[The pathology of adverse events with immune checkpoint inhibitors]. / Pathologie der Nebenwirkungen von Immune-Checkpoint-Inhibitoren.

BACKGROUND: Immunotherapy has gained importance with the development of new effective cancer treatments. Immune checkpoint inhibitors (ICI) are monoclonal antibodies that promote T­cell mediated tumor immune rejection. Checkpoint blockade also carries the risk of inducing autoimmune reactions ("immune related adverse events", irAEs). The diagnosis and classification of irAEs constitute a new and important field in pathology. AIM: Practice-oriented review of the diagnosis and classification of irAEs. MATERIALS AND METHODS: Structured, selective literature review based on PubMed und UpToDate ® online. RESULTS: The most common irAEs affect the skin, the gastrointestinal tract, the liver, and the respiratory system. The correct diagnosis and classification of irAEs by an interdisciplinary care team is essential for appropriate therapy and the prevention of long-term sequelae. Other important irAEs affect the endocrine organs, the heart, the joints, the kidneys and the nervous system. Because of their rarity and/or limited options for bioptic diagnosis, only limited data on the morphology and pathophysiology of these irAEs are currently available. Autopsies carried out after ICI therapy constitute an important element of quality control and allow better documentation of the incidence and pathogenesis of irAEs. DISCUSSION: Pathology plays a central role in the diagnosis and treatment of irAEs. Future studies may contribute to a better mechanistic understanding of irAEs for individualized knowledge-based risk assessment.

Hepatitis From Spiroplasma sp. in an Immunocompromised Patient.

A 70-year-old lung transplant recipient patient was admitted with fever, nausea, abdominal pain, peripheral edema and pronounced weakness. An initial work-up for presumed infection revealed cholestatic hepatitis, leukocytosis and thrombocytopenia, but failed to detect a pathogen. An increased glucose uptake exclusively in the liver was demonstrated by positron emission tomography. Liver biopsy showed basophilic inclusions in the cytoplasm of hepatocytes. Broad- range 16S rRNA gene PCR followed by sequence analysis yielded Spiroplasma sp. in two independent blood samples and the liver biopsy, confirming Spiroplasma sp. as the causative agent. Antibiotic treatment with doxycycline and azithromycin led to complete recovery.

[Calcified]. / Verkalkt.

A 73-year-old woman was referred due to an acute and progressive worsening of a previously mildly impaired kidney function of unknown origin. The kidney biopsy showed a phosphate nephropathy. We identified Colophos®, a phosphate-containing purgative as the causing agent, which the patient had received for bowel cleansing for a colonoscopy one day before the detection of the acute kidney failure. During the following months the kidney function initially declined further and then improved. Most cases of phosphate nephropathy are associated with the ingestion of phosphate-containing purgatives. Persons at risk are women, elderly persons, patients with impaired kidney function, hypertension, and dehydration. The consequence is sometimes an irreversible tubulointerstitial injury that can lead to end-stage renal disease in a minority of the cases.

[Rheumatoid arthritis and interstitial lung alterations - a clear case, isn't it?]. / Rheumatoide Arthritis und interstitielle Lungenver-änderungen - Ein klarer Fall! Oder eben doch nicht?

In a patient with rheumatoid arthritis (RA) and asymptomatic, diffuse reticulo-nodular lung parenchymal alterations with upper lobe predominance, a Caplan syndrome (CS) was diagnosed. According to the size of the pulmonary nodules, classification into two subtypes of the CS has been proposed: the classic (Caplan) type and the silicotic type. Patients with CS often present with considerable x-ray or computertomographic changes but relatively few symptoms. However, in case of respiratory symptoms, infectious complications or pneumotoxic side effects of the immunsuppressive/immune-modulating pharmacotherapy for RA must be encountered in the differential diagnosis.

[Anti-RNA polymerase III antibodies in scleroderma renal crisis]. / Anti-RNA-Polymerase-III-Antikörper bei renaler Krise der systemischen Sklerose.

HISTORY AND CLINICAL FINDINGS: A 67-year old patient underwent a kidney biopsy because of newly diagnosed hypertension, haemolytic anemia with fragmentocytes and acute kidney failure requiring dialysis therapy. The biopsy showed thrombotic microangiopathy. Since last winter Raynaud's phenomenon and changes of hands and lips were recognised. INVESTIGATIONS: Initial immunological tests revealed anti-nuclear antibodies (ANA) but neither anti-centromere nor anti-Scl70 antibodies. The positive analysis of anti-RNA polymerase III antibodies confirmed the clinical suspicion of scleroderma renal crisis in the setting of first diagnosis of systemic sclerosis. TREATMENT AND COURSE: After diagnosis therapy with lisinopril, candesartan and amlodipin was established. Four months after discharge dialysis dependency persisted. CONCLUSION: Scleroderma renal crisis is an important differential diagnosis in the setting of acute kidney failure. Medical history, clinical examination and immunological test confirm the diagnosis. The mainstay of therapy is aggressive blood pressure control with ACE-inhibitors (or angiotensin receptor blocking agents).

Second transurethral resection of superficial transitional cell carcinoma of the bladder: a must even for experienced urologists.

INTRODUCTION: As even experienced urologists have a high percentage of persisting carcinoma after transurethral bladder tumour resection (TUR-B) the importance of a routine second resection in the management of transitional cell carcinoma (TCC) of the bladder is defined. PATIENTS AND METHODS: The medical records of all patients treated with TUR-B at our institution between January 1989 and September 2000 were reviewed. 214 patients with pTa and pT1 carcinoma undergoing a second resection 4-6 weeks later were included in the analysis. The rate of persisting carcinoma in the second resection was compared to the actual tumour stage and grade, the patient's age, sex and the experience of the urologist performing the resection. RESULTS: Of the 214 patients 99 had pTa and 115 pT1 carcinoma. The rate of persisting tumour in the second resection was 27% in pTa and 37% in pT1 carcinoma. This rate was independent of the patient's age and sex. Urologists in training had an equally low rate of persisting carcinoma in the second resection compared to senior urologists (p = 0.08). CONCLUSIONS: Routine second resection of superficial transitional cell carcinoma of the bladder should be part of the treatment even in larger operative experience.

Normal gas exchange after 30-h ischemia and treatment with phosphodiesterase inhibitor PDI747.

OBJECTIVE: Phosphodiesterases (PDEs) negatively regulate the concentrations of cAMP and/or cGMP, which act as downstream second messengers to the prostaglandins. PDE type-4 (PDE4) is selective for cAMP and is found in high concentrations in endothelial, epithelial, and different blood cells. The aim of this study was to evaluate if PDI747, a novel selective inhibitor of PDE4, can restore pretransplant cAMP levels and thereby posttransplant organ function after prolonged cold ischemia. METHODS: Left lung transplantation was performed in pigs (25-31 kg). Donor lungs were flushed with low potassium dextran glucose (LPDG) solution only (control, n=5)or, in addition with 1 micromol of PDI747 (PDI747, n=5) and stored for 30 h at 1 degrees C. PDI747 animals further received a bolus of PDI747 (0.3 mg/kg) 15 min prior to reperfusion and a continuous infusion (0.3 mg/kg per hour) during the 5 h after reperfusion. After occlusion of the right pulmonary arteries and the right main bronchus, hemodynamic and gas exchange parameters and extravascular lung water (EVLW) levels of the transplanted lung were assessed. RESULTS: Two control animals died of severe lung edema leading to heart failure (control, n=3). One animal in the treatment group was excluded due to a patent ductus arteriosus (PDI747, n=4). Gas exchange at the end of the experiment was restored to normal levels in the PDI747 group (Pa, O(2) 47.6+/-11.2 kPa, Pa,CO(2) 6.4+/-1.8 kPa) but not in the control group (Pa, O(2) 7.7+/-2.9 kPa, Pa, CO(2) 11.9+/-3.0 kPa, P(PaO2)<0.0001, P(Pa, CO2)=0.06). Extravascular lung water (EVLW) was normal in the PDI747 group (8.5+/-1.1 ml/kg) and clearly elevated in the control group (16.2+/-5.6 ml/kg, P=0.007). Airway pressure in the PDI747 group was significantly lower than in the control group (7.8+/-0.5 cm H(2)O vs. 11.3+/-0.6 cm H(2)O, respectively, P<0.0001). The free radical mediated tissue injury measured by lipid peroxidation (TBARS) was significantly reduced (P=0.001) in the PDI747 group. CONCLUSIONS: With the inhibition of PDE4 with PDI747 we achieved normal gas exchange, no posttransplant lung edema, normal airway pressures, and a reduced free radical injury after 30 h of cold ischemia.

Bronchoscopic radioisotope injection for sentinel lymph-node mapping in potentially resectable non-small-cell lung cancer.

OBJECTIVE: Prospective study to evaluate the feasibility of a preoperative bronchoscopic radioisotope application, followed by conventional sentinel lymph-node (SLN) identification and to investigate the occurrence and distribution of micrometastases in relation to SLN activity. METHODS: Twenty patients with a mean age of 63 years and proven clinical stage T1-3 N0-1 non-small-cell lung cancer (NSCLC) were included. A dosage of 80MBq radiolabeled technetium-99m nanocolloid was endoscopically administrated on intubated patients in the operation theatre. At thoracotomy, scintigraphic readings of both the primary tumor and hilar and mediastinal lymph-node stations were obtained with a hand-held gamma-counter. Patients underwent lung resection and mediastinal lymphadenectomy. Radiolabeled nodes were also examined separately on back-table. SLNs were defined as the hottest nodes or nodes with at least one-tenth of the radioactivity of the hottest nodes. SLNs pathologic assessment included standard examination using hematoxylin and eosin staining on step sections and immunohistochemistry (ICH) for cytokeratins. RESULTS: Identification of SLNs was possible in 19/20 (95%) patients after bronchoscopic radioisotope application. In 7/19 (37%) patients, a unique SLN was identified, whereas in 12/19 (63%) patients, nodes from two different stations could be classified as SLNs. Metastatic nodal disease was found in 9/19 (47%) patients. ICH revealed micrometastases in 2/12 (17%) patients, initially classified nodal negative. Pathologic negative SLNs were a predictor for absence of metastatic nodal disease after mediastinal lymphadenectomy. No complication related to the procedure was observed. CONCLUSION: Our preliminary results suggest that preoperative bronchoscopic radioisotope injection for SLN identification is a safe and simple method, improving accuracy of SLN detection in comparison to intraoperative technique. The absence of metastases in the SLNs seems to predict a negative nodal status accurately.

[Elevated liver values of uncertain origin]. / Unklare Leberwerterhöhung.

A 31-year old Egyptian was referred to evaluate the etiology of elevated liver enzymes. The patient had been suffering from diabetes type 1 for three years and complained about episodes of light diarrhea. Laboratory investigation revealed a moderate elevation of cholestatic enzymes. Ultrasound examination and computed tomography did not show mechanical biliary obstruction. Drug-induced cholestasis, viral hepatitis and primary biliary cirrhosis could be excluded as well. Finally, schistosomiasis mansoni was diagnosed by microscopic stool examination as well as histological evaluation of biopsy specimens obtained during colonoscopy. This parasitic disease may cause slowly progressive liver injury by the release of schistosome eggs into the portal vein system. Histological evaluation of liver specimens of this patient showed portal inflammation and the presence of pigmented macrophages. This pattern, though unspecific, was consistent with the diagnosis of schistosomiasis mansoni. Treatment with praziquantel resulted in regression of diarrhea episodes and normalization of cholestatic enzymes within three months.

Pulmonary granulomas after tumour necrosis factor alpha antagonist therapy.

Tumour necrosis factor alpha (TNFalpha) antagonists are an established therapeutic option in Crohn's disease and rheumatoid arthritis. In recently published studies these agents have been used with great success, but little is known about any side effects or long term consequences. They increase the frequency of infections with mycobacteria, where TNFalpha is thought to be an important host defence factor. We describe one patient who was treated with TNFalpha antagonists and later developed pulmonary granulomas with caseating necrosis without detection of mycobacteria or any other pathogens. Possible mechanisms involved in this newly recognised side effect are discussed.

Fas ligand gene transfer combined with low dose cyclosporine A reduces acute lung allograft rejection.

The interaction between Fas and its ligand (FasL) induces apoptosis in the Fas-expressing cell. We hypothesized that liposome-mediated FasL gene transduction to the lung allograft, in addition to low-dose immunosuppression, might reduce acute rejection. Orthotopic left lung allotransplantation was performed in male rats (Brown Norway to Fischer F344). FasL gene transfer was performed by use of the plasmid pBCMGSNeo carrying the gene coding for murine FasL and the cationic liposome GL#67:DOPE. Six hundred and sixty micrograms of DNA in 250 microl H2O and 0.5 micromol GL#67 in 250 microl H2O were diluted to 5 ml with saline solution. This emulsion (20 degrees C) was instilled retrogradely through the left pulmonary vein after flushing with LPD solution (20 ml, at 4 degrees C). Subsequently, the graft was stored at 10 degrees C for 3 h. A single dose of cyclosporine A (CsA; 2.5 mg/kg i.m.) was given to all groups 48 h after the transplantation. In group 1 (n = 6), FasL/GL#67 was instilled as described. In group 2 (n = 5), GL#67 was given without DNA. Group 3 (n = 5) animals received CsA only. Five days after transplantation, gas exchange was assessed after exclusion of the contralateral native lung (FiO2 = 1.0). Grafts were flushed with saline solution and fixed in formaldehyde for histological evaluation. No statistical difference in gas exchange (PaO2) between the two control groups 2 (6.4 +/- 0.4 kPa) and 3 (7.4 +/- 0.4 kPa) could be detected 5 days postoperatively (P = 0.9). In contrast, grafts transduced with FasL (group 1) had significantly better gas exchange on postoperative day 5 (PaO2: group 1 37.0 +/- 10.6 kPa vs group 2 6.4 +/- 0.41 kPa; P = 0.002). Two animals in group 1 revealed no or only minimal improvement in gas exchange. Histologically, all lung specimen of all groups showed signs of acute rejection (A2). Leukocyte infiltrates, rated by two independent observers, were less severe in all group 1 animals. Liposome-mediated FasL gene transfer at the time of harvest in combination with low-dose CsA reduces acute rejection in four out of six animals in this model of rat lung allotransplantation.

Apoptosis induced by ischemia and reperfusion in experimental lung transplantation.

BACKGROUND: Apoptosis is a distinct form of single-cell death in response to injury. Time course of apoptosis in lung parenchymal cells during posttransplant reperfusion and the influence of oxygen content during preservation on apoptosis of parenchymal cells are studied. METHODS: Orthotopic syngenic single left lung transplantation was performed in male Fischer (F344) rats after 18 hours of cold ischemia (n = 5 in all groups). Apoptotic cells were stained by the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) technique. Strictly TUNEL-positive pneumocytes were counted on anonymized slides by a pathologist on 100 fields (x400) per specimen (mean +/- SEM). RESULTS: The peak of apoptotic pneumocytes occurred 2 hours after reperfusion (16.8 +/- 2.2 pneumocytes/100 fields [p/100f]; p = 0.000012 vs controls, lungs fixed after 18 hours of ischemia), whereas the lowest level of apoptotic pneumocytes was seen in lungs fixed after harvest (1.4 +/- 0.51 p/100f) and lungs not undergoing reperfusion (2.8 +/- 0.49 p/100f). Four hours after reperfusion, the number of apoptotic pneumocytes was lower than 2 hours after reperfusion (13.6 +/- 3.1 p/100f; p = 0.00032 vs controls), with a further decline at 8 hours (6.4 +/- 1.5 p/100f) and 12 hours after reperfusion (4.0 + 1.2 p/100f). Interestingly, lungs inflated with N2 before storage revealed a significantly lower level of TUNEL-positive pneumocytes 2 hours after reperfusion (8.8 2.0 p/100f) compared with lungs inflated with 100% O2 (p = 0.0052). CONCLUSIONS: Apoptosis of pneumocytes after posttransplant lung reperfusion is a very early event. Prolonged hypothermic preservation without reperfusion, however, does not lead to an elevated rate of apoptotic pneumocytes in lung grafts.

[Special problems after lung transplantation: walking a tightrope between infection and graft rejection]. / Spezielle Probleme nach Lungentransplantation: eine Gratwanderung zwischen Infektion und Abstossungsreaktion.

Between November 1992 and September 1999 84 lungs have been transplanted at University Hospital Zurich. Currently the 1-year survival rate is up to 85%. However, long-term success is limited by the development of chronic rejection in the form of bronchiolitis obliterans. The risk factors are repeated episodes of acute rejection and infections, due to cytomegalovirus in particular. Both can occur in asymptomatic patients and are sometimes detected only by transbronchial lung biopsy. At the Zurich Lung Transplant Centre biopsies are performed as surveillance biopsies in asymptomatic patients in the first 6 months after transplantation, for clinical indications and as follow-up biopsies after a pathological result. Open lung biopsies are performed for special indications only. We evaluated 408 transbronchial biopsies taken between November 1992 and September 1999. Relevant findings were present in 46% of biopsies in symptomatic patients. Relevant acute rejection episodes were diagnosed in 15% of surveillance biopsies. Overall, 72% of acute rejection episodes requiring therapy and 33% of biopsies detecting cytomegalovirus were found in surveillance biopsies. 7 of 11 late (> 45 days postoperative) and 1 of 5 early (< or = 45 days postoperative) open lung biopsies revealed new diagnoses. Transbronchial biopsy after lung transplantation is at present the gold standard for diagnosis of acute rejection and cytomegalovirus pneumonia of the lung.

[Heart transplantation: life-long biopsies for prevention of rejection?]. / Herztransplantation: Lebenslänglich Biopsien zur Vermeidung einer Abstossung?

The transplantation of a heart restores the quality of life and productivity to patients who have experienced severe loss of contractility of heart muscle during an infection or as a result of long-lasting chronic heart disease. Monitoring for allograft rejection requires expensive procedures whereby, with catheterisation of the right heart, endomyocardial biopsies are retrieved. Evaluation by the pathologist uses a standardised diagnostic scheme which is in use worldwide. We have tested the interobserver agreement in a very heterogeneous group of examining pathologists and found moderate agreement with a kappa value of 0.52. The development of other methods to improve and even to replace invasive procedures for monitoring acceptance/rejection of a cardiac allograft requires interdisciplinary cooperation.

[Pseudomonas pneumonia--an important differential pulmonary infiltration diagnosis in AIDS]. / Die Pseudomonas-Pneumonie--eine wichtige Differentialdiagnose pulmonaler Infiltrate bei Aids.

Bacterial pneumonias are the most common pulmonary complication in HIV-infected patients. Up to now, H. influenzae and S. pneumoniae have been described as the most important germs. Within a period of 4 years we diagnosed 15 cases of pneumonia caused by P. aeruginosa. All patients were in HIV stage C3; 3F, 12M; median age 34 (24-54) years; median CD4 count 10 (0-130) microliters. Except for 3 nosocomial pneumonias, all others were community-acquired. Only 3 patients had neutropenia < 1000/microliter; 7 were intravenous drug abusers. Morphologically there were 6 cases of abscess pneumonia, in 3 of which pleural drainage was necessary because of pyopneumothorax. 4 patients showed bilateral infiltrates that could not be differentiated from those of P. carinii pneumonia. Our diagnosis was based on quantitative cultures of broncho-alveolar lavage fluid (9 cases, two of them with concurrent positive blood cultures/positive cultures of the pleural fluid), pleural puncture (one case), sputum in pneumonias responding only to antipseudomonas therapy (3 cases), and autopsy (2 cases). 8 patients died of pseudomonas pneumonia within 1-3 months despite therapy. 7 patients received pseudomonas-specific combination therapy, but all died after median 9 (4-15) months of the underlying illness. In 3 cases recurrent pseudomonas pneumonia could be documented bacteriologically. We conclude that in HIV-infected patients pneumonia caused by P. aeruginosa is a significant and severe pulmonary complication.