Prognostic Significance of PD-L1 in Patients with Non-Small Cell Lung Cancer: A Large Cohort Study of Surgically Resected Cases.

INTRODUCTION: The aim of our analysis was to evaluate the prognostic effect of programmed cell death ligand-1 (PD-L1) expression in patients with non-small cell lung cancer (NSCLC). METHODS: PD-L1 expression among 1070 surgically resected NSCLC specimens was evaluated by immunohistochemical analysis. Data were analyzed using Cox proportional hazard models adjusting for age, sex, smoking status, histologic type, stage, and performance status. RESULTS: Sixty-eight patients (6%) were strongly PD-L1 positive and 410 (38%) were weakly PD-L1 positive. A significantly higher prevalence of PD-L1 positivity was observed among patients with squamous cell carcinoma and among stage IIIB and IV patients. PD-L1 expression may be associated with poorer overall survival, with an adjusted hazard ratio of 1.56 (95% confidence interval [CI]: 1.08-2.26, p = 0.02) for strong PD-L1 positivity, 1.18 (95% CI: 0.96-1.46; p = 0.12) for weak PD-L1 positivity, and 1.23 (95% CI: 1.00-1.51; p = 0.05) for the combined strongly and weakly positive groups compared with PD-L1 negativity. Negative prognostic effect of PD-L1 expression was not statistically significant after adjustment for postoperative chemotherapy or radiotherapy. Similar results were observed for progression-free survival. Among stage I patients, the disease recurrence rate was higher in the PD-L1-positive versus in the PD-L1-negative group (48% versus 27%, p < 0.001), with an adjusted hazard ratio for disease-free survival of 2.01 (95% CI, 1.08-3.73; p = 0.03) for strong PD-L1 positivity and 1.57 (95% CI, 1.17-2.11; p = 0.003) for weak PD-L1 positivity compared with PD-L1 negativity. CONCLUSIONS: Tumor PD-L1 expression may be associated with poor prognosis in patients with NSCLC, although its significance weakens when postoperative therapy is considered.

Melanotic neuroectodermal tumor of infancy. Clinicopathological, immunohistochemical, and flow cytometric study.

Twenty cases of melanotic neuroectodermal tumor of infancy (MNTI) are reported. The patients (13 females, seven males), whose ages ranged from 1 to 9 months (mean, 5 months), typically presented with a rapidly growing mass. Tumor sites included the maxilla (13 cases), mandible (three cases), dura (two cases), brain (one case), and skull/orbit (one case). The mean tumor size was 3.5 cm (range, 1.0-10.0 cm). Follow-up was obtained on 12 cases. Five tumors (45%) recurred within 4 months of diagnosis, but none metastasized. One surgical death occurred. Histologic appearance was distinctive, with tubular or alveolar formations of large melanin-containing cells around nests of smaller neuroblastic cells possessing scant or fibrillar cytoplasm. Twelve tumors were studied immunohistochemically; tumor was positive for cytokeratin in 12 of 12, for HMB 45 in 12 of 12, for vimentin in seven of eight, and for epithelial membrane antigen (EMA) in four of nine tumors, mainly in the large cells. Neuron-specific enolase (NSE) (seven of 12) and Leu 7 (nine of 12) were positive in small and large cells; some tumors also expressed synaptophysin (four of 12), glial fibrillary acidic protein (GFAP, three of 12 tumors), or S-100 protein (two of 12 tumors). No staining was found for chromogranin, desmin, or carcinoembryonic antigen (CEA). Eight of 10 tumors studied had interpretable results on flow cytometry (FCM) (four DNA diploid, three DNA aneuploid, and one DNA diploid with a prominent shoulder). Tumor recurred locally in two of five cases with follow-up, and we were unable to demonstrate the usefulness of FCM in predicting recurrences. Further studies are necessary to define better the potential usefulness of FCM in predicting aggressive behavior. Distinctive morphology and multiphenotypic (epithelial, neural, melanocytic) expression distinguish MNTI from melanoma and metastatic neuroblastoma.

Cytotoxic activity of graft-infiltrating lymphocytes correlates with cellular rejection in cardiac transplant patients.

Lymphocytes propagated from allografts have shown a wide spectrum of activity during rejection including cytotoxicity, proliferation, and lymphokine production. It is necessary to correlate these activities to the rejection process to understand the in vivo immune response. The frequent need to obtain a biopsy of human cardiac allografts permits the evaluation of the function of the graft-infiltrating lymphocytes (GIL) as related to development of the rejection process. Lymphocyte cultures established from biopsies taken before, during, and after rejection episodes of grade 1.0 or greater were assayed for surface antigen expression using flow cytometry, proliferative activity using a primed lymphocyte test (PLT), and cytotoxicity using a cell-mediated lympholysis assay. Fifteen rejection episodes were followed from 10 patients. Two patients were followed through two different rejection episodes and one patient through four rejection episodes. CD8+ cells usually predominated during the rejection episode. Following the rejection episodes the GIL showed a shift toward higher proportion of CD4+ cells. Most cultures taken prior to and during rejection episodes (8/9 and 12/13 assayed, respectively) demonstrated greater than 30% killing of targets bearing donor-related HLA antigens. Seven of 15 cultures remained cytotoxic after a rejection episode whereas 8 of 15 lost cytotoxicity. The patients whose cultures remained cytotoxic after a rejection episode went on to further rejection episodes at 6, 7, 11, 20, 37, or 118 days later. Those patients whose cultures were no longer cytotoxic did not experience any subsequent rejection episode until at least 257 days later.(ABSTRACT TRUNCATED AT 250 WORDS)

Clonal analysis of graft-infiltrating lymphocytes from renal and cardiac biopsies. Dominant rearrangements of TcR beta genes and persistence of dominant rearrangements in serial biopsies.

Graft-infiltrating lymphocytes from both human renal and cardiac allografts were propagated in interleukin 2 in order to evaluate rearrangements in the T-cell receptor (TcR) beta-chain genes. Individual biopsies from renal allografts during episodes of cellular rejection were examined as well as multiple biopsies of heart transplant patients from whom endomyocardial samples were taken prior to, during, and after episodes of rejection. TcR beta-chain rearrangements were evaluated in Southern blots using DNA extracted from interleukin 2-propagated cells and digested with restriction endonucleases permitting assessment of rearrangements to both C beta 1 and C beta 2. Rearrangements shared among greater than 5% of the "bulk" culture appear as nongermline bands when hybridized with a C beta probe. Single-cell progeny were generated from limiting dilution, and the rearrangements among the cloned progeny compared to the "bulk" of the cultured progeny of graft-infiltrating lymphocytes. The results indicate that "dominant" rearrangements are a common feature of renal allograft-infiltrating lymphocytes (14 of 15 cases examined). Since the number of cells which can be recovered from a given cardiac biopsy may be limiting, evaluation of clonal dominance from these cultures is more difficult to evaluate. However, sharing of "dominant" rearrangements among multiple biopsies from the same cardiac allograft patient indicates an in vivo selection for T cells with the same receptor rearrangement. Analysis of individual clones showed 3/33 clones from a renal allograft sharing the "dominant" rearrangement noted in the bulk culture, but none of these "dominant" clones showed antidonor specificity.(ABSTRACT TRUNCATED AT 250 WORDS)

Fetal rhabdomyoma of the head and neck: a clinicopathologic and immunophenotypic study of 24 cases.

Twenty-four fetal rhabdomyomas (FRMs) of the head and neck occurring in 16 male and seven female patients (sex unknown in one), ranging from 3 days to 58 years of age (median, 4.5 years) are reported. Ten patients (42%) were < or = 1 year old, six lesions (25%) were congenital, and 11 lesions (46%) occurred in patients > or = 15 years of age. The median tumor size was 3.0 cm (range, 1.0 to 12.5 cm). The FRMs presented as well-defined, solitary masses arising within the soft tissue or mucosa (2:1) of the head and neck. The median follow-up in 15 cases was 48 months (range, 2 months to 52 years) after diagnosis. With the exception of one patient with a local recurrence, all patients were either alive and well or dead of unrelated causes. Eight cases, regarded as "classic" FRM, consisted predominantly of bland, primitive spindled cells associated with delicate, elongated skeletal muscle cells reminiscent of fetal myotubules that were haphazardly arranged in an abundant fibromyxoid stroma. The remaining 16 cases, designated as "intermediate" FRM, displayed both a greater degree and a greater number of cells with skeletal muscle differentiation as well as a variety of distinctive cytologic and architectural features. These included the presence of large, ganglion cell-like rhabdomyoblasts with vesicular nuclei and prominent nucleoli, interlacing ribbon or strap-like rhabdomyoblasts with deeply acidophilic cytoplasm, broad bundles of more delicate spindled rhabdomyoblasts arranged in fascicles simulating smooth muscle, an occasional plexiform pattern with infiltration of adipose tissue and skeletal muscle, focal intimate association with peripheral nerves, and rare areas of fibroblastic proliferation. Mitoses were not found in 19 of the 24 FRM cases, but in five tumors there were 1 to 14 mitoses/50 high-power fields. Marked nuclear atypia, anaplasia, and a "cambium layer" were uniformly absent. The FRMs typically stained for myoglobin, desmin, and muscle-specific actin with focal or rare staining for vimentin, smooth muscle actin, S-100 protein, glial fibrillary acidic protein, and Leu-7. Cytokeratin, epithelial membrane antigen, and CD68 antigen (with KP1) were not detected. This study expands on previous reports of FRM and demonstrates that it has both a broader age range and histologic spectrum than previously recognized. The mitotic rates of FRM as well as certain histologic features overlap with rhabdomyosarcoma; the lack of marked nuclear atypia is an important distinguishing feature.(ABSTRACT TRUNCATED AT 400 WORDS)

Ehrlichiosis mimicking thrombotic thrombocytopenic purpura. Case report and pathological correlation.

Human ehrlichiosis is a tick-borne zoonosis caused by the newly described human hematotropic rickettsiae, Ehrlichia chaffeensis. The pathology and pathogenesis of human ehrlichiosis have not been adequately studied. Even with immunoperoxidase, the only previously known method to detect these organisms in tissue, ehrlichae are difficult or impossible to identify. This led many investigators to speculate that the pathogenesis of ehrlichiosis was not caused directly by the organism but could be caused by host-mediated injury. In this case study, a patient presented with rapidly progressive central nervous system symptoms and severe thrombocytopenia, prompting a presumptive diagnosis of thrombotic thrombocytopenic purpura (TTP). Despite corticosteroids, and later, antibiotics, the patient rapidly deteriorated and died. Postmortem examination showed hemorrhages in multiple organs and mononuclear inclusions of infection with a monocytic ehrlichia. Other findings included widespread lymphohistiocytic perivascular infiltrates, focal hepatic necroses, interstitial pneumonitis, interstitial nephritis, mononuclear phagocyte invasion and proliferation in splenic, liver, and bone marrow, and hemophagocytosis. The diagnosis was proven by serology, immunohistology with both polyclonal and monoclonal anti E chaffeensis, and polymerase chain reaction on paraffin-embedded tissues using E chaffeensis-specific oligonucleotide primers. The presence of numerous ehrlichia with notable tissue and cellular injury but without a marked host response indicate that unlike other cases of documented human ehrlichiosis, this patient died after significant direct ehrlichia-mediated injury, and that immune mechanisms initiated after ehrlichiosis played little if any role in the pathogenesis.

Adult rhabdomyoma of the head and neck: a clinicopathologic and immunophenotypic study.

Twenty-seven cases of adult rhabdomyoma (ARM) of the head and neck are reported. The 20 male and seven female patients ranged in age from 33 to 80 years (median age, 60 years). Symptoms included airway obstruction and a mass within the mucosa or soft tissue. Median tumor size was 3.0 cm (range, 1.5 to 7.5 cm). Seven patients (26%) presented with multinodular tumors and one tumor was multicentric. Follow-up was available in 19 cases and ranged from 2 months to 18.5 years after diagnosis (median, 6.0 years). Lesions recurred locally in eight cases (42%) 2 to 11 years after diagnosis (median, 6 years). One recurrence was multicentric. Histologically, ARM was composed of closely packed, large polygonal cells having abundant, eosinophilic, granular, or vacuolated glycogen-rich cytoplasm with focal cross-striations. Immunohistochemical stains confirmed skeletal muscle differentiation; the majority of tumors stained for myoglobin (21 of 21 tumors), muscle-specific actin (21 of 21 tumors), and desmin (19 of 21 tumors). Focal or rare immunoreactivity for vimentin (six of 17 cases), alpha-smooth muscle actin (17 of 20 cases), S-100 protein (14 of 21 cases), and Leu-7 (10 of 20 cases) also was detected. Cytokeratin, epithelial membrane antigen, glial fibrillary acidic protein, and CD68 antigen (with KP1) were not found. The characteristic histology and immunophenotype distinguish ARM from other lesions with which it is frequently confused, including granular cell tumor, hibernoma, oncocytoma, and paraganglioma. The expression of alpha-smooth muscle actin has not been reported previously in ARM; its presence could reflect aberrant expression of smooth muscle actin in skeletal muscle or possibly be a recapitulation of early skeletal muscle embryogenesis.

Presence of an endothelial antigen on the syncytiotrophoblast of human chorionic villi: detection by a monoclonal antibody.

We describe a monoclonal antibody, B721. This antibody reacts with an antigen present on vascular endothelium and on the syncytiotrophoblast of term chorionic villi. The antigen is absent from the trophoblast of the chorion, from the amniotic epithelium, and from normal peripheral blood or lymph node lymphocytes. We discuss the possible functional roles of the antigen. We propose that the syncytiotrophoblast, by expressing endothelial antigens, mimics endothelium and may perform endothelial functions.

Inflammatory linear verrucous epidermal nevus in patients with positive results of tests for human immunodeficiency virus 1.

Inflammatory linear verrucous epidermal nevi are rare lesions that have many similarities to psoriasis on histologic examination, and are resistant to therapy. The two lesions reported occurred in patients with positive results of tests for human immunodeficiency virus 1 and showed features consistent with psoriasis. Results of tests for immunohistochemical markers were also consistent with previous findings and expected staining patterns in lesions of psoriasis. Our findings suggest that inflammatory linear verrucous epidermal nevi represent a clonal dysregulation in growth, probably secondary to an inflammatory stimulus. Since human immunodeficiency virus 1 has been associated with onset and exacerbation of psoriasis, perhaps this virus or another secondary infection associated with human immunodeficiency virus 1 infection could also play a role in the onset of this rare lesion.

Expression of the HER-2/neu proto-oncogene in serous ovarian neoplasms.

BACKGROUND: It is unclear whether HER-2/neu proto-oncogene expression in ovarian epithelial neoplasms is related to prognosis. METHODS: The authors performed immunohistochemical stains on 20 serous tumors of low malignant potential (STLMP) in Stages I and II and 19 serious carcinomas in the same stages. They used three different commercial antibodies to make comparisons. RESULTS: Two of four Stage I STLMP in patients who experienced disease progression showed positive staining for the gene product, whereas none of seven Stage I nonprogressive STLMP showed positive staining. Five of the six Stage III nonprogressive STLMP showed positive staining, whereas none of three Stage III STLMP that progressed showed positive staining. Three carcinomas (one Stage I and two Stage III) also showed positive staining. CONCLUSIONS: Expression of HER-2/neu may be associated with high stage in serous ovarian neoplasms, but it is not likely to identify the small fraction of patients with STLMP who will experience disease progression.

Characterization of a monoclonal antibody that reacts with an activation antigen on human B cells: reactions on mitogen-stimulated blood lymphocytes and cells of normal lymph nodes.

We describe a monoclonal antibody that reacts with human B-lymphoid cells. We have characterized the reactions of this antibody on normal blood lymphocytes, with and without pokeweed mitogen stimulation, bone marrow lymphocytes, and on frozen sections of normal lymph nodes. The antibody, B532, appears to recognize an activation antigen on human B cells. This activation antigen can apparently be induced both by infection with Epstein-Barr virus and by stimulation with antigens and mitogens, but it is lost on plasma cells. In normal lymph nodes, the antigen is confined to germinal center cells and some of the cells of the "mantle" that surrounds germinal centers. The antigen is not present on T cells.

Characterization of a monoclonal antibody that reacts with activated/proliferating cells and subsets of leukemia cells.

This report describes a murine IgG2A monoclonal antibody, called L22, derived by immunizations with an Epstein-Barr virus-negative large cell lymphoma B cell line. The antigen detected by L22 is not present on normal peripheral blood cells, but is present on cells stimulated by various mitogens. The proportion of L22+ cells correlates closely with blastogenesis and 125I-uridine uptake. L22 precipitates a 89,500-dalton antigen under reducing conditions, and a 180,000-dalton antigen under nonreducing conditions. The immunoreactivity, molecular weight of the antigen, sequential immunodepletion, and blocking experiments suggest that L22 reacts with the transferrin receptor, although it did not specifically block transferrin. L22 reacts with a variable proportion of cells from virtually all human myeloid, lymphoid, and solid tumor cell lines tested. Expression of the antigen is relatively constant within a given cell line and varies to only a limited extent with DNA content or cell cycle. The antigen has been identified on rare lymph node cells in certain reactive and malignant conditions. The antibody reacts with a variable number of peripheral blood cells in certain cases of myeloid and lymphoid leukemias, but does not react with peripheral lymphocytes from patients with inflammatory conditions. Its reactivity suggests possible utility in subclassification of leukemias, and perhaps in immunotherapy, in view of the limited reactivity with nonproliferating cells.

Expression of an endothelial surface antigen on activated human lymphocytes: lymphocyte subset distribution and kinetics of antigen activation.

In this study we have utilized a monoclonal antibody, B721, to demonstrate the expression of an endothelial surface antigen on activated human lymphocytes. Using one- and two-color flow cytometry we have demonstrated that this antigen appears in vitro on cultured lymphocytes stimulated by mitogen or by MLC. The appearance and expression of the antigen are similar regardless of the stimulus. The antigen first appears on Day 2 of culture and expression continues through Day 6 of culture. At the time of its maximum expression, the antigen is present on a majority of B lymphoblasts and CD8 T lymphoblasts, but is present on only a subpopulation of CD4 T lymphoblasts. This antigen appears distinct from other lymphocyte activation antigens, endothelial antigens, and trophoblast antigens. It may play a role in lymphocyte activation and immune responses.

Immunohistologic analysis of lymphoid infiltrates in primary Sjogren's syndrome using monoclonal antibodies.

The characterization of lymphocytes infiltrating salivary glands in patients with primary Sjogren's syndrome (1 degree SS) yields insights to disease pathogenesis that are not revealed by studies of the corresponding peripheral blood lymphocytes (PBL) alone. We analyzed salivary gland lymphocytes (SGL) and PBL in 14 patients with untreated 1 degree SS using monoclonal antibodies that detect T cells, T cell subsets, B cells, and antigens associated with lymphocyte activation. A four-step biotin-avidin immunoperoxidase technique was used for salivary gland frozen sections; cell suspensions and PBL were stained cytofluorographically. A predominance of T cells (Leu 1 = L17F12; Leu 4 = OKT3) was found in SGL (greater than 75%) and PBL (76 +/- 9%) with the majority belonging to the Leu 3a (OKT4) subset. A minority of B cells (anti-delta, -kappa, -lambda) was present in both SGL and PBL; however, a subset of B cells defined by monoclonal antibody B532 was present in SGL (5 to 20%) but was absent from PBL. An increased prevalence of activation antigens (Ia; OKT10) was found on SGL T cells (greater than 50% positive) compared to PBL T cells (less than 15% positive). These studies demonstrate that specific antigenic markers on lymphocytes at the site of inflammation in 1 degree SS differ significantly from those of the corresponding PBL. These differences emphasize that theories of disease pathogenesis of 1 degree SS must include studies on SGL.

AIDS-related Kaposi's sarcoma displays differential expression of endothelial surface antigens.

The authors studied 11 cases of Kaposi's sarcoma (KS) in patients with the acquired immunodeficiency syndrome (AIDS) for their reactivity with two monoclonal antibodies (B721 and E431) that recognize endothelial cell surface antigens. Reactivity of these antibodies with KS was compared with the reactivity of other known endothelial markers (F8rAg, Ia, HCL-1). Staining was done with avidin-biotin-alkaline phosphatase immunohistochemistry on acetone-fixed frozen sections. In all samples of tumor both the spindle cell component and the vascular lining cells stained with both B721 and E431. In general, the spindle cells stained less intensely than did the vascular lining cells. There was both intratumor and intertumor variability. B721 and E431 are proposed as two additional markers for KS, and it is suggested that their reactivity with the tumor supports the hypothesis that KS is derived from vascular endothelium. The possibility is also raised that the variability of staining for vascular markers could have diagnostic possibilities, and further studies for investigation of this hypothesis are suggested.

Melanocytic activation in HIV-1 disease: HMB-45 staining in common acquired nevi. Military Medical Consortium for the Advancement of Retroviral Research.

BACKGROUND: An increase in pigmented lesions has been reported in HIV-1-infected patients. In a study of HIV-1-positive patients, we have seen patients who noticed new or changing pigmented lesions. OBJECTIVE: The goal of this study was to determine to what degree these pigmented lesions showed evidence of significant melanocytic proliferation as opposed to increased pigment production without significant melanocytic proliferation. METHODS: Biopsy specimens were studied with routine light microscopy and immunohistochemical stains including S-100 protein, HMB-45, and proliferating cell nuclear antigen. RESULTS: The lesions included two malignant melanomas and 42 benign melanocytic lesions. Significant staining of dermal melanocytes with HMB-45 was present in two of three melanomas and in 19 of 42 nevi. With stains for proliferating cell nuclear antigen there was a positive reaction in the dermal component of both melanomas and a negative reaction in the dermal cells of the nevi. CONCLUSION: In some HIV-1-infected patients there is stimulation of melanosome production without significant melanocyte proliferation.

Immunocytochemistry in the differential diagnosis of effusions: use of logistic regression to select a panel of antibodies to distinguish adenocarcinomas from mesothelial proliferations.

Many studies have shown immunohistochemistry to be beneficial in discriminating between adenocarcinoma and mesothelial reactions in effusions. Although many of these studies suggest using a panel of antibodies, none of them used statistical methods to optimize their choice of assays. In the current study, stepwise logistic regression was applied to our data to select an appropriate panel of antibodies to differentiate between adenocarcinoma and all types of mesothelial proliferations. One hundred effusions (64 cases of adenocarcinoma, 27 cases of benign mesothelial proliferations, and 9 cases of malignant mesothelial proliferations) were analyzed for their reactivity with anti-EMA, anti-MFG, anti-CEA, Leu-M1, B72.3, and the newly described epithelial membrane marker BER-EP4. An abbreviated panel consisting of anti-CEA, EMA, and B72.3 was shown to be sufficient in over 95% of our cases to accurately characterize a given effusion. When all three assays are negative, a diagnosis of adenocarcinoma is extremely unlikely, while when two or three of the assays are positive a diagnosis of adenocarcinoma is almost certain. The use of stepwise logistic regression has proven useful in the design of antibody panels as an adjunct to the differential diagnosis of effusions and may be applicable to the selection of panels in other diagnostic problems.

Analysis of B-cell antigens in normal reactive lymphoid tissue using four B-cell monoclonal antibodies.

Lymph nodes from 13 cases of reactive hyperplasia were examined with four different monoclonal antibodies to B cells. B-1 recognizes an antigen of 30,000 daltons on B cells. CB-2 was prepared with normal spleen and binds to a glycolipid. BA-1 labels surface immunoglobulin-positive cells, but not T lymphocytes or monocytes. B-532 recognizes an antigenic determinant of 45,000 daltons. Using the immunoperoxidase method on frozen sections of reactive lymph nodes, the staining patterns of these four unique antibodies showed dramatic differences. B-1 labeled 80%-90% of the germinal center cells and 10%-50% of the mantle region. Few interfollicular cells were positive. CB-2 stained predominantly in the mantle area (50%-90% positive cells), with moderate staining in the germinal center as well and less than 1% positive cells in the diffuse cortex. BA-1 exhibited predominant labeling in the mantle (50%-90%), with little staining in the germinal center. A large number of cells in the interfollicular, subcapsular, and medullary regions expressed the BA-1 antigen. The B-5 antibody demonstrated intense staining in the follicle (50%-95%). This staining often appeared to be polarized within the germinal center. The mantle zone demonstrated staining of 30%-50% of the cells. The different staining patterns of the B-cell antibodies, as demonstrated by the in situ distribution of positive cells within the lymph node, may reflect stages of development or activation of the B-cell population.