In vitro and in vivo comparison of 18F and 123I-labeled ML10 with 68Ga-Cys2-AnxA5 for molecular imaging of apoptosis.

AIM: Recently, 18F-labeled 2-(5-fluoropentyl)-2-methylmalonic acid or ML10 has been proposed as a promising PET tracer for imaging of apoptosis. In this study we compared 18F-ML10, the 123I labeled 5-iodo derivative (123I-ML10) and a 68Ga-labeled Annexin A5 (AnxA5) and evaluated them as apoptosis tracers in several distinct models. METHODS: In vivo stability and biodistribution were studied in healthy mice. Apoptosis imaging was evaluated in anti-Fas treated mice and mice with muscular apoptosis. Furthermore, 18F-ML10 and 68Ga-Cys2-AnxA5 were evaluated in a rat model with reperfused liver infarct and a rat model with cerebral infarct as well as in Daudi tumor bearing mice, before and after treatment with cyclophosphamide and/or radiotherapy. RESULTS: 18F-ML10 and 68Ga-Cys2-AnxA5 were both stable, while 123I-ML10 metabolized very quickly in vivo. All tracers showed a 3-4 times higher uptake in apoptotic muscular tissue in comparison to that in healthy muscular tissue. Animals with anti-Fas induced hepatic apoptosis showed an increased liver uptake which was most pronounced for 18F-ML10. The uptake of both 18F-ML10 and 68Ga-Cys2-AnxA5 increased in the apoptotic region surrounding the cerebral infarction and the reperfused liver infarction. Tumor uptake of 68Ga-Cys2-AnxA5, but not of 18F-ML10, was statistically significantly higher after therapy as measured with PET/MRI. CONCLUSION: All radiotracers were able to detect apoptosis in vitro and in vivo in each of the studied animal models of apoptosis. 68Ga-Cys2-AnxA5, but not 18F-ML10, allowed to visualize the effect of tumor therapy in a statistically significant way.

Translocation of the insulin-regulated aminopeptidase to the cell surface: detection by radioligand binding.

BACKGROUND AND PURPOSE: Insulin-regulated aminopeptidase (IRAP) and the insulin-dependent glucose transporter GLUT4 colocalize in specific intracellular vesicles (that is, GLUT4 vesicles). These vesicles move slowly to the cell surface, but their translocation is markedly enhanced by insulin, resulting in higher glucose uptake. Previous studies of the insulin-mediated translocation of IRAP to the cell surface have been hampered by the laborious detection of IRAP at the cell surface. We aimed to develop a more direct and faster method to detect IRAP. To this end, we used model systems with well-characterized IRAP: CHO-K1 cells expressing endogenous IRAP and recombinant HEK293 cells expressing human IRAP. A more widespread application of the method was demonstrated by the use of 3T3-L1 adipocytes. EXPERIMENTAL APPROACH: After stimulation of the cells with insulin, internalization of IRAP was inhibited by the addition of phenyl arsine oxide (PAO). Then, cell-surface IRAP was detected by the high-affinity binding of radiolabelled angiotensin (Ang) IV (either 125I or 3H). KEY RESULTS: We monitored the time- and concentration dependence of insulin-mediated translocation of IRAP in both cell lines and 3T3-L1 adipocytes. A plateau was reached between 6 and 8 min, and 10(-7) M insulin led to the highest amount of IRAP at the cell surface. CONCLUSIONS AND IMPLICATIONS: Based on the capacity of the IRAP apoenzyme to display high affinity for radiolabelled Ang IV and on the ability of PAO to inhibit IRAP internalization, we developed a more direct and faster method to measure insulin-mediated translocation of IRAP to the cell surface.

Long-term maintenance of calcineurin inhibitor monotherapy reduces the risk for squamous cell carcinomas after kidney transplantation compared with bi- or tritherapy.

The incidence of skin cancer after organ transplantation is mainly related to type, level, and duration of immunosuppression. The immunosuppressive minimization strategy reduces skin malignancies, but no data are available concerning long-term calcineurin inhibitor (CNI) monotherapy compared with bi- or tritherapy. We studied the benefits of long-term CNI monotherapy (>6 years of exposure) with regard to the incidence of squamous cell carcinomas (SCC) and basal cell carcinomas (BCC) compared with bi- or tritherapy, among first renal allograft adult recipients who were more than 6 years posttransplantation. Among 294 renal transplantations performed between 1986 and 1999, 80 patients received CNI monotherapy (MT) and 86 patients bi- or tritherapy (BTT) with a follow-up of more than 6 years. MT patients were older, had longer follow-up, and fewer biopsy-proven acute rejection episodes. The incidence of SCC was 15.9 SCC/1000 patients/year for MT vs 26.2 for BTT (P = .07). The incidence was significantly lower for patients older than 40 years (22.4 vs 56, respectively; P < .01). The incidence of BCC was 28.3 BCC/1000 patients/year for MT and 10.1 for BTT (P = .05), which failed to show a significant difference in patients older than 40 years (39.7 vs 25, respectively; P = .09). The ratio of SCC/BCC in MT was maintained around 1/2 over time, while it exceeded 2/1 in BTT after 12 years posttransplantation. Patient survival was comparable between the 2 groups. A higher graft survival rate was observed in the MT group. CNI monotherapy should be considered to be a beneficial, safe immunosuppressive minimization strategy for SCC in selected recipients.

Acute immuno-allergic interstitial nephritis caused by fluindione.

Fluindione is a vitamin K antagonist that is commonly prescribed for the treatment of cardiovascular disease and venous thromboembolism in France. Bleeding is the most common side effect of fluindione, whereas hypersensitivity reactions are rare. We describe here a patient with acute immuno-allergic interstitial nephritis caused by fluindione. Initial symptoms included fever, eosinophilia, low albuminuria, microscopic hematuria, eosinophiluria and acute renal failure. Kidney biopsy showed severe interstitial nephritis with interstitial edema, inflammatory infiltrates and tubulorrhexis. Fluindione withdrawal and corticosteroid treatment resulted in rapid recovery of renal function. A review of the literature revealed a very low incidence of fluindione-induced interstitial nephritis, with variable renal and extra-renal signs. Early recognition of this rare complication may prevent the development of severe chronic renal injury.

Cytomegalovirus prophylaxis with intravenous polyvalent immunoglobulin in high-risk renal transplant recipients.

Cytomegalovirus (CMV) seronegative renal allograft recipients (R-), particularly those with a graft from a CMV-seropositive donor (D+), are at high risk for primary CMV infection. CMV resistance to antiviral oral therapy is an emerging problem in renal transplantation, prompting development of new prophylactic strategies. We retrospectively studied the 1-year posttransplantation incidence of CMV infection in high-risk renal transplant recipients, in whom polyvalent intravenous immunoglobulins (IVIg) were used as prophylaxis. Forty R- patients received immunoprophylaxis by polyvalent IVIg (0.25 g/kg weekly for 8 weeks, starting on the operative day). CMV serological tests remained negative in eight patients (20%). Eight patients (20%) had asymptomatic CMV infection while 24 (60%) developed CMV syndrome and were treated with gancyclovir (10 mg/kg/day intravenously for 3 weeks). None had CMV disease or opportunistic infection. Six patients (15%) had biopsy-proven acute rejection, which followed CMV syndrome in three cases. One-year renal allograft and patient survivals were 95% and 97.5%, respectively. Mean serum creatinine level was 124 +/- 33 micromol/L at 1 year. Clinical tolerance of IVIg was excellent, without any episode of acute renal failure. Polyvalent IVIg provides effective prophylaxis in renal transplant recipients at high risk for CMV infection and is associated with excellent 1-year allograft survival. Because of their immunomodulatory functions, IVIg may have a beneficial effect on the incidence of acute and chronic rejection and allograft survival. A randomized prospective study is required to evaluate long-term effects of CMV prophylaxis with polyvalent IVIg compared to antiviral agents in renal transplant recipients.

Synthesis, radiosynthesis, and in vitro characterization of [125I]-2- iodo-L-phenylalanine in a R1M rhabdomyosarcoma cell model as a new potential tumor tracer for SPECT.

[125I]-2-iodo-L-phenylalanine, a new radioiodinated phenylalanine analog was evaluated as a potential specific tumor tracer for SPECT. The tracer is obtained with an overall radiochemical yield of at least 98%, a purity of > 99%, and a specific activity of 11 MBq/mmol in one pot Kit conditions using the Cu1+ assisted isotopic exchange. The tracer is evaluated in vitro using R1M rat rabdomyosarcoma cells in HEPES buffer with and without Na+ ions and in MEM buffer. The uptake of [125I]-2-iodo-L-phenylalanine follows a reversible pseudo-first-order reaction which is the same in presence and absence of Na+ ions, but the compound is not incorporated into the cell proteins. The reversible uptake is proven to occur with the same affinity as L-henylalanine by a saturable transport system which is competitively inhibited by BCH, an L transport type selective molecule. Trans-stimulation of the efflux by BCH and typical L transported amino acids shows that the transporter is of the antiport type and fulfils all the properties of the LAT1 heterodimer transport system. [125I]-2-iodo-L-phenylalanine is thus a phenylalanine analog that for the uptake uses for the major part the LAT1 transport system which is known to be over-expressed in tumor cells. This, together with the easy Kit preparation, makes [123I]-2-iodo-L-phenylalanine a promising tumor specific tracer for SPECT.

Proximal tubular dysfunction in primary Sjögren's syndrome: a clinicopathological study of 2 cases.

Tubulointerstitial nephritis is the most common renal complication in primary Sjögren's syndrome (SS). It is usually associated with symptoms of distal tubular dysfunction, type I (distal) renal tubular acidosis (RTA) and nephrogenic diabetes insipidus. Proximal tubular abnormalities are considered to be less frequent, and Fanconi's syndrome has been only exceptionally reported in patients with SS. We describe 2 patients with primary SS, characterized by xerostomia, dry eyes, extensive lymphocytic infiltrate on salivary gland biopsy, positive tests for anti-SSA/SSB antibodies and/or antinuclear antibodies, who presented in renal failure with proteinuria, microscopic hematuria and type I RTA. Further studies revealed proximal tubular dysfunction, including renal glucosuria, generalized aminoaciduria, phosphaturia, uricosuria, together with proximal (type II) RTA in 1 case. Neither of these patients had Bence Jones proteinuria or monoclonal gammopathy. Kidney biopsy showed focal proximal tubulitis, associated with proximal tubular cell atrophy and dedifferentiation, and diffuse interstitial nephritis with fibrosis. No significant glomerular or peritubular deposits of immunoglobulin light or heavy chain were observed. These findings demonstrate that diffuse, distal and proximal, tubular dysfunction may occur in patients with SS and interstitial nephritis. Lymphocytic infiltration of proximal tubular cells is probably involved in the pathogenesis of Fanconi's syndrome in SS. However, the mechanisms involved in the alteration of sodium-dependent apical transports remain to be elucidated.

Treatment of B-lymphoproliferative disorder with a monoclonal anti-interleukin-6 antibody in 12 patients: a multicenter phase 1-2 clinical trial.

Severe T-cell immunodeficiency after solid organ or bone marrow transplantation may result in the uncontrolled outgrowth of latently Epstein-Barr virus-infected B cells, leading to B-lymphoproliferative disorder (BLPD). Given the potentially important pathogenic role of IL-6 in BLPD, it was tested whether the in vivo neutralization of IL-6 by a monoclonal anti-IL-6 antibody could contribute to the control of BLPD. Safety and efficacy were assessed in 12 recipients of transplanted organs who had BLPD refractory to the reduction of immunosuppression over 8 days. Five patients received 0.4 mg/kg per day. The next 7 patients received 0.8 mg/kg per day. Treatment was scheduled to last 15 days. It was completed in 10 patients, and in the other 2 patients was discontinued early (days 10 and 13, respectively) because of disease progression. Treatment tolerance was good, and no major side effects were observed. High C-reactive protein levels were found in 9 patients before treatment but were normalized under treatment in all patients, demonstrating efficient IL-6 neutralization. Complete remission (CR) was observed in 5 patients and partial remission (PR) in 3 patients. Relapse was observed in 1 of these 8 patients in whom remission was observed. This relapse was unresponsive to treatment. Disease was stable in 1 patient, but it progressed in 3 patients. Seven patients are alive and well. Two patients died because of disease progression, and 3 patients died while in CR (chronic rejection in 2 patients and BLPD sequelae in 1 patient). These data suggest that the anti-IL-6 antibody is safe and should be further explored in the treatment of BLPD.

[Treatment of different types of pain]. / Traitement des différents types de douleurs.

Accurate assessment of pain is the key to appropriate analgesia. This necessitates not only an understanding of the organic component, but also a comprehension of the role played by the mental, social and spiritual dimensions in the individual patient's suffering. It implies that the entire care team must be involved in pain management. The nature of a patient's pain is one predictor of the response to treatment. It is mainly characterized by its location, intensity, extent, timing and type (excessive nociception, neurogenic, or mixed), the circumstances in which it appears, and any accompanying signs. The choice of analgesic for treating pain due to excessive nociception was greatly facilitated by the introduction of the WHO three-step approach. Better knowledge of the pharmacological and pharmacokinetic properties of the different analgesics has contributed to increase their efficacy and tolerability. Certain types of pain of neurogenic origin respond poorly to both opiate and non opiate analgesics. They can be treated with other drugs whose mechanisms of action in pain relief are not fully understood. They include the following; antidepressants (amitriptyline, nortriptyline, desipramine and doxepine); anticonvulsants (carbamazepine, phenytoin, valporic acid and clonazepam); antiarrhythmic agents (lidocaine, mexiletine, flecainide and tocainide). The unwanted effects of these different treatments, together with psychological disturbances induced by the underlying disease, can call for the use of antiemetics, laxatives, spasmolytics, glucocorticoids and psychotropic agents (anxiolytics, neuroleptics and antidepressants). Finally, in many cases, better pain relief is obtained by combining drug-based therapy with other interventions such as radiation therapy, neurosurgery, and psychological/behavioral approaches. All these means must be chosen and used according to each individual patient's needs. Pain must be considered as a disease that can and must be eliminated or at least attenuated.

Cyclosporin maintenance monotherapy after renal transplantation: what factors predict success?

The use of cyclosporin monotherapy as maintenance immunosuppression in primary cadaveric renal transplant recipients is not popular except in a few European centres. Corticosteroid withdrawal is becoming more popular, and is usually attempted with the newer immunosuppressants which have a more corticosteroid-sparing effect than cyclosporin. The adverse effects and morbidity associated with maintenance regimens consisting of 2 or 3 immunosuppressive drugs are well known, but the potential benefits of cyclosporin monotherapy must be balanced against an increased risk of graft loss by rejection. We selected patients for a trial of corticosteroid withdrawal and subsequent cyclosporin monotherapy. These patients received an individually designed immunosuppressive regimen with careful control of cyclosporin trough concentrations. The cyclosporin formulations used were its original oil-based solution or gelatin capsule (Sandimmun, Sandimmune )until mid-1996 and then the microemulsion formulation (Neoral). Corticosteroid withdrawal was attempted in 89% of patients with a graft functioning at 3 months after transplantation and was effective in 88% of them. At a mean follow-up time of 98 +/- 23 months, 69% of grafts were functioning and 92% of patients were alive. 50% of patients with a functioning graft were receiving long term cyclosporin monotherapy. Mild rejection episodes occurred in 6% of patients receiving cyclosporin monotherapy per year of treatment, and chronic rejection caused graft loss in 1.4% of patients per year of treatment. Comparison of successful and unsuccessful outcomes allows us to define favourable predictive factors. For corticosteroid withdrawal these are: older recipient age, lower creatininaemia at months 6 and 8 and higher trough cyclosporin concentrations at month 6. For cyclosporin monotherapy these are: later timing of azathioprine withdrawal, recipient age >25 years, donor age

Cast nephropathy in mu heavy chain disease.

The occurrence of kidney diseases was very rarely reported in heavy chain diseases (HCD). At variance with gamma and alpha HCD in which there is no free light chain secretion, about two-thirds of mu HCD patients have urinary Bence Jones (BJ) proteins. We report on a 66 year-old man affected with typical mu HCD who developed renal failure after a 3-year follow-up. He had presented with chronic lymphocytic leukemia with bone marrow vacuolated plasma cells, serum mu HCD protein and serum and urine BJ protein. After an apparent hematological remission following fludarabine therapy, anemia and blood hyperlymphocytosis recurred together with microscopic hematuria, proteinuria and increased creatininemia. Kidney biopsy showed numerous tubular eosinophilic casts which stained for kappa chain determinants by immunofluorescence and an interstitial infiltration by lymphocytes and plasma cells. The hematological and renal condition improved after reinitiation of chemotherapy. This appears to be the first documented report of a light chain-dependent visceral complication in HCD.

High prevalence and usual persistence of serum monoclonal immunoglobulins evidenced by sensitive methods in renal transplant recipients.

BACKGROUND: The occurrence of serum monoclonal immunoglobulins in kidney transplant recipients is well known but their significance and predictive value for the occurrence of lymphoma are a matter of debate. We therefore conducted a study of monoclonal immunoglobulins by a sensitive method during the long-term follow up of grafted patients. METHODS: Monoclonal immunoglobulins were characterized by high-resolution electrophoresis, conventional immunoelectrophoretic analysis, and a sensitive Western blotting procedure in the serum from 84 renal transplant recipients prior to grafting and subsequently, with a 1-8-year follow-up and excluding the patients who developed posttransplant lymphoma. RESULTS: Low abundance monoclonal immunoglobulins were detectable prior to transplantation in 56 cases (66.6%) and after graft in 72 cases (85.5%) (and in 1 case (1.2%) and 18 cases (21.4%) of cases respectively, by immunoelectrophoresis). These abnormalities were often multiple in individual sera. Monoclonal components detected by immunoblotting were transient in 23.8% of patients only (whereas those evidenced by immunoelectrophoresis usually became undetectable by this method) and their pattern was remarkably stable in the majority of cases. The frequency of post-transplant monoclonal immunoglobulins was higher in patients of more than 50 years of age than in younger patients. The appearance of monoclonal components after grafting and their transient character correlated with CMV infections. No correlation was found with various other parameters. The isotypic distribution of monoclonal immunoglobulins with an IgM, IgG3, and IgG1 predominance and an abnormally low kappa/lambda ratio was the same as that observed in various immunodeficiency states. The monoclonal immunoglobulin pattern in three further patients who developed post-transplant lymphoma was unremarkable. CONCLUSION: Monoclonal immunoglobulins hence are not discriminant for lymphoma and their characterization does not appear to be necessary in the evaluation of followed up grafted patients, at least for a prediction of post-transplant lymphoma.

Comet assay demonstrates a higher ultraviolet B sensitivity to DNA damage in dysplastic nevus cells than in common melanocytic nevus cells and foreskin melanocytes.

We used the single cell gel electrophoresis assay (comet assay) to study ultraviolet B (UVB)-induced DNA damage in pigment cells. This assay detects DNA damage, mainly DNA strand breaks and alkali labile sites in the DNA molecule. We studied the effect of biologically relevant doses (comparable to 2-3 MED (minimal erythemal dose) for in vivo irradiated full-thickness skin) of monochromatic UVB light of 302 nm on cultured melanocytes derived from foreskin, common melanocytic nevi, and dysplastic nevi. We were able to demonstrate a linear dose-response relationship between UV dose and the migration coefficient of the comet tail in all three types of pigment cells. Nevus cells originating from dysplastic nevi showed the highest sensitivity to UVB irradiation: 65% higher induction of DNA damage compared to the induction in foreskin melanocytes. Common melanocytic nevus cells were most resistant and showed a 30% lower induction of DNA damage in comparison to foreskin melanocytes. Differences in chromatin structure and cell cycle profile may influence the results of the comet assay. Control experiments with x-ray irradiation, which is well known to produce direct DNA strand breaks via radical formation, revealed only small differences between the three types of melanocytic cells. It is unlikely, therefore, that intrinsic nuclear characteristics may account for the observed differences.

A kidney biopsy is clearly mandatory to confirm the indication of plasma exchanges in adult haemolytic uraemic syndrome.

In case of haemolytic uraemic syndrome, it is not always possible to identify on a pure clinical basis the different kidney lesions responsible for the syndrome. We report a series of six cases without thrombotic microangiopathy, which emphasizes the need to perform a kidney biopsy as early as possible, so as to confirm the actual usefulness of plasma exchanges (PE) commonly carried out in emergency in every case of adult haemolytic uraemic syndrome. PATIENTS AND METHODS--Files of patients who were treated for haemolytic uraemic syndrome over the past 14 years were reviewed. Patients in whom thrombotic microangiopathy had been excluded by renal histology data were studied. Every patient was promptly treated with hypotensive drugs, so as to obtain blood pressure levels not exceeding 160-90 mmHg. Dialysis was performed in two patients. Daily PE with fresh frozen plasma were carried out in three patients as early as the first 24 hours after admission, and discontinued immediately after thrombotic microangiopathy could be excluded. RESULTS--All the patients met the usual criteria for diagnosis of haemolytic uraemic syndrome. Elevated liver enzymes were also found in the four cases of preeclampsia, consisting with diagnosis of severe HELLP syndrome. One case was associated with oestrogen therapy. Glomerular lesions were seen in four patients: slight endotheliosis in three cases of preeclampsia; marked lesions of IgA mesangial deposits in the patient who had been treated by contraceptive pill. Three patients had acute tubular necrosis and three had intense lesions of nephrosclerosis. Complete remission was obtained in every case of preeclampsia. Renal failure persisted in two cases (IgA glomerulopathy and one case of nephrosclerosis). DISCUSSION--The histological heterogeneity of haemolytic uraemic syndrome has been already well demonstrated. Typical lesions of thrombotic microangiopathy are usually classified into predominant glomerular lesions, pure arteriolar and mixed lesions. In other cases, thrombotic microangiopathy is not found: kidney lesions may be glomerular (endotheliosis, various subtypes of glomerulonephritis), tubular (acute tubular necrosis) or vascular (nephroangiosclerosis). In every aetiological circumstance, several different lesions may be found together. The usefulness of PE has been proved in thrombotic thrombocytopenic purpura, has been suggested in haemolytic uraemic syndrome and to a lesser extent in persistently severe HELLP syndrome. Unfortunately, none of these reports gave any information about kidney lesions responsible of acute renal failure. CONCLUSION--The haemolytic uraemic syndrome is a syndrome: thrombotic microangiopathy has to be proven when treatment by PE is planned, except in some severe clinical circumstances.

Monoclonal Ig L chain and L chain V domain fragment crystallization in myeloma-associated Fanconi's syndrome.

Monoclonal free L chains secreted in immunoproliferative disorders are frequently involved in renal complications, including a specific proximal tubule impairment, the Fanconi's syndrome, which is generally featured by intracellular crystallization of L chain-related material. In a patient with myeloma-associated Fanconi's syndrome, hexagonal crystals (most surrounded by smooth membranes) were found in kidney proximal tubular cells and bone marrow plasma cells and phagocytes. The sequence of the patient's monoclonal kappa-chain was deduced from that of identical kappa-cDNA clones from the tumoral plasma cells. Small protein-enriched gel filtration fractions from urine yielded crystals morphologically similar and with the same 60 A periodicity on electron micrographs as those found in the cells. N-terminal sequencing and mass spectrometry studies showed that the crystals contained a 107-amino acid fragment (with a C-terminal lysine) corresponding to the V domain together with a low proportion of the entire kappa-chain. In vitro trypsin and pepsin treatment of the native entire kappa-chain yielded a homogeneous V domain fragment which, contrary to other monoclonal kappa-chains, was completely resistant to further proteolytic attack. The patient's kappa-chain also displayed an unusual self-reactivity, as demonstrated by a Western blot technique. The peculiar proneness of the V domain to resist proteolysis and to form crystals might prevent the normal cell catabolism of the L chain and lead to crystallization and renal impairment.

Complementary DNA sequence of human amyloidogenic immunoglobulin light-chain precursors.

The primary structure of three amyloid precursor light chains was deduced from the sequence of complementary DNA (cDNA) from bone marrow cells from patients affected with classical lambda (patient Air) or kappa (patient Arn) amyloidosis and from a patient (Aub) in whom lambda amyloid deposits were unusual by their perimembranous location in the kidney glomerulus. All three RNAs were of normal size, as estimated by Northern blotting, and encoded normal-sized light chains. The deduced light-chain sequence from patient Arn was related to the V kappa 1 subgroup, and included ten residues that had not been previously reported at these positions, only one of which (Leu-21) was located in a beta-sheet (4-2). The unusual presence of Asn-70 determined a potential N-glycosylation site. The sequence of the light chain from patient Air belonged to the V lambda 1 subgroup, and included three unusually located amino acid residues, one of which had already been reported in an amyloidogenic lambda-chain. The sequence of the light chain from patient Aub was related to the V lambda 3 subgroup, and contained five amino acid residues that had not previously been described at the corresponding positions; two of them (His-36 and Ser-77) were located in beta-sheets (3-1 and 4-3 respectively). This sequence was also peculiar because of the presence of numerous acidic residues in the complementarity-determining regions. Such unusual primary structures might be responsible for the amyloidogenic properties of these light-chain precursors.

Primary structure of a monoclonal kappa chain in myeloma with light chain deposition disease.

Previous data suggest that structural abnormalities of immunoglobulin light chains may be responsible for non-amyloid light chain deposition disease (LCDD). We report on the complete primary sequence deduced from complementary (c)DNA analysis of a normal-sized kappa chain in a case of myeloma-associated LCDD. The patient's urine contained a kappa type Bence-Jones protein made of monomers and dimers of an unglycosylated kappa chain. The bone marrow myeloma cells contained intracellular kappa and gamma chains by immunofluorescence. Biosynthesis experiments showed the production of normal-sized gamma chains and of kappa chains with the same apparent molecular mass (Mr) in SDS gels as the urinary kappa chain (26,000-27,000). These kappa chains were secreted as assembled IgG molecules and as a large excess of free monomers and dimers. The complete sequence of two identical cDNA clones derived from a normal-sized kappa messenger RNA indicated that this kappa chain belonged to the rare V kappa IV subgroup. The kappa mRNA had an overall normal structure made up of the V kappa IV sequence rearranged to J kappa 1 and followed by a normal constant exon of the Km(3) allotype. The variable region differed from the V kappa IV-J kappa 1 germline sequence by 17 amino acid substitutions. The peculiar sequence of the variable region of this kappa chain of a rare subgroup might relate to its tissue deposition.

[Glomerulopathies in monoclonal dysglobulinemias]. / Glomérulopathies des dysglobulinémies monoclonales.

Glomerular lesions in monoclonal gammapathies include AL amyloidosis, light chain and monoclonal immunoglobulin deposit disease (LCDD), cryoglobulinemias, Waldenström's macroglobulinaemia and a new entity, atypical membranous glomerulonephritis with organised monoclonal IgG deposits. Present data on deposited material of immunoglobulin origin and immunoglobulin synthesis in amyloidosis and LCDD are reviewed.