocardial evaluation (23 cases).

RESULTS

Cardiac alterations were observed in 94.4%; 74% showed variable degrees of cardiac dilation not related to known cardiovascular diseases. Eighty-two percent (81.8%) of patients with biventricular dilation showed diffuse-regressive alterations (thinning and waving cardiomyocytes with increase of lipofuscin pigment granules). Myocarditis was diagnosed in 27 cases (28.7%), 16 (59.3%) of known etiology. The ultra structural study has revealed cardiomyocytes alterations (mitochondriosis, loss of myofibrils, increase in the amount of perinuclear-lipofuscin pigment granules) associated to activation signals of capillary-endothelial cells (enhancement of pseudopodia and transcellular channels). Cardiomyocytes' apoptosis was demonstrated at structural level in 10 (43.5%) patients; tumor necrosis factor alpha (TNF alpha) was detected in 17/18 cases.

CONCLUSIONS

This pioneer study described the association of histopathological and ultra structural findings (thinning and waving cardiomyocytes with increase of lipofuscin pigment granules, mitochondriosis and loss of myofibrils) with different degrees of cardiac-chamber dilation probably representing a spectrum of alterations that would lead to myocardial dysfunction and development of HIV-related cardiomyopathy. Cardiomyocytes' apoptosis observed at ultra structural level and demonstration of TNF alpha associated to described alterations suggest that this cytokine plays an important role in both negative-inotropic effect and capacity to induce apoptosis through death receptor-controlled pathway.

The inflammatory response in drug-induced acute urticaria: ultrastructural study of the dermal microvascular unit

BACKGROUND

Drug exposure is one of the main aetiologies of urticaria and represents the second most common cause in acute urticarias. Studies involving the ultrastructural aspects of urticaria are relatively rare in the literature. Most of the articles published report on skin biopsies of experimentally induced urticaria, and acute urticaria has been studied even less from a morphological point of view.

OBJECTIVES

The aims of this study were to observe ultrastructural cell characteristics in five patients with drug-induced acute urticaria and possible aspects of the inflammatory skin response.

METHODS

Clinical manifestations, light microscopy and transmission electron microscopy were evaluated.

RESULTS

With light microscopy, a mild perivascular lymphocyte-monocyte infiltrate was observed with few neutrophils and dermal oedema in skin biopsies of five patients. With electron microscopy, a mild vascular dilatation was observed, with platelets in the lumen and several lymphocytes and dendritic cells close to the superficial dermal vessels. Some mast cells appeared normal, whereas others were granule-depleted. In some areas, mast cells, lymphocytes and satellite dendritic cells were closely associated, as well as some macrophages. A significant number of plasma cells, eosinophils and polymorphonuclear neutrophils were not observed; however, the presence of lymphocytes and macrophages was significant. The epidermis and the dermal-epidermal junction were preserved, except for a discrete oedema in keratinocytes.

CONCLUSIONS

The ultrastructural aspect of drug-induced acute urticaria is similar to that observed in urticaria caused by Urtica dioica, intradermal histamine and cold urticaria. The presence of the cellular triad with mast cells, dendritic (or satellite) cells and lymphocytes suggests a functional interaction of these cells. These findings support the possible existence of mechanisms in the dermis that may participate in protective and/or injurious vasocentric immune reactions.

Revisiting the liver in human yellow fever: Virus-induced apoptosis in hepatocytes associated with TGF-β, TNF-α and NK cells activity

Flavivirus infection as dengue and yellow fever persists as a terrible menace to pandemics, due to Aedes prevalence in the Americas. Yellow fever is characterized by hepatocyte damage, with steatosis, apoptosis and necrosis, mainly in the midzonal region of the liver, but the injury mechanism has not been studied at the light of recent knowledge, such as the advances in cell death mechanisms, inflammatory response and cytokine cell expression tools. We studied 53 human liver paraffin embedded blocks from patients who died with yellow fever, all with histological demonstration of higher prevalence of apoptosis over necrosis and mild disproportionate inflammatory response. Viral antigens were found most frequently in hepatocytes from the midzonal area than other lobule areas, as detected by specific immunohistochemistry. Infiltrating cell subpopulations showed mainly CD4+ T lymphocytes, with small numbers of CD8+ cytotoxic lymphocytes, CD20+ B lymphocytes, NKT+ cells and S100+ dendritic cells in the sites of inflammation, as compared to normal and leptospirosis liver blocks. Some cells expressed TNF-alpha and IFN-gamma, but a much more intense proportion of TGF-beta expressing cells were found, suggesting both a Th1 and Th3 patterns of immune response in yellow fever. Most affected hepatocyte presented apoptosis markers that appear at the cell death main pathway in this infection. Viral antigens, which production could interfere in hepatocyte biology, could induce the activation of apoptosis cascade, but TGF-beta was also an apoptosis promoter. Our finding supports the key effect of the yellow fever virus in hepatocyte injury, resulting in prevalence of apoptosis over necrosis, aside from a TGF-beta action induced by the inflammatory response.

Pruritic papular eruption associated with HIV-etiopathogenesis evaluated by clinical, immunohistochemical, and ultrastructural analysis

Pruritic Papular Eruption with Human Immunodeficiency Virus infection (PPE-HIV) is characterized by symmetrically distributed papules with pruritus in the skin of patients suffering advanced HIV infection. Although known since 1985, the etiology of this symptomatic dermatitis is unclear. We set out to characterize the phenotype of the infiltrating cells and the cytokine profile in the lesions, as an attempt to contribute to determining its etiopathogenesis. Clinical data and histological, immunohistochemical, and ultrastructural features of skin biopsies from 20 HIV patients with PPE were studied. The histopathological aspects, cell immunophenotypes, and cytokine expressions in the lesions where quantified and compared to perilesional skin, and to those in the clinically normal skin of HIV patients without PPE-HIV (n=11) and those in normal skin samples from HIV negative individuals (n=10). PPE-HIV occurred mainly in HIV patients with mean CD4+ counts of 124.6 +/- 104 lymphocytes/mm3. Furthermore, their eosinophil counts were significantly increased. The skin lesions were characterized by a predominantly perivascular dermal lymphohistiocytic inflammatory infiltrate. Langerhans cells were normally distributed in the epidermis and seen among the cellular components of dermal infiltrates. The density of CD8+ lymphocytes was elevated and the density of CD4+ cells was reduced in dermal infiltrates. Interleukin 5 was the predominant cytokine in the lesions. Electron microscopic analysis didn't disclose HIV or other infectious agents in the lesions. These results refute the hypothesis of an infectious etiology of PPE-HIV. CD8+ lymphocytes and Langerhans cells seem to have roles in the pathogenesis of PPE-HIV. The increased frequency of IL5 was associated with abundant eosinophils in the lesions, suggesting a type Th2 response in this dermatitis.

Synthesis and antileishmanial activities of novel 3-substituted quinolines

The antileishmanial efficacy of four novel quinoline derivatives was determined in vitro against Leishmania chagasi, using extracellular and intracellular parasite models. When tested against L. chagasi-infected macrophages, compound 3b demonstrated 8.3-fold greater activity than did the standard pentavalent antimony. No significant activity was found for compounds 3a, 4a, and 4b. The antilesihmanial effect of compound 3b was independent of host cell activation, as demonstrated by nitric oxide production. Ultrastructural studies of promastigotes treated with compound 3b showed mainly enlarged mitochondria, with matrix swelling and reduction in the number of cristae. Synthetic analogues based on the quinoline ring structure, already an established template for antiparasitic drugs, could provide further useful compounds.

Ultrastructural study of the pancreas in AIDS

INTRODUCTION

Frequent histologic changes (90%) in the pancreas suggesting protein-energy malnutrition were found in a previous necropsy study of pancreas morphology in patients with AIDS. However, additional studies were required to clarify subcellular changes.

AIM

To ultrastructurally analyze pancreas changes in AIDS patients through transmission electron microscopy.

METHODOLOGY AND RESULTS

Pancreas specimens for necropsy were obtained from nine consecutive AIDS patients and four normal controls. A semiquantitative histologic and ultrastructural analysis of exocrine pancreas was carried out with the following findings: preserved pancreas structure with little autolysis, marked decrease in zymogen granules (100%), increased lipofuscin pigment (80%), augmented and dilated rough endoplasmic reticulum (100%), and increased number and size of mitochondria. The Golgi complex could be identified only in two cases. In all cases, acinar nuclei were decreased in size, with peripherally condensed chromatin and undulated membrane suggesting early apoptosis. In addition, immunohistochemical evaluation of the pancreas was carried out to detect opportunistic agents.

CONCLUSION

Decreased zymogen granules, acinar atrophy, increased lipofuscin pigment, and rarefying Golgi complex represent the morphologic substrate of protein-energy malnutrition in AIDS patients. The combination of rough endoplasmic reticulum and mitochondria changes could be due to the need for supplying vital plasma proteins rather than exportation protein synthesis associated, or not, with the deleterious effects of inflammatory cytokines and/or therapy for disease.

Involvement of the pancreas in AIDS: a prospective study of 109 post-mortems

BACKGROUND

Pancreatic involvement in AIDS is rarely mentioned in medical literature.

AIMS

To identify the main morphological patterns of the pancreas using optical and electron microscopy in AIDS patients.

DESIGN

An open, prospective, and sequential study in a tertiary institutional hospital.

METHODS

Consecutive post-mortems of 109 AIDS patients and 38 controls (1995). Baseline characteristics of AIDS patients and controls were evaluated. Morphological analysis consisted of: (i) semi-quantitative score of acinar and parenchymal elements; (ii) qualitative analysis of ducts, vascular components, nerves, and Langerhans' islets; (iii) specific stains and immunohistochemistry for opportunistic agents; (iv) ultrastructural data.

RESULTS

The mean age of AIDS patients was 37 years; 80% were male; 60% were white; 21% were alcoholic. All patients with AIDS had normal blood amylase, blood glucose, and pancreatic ultrasound. Histological findings were: acinar atrophy (60%), few zymogen granula in acinar cytoplasm (52%), abnormalities in acinar nucleus (65%), pancreatic steatosis (66%), and focal necrosis (17%). Immunohistochemistry revealed: mycobacteriosis (22%), toxoplasmosis (13%), cytomegalovirus (9%), Pneumocystis carinii (9%), and HIV p24 antigen in macrophage cytoplasm (22%). Ultrastructural examination showed: decreased zymogen granula, enlargement and proliferation of the endoplasmic reticulum and mitochondria, nuclear abnormalities, and increased lipid droplets in acinar cytoplasm.

CONCLUSION

Pancreatic involvement in AIDS is very frequent (90%) and is usually asymptomatic. Morphological changes showed three patterns of pancreatic alterations: 'nutritional-like', inflammatory and both of these together. The 'nutritional-like' pattern (atrophy, few zymogen granula and steatosis) may be due to many factors such as nutritional characteristics (Kwashiorkor-like) induced by the HIV infection or related to the HIV virus itself.