Targeting a membrane-proximal epitope on mesothelin increases the tumoricidal activity of a bispecific antibody blocking CD47 on mesothelin-positive tumors

Mesothelin (MSLN) is a cell surface glycoprotein overexpressed in several solid malignancies, including gastric, lung, mesothelioma, pancreatic and ovarian cancers. While several MSLN-targeting therapeutic approaches are in development, only limited efficacy has been achieved in patients. A potential shortcoming of several described antibody-based approaches is that they target the membrane distal region of MSLN and, additionally, are known to be handicapped by the high levels of circulating soluble MSLN in patients. We show here, using monoclonal antibodies (mAbs) targeting different MSLN-spanning epitopes, that the membrane-proximal region resulted in more efficient killing of MSLN-positive tumor cells in antibody-dependent cell-mediated cytotoxicity (ADCC) assays. Surprisingly, no augmented killing was observed in antibody-dependent cellular phagocytosis (ADCP) by mAbs targeting this membrane-proximal region. To further increase the ADCP potential, we, therefore, generated bispecific antibodies (bsAbs) coupling a high-affinity MSLN binding arm to a blocking CD47 arm. Here, targeting the membrane-proximal domain of MSLN demonstrated enhanced ADCP activity compared to membrane-distal domains when the bsAbs were used in in vitro phagocytosis killing assays. Importantly, the superior anti-tumor activity was also translated in xenograft tumor models. Furthermore, we show that the bsAb approach targeting the membrane-proximal epitope of MSLN optimized ADCC activity by augmenting FcγR-IIIA activation and enhanced ADCP via a more efficient blockade of the CD47/SIRPα axis.

The effect of long-range order on intermolecular interactions in organic semiconductors: zinc octaethyl porphyrin molecular thin film model systems

In order to optimize the performance of devices based on porphyrin thin films it is of great importance to gain a physical understanding of the various factors which affect their charge transport and light-harvesting properties. In this work, we have employed a multi-technique approach to study vacuum deposited zinc octaethyl porphyrin (ZnOEP) thin films with different degrees of long-range order as model systems. An asymmetrical stretching of the skeletal carbon atoms of the porphyrin conformer has been observed and attributed to ordered molecular stacking and intermolecular interactions. For ordered films, a detailed fitting analysis of the X-ray absorption near edge structure (XANES) using the MXAN code establishes a symmetry reduction in the molecular conformer involving the skeletal carbon atoms of the porphyrin ring; this highlights the consequences of increased π-π stacking of ZnOEP molecules adopting the triclinic structure. The observed asymmetrical stretching of the π conjugation network of the porphyrin structure can have significant implications for charge transport and light harvesting, significantly influencing the performance of porphyrin based devices.

Co-engaging CD47 and CD19 with a bispecific antibody abrogates B-cell receptor/CD19 association leading to impaired B-cell proliferation

CD19 is a B cell-specific receptor that regulates the threshold of B cell receptor (BCR)-mediated cell proliferation. A CD47xCD19 bispecific antibody (biAb) was generated to target and deplete B cells via multiple antibody-mediated mechanisms. Interestingly, the biAb, constructed of a CD19 binding arm and a CD47 binding arm, inhibited BCR-mediated B-cell proliferation with an effect even more potent than a CD19 monoclonal antibody (mAb). The inhibitory effect of the biAb was not attributable to CD47 binding because a monovalent or bivalent anti-CD47 mAb had no effect on B cell proliferation. Fluorescence resonance energy transfer analysis demonstrated that co-engaging CD19 and CD47 prevented CD19 clustering and its migration to BCR clusters, while only engaging CD19 (with a mAb) showed no impact on either CD19 clustering or migration. The lack of association between CD19 and the BCR resulted in decreased phosphorylation of CD19 upon BCR activation. Furthermore, the biAb differentially modulated BCR-induced gene expression compared to a CD19 mAb. Taken together, this unexpected role of CD47xCD19 co-ligation in inhibiting B cell proliferation illuminates a novel approach in which two B cell surface molecules can be tethered, to one another in order, which may provide a therapeutic benefit in settings of autoimmunity and B cell malignancies.

Preclinical Development of a Bispecific Antibody that Safely and Effectively Targets CD19 and CD47 for the Treatment of B-Cell Lymphoma and Leukemia

CD47, an ubiquitously expressed innate immune checkpoint receptor that serves as a universal "don't eat me" signal of phagocytosis, is often upregulated by hematologic and solid cancers to evade immune surveillance. Development of CD47-targeted modalities is hindered by the ubiquitous expression of the target, often leading to rapid drug elimination and hemotoxicity including anemia. To overcome such liabilities, we have developed a fully human bispecific antibody, NI-1701, designed to coengage CD47 and CD19 selectively on B cells. NI-1701 demonstrates favorable elimination kinetics with no deleterious effects seen on hematologic parameters following single or multiple administrations to nonhuman primates. Potent in vitro and in vivo activity is induced by NI-1701 to kill cancer cells across a plethora of B-cell malignancies and control tumor growth in xenograft mouse models. The mechanism affording maximal tumor growth inhibition by NI-1701 is dependent on the coengagement of CD47/CD19 on B cells inducing potent antibody-dependent cellular phagocytosis of the targeted cells. NI-1701-induced control of tumor growth in immunodeficient NOD/SCID mice was more effective than that achieved with the anti-CD20 targeted antibody, rituximab. Interestingly, a synergistic effect was seen when tumor-implanted mice were coadministered NI-1701 and rituximab leading to significantly improved tumor growth inhibition and regression in some animals. We describe herein, a novel bispecific antibody approach aimed at sensitizing B cells to become more readily phagocytosed and eliminated thus offering an alternative or adjunct therapeutic option to patients with B-cell malignancies refractory/resistant to anti-CD20-targeted therapy. Mol Cancer Ther; 17(8); 1739-51. ©2018 AACR.

Evidence for a Strong Topological Insulator Phase in ZrTe_{5}

The complex electronic properties of ZrTe_{5} have recently stimulated in-depth investigations that assigned this material to either a topological insulator or a 3D Dirac semimetal phase. Here we report a comprehensive experimental and theoretical study of both electronic and structural properties of ZrTe_{5}, revealing that the bulk material is a strong topological insulator (STI). By means of angle-resolved photoelectron spectroscopy, we identify at the top of the valence band both a surface and a bulk state. The dispersion of these bands is well captured by ab initio calculations for the STI case, for the specific interlayer distance measured in our x-ray diffraction study. Furthermore, these findings are supported by scanning tunneling spectroscopy revealing the metallic character of the sample surface, thus confirming the strong topological nature of ZrTe_{5}.

Extended co-expression of inhibitory receptors by human CD8 T-cells depending on differentiation, antigen-specificity and anatomical localization

Inhibitory receptors mediate CD8 T-cell hyporesponsiveness against cancer and infectious diseases. PD-1 and CTLA-4 have been extensively studied, and blocking antibodies have already shown clinical benefit for cancer patients. Only little is known on extended co-expression of inhibitory receptors and their ligands. Here we analyzed the expression of eight inhibitory receptors by tumor-antigen specific CD8 T-cells. We found that the majority of effector T-cells simultaneously expressed four or more of the inhibitory receptors BTLA, TIM-3, LAG-3, KRLG-1, 2B4, CD160, PD-1 and CTLA-4. There were major differences depending on antigen-specificity, differentiation and anatomical localization of T-cells. On the other hand, naive T-cells were only single or double positive for BTLA and TIM-3. Extended co-expression is likely relevant for effector T-cells, as we found expression of multiple ligands in metastatic lesions of melanoma patients. Together, our data suggest that naive T-cells are primarily regulated by BTLA and TIM-3, whereas effector cells interact via larger numbers of inhibitory receptors. Blocking multiple inhibitory receptors simultaneously or sequentially may improve T-cell based therapies, but further studies are necessary to clarify the role of each receptor-ligand pair.

Extended co-expression of inhibitory receptors by human CD8 T-cells depending on differentiation, antigen-specificity and anatomical localization

Inhibitory receptors mediate CD8 T-cell hyporesponsiveness against cancer and infectious diseases. PD-1 and CTLA-4 have been extensively studied, and blocking antibodies have already shown clinical benefit for cancer patients. Only little is known on extended co-expression of inhibitory receptors and their ligands. Here we analyzed the expression of eight inhibitory receptors by tumor-antigen specific CD8 T-cells. We found that the majority of effector T-cells simultaneously expressed four or more of the inhibitory receptors BTLA, TIM-3, LAG-3, KRLG-1, 2B4, CD160, PD-1 and CTLA-4. There were major differences depending on antigen-specificity, differentiation and anatomical localization of T-cells. On the other hand, naive T-cells were only single or double positive for BTLA and TIM-3. Extended co-expression is likely relevant for effector T-cells, as we found expression of multiple ligands in metastatic lesions of melanoma patients. Together, our data suggest that naive T-cells are primarily regulated by BTLA and TIM-3, whereas effector cells interact via larger numbers of inhibitory receptors. Blocking multiple inhibitory receptors simultaneously or sequentially may improve T-cell based therapies, but further studies are necessary to clarify the role of each receptor-ligand pair.

Exhaustion of tumor-specific CD8⁺ T cells in metastases from melanoma patients

In chronic viral infections, CD8⁺ T cells become functionally deficient and display multiple molecular alterations. In contrast, only little is known of self- and tumor-specific CD8⁺ T cells from mice and humans. Here we determined molecular profiles of tumor-specific CD8⁺ T cells from melanoma patients. In peripheral blood from patients vaccinated with CpG and the melanoma antigen Melan-A/MART-1 peptide, we found functional effector T cell populations, with only small but nevertheless significant differences in T cells specific for persistent herpesviruses (EBV and CMV). In contrast, Melan-A/MART-1-specific T cells isolated from metastases from patients with melanoma expressed a large variety of genes associated with T cell exhaustion. The identified exhaustion profile revealed extended molecular alterations. Our data demonstrate a remarkable coexistence of effector cells in circulation and exhausted cells in the tumor environment. Functional T cell impairment is mediated by inhibitory receptors and further molecular pathways, which represent potential targets for cancer therapy.

Recurrent and de novo diabetic nephropathy in renal allografts

BACKGROUND

Histologic findings of diabetic nephropathy (DN) are observed in allografts of patients with pretransplant (PreTx) diabetes mellitus (DM) and in patients who develop DM posttransplant (PostTx). Patients with allograft biopsies (Bx) were retrospectively studied to determine the incidence of recurrent and de novo DN and to ascertain what, if any, risk factors predispose to histologic DN in either patient population.

METHODS

From the renal transplant services at four hospitals from 1992 to 2000, the authors identified all patients with PreTxDM and PostTxDM (n=81). Those with renal biopsies performed >/=18 months PostTx were classified according to the presence or absence of histologic DN (Bx-positive, n=23; Bx-negative, n=35). Patients were then subdivided into four categories-recurrent DN (n=16), de novo DN (n=7), no recurrent DN (n=27), and no de novo DN (n=8)-for analyses.

RESULTS

Among these 58 patients, 74.1% had PreTx and 25.9% had PostTx diabetes. Of those with histologic DN, 69.6% were recurrent DN and 30.4% were de novo DN, making de novo DN at least as likely to develop as recurrent DN. After the onset of diabetes in the de novo population, the time to development of histologic DN was similar in the recurrent and the de novo patients (6.68+/-3.86 years vs. 5.90+/-3.13 years, P=0.66) and more rapid than previously reported. Apart from a more frequent family history of hypertension in patients with allograft DN compared with those without allograft DN, known risk factors for the development of native DN did not significantly differ among patients in the four cohorts. Proposed risk factors related to transplantation did not correlate with the development of recurrent or de novo DN.

CONCLUSION

Among patients with histologic DN, de novo DN occurred at least as frequently as recurrent DN, and the time to onset of histologically apparent DN was more rapid than previously reported. Neither the usual clinical predictors of DN nor clinical variables related to transplantation clearly distinguished the group with DN from the group without it, potentially implicating novel mechanisms in its pathogenesis.

Analysis and toxicity of methomyl and ametryn after biodegradation

The controlled biodegradation of ametryn and methomyl has been performed, in accordance with the OECD Zahn-Wellens/EMPA procedure, by use of an enriched mixture of activated sludge collected from three domestic waste-water-treatment plants (WWTP). During the process concentrations of ametryn and methomyl in the water samples were isolated by solid-phase extraction (SPE); recovery rates were 98.9 and 93.2 for methomyl and ametryn, respectively. Liquid chromatography-mass spectrometry (LC-MS) was used to determine final pesticide concentrations and for metabolite identification. The efficiency of aerobic biodegradation of ametryn and methomyl was evaluated by measuring both the decrease in the concentration of the pesticides and global properties such as the chemical oxygen demand (COD). The acute toxicity of ametryn and methomyl was evaluated by use of the ToxAlert100 biological test, which is based on inhibition of the bioluminescence of Vibrio fischeri. There was significant correlation between results from primary and ultimate biodegradation and those from determination of toxicity. Pesticide concentrations were always reduced to below the limit of detection in less than 17 days. High COD removal (90-96%) was achieved in 28 and 18 days for methomyl and ametryn, respectively.

Glomerular mRNAs in human type 1 diabetes: biochemical evidence for microalbuminuria as a manifestation of diabetic nephropathy

BACKGROUND

In patients with type 1 diabetes, some consider microalbuminuria to be a predictor of diabetic nephropathy while others believe it is an early feature of diabetic nephropathy.

METHODS

Levels of mRNAs that are of pathogenetic relevance in diabetic nephropathy were compared in glomeruli isolated from microalbuminuric and overtly proteinuric subjects and in control normoalbuminuric diabetic subjects and living renal transplant donors.

RESULTS

In subjects with microalbuminuria and overt proteinuria, glomerular mRNAs were virtually identical and approximately twofold higher for connective tissue growth factor (CTGF; P < 0.01) and collagen alpha2(IV) (P < 0.03) compared to living renal donors and normoalbuminuric patients. Glomerular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) levels were not significantly different among the groups (P = 0.4). Weak but statistically significant correlations were noted between CTGF mRNA and albuminuria (assessed by rank), fractional mesangial surface area, and a composite renal biopsy index. Glomerular CTGF mRNA correlated inversely with creatinine clearance. Glomerular collagen alpha2(IV) mRNA levels correlated with albuminuria (by rank) and less strongly with fractional mesangial area.

CONCLUSION

To our knowledge, these data provide the first biochemical evidence demonstrating that the glomeruli of microalbuminuric patients and those with overt proteinuria do not differ significantly. The data support the concept that microalbuminuria is not "predictive" of diabetic nephropathy, but rather is an earlier point in the spectrum of diabetic nephropathy.

[Single-compartment knee arthroplasty prosthesis and idiopathic necrosis of the medial tibia surface]

PURPOSE OF THE STUDY

Idiopathic necrosis of the medial articular surface of the tibia is exceptional. Diagnosis is quite difficult and often made late. Among the different treatments proposed, we preferred single-compartment arthroplasty.

MATERIAL AND METHODS

We report 8 cases in women with a mean age of 71.1 years. Diagnosis was suspected due to drug-resistant knee pain, particularly frequent at night, initially with radiographically normal knees. The first radiographic signs, seen 3 months after the onset of pain, were pathognomonic for osteonecrosis evidencing subchondral defects of the tibial surface with a dense peripheral rim and apparently "sequestered" in a notch. Bone scintigraphy evidenced intense uptake in the medial compartment. MRI confirmed the diagnosis evidencing a band of low intensity signals completely surrounding a sequestered zone reaching the cortical. This band was stable and irreversible. In 5 cases CT scan and in 3 cases tomography identified the width and height of the necrotic area that was limited to the medial compartment in all cases. All patients were treated with a single compartment implant. The diagnosis of necrosis was confirmed at pathology.

RESULTS

At 4,6 years of mean follow up all patients had an excellent outcome, "forgetting" their knee. No lucent lines developed along the femoral or tibial implants.

DISCUSSION

Necrosis of the medial articular surface of the tibia is exceptional and often diagnosed late by bone scintigraphy or MRI. Surgical treatment is usually based on tibial osteotomy for valgisation or a single or three-compartment prosthesis. In our 8 cases, the necrosis was limited to the medial compartment, warranting our therapeutic option.

Glomerular type IV collagen in patients with diabetic nephropathy with and without additional glomerular disease

BACKGROUND

Type IV collagen is a constituent of mesangial matrix and is increased in amount in many forms of glomerular injury.

METHODS

We performed renal biopsies in patients who (1) were donating a kidney to a relative (LRD, N = 6), (2) had diabetic glomerulopathy with or without nephrosclerosis (DM, N = 6), or (3) had diabetic glomerulopathy with a superimposed glomerular lesion (DM+, N = 5). Glomerular collagen alpha2(IV) and control glyceraldehyde-3-phosphate dehydrogenase (GAPDH) mRNAs were measured, and the former correlated with clinical and morphological data to assess its usefulness in reflecting glomerular injury.

RESULTS

Collagen alpha2(IV) mRNA levels were lowest in LRD (2.9 +/- 0.6 attomol/glomerulus), higher in DM (5.9 +/- 1.6, P = 0.05), and highest in DM+ (12.7 +/- 2.8 attm/glomerulus, P < 0.05 vs. LRD and vs. DM). Control GAPDH mRNA levels were not significantly different (P > 0.05). Levels of proteinuria, serum creatinine, and glomerular size did not correlate with collagen alpha2(IV) mRNA levels. The fractional mesangial area and the fractional mesangial area occupied by type IV collagen were higher in both diabetic groups than in LRD (P < 10-6), but the intensity of type IV collagen staining in the diabetic patients was significantly less than that seen in the LRD (P < 0.01). In DM+ patients, extramesangial type IV collagen was present. Fractional mesangial area and glomerular collagen alpha2(IV) mRNA levels correlated (r = 0.45, P < 0.05).

CONCLUSION

These data are consistent with a view of diabetic nephropathy as a lesion of increased alpha2 type IV collagen transcription, increased total amount of collagen present, but decreased mesangial density relative to other matrix molecules. These data further demonstrate that glomerular injury superimposed on diabetic nephropathy contributes to additional structural damage by inducing increased synthesis of type IV collagen at extramesangial sites.

[Osteolysis after total knee prosthesis]

PURPOSE OF THE STUDY

The aim of our work was to study X-rays showing osteolysis after 5 years and more in 122 prosthesis and to try and assess such complication, often described in the United States but seldom in Europ.

MATERIAL

We are dealing here with 122 retaining posterior cruciate ligament, mostly cementless prothesis implanted between 1985 and 1992 84 chromium-cobalt prosthesis (PCA and Themis) implanted in 34 males and 88 females with an average age of 67 (45-81), 87,7 p. 100 had femoral cementless components and 70 p. 100 tibial cementless components.

METHODS

All patients were examined and had X-rays at an average of 6,9 years. Specially considered were X-rays showing a possible osteolysis. We looked for possible complication (external laxity, anterior femoral dislocation and polyethylene wear), assessment of the mechanical axis and for clinical results (Hungerford score)

RESULTS

Revisions: 19 arthroplasties were revised for PE wear tibial loosening metallosis or patella problems The postoperative score according to Hungerford was 84,5 p. 100 for PCA prosthese and 87 p.100 for the Themis. On the X-rays were only few osteolysis to be found: 9 cases (7,3 p. 100). For the PCA series: 3 femoral osteolysis, 1 tibial at 12 years, and one patellar osteolysis. For the Themis series: no femoral osteolysis, 3 tibial and one patellar osteolysis. Osteolysis are apparent on X-rays in profile for the femur and the patella, and in both profile and frontal X-rays for the tibia. Clinicaly 4 osteolysis really asymptomatic were not re-operated. 5 were revised: one 11 years later for femoral and tibial loosening, two for a patellar loosening, the other two patients had to be reoperated on for metallism (titanium's femoral component) and for those two instances osteolysis were discovered during the complication.

DISCUSSION

Osteolysis after TKA appears unusual in our experience without bearing on frequency finded by american authors with a lesser follow-up (Engh 11,1 p. 100 after 4,5y, Peters 16 p. 100 after 2,9 y, Robinson 9,18 p. 100 after 4,6 y). American litteratur analysis shows that the important number of osteolysis is due to: - either to dual-metal using (Co-Cr component with Titanium screws for exemple), - or bad quality of polyethylene (compressed), - or a bad design of former prosthesis.

CONCLUSION

Interface illness, linked to the production of wear debris, osteolysis after total knee arthroplasty is rarer than after a hip one, probably because size of debris is different, larger in knee than in hip. It is likely that the improvement of PE quality, design of prosthesis, as well as a better knowledge of osteolysis mechanism will allow to delay this complication wich is in a long term ineluctable.

Structure of sulfur-substituted rhodanese at 1.36 A resolution

1.36 A resolution X-ray diffraction data have been recorded at 100 K for bovine liver sulfur-substituted rhodanese, using synchrotron radiation. The crystal structure has been refined anisotropically to a final R factor of 0.159 (Rfree = 0.229) for 53034 unique reflections. The model contains 2327 protein atoms and 407 solvent molecules, with a good geometry. The high resolution allows full details for helices, beta-sheets, tight turns and of all inter- and intramolecular interactions stabilizing the enzyme molecule to be given. The situation at the active site is described, particularly in regard to the network of hydrogen bonds made by Sgamma and Sdelta of the sulfur-substituted catalytic Cys247 and surrounding groups and solvent molecules. The replacement of the precipitant ammonium sulfate with cryoprotectants in the crystal-suspending medium led to the removal of the sulfate ion from the enzyme active site. Only limited changes of the enzyme structure have been found as a result of the drastic change in the crystal medium.

Patient death or renal graft loss within 3 yr of transplantation in a county hospital: importance of poor initial graft function

Our purpose was to study the factors predictive of graft loss or patient death within 3 yr of renal transplant in a county population. 363 renal transplants performed between 1984 and 1991 at the Harbor-UCLA Medical Center were reviewed. There were 16 recipients (4%) who died and 76 (21%) who lost their grafts within 3 yr. Known causes of death were cardiac (44%), infection (38%) and malignancy (6%). There was a higher proportion of diabetics (44%), hypertensives (69%) and those with a past cardiac history (38%). There was also a high delayed graft function rate (56%). Of the 76 grafts that failed in the first 3 yr, 14% were due to noncompliance, 20% to grafts that never functioned, 9% to technical problems, 21% to acute rejection, 9% to recurrent disease and 26% to chronic rejection. The noncompliance group were younger (mean 34 yr), and more likely to be a first transplant (90%) and be non-white (82%). The rejection group was significant for high delayed graft function rate (84%) and frequent and early rejection (76% at least one rejection). We conclude that fair organ allocation requires a balance between equity and utility, but patient death or graft loss within 3 yr benefits neither the patient or society. Patient survival may be improved with diligent cardiac evaluation, particularly in older patients and diabetics. Patient education and monitoring for noncompliance is essential, particularly in young first-time recipients. Maneuvers to decrease delayed graft function are essential to improve long-term results.

Improved survival of en bloc renal allografts from pediatric donors

PURPOSE

We developed a technical and immunological protocol to increase survival of renal transplants from pediatric donors.

MATERIALS AND METHODS

En bloc kidneys (22) were procured from donors weighing 2 to 14 kg. (1 to 60 months old) and transplanted into adult recipients. In group 1 (12 patients) sequential therapy was used for kidneys with more than 35 hours of cold storage and immediate triple therapy (cyclosporine, azathioprine and prednisone) was used for those with less than 35 hours of cold storage. In group 2 (10 patients) OKT3 induction therapy was used. Mean followup was 4.7 years.

RESULTS

Mean blood pressure at 1 and 4 years was not significantly different between the groups. Mean serum creatinine was not significantly different between the groups at 1 year but it was significantly less in group 2 at 4 years (1.9 +/- 1.0 versus 1.2 +/- 0.24 mg./dl., p <0.05). At 1 year of followup the complication rate was 75% in 9 of 12 patients in group 1, including 4 infections or leaks (2 lost), 6 rejections (3 lost) and 3 cases of thrombosis or hemorrhage, and 20% (p <0.01) in group 2 (1 patient had the hemolytic uremic syndrome leading to graft loss). Graft survival was significantly greater in group 2 at all 4 years of followup (p = 0.05).

CONCLUSIONS

The success of pediatric en bloc renal transplantation can be enhanced by induction therapy in healthy recipients.

Interleukin-12 mRNA levels in renal allograft fine-needle aspirates do not correlate with acute transplant rejection

TH1 cytokines, including gamma-interferon (IFN), are critical in the initiation and progression of allograft rejection. As interleukin (IL)-12 up-regulates gamma-IFN, we assessed the role of IL-12 in human transplant rejection. Twenty renal allograft fine-needle aspirates from 19 patients were obtained, evaluated in the standard fashion, and assessed for gamma-IFN and IL-12p40 subunit mRNA levels using nested reverse transcriptase polymerase chain reaction. Ten aspirates demonstrated acute rejection by clinical criteria, and 9 of the 10 aspirates contained gamma-IFN while only 3 demonstrated IL-12; there were no distinguishing characteristics for these 3 patients with regard to therapy, or time of onset and severity of rejection. Seven patients without clinical or morphologic rejection failed to demonstrate gamma-IFN or IL-12. Three patients had discrepant findings; there was no morphologic rejection, yet all 3 patients contained gamma-IFN and 1 patient demonstrated rejection on subsequent biopsy. However, only 1 aspirate exhibited IL-12 and this patient had no documented subsequent rejection. This study confirms the association of gamma-IFN mRNA with acute rejection. In contrast, IL-12 mRNA does not appear to play a key role early in the rejection process.

Revision technique for failed unicompartmental knee arthroplasty

The main objective is to fit a total tricompartmental knee prosthesis. Conserving the ligaments and preserving the healthy bone are therefore the two main requirements. The surgical approach is, in most cases, parapatellar anteriorly and medially except in certain specific cases (lateral UKA). Total synovectomy is always necessary. The condition of the posterior cruciate ligament (PCL) should be evaluated with great precision, as this will indicate the type of revision prosthesis to be used. Bone cuts will be performed with the unicompartmental prosthesis in place. Bone grafts or filling blocks are rarely used; they are most often used in revising cemented unicompartmental knee prostheses.

Monitoring changes in cyclosporine dosage by trough level testing

The concept of a narrow therapeutic window has guided the management of transplant recipients on cyclosporine immunosuppression since its inception more than a decade ago. The need to maintain immunosuppression and avoid toxicity imposed the requirement of monitoring cyclosporine levels within a limited range. The use of circulating trough levels to aid in the adjustment of dosage, however, has also led to controversies. Trough levels did not immediately reflect the dose, and circulating drug levels varied even in the absence of dose changes, indicating the role of factors other than the dose. By introducing a time factor or delay between the dose and trough levels, the sequential delay analysis allows a clearer demonstration of the relationship between doses and trough levels. Using dose adjustments as markers, corresponding changes in the trough levels were observed for most markers after a short delay. The existence of a time factor imposes some restrictions on the scheduling of dose changes and trough level tests. Adjustments in dose need to be separated to avoid interference from each other and the frequency of testing after a change increased to assure its detection. Consideration of the delay should aid in the adjustment of doses and provide an initial step in the understanding of other factors in the relationship between the dose and circulating trough levels.

Intrarenal extramedullary erythropoiesis in renal allograft fine-needle aspirates

Recombinant human erythropoietin (rhEPO) is widely used in patients with end-stage renal disease and occasionally in renal allograft recipients to correct anemia. Red blood cell production is markedly increased by rhEPO; however, no extramedullary erythropoiesis (EME) has been associated with this hormone. We observed intrarenal EME in five allograft fine-needle aspirates performed for reduced graft function in four patients between 3.7 and 7 weeks following transplantation. These four patients received rhEPO during dialysis and three resumed rhEPO therapy after transplantation; all four remained anemic. Donors were between 13 months and 13 years of age, with one pediatric and three adult recipients. Aspirates with apparently incidental EME contained all stages of red blood cell precursors, but these cells were not observed in corresponding peripheral blood samples. The hematopoietic cells could be readily distinguished from cells of lymphoid origin. There were no correlations between intragraft EME and aspirate or clinical diagnosis referable to renal dysfunction. Aspirates performed prior to 3.7 weeks or after 7 weeks did not demonstrate EME. These data suggest that endogenous EPO and rhEPO in anemic patients receiving pediatric renal allografts may activate red blood cell precursors in the young graft, inducing intrarenal EME. Recognition of this entity is important to distinguish it from immune activation or malignancy within the donor organ.

Differentiation of cytomegalovirus infection from acute rejection using renal allograft fine needle aspirates

Cytomegalovirus (CMV) infection is an important cause of renal allograft dysfunction and may be difficult to distinguish from acute transplant rejection both clinically and histologically. To establish the early diagnosis of CMV infection, we used immunohistochemical staining with antibodies against CMV early nuclear protein (CMV-A) and histocompatibility leukocyte class II antigen (DR) in renal transplant fine needle aspirates. Fifty-eight aspirates from 27 patients were assessed, 53 for CMV-A and 53 for DR. Positive staining was defined as greater than or equal to 35% stained tubular cells for CMV-A and greater than or equal to 30% stained tubular cells for DR. Clinical diagnoses were made retrospectively without using the information obtained from aspirate diagnoses. CMV-A staining was negative in 44 aspirates, none at the time of CMV infection. CMV-A was positive in nine aspirates, seven during CMV infection (78%, P less than 0.00001 versus CMV-A negative). DR staining was never present in the absence of acute rejection. All aspirates performed during acute rejection had positive DR staining (P less than 0.00001 versus DR negative). Aspirates with acute rejection comprised 80% of all DR-positive aspirates, whereas those with CMV infection included only 13%. The percent CMV-A staining increased with CMV disease progression; DR staining decreased after successful treatment of acute rejection. These data demonstrate that CMV-A staining is associated with CMV infection whereas DR staining is not. DR staining is specifically related to acute rejection. CMV-A and DR staining of fine needle aspirates is a potentially valuable diagnostic tool to distinguish rapidly between CMV infection and acute transplant rejection as the etiology of renal allograft dysfunction.

Treatment of slipped upper femoral epiphysis: 80 cases operated on over 10 years (1968-1978)

Guidelines are proposed for the treatment of slipped upper femoral epiphysis based on the analysis of 80 cases. Treatment is strictly surgical, but the procedure to be employed depends on the degree of displacement. Major operations are reserved for maximum tilting of the epiphysis: Dunn's operation when the growth plate is still open, trochanteric osteotomy once it has closed. Complications of treatment are epiphyseal necrosis and stiffness.

Diagnostic immunopathology of the kidney biopsy in rheumatic diseases

Nephropathies found in systemic lupus erythematosus (SLE), progressive systemic sclerosis, rheumatoid arthritis, Sjögren's syndrome, and mixed connective tissue disease are discussed. Pathogenetic insights derived from the study of kidney tissue are highlighted and clinicopathologic correlations indicated. The question of whether to perform kidney biopsy in lupus patients is also addressed.

[Post-traumatic discoligamentous lesions of the lower cervical spine : delayed diagnosis of a second lesion (author's transl)]

Unilateral luxation of the lower cervical spine was diagnosed following injury in a patient, an associated severe subjacent ligamentous sprain remaining undetected until a later date. The reasons for the delay in making the second diagnosis are exposed. The possibility of employing peridurography in order to treat these discoligamentous lesions simultaneously, is discussed.