Real-time and non-invasive acute lung rejection diagnosis using confocal LASER Endomicroscopy in lung transplant recipients: Results from the CELTICS study

BACKGROUND AND OBJECTIVE

Traditionally, the diagnosis of acute rejection (AR) relies on invasive transbronchial biopsies (TBBs) to obtain histopathological samples. We aimed to evaluate the diagnostic yield of probe-based confocal laser endomicroscopy (pCLE) as a complementary and non-invasive tool for ACR screening, comparing its results with those obtained from TBBs.

METHODS

Between January 2015 and April 2022, we conducted a retrospective study of all lung transplant recipients aged over 18 years at Toulouse University Hospital (France). All patients who underwent bronchoscopies with both TBBs and pCLE imaging were included. Two experienced interpreters (TV and MS) reviewed the pCLE images independently, blinded to all clinical information and pathology results.

RESULTS

From 120 procedures in 85 patients, 34 abnormal histological samples were identified. Probe-based confocal laser endomicroscopy revealed significant associations between both alveolar (ALC) and perivascular (PVC) cellularities and abnormal histological samples (p<0.0001 and 0.003 respectively). Alveolar cellularity demonstrated a sensitivity (Se) of 85.3 %, specificity (Spe) of 43 %, positive predictive value (PPV) of 37.2 % and negative predictive value (NPV) of 88.1 %. For PVC, Se was 70.6 %, Spe 80.2 %, PPV 58.5 % and NPV 87.3 %. Intra-interpreter correlation (TV) was 88.3 % for the number of vessels (+/-1), 98.3 % for ALC and 90 % for PVC. Inter-interpreter correlation (TV and MS) was 80 % for vessels (+/-1), 97.5 % for ALC and 83.3 % for PVC.

CONCLUSION

Our study demonstrates the feasibility of incorporating pCLE into clinical practice, demonstrating good diagnostic yield and reproducible outcomes in the screening of AR in lung transplant recipients.

Blood CD9+ B cell, a biomarker of bronchiolitis obliterans syndrome after lung transplantation

Bronchiolitis obliterans syndrome is the main limitation for long-term survival after lung transplantation. Some specific B cell populations are associated with long-term graft acceptance. We aimed to monitor the B cell profile during early development of bronchiolitis obliterans syndrome after lung transplantation. The B cell longitudinal profile was analyzed in peripheral blood mononuclear cells from patients with bronchiolitis obliterans syndrome and patients who remained stable over 3 years of follow-up. CD24^hi CD38^hi transitional B cells were increased in stable patients only, and reached a peak 24 months after transplantation, whereas they remained unchanged in patients who developed a bronchiolitis obliterans syndrome. These CD24^hi CD38^hi transitional B cells specifically secrete IL-10 and express CD9. Thus, patients with a total CD9⁺ B cell frequency below 6.6% displayed significantly higher incidence of bronchiolitis obliterans syndrome (AUC = 0.836, PPV = 0.75, NPV = 1). These data are the first to associate IL-10-secreting CD24^hi CD38^hi transitional B cells expressing CD9 with better allograft outcome in lung transplant recipients. CD9-expressing B cells appear as a contributor to a favorable environment essential for the maintenance of long-term stable graft function and as a new predictive biomarker of bronchiolitis obliterans syndrome-free survival.

[Proteomics, a new tool for an accurate typing of amyloidosis]

Amyloidosis is a rare group of diseases related to extracellular deposition of proteins in an insoluble beta-pleated sheet structure presenting a characteristic apple-green birefringence under polarized light after Congo red staining. Thirty types of proteins are known to cause amyloidosis. The accurate identification of the amyloid protein is of paramount importance since it is a key step for the clinical management and personalized treatment. Amyloid typing is usually based on immunohistochemistry and immunofluorescence on tissular sections. This approach has several limits leading to a subtyping failure rate of 15 to 58% of cases. To overcome these difficulties, proteomic methods have been developed to characterize directly the amyloid protein. The most advanced technique carried out on fixed and paraffin-embedded tissue consists of laser microdissection followed by mass spectrometry. The type of amyloidosis can be determined in more than 95% of cases. However, the experience for this technique is very limited apart from the Mayo Clinic (Rochester, United States). In France, a very close proteomic assay has been implemented in the department of pathology of Foch Hospital with similar results. The introduction of proteomics in clinical practice represents a major improvement for typing amyloidosis. In this article, we discuss the benefits and limits of the different techniques used for amyloid classification and we briefly report our proteomic results.

Immunohistochemical study of HLA-G expression in lung transplant recipients

Human leukocyte antigen-G (HLA-G), a nonclassical HLA class I protein, promotes immune tolerance of solid-organ allografts, yet its role in lung transplantation (LTx) is unknown. We examined the expression of HLA-G in lung allografts through immunohistochemistry by a cross-sectional study of 64 LTx recipients, classified into four groups (stable patients, acute rejection [AR], bronchiolitis obliterans syndrome [BOS] and symptomatic viral shedders). A marked expression of HLA-G in bronchial epithelial cells (BEC) was frequently observed in stable recipients (n = 18/35 [51%]), but not in patients with AR (n = 14) or with BOS (n = 8). HLA-G was also expressed by 4 of 7 symptomatic viral shedders. In addition, HLA-G-positive patients from the stable group (n = 35) experienced lower incidence of resistant AR and/or BOS during long-term follow-up, as compared with their HLA-G-negative counterparts. Finally, in vitro data showed that interferon-gamma, a cytokine present in lung allograft microenvironment, upregulated HLA-G mRNA and protein expression in primary cultured human BEC. We conclude that HLA-G expression in the bronchial epithelium of lung allograft is elevated in some LTx recipients in association with their functional stability, suggesting a potential role of HLA-G as a tolerance marker.

Pathomechanisms of cyst formation in pulmonary light chain deposition disease

Cystic lung light chain deposition disease (CL-LCDD) is a recently described rare disorder characterised by numerous cysts and diffuse monoclonal nonamyloid light chain deposits surrounded by macrophagic giant cells. The mechanisms responsible for cyst development remain unknown. The objectives of the present study were to analyse the major components of the pulmonary extracellular matrix in CL-LCDD and to determine the influence of metalloproteinases (MMPs) by comparison with other cystic lung disorders. A virtually complete degradation of the elastic network was found in CL-LCDD. To a lesser degree, loss of fibrillar and basement membrane collagens was also observed. Macrophagic giant cells expressed MMP-1, MMP-2, MMP-9, MMP-12 and MMP-14 and in situ zymography highlighted a strong gelatinolytic activity. As in CL-LCDD, cystic lesions in Langerhans' cell histiocytosis (LCH) and lymphangioleiomyomatosis (LAM) were characterised by the lack of elastic fibres. Similarly, MMP were expressed in CL-LCDD and LCH but the labelled cells were different. In contrast, few MMPs were detected in LAM. In conclusion, elastolysis is common to cystic lung light chain deposition disease and other cystic lung disorders, suggesting its implication in cyst formation. Moreover, in cystic lung light chain deposition disease, a role of metalloproteinases in elastolysis is strongly indicated by the metalloproteinase expression and activity pattern.

Light chain deposition disease involving the airways: diagnosis by fibreoptic bronchoscopy

Light chain deposition disease (LCDD) infrequently affects the lungs and usually causes damage to the parenchyma, while bronchial involvement appears to be very rare. The present authors report the case of a 64-yr-old female with LCDD characterised by asymptomatic airway involvement. Ten months after excision of a poorly differentiated vaginal carcinoma, a routine chest computed tomography (CT) scan revealed two lung cysts, several bilateral nodules and diffuse bronchial thickening. Pulmonary function tests were normal. Fibreoptic bronchoscopy showed marked diffuse mucosal thickening with highly conspicuous vascular plexuses. Nonamyloidal deposits were found in the bronchial wall, but no definite diagnosis could be proposed. On follow-up, the patient was still asymptomatic and the CT scan and endoscopic appearance remained unchanged. The final diagnosis of kappa LCDD was established 18 months later by another series of bronchial biopsies with frozen samples. Interestingly, electron microscopy showed dense granular deposits associated with nonamyloidal fibrils. An increased number of lung cysts were observed 32 months after identification of bronchial abnormalities, confirming the progressive nature of the disease. No extrapulmonary deposits or immunoproliferative disorder were found. In conclusion, light chain deposition disease, which may remain latent for several years, can entirely involve large airways and may be diagnosed by bronchial biopsy.

Erythropoietin and erythropoietin receptor coexpression is associated with poor survival in stage I non-small cell lung cancer

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Background: The role of erythropoietin (EPO) and its receptor (EPO-R) in tumor biology is under active investigation. This study was designed to evaluate the prognostic impact of EPO and EPO-R expression in stage I non-small cell lung cancer (NSCLC) patients. Methods: EPO and EPO-R expression in 158 tumor samples from resected stage I NSCLC was evaluated using immunohistochemistry and tissue-array technology. Disease specific survival time was calculated from the date of surgery to death from cancer-related causes. Results: EPOR and EPO were highly expressed in 20.9% and 35.4% of the tumors respectively. High EPO-R compared to negative or low level of expression was associated with a poor 5-year disease specific survival (60.6% versus 80.8%, logrank test: p=0.01). High EPO compared to negative and low level of expression was associated with a trend toward a poor 5-year disease specific survival (69.6% versus 80.4%, logrank test: p=0.13). High level of EPO-R and EPO coexpression compared to other groups of patients was associated with a poor 5- year disease specific survival (50.0% versus 80.0% of survival at the end of follow-up, logrank test: p=0.005). In multivariate analysis for disease specific survival, high level of EPO-R and EPO coexpression was an independent prognostic factor for disease specific survival (HR 2.214, 95% CI: 1.012–4.848, p=0.046). Conclusions: These results establish for the first time the pejorative prognostic value of EPO and EPO-R expression in early stage resected NSCLC and suggest a potential paracrine and/or autocrine role of endogenous EPO in NSCLC aggressiveness.

No significant financial relationships to disclose.

From humoral rejection to generalized thrombotic microangiopathy--role of acquired ADAMTS13 deficiency in a renal allograft recipient

A 9-year-old renal transplant recipient presented with elevated serum creatinine levels 4 years post-transplant renal biopsy revealed humoral rejection including lesions suggestive for thrombotic microangiopathy (TMA). He received methylprednisolone pulses followed by a normalization of serum creatinine. Two more steroid responsive acute rejection episodes occurred. Two months later he presented rapidly progressive life threatening symptoms including bilateral pyramidal syndrome and hemoptysis. Serum haptoglobin became undetectable at this time and platelet count decreased (70000/microl), suggesting TMA. Cerebral MRI revealed generalized ischemic white matter lesions. ADAMTS13 activity decreased to < 5%. Daily plasma exchanges (PE) resulted in immediate improvement. All attempts to discontinue PE were unsuccessful. Transplantectomy resulted in normalization of generalized symptoms, hemolysis and ADAMTS13 activity (110%). Multi-organ involvement has never been reported in acquired ADAMTS13 deficiency post-transplant. Rapid resolution after transplantectomy might suggest that renal TMA was responsible for acquired ADAMTS13 deficiency and thereby triggered the generalization of TMA lesions.

Exhaled NO may predict the decline in lung function in bronchiolitis obliterans syndrome

Bronchiolitis obliterans syndrome (BOS) remains the leading cause of morbidity/mortality following lung transplantation. In recipients with BOS, markers predicting the decline in lung function are needed. The aim of this longitudinal study was to determine whether exhaled nitric oxide fraction (FeNO) measurements provide useful information for discriminating patients with unstable BOS from those with stable BOS. During a 14-month period, 145 FeNO measurements were performed in 50 lung transplant recipients. Among them, 16 recipients with BOS (32 FeNO measurements) were analysed. For each FeNO measurement, the patients were classified into three groups according to the decline in forced expiratory volume in one second (FEV1) within the following 6 months: 1) stable BOS free; 2) stable BOS (decline in FEV1 of <5%); and 3) unstable BOS (decline in FEV1 of > or =15%). The mean FeNO in patients with unstable BOS was significantly increased compared with that in stable BOS-free patients (18.4+/-5.7 versus 9.7+/-3.7 ppb) and that in patients with stable BOS (18.4+/-5.7 versus 9.7+/-3.3 ppb). The present findings suggest that, in patients with bronchiolitis obliterans syndrome, a raised exhaled nitric oxide fraction may predict the development of worrisome functional impairment during long-term follow-up.

Méningiome intra-osseux de la voûte du crâne : confrontation anatomo-radiologique

Intraosseous meningiomas are rare ectopic meningiomas. The authors report the case of a hyperostotic intraosseous meningioma of the parietal bone without dural extension. The preoperative imaging findings, as well as imaging features of the surgical specimen and pathologic findings are discussed.

Diffusion-weighted MR imaging and pathologic findings in adult cerebellar medulloblastoma

OBJECTIVES, MATERIALS AND METHODS: The authors present the diffusion-weighted MR imaging and pathologic findings in two adult patients with cerebellar medulloblastoma.

RESULTS

Both presented with a vermian mass of the posterior fossa with low signal on SE T1 weighted images, and moderate enhancement of the mass after gadolinium injection. The tumors were of high intensity on diffusion-weighted images with low ADC value. The ADC values (x10(-3) mm2/s) were respectively 0.60 +/- 0.06 and 0.59+/-0.11 (tumor), and 0.65 +/- 0.04 and 0.67 +/- 0.07 (cerebellar white matter). Tumors were highly cellular and composed of densely packed small round cells with hyperchromatic nuclei and scanty cytoplasm.

CONCLUSION

diffusion-weighted MR imaging may be useful for the diagnosis of cerebellar medulloblastoma, due to their high cellularity and high nuclear-to-cytoplasmic ratio.

[Diagnostic strategy when confronted with a moderate and prolonged increase of transaminases]

TWO TYPES OF SITUATIONS: Measurement of transaminase serum activity is a common biological test. Although the etiological scope of acute and severe hyper-aminotransferase is codified and limited, that of prolonged and moderate hyper-aminotransferase is much broader. IN THE CASE OF PROLONGED AND MODERATE INCREASE IN TRANSAMINASE SERUM ACTIVITY: The discovery of this abnormality during systematic biological controls is a frequent situation, and its management is relatively well standardised. It requires a rigorous diagnostic strategy, which includes the search for consumption of alcohol, overweight, chronic hepatic disease of viral origin and the nature of the medicinal products ingested. FROM AN ETIOLOGICAL POINT OF VIEW: The most frequent causes of moderate and prolonged hyper-aminotransferase are alcohol abuse, overweight, non-insulin-dependent diabetes, dyslipaemia, viral hepatitis and medicinal products. However, less frequent hepatic or extra-hepatic causes must not be neglected.

Intrahepatic cholangiocarcinoma and hepatolithiasis: an unusual association in Western countries

Hepatolithiasis is uncommon in Western countries and the relationship with cholangiocarcinoma is unusual. We report the association of hepatolithiasis and a cholangiocarcinoma in a Caucasian patient with a 17-year history of recurrent pancreatitis associated with hepatolithiasis. We discuss work-up and surgical treatment, and stress the need to keep in mind the possible association between hepatolithiasis and cholangiocarcinoma even in Western countries.

[Epithelioid hemangioendothelioma associated with nodular regenerative hyperplasia]

Epithelioid hemangioendothelioma of the liver is a rare neoplasm of vascular origin. We report a case of epithelioid hemangioendothelioma occurring in a patient with nodular regenerative hyperplasia. This association suggests that some hepatic vascular changes might promote the growth of epithelioid hemangioendothelioma.

[Cellular angiofibroma. A rare vulvar tumor. Report of a case]

Cellular angiofibroma is a rare tumor. We report a vulvar case in a 37 year old woman. This nodular, well circonscribed tumor consists of bland spindle cells, numerous thin or thick often hyalinized vessels and adipocytes. The stromal cells are positive for vimentin and negative for CD34, protein S100, smooth muscle actin, desmin, epithelial membrane antigen and cytokeratin. Cellular angiofibroma is a benign tumor that has to be differentiated from aggressive angiomyxoma, angiomyofibroblastoma, glomangiopericytoma, spindle cell lipoma, solitary fibrous tumor and perineurioma.

[Epithelioid leiomyosarcoma of the uterine cervix. Report of a case]

We report a case of an epithelioid leiomyosarcoma of the uterine cervix in a 42 year-old woman. This is a very rare tumor. Usually, the presenting symptoms are vaginal bleeding and abdominal pain. Two problems have to be solved by the microscopy: to prove the smooth muscle differentiation of the tumor and to assert the malignancy. Surgery remains the basis of therapy. Prognosis is poor.

Giant cell arteritis localized to the colon associated with Crohn's disease

AIMS

Intestinal vasculitis is uncommon and usually accompanies systemic vasculitis. Although intestinal vascular changes including vasculitis have been studied intensively, and are found regularly in Crohn's disease, giant cell arteritis is distinctly unusual. We describe a case of giant cell arteritis localized to the colon of an 18-year-old girl suffering from Crohn's disease.

METHODS AND RESULTS

After three years of medical treatment, the patient underwent a proctocolectomy. The medium-sized arteries of the mesocolon demonstrated striking changes characterized by intimal fibrous thickening and an inflammatory infiltrate with giant cells, most predominant at the intima-media junction. Epithelioid cells and sarcoid-like granulomas were not observed. The internal elastic lamina was fragmented. Neither clinical symptoms nor laboratory findings showed evidence of systemic vasculitis. Neither the chest CT scan nor the echo-Doppler of the temporal arteries, supra-aortic and abdominal vessels revealed any abnormality.

CONCLUSIONS

This case illustrates an extremely rare feature in the spectrum of vascular lesions in Crohn's disease which have to be differentiated from temporal and Takayasu's arteritis.

[Plurifocal testicular hamartomas and testicular feminization syndrome]

We report the case of a 14-year-old girl with a testicular feminization syndrome. The inguinal cryptorchid testis contained plurifocal hamartomas ranging from 0.5 to 1 cm. They were composed of tubules lined by cylindrical Sertoli cells immunoreactive for alpha-inhibin and p30/32(MIC2). The stroma contained few Leydig cells. Ultrastructural study showed tubules with immature Sertoli cells. The testicular feminization syndrome is caused by mutations of the androgen receptor gene. Patients with male genotype 46, XY have a female morphotype with external sexual organs without ambiguity. They have neither uterus nor ovary but two cryptorchid testis in which sex-cord stromal tumors can develop. Their malignant transformation is rare but requires preventive bilateral orchidectomy.

[Mesothelial cyst of the adrenal gland]

We report a case of a mesothelial adrenal cyst which was incidentally discovered in a 38-year old woman. The diagnosis was confirmed by an immunohistochemistry study. Adrenal cysts are rare. They occur more commonly in female patients during the 4th and 5th decades and are usually asymptomatic. Adrenal cysts are divided into four groups : parasitic, epithelial, endothelial cysts and pseudocysts. The management is still discussed : follow-up, surgical resection or fine-needle aspiration.

[Cellular neurothekeoma, a rare cutaneous tumor. Anatomo-clinical and immunohistochemical study of 2 cases]

Cellular neurothekeoma is an unusual cutaneous tumor described in 1986. We report two new cases in 14-year-old girls. Both tumors measured less than one centimeter and were located on the forearm and the shoulder. They had a plexiform architecture and were developed in the dermis and the dermo-hypodermic junction. Spindle and epithelioid tumor cells were immunoreactive for vimentin, NKI-C3, NSE, CD68 and smooth muscle actin. There was no recurrence 2 and 7 months after the operation. Cellular neurothekeoma is a benign tumor. Its histogenesis is still unknown. Histological and immunohistochemical features, with positivity of the tumor cells for NKI-C3, a non specific melanocytic marker, and negativity for S-100 protein and HMB-45, allow to differentiate cellular neurothekeoma from myxoid neurothekeoma and melanocytic tumors.

[Cystic mesothelioma of the peritoneum in a male]

We report a case of cystic mesothelioma of the peritoneum in a young male with local recurrences and whose diagnosis was confirmed by standard histological studies and immunohistochemistry. This rare tumor appears generally in young females through abdominal pain and mass. Local recurrences without distant metastases are a feature of this pathology. The adequate treatment requires complete resection.

Whipple's disease: benefit of the fine-needle aspiration cytology from lymph nodes

We report a case of Whipple's disease with predominant neurological symptoms and without any clinical digestive sign. The diagnosis was suspected by fine-needle aspiration from an axillary lymph node and confirmed by the duodenal biopsy and ultrastructural results. Whipple's disease is a rare, chronic, systemic infectious disease. Electron microscopy and PCR on paraffin blocks are very helpful when histologic findings are not discriminant. On cytologic examination, the major differential diagnosis is mycobacterial adenitis. Here we highlight the possibility of diagnosis Whipple's disease on mere cytological material.

[Isolated vasculitis of the spermatic cord]

The authors report a case of isolated spermatic cord vasculitis associated with testicular infarct in a 75-year-old man. No clinical symptoms or serological markers of a systemic disease were found. This is a rare disease which cannot be diagnosed without histological examination and which requires follow-up because of a risk of progression to autoimmune disease.