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PubMedDate not supplied

A rat model of pregnancy-induced sensitization to transplants.

Previous pregnancy is a known risk factor for alloantibody production and graft rejection in clinical transplantation. However, in previous rat models, immune responses to RT1.A antigens induced by allogeneic pregnancy resulted in prolonged survival of subsequent allografts. This study was designed to investigate the effects of a previous pregnancy on alloantibody response, complement activation, and allograft survival in a highly immunogenic rat strain combination. C6-sufficient and -deficient female PVG.1U (RT1.A(u)B(u)) rats were mated with allogeneic PVG.R8 (RT1.A(a)B(u)) males or control isogeneic PVG.1U (RT1.A(u)B(u)) males. Three weeks after parturition, experimental and control females received cardiac allografts from female PVG.R8 donors. A low dose of cyclosporine (CsA, 5 mg/kg on alternate days) was used for immunosuppression after transplantation. Allogeneic, but not control isogeneic, pregnancy elicited a weak, transient IgG alloantibody response that declined before transplantation. Experimental female recipients produced a rapid, vigorous IgM and IgG alloantibody response to the transplant despite CsA treatment. C6-sufficient recipients rejected their transplants at an accelerated rate (5 days, n = 6) compared with control animals (7 days, n = 5). In contrast, allografts to C6-deficient recipients functioned until sacrifice at 90 days in both the experimental group (n = 7) and control group (n = 4). Most experimental C6-deficient recipients continued to produce strong IgG alloantibodies for 90 days. Complement activation resulting from the alloantibody response was evidenced by the diffuse deposition of C3d on the vascular endothelium of the grafts. In summary, previous pregnancy leads to memory alloantibody responses that accelerate allograft rejection even with immunosuppression. Membrane attack complex is required for accelerated rejection induced by previous pregnancy.

Animals↗
PubMed2005

The gamma subunit of the eighth complement component (C8) in rainbow trout.

Of the 35 proteins, enzymes, receptors and regulatory components of the complement system, C8gamma is unique in that it is the only lipocalin. C8gamma is a subunit of the C8 molecule, which is one of the five components (C5b, C6, C7, C8 and C9) that interact as a consequence of complement activation to form the membrane attack complex. Until now, C8gamma has been characterized only in mammalian species. In order to elucidate the phylogeny of this molecule, we have cloned the C8gamma subunit in rainbow trout (Oncorhynchus mykiss), a teleost fish representing a critical point in the evolutionary divergence of the complement system. The deduced amino acid sequence of trout C8gamma shows significant identity (37%) to the human C8gamma homolog and much lower to the other known lipocalins. The lipocalin domain is present and all the cysteine residues are conserved. The trout C8gamma gene is probably present as a single copy in the trout genome showing a differential expression pattern among tissues investigated.

Amino Acid Sequence↗
PubMed2002

Complement activation in chromosome 13 dementias. Similarities with Alzheimer's disease.

Chromosome 13 dementias, familial British dementia (FBD) and familial Danish dementia (FDD), are associated with neurodegeneration and cerebrovascular amyloidosis, with striking neuropathological similarities to Alzheimer's disease (AD). Despite the structural differences among the amyloid subunits (ABri in FBD, ADan in FDD, and Abeta in AD), these disorders are all characterized by the presence of neurofibrillary tangles and parenchymal and vascular amyloid deposits co-localizing with markers of glial activation, suggestive of local inflammation. Proteins of the complement system and their pro-inflammatory activation products are among the inflammation markers associated with AD lesions. Immunohistochemistry of FBD and FDD brain sections demonstrated the presence of complement activation components of the classical and alternative pathways as well as the neo-epitope of the membrane attack complex. Hemolytic experiments and enzyme-linked immunosorbent assays specific for the activation products iC3b, C4d, Bb, and C5b-9 indicated that ABri and ADan are able to fully activate the complement cascade at levels comparable to those generated by Abeta1-42. ABri and ADan specifically bound C1q with high affinity and formed stable complexes in physiological conditions. Activation proceeds approximately 70-75% through the classical pathway while only approximately 25-30% seems to occur through the alternative pathway. The data suggest that the chronic inflammatory response generated by the amyloid peptides in vivo might be a contributing factor for the pathogenesis of FBD and FDD and, in more general terms, to other neurodegenerative conditions.

Alzheimer Disease↗
PubMed2004

Effects of complement C5 on apoptosis in experimental autoimmune encephalomyelitis.

Complement activation is involved in the initiation of Ab-mediated inflammatory demyelination in experimental autoimmune encephalomyelitis (EAE). At a sublytic dose, the C5b-9 membrane attack complex protects oligodendrocytes (OLG) from apoptosis. Using C5-deficient (C5-d) mice, we previously showed a dual role for C5: enhancement of inflammatory demyelination in acute EAE, and promotion of remyelination during recovery. In this study, we investigated the role of C5 in apoptosis in myelin-induced EAE. In acute EAE, C5-d and C5-sufficient (C5-s) mice had similar numbers of total apoptotic cells, whereas C5-s had significantly fewer than C5-d during recovery. In addition, although both groups of mice displayed TUNEL(+) OLG, there were significantly fewer in C5-s than in C5-d during both acute EAE and recovery. Gene array and immunostaining of apoptosis-related genes showed that Fas ligand expression was higher in C5-s. In C5-s mice, Fas(+) cells were also higher than in C5-d mice in acute EAE; however, these cells were significantly reduced during recovery. Together, these findings are consistent with the role of C5, possibly by forming the membrane attack complex, in limiting OLG apoptosis in EAE, thus promoting remyelination during recovery.

Acute Disease↗
PubMed2004

The possibilities and pitfalls for anti-complement therapies in inflammatory diseases.

The complement system is a key component of innate immunity, acting to protect the host from micro-organisms such as bacteria and other "foreign" threats, including tumor cells. However, excessive activation of complement can injure the host and can even be life threatening. These toxic effects are caused primarily by the excessive production of the anaphylatoxins C3a and C5a during complement activation and excessive formation of membrane attack complex on the host cell membrane. Many inflammatory diseases, including rheumatoid arthritis and glomerulonephritis, are thought to involve excessive activation of complement, both for their development and perpetuation. Uncontrolled complement activation is also implicated in post-ischemic inflammation and tissue damage and in sepsis. Therefore, it is important to regulate the complement system to treat disease. There are still no broadly applicable agents for the therapeutic regulation of excessive complement activation. However, there are now some agents in the development that might provide useful anti-complement therapies in the near future. Current strategies include the use of neutralizing antibodies, small synthetic antagonists, soluble recombinant forms of the natural complement regulators, and gene therapies to control excessive complement activation. Here we describe these new agents, their strengths and weaknesses and progress in testing the agents in relevant animal models.

Animals↗
PubMed2000

CD59 protects rat kidney from complement mediated injury in collaboration with crry.

BACKGROUND: As previously reported, the membrane-bound complement regulator at the C3 level (Crry/p65) is important in maintaining normal integrity of the kidney in rats. However, the role of a complement regulator at the C8/9 level (CD59) is not clear, especially when activation of complement occurs at the C3 level. The aim of this work was to elucidate the in vivo role of CD59 under C3 activating conditions. METHODS: Two monoclonal antibodies, 5I2 and 6D1, were used to suppress the function of Crry and CD59, respectively. In order to activate alternative the pathway of complement, the left kidney was perfused with 5I2 and/or 6D1 and was recirculated. RESULTS: In the kidneys perfused with 5I2 alone, deposition of C3 and membrane attack complex (MAC) was observed in the peritubular capillaries, vasa recta, and tubular basement membranes. Cast formation, tubular dilation and degeneration, and cellular infiltration were observed at days 1 and 4, and they recovered by day 7. Further suppression of CD59 by 6D1 significantly enhanced the deposition of MAC and worsened the already exacerbated tubulointerstitial injury. These effects of 6D1 were dose dependent. Perfusion with 6D1 alone did not induce histologic damage or MAC deposition in the tubulointerstitium. CONCLUSIONS: In rats, CD59 maintains normal integrity of the kidney in collaboration with Crry in rats against complement-mediated damage in vivo.

Animals↗
PubMed2000

High prevalence of complement component C6 deficiency among African-Americans in the south-eastern USA.

Complement component C6 is a part of the membrane attack complex that forms a pore-like structure in cell membranes following complement activation. Deficiency of terminal complement components including C6 predisposes individuals to infection with Neisseriae. Using polymerase chain reaction/single-strand conformation polymorphism analysis followed by DNA sequencing, we screened genomic DNA from 200 randomly chosen blacks and an equal number from whites for three loss-of-function C6 mutations. Ten blacks and two whites were found to be heterozygous for one of the mutations. Two of the mutations, 1195delC and 1936delG, were found exclusively in black individuals. A third previously undescribed mutation, 878delA, was found at equal frequency among the two groups. The difference between the two groups was significant (P = 0.027), indicating that C6 deficiency due to these three mutations is more common among blacks than whites in the local area, principally Jefferson County, Alabama. In addition, three previously undescribed point mutations, two of which result in amino acid substitutions, were identified within exon 6. A review of the county health department records over the past 6 years revealed a higher incidence of meningococcal meningitis in blacks due to serogroups Y and W-135 which paralleled the difference in the estimated prevalence of C6 deficiency. Among black residents of the county (n = 235 598) there were 15 cases of meningitis due to these two serogroups, compared with two cases in the white population (n = 422 604) (P = 0.002). We conclude that C6 deficiency is more common among blacks than whites in the south-eastern United States, with a frequency approaching 1 in 1600 black individuals.

Amino Acid Sequence↗
PubMed1985

Proteolytic modification of human complement protein C9: loss of poly(C9) and circular lesion formation without impairment of function.

We have compared the ability of thrombin-cleaved C9 (C9n) with that of native C9 to produce tubular or ring-like poly(C9) and to express the classical complement lesion on target membranes. Three procedures were used to produce poly(C9): (i) limited proteolysis with trypsin, (ii) interaction with small unilamellar lipid vesicles, and (iii) incubation with a 2- to 4-fold molar excess of ZnCl2. In contrast to C9, which could be converted to tubular poly(C9), C9n was converted to smaller peptides by the first procedure and was aggregated into string-like poly(C9) by the other two methods. C9-depleted human serum (R-9 serum) was reconstituted with either C9 or C9n and these sera were then used to lyse sensitized sheep erythrocytes. Numerous classical complement lesions could be detected on ghost membranes obtained from cells lysed by C9-reconstituted R-9 serum but only a few on ghost membranes produced by C9n-reconstituted R-9 serum. C9n was shown to be hemolytically as active as C9 even when tested under "single-hit" conditions and it was about twice as efficient when compared with C9 in releasing sucrose and inulin from resealed ghosts. These results are interpreted to indicate that formation of the classical complement lesion is only incidental to lysis and not an obligatory event and that enlargement of the "functional pore size" of the complement lesion is not linked to formation of a circular membrane attack complex.

Complement C9↗
PubMed1989

Immunohistochemical localisation of terminal complement component C9 in experimental allergic encephalomyelitis.

The deposition of terminal complement component C9 within the central nervous system (CNS) has been studied immunohistochemically in three models of experimental allergic encephalomyelitis (EAE) in the rat; inflammatory EAE induced by the passive transfer of myelin basic protein-specific T cells (tEAE), antibody-mediated, demyelinating tEAE and a subacute/chronic model induced by active immunisation with guinea pig spinal cord tissue in adjuvant. Two distinct patterns of C9 reactivity were observed, a diffuse staining of the tissue adjacent to inflammatory lesions, similar to that seen for other extra-vasculated serum proteins, and also granular, sometimes fibrillar C9 deposits around some inflammed vessels and in areas of active demyelination. The latter staining pattern was most pronounced in animals with acute antibody-mediated demyelinating tEAE, in which extensive, but transient, subpial and perivascular granular deposits of C9 were associated with regions of acute demyelination. A similar pattern of granular C9 reactivity was also associated with demyelinating lesions in animals with actively induced chronic progressive EAE. However, these C9 deposits were not observed in rats with purely inflammatory, clinically mild tEAE, although C9 deposition was occasionally observed around a small number of inflammed vessels in animals with hyperacute, lethal tEAE. These observations demonstrate that deposition of C9, the major component of the cytolytic membrane attack complex, in EAE is related to myelin injury rather than CNS inflammation.

Animals↗
PubMed2001

Intraglomerular synthesis of complement C3 and its activation products in IgA nephropathy.

BACKGROUND: Complement activation is thought to be pathologically important in IgA nephropathy (IgAN). Although C3 deposition in the mesangium is found in IgAN, the origin of C3 is not clear. We recently demonstrated intraglomerular C3 synthesis in the human kidney; however, the activation and pathological role of locally synthesized C3 remains unclear. Here we performed nonradioactive in situ hybridization for C3 mRNA and immunohistochemistry for C3 and its activation products, such as C3d and membrane attack complex (MAC), to determine whether locally produced C3 in glomeruli was activated in IgA nephropathy. METHODS: Renal samples from 14 patients with IgAN and 5 with minimal change nephrotic syndrome (MCNS) were examined. Uninvolved portions of surgically removed kidneys with tumors served as normal controls. RESULTS: C3 mRNA was not detected in glomeruli in control tissue and MCNS, but was strongly expressed in resident glomerular cells of IgAN, including mesangial cells, glomerular epithelial cells and the cells of Bowman's capsule. Examination of serial sections disclosed that more than 70% of cells positive for C3 mRNA were also stained for C3 protein, C3d, and MAC. Double staining for in situ hybridization and immunohistochemistry also revealed that those C3 mRNA signals were present in intraglomerular cells positive for C3. The expression of C3 mRNA and MAC in glomeruli correlated significantly with the degree of mesangial matrix expansion. CONCLUSIONS: Our results demonstrated that locally synthesized C3 is activated in the glomeruli of IgAN and that its expression correlated with the severity of mesangial matrix expansion. These findings suggest that activation of C3 may be involved in tissue injury in IgAN through the formation of membrane attack complex.

Adolescent↗
PubMed1994

Structure of a soluble, glycosylated form of the human complement regulatory protein CD59.

BACKGROUND: CD59 is a cell-surface glycoprotein that protects host cells from complement-mediated lysis by binding to and preventing the normal functioning of the complement proteins C8 and/or C9 which form part of a membrane penetrating assembly called the membrane attack complex. CD59 has no structural similarity to other complement proteins, but is an example of a plasma protein domain type found also in murine Ly-6 proteins and the urokinase-type plasminogen activator receptor. RESULTS: CD59 was purified from human urine, retaining the N-glycan and at least some of the non-lipid component of the glycosylphosphatidylinositol membrane anchor. The three-dimensional structure of the protein component has been determined in the presence of the carbohydrate groups using two-dimensional NMR spectroscopy. The protein structure is well defined by the NMR data (root mean square deviation from the mean structure of 0.65 A for backbone atoms and no distance constraint violations greater than 0.4 A). Structure calculations were also carried out to model the orientation of the N-acetylglucosamine residue that is directly linked to Asn18. CONCLUSIONS: The main features of the protein structure are two antiparallel beta-sheets (a central one with three strands and another with two), a short helix that packs against the three-stranded beta-sheet, and a carboxy-terminal region that, although lacking regular secondary structure, is well defined and packs against the three-stranded beta-sheet, on the opposite face to the helix. We have used the structure, in combination with existing biochemical data, to identify residues that may be involved in C8 binding.

Amino Acid Sequence↗
PubMed2006

Complement regulator CD59 deficiency fails to augment susceptibility to actively induced experimental autoimmune myasthenia gravis.

Complement deficient mice are resistant to experimental autoimmune myasthenia gravis (EAMG), suggesting a pivotal role for the membrane attack complex (MAC) in EAMG pathogenesis. To test the significance of MAC regulation in EAMG pathogenesis, CD59 KO and wild type mice were immunized with acetylcholine receptor (AChR). Interestingly, deletion of CD59, the regulator of MAC assembly, failed to augment EAMG susceptibility. The CD59 KO mice had reduced serum anti-AChR IgG1, IgG2b and complement levels. Their lymph node cell IL-2 production and lymphocyte proliferation response to AChR were reduced. The data challenge the current paradigm that CD59 is solely involved in MAC regulation and suggest a role for this molecule in antigen-driven T cell and B cell activation.

Animals↗
PubMed1990

Complement components and receptors: deficiencies and disease associations.

The complement system, accessory to many immunological functions, consists of a number of interdependent components and receptors. Numerous in vitro approaches have elucidated the biological role of these components and receptors. However, it is the in vivo "natural" experiments that underscore their importance. The phagocytosis and subsequent digestion of pyogenic bacteria is significantly enhanced by the fixation of the third complement component to the bacterial cell wall. Equally important is the intact expression of a receptor (CR3) for the C3b cleavage fragment. Breakdown in this ligand-receptor interaction due to either C3 or CR3 deficiency leads to pyogenic infection. Interestingly, C3-deficient individuals do not demonstrate leukocytic infiltration at the site of infection. Undoubtedly, this is due to the lack of C5 convertase and failure to produce C5a. CR3-deficient individuals, on the other hand, do demonstrate leukocytosis since the third complement component is functional. C3 deficiency is not necessarily a primary lesion and may be secondary to factor I deficiency. In this case, the C3b fragment, along with factor B, acts as a C3 convertase. Inefficient inactivation of C3b, due to factor I deficiency, leads to the uncontrolled consumption of the third component, resulting in C3 deprivation. It appears that phagocytosis by neutrophils and monocytes followed by enzyme-interaction is not sufficient for destruction of the Neisseria organisms. In addition to this leukocyte activity, an intact membrane attack complex, composed of the late complement components C5, 6, 7, 8, and 9, is required for the lysis of these bacteria. This is supported by findings that individuals deficient in late components are highly susceptible to systemic Neisseria infections. Diseases of an autoimmune nature are frequently associated with a deficiency of one of the early complement components C1, C2, or C4 and a deficiency of erythrocytic CR1 receptors as well. This may suggest that proper interaction between a complement fragment of the immune complex with the complement receptor expressed on the erythrocyte is important for proper management and clearance of the complex. Deficiency of the early complement components would prevent the activation of C3 and the fixation of a resulting C3 cleavage product. In this case, erythrocytes would be unable to participate in the transport of the immune complex to the reticuloendothelial system. Instead, tissue deposition of the complex would occur more readily, contributing to the pathologic process. Provided that the early complement cascade were intact, deficiency of erythrocytic CR1 receptors would contribute to the pathologic response for the same reason.(ABSTRACT TRUNCATED AT 400 WORDS)

Autoimmune Diseases↗
PubMed1991

Ultrastructural and biochemical observations on antineutrophil antibody- and complement-induced immuno-injury to equine neutrophils.

Antibody-induced damage to neutrophils was studied to elucidate processes associated with destruction of neutrophils in immune-mediated neutropenias. Cytomorphological changes and release of certain cellular constituents were determined for neutrophils treated with an antineutrophil serum in the presence or absence of rabbit complement. Neutrophils exposed to the antineutrophil serum alone showed endocytotic vacuoles and degranulation. In contrast, neutrophils exposed to the antineutrophil serum and complement showed marked morphologic changes. The plasma membrane developed numerous vesicles, villous processes and minute areas of bilayer discontinuity. Highly damaged cells exhibited cellular and nuclear swellings, disruption of cytoplasmic integrity and disordered distribution of lysosomal granules. Cytoplasmic constituents (K+ and lactate dehydrogenase) were released extracellularly from neutrophils exposed to the antineutrophil serum with or without complement. Cytological changes induced by the antineutrophil serum and complement were analogous to those reported for leucocytes exposed to the activated complement components C5b-9 (the membrane attack complex) and bacterial toxins. It was concluded that the cytological abnormalities observed were most probably associated with immune-mediated damage to the cell membrane, leading to leakage of cytoplasmic constituents like K+, colloidal osmotic swelling, and disruption of the cytoskeletal system.

Alkaline Phosphatase↗
PubMed2004

An immunohistochemical study on complement component C3 in juvenile Atlantic halibut (Hippoglossus hippoglossus L.).

The complement systems of fish are well developed and play an important role in the immune response. Complement C3 is the central protein of all three activation pathways, being the major opsonin of the complement system and essential for the generation of the membrane attack complex. Very little is known about the development of the complement system in fish. In this study, we detect the presence of C3 in halibut larvae from the age of 37 degrees d post hatching until 1050 degrees d (i.e. 5-99 d post hatching) using immunohistochemistry with specific antibodies produced against the beta-chain of halibut C3. At the different stages of larval maturation, C3 was detectable in yolksac, muscle, liver, brain, chondrocytes, spinal chord, eye, heart, stomach, intestines, oesophagus, pharynx and kidney. Our findings suggest a role of complement in the formation and generation of different organs, besides its important functions in the immune defence against invading pathogens.

Animals↗
PubMed2004

Complement components C5 and C7: recombinant factor I modules of C7 bind to the C345C domain of C5.

Studies reported over 30 years ago revealed that latent, nonactivated C5 binds specifically and reversibly to C6 and C7. These reversible reactions are distinct from the essentially nonreversible associations with activated C5b that occur during assembly of the membrane attack complex, but they likely involve some, perhaps many, of the same molecular contacts. We recently reported that these reversible reactions are mediated by the C345C (NTR) domain at the C terminus of the C5 alpha-chain. Earlier work by others localized the complementary binding sites to a tryptic fragment of C6 composed entirely of two adjacent factor I modules (FIMs), and to a larger fragment of C7 composed of its homologous FIMs as well as two adjoining short consensus repeat modules. In this work, we expressed the tandem FIMs from C7 in bacteria. The mobility on SDS-polyacrylamide gels, lack of free sulfhydryl groups, and atypical circular dichroism spectrum of the recombinant product rC7-FIMs were all consistent with a native structure. Using surface plasmon resonance, we found that rC7-FIMs binds specifically to both C5 and the rC5-C345C domain with K(D) approximately 50 nM, and competes with C7 for binding to C5, as expected for an active domain. These results indicate that, like C6, the FIMs alone in C7 mediate reversible binding to C5. Based on available evidence, we suggest a model for an irreversible membrane attack complex assembly in which the C7 FIMs, but not those in C6, are bound to the C345C domain of C5 within the fully assembled complex.

Amino Acid Motifs↗
PubMed2002

Role of the human C8 subunits in complement-mediated bacterial killing: evidence that C8 gamma is not essential.

Human C8 is one of five complement components (C5b, C6, C7, C8 and C9) that interact to form the cytolytic membrane attack complex (MAC) on bacterial cell membranes. It is an oligomeric protein composed of a disulfide-linked C8 alpha-gamma heterodimer and a non-covalently associated C8 beta chain. Previous studies revealed that C8 alpha and C8 beta have distinct roles in the formation of the MAC on simple cells such as erythrocytes and that both subunits are essential for cell lysis. These studies also determined that C8 gamma is not required for expression of MAC hemolytic activity. To determine if these conclusions are applicable to more biologically relevant systems, the C8 subunits were examined for their ability to support complement-mediated killing of Gram-negative bacteria. Results indicate: (1) C8 alpha-gamma, C8 alpha, C8 beta and C8 gamma have no independent bactericidal activity; (2) bacterial killing requires C8 beta and either C8 alpha-gamma or C8 alpha; (3) C8 alpha is an effective substitute for C8 alpha-gamma in bacterial killing; and (4) C8 gamma enhances, but is not required for C8 bactericidal activity. Together, these data suggest that C8 alpha and C8 beta have correspondingly similar roles in MAC-mediated lysis of erythrocytes and bacterial killing. Furthermore, they provide the first direct evidence that C8 gamma is not required for complement-mediated killing of Gram-negative bacteria.

Blood Bactericidal Activity↗
PubMed2004

Pathological study on the relationship between C4d, CD59 and C5b-9 in acute renal allograft rejection.

In order to evaluate the activation or inhibition of the later phases of classical complement cascade in renal allograft presenting with acute rejection, particularly with C4d deposition on the peritubular capillary (PTC), we observed the expression of CD59 and C5b-9 on the PTC. Subjective cases were divided into two groups, an acute rejection group, of 4 males and 6 females, and a normal donor group, of 5 males and 5 females. Renal biopsies were performed at the onset of acute rejection and at the transplant operation, before reperfusion. C4d deposition on PTC was found in three of 10 cases (30%) with biopsy proven acute rejection, whereas CD59 on PTC was positively expressed in all of the rejection cases. Although C5b-9 was not observed on PTC in the acute rejection group, it was intensively deposited on the tubular basement membrane (TBM) in five cases, including the three with positive C4d on PTC. In the normal donor group, CD59 on PTC was intensively observed, whereas C5b-9 was weakly expressed on TBM. CD59, a complement regulatory factor, works as an inhibitory factor against the formation of C5b-9, a membrane attack complex. From our data, we noted the dissociation between the depositions of C4d and C5b-9 on PTC. The substantially expressed CD59 on PTC may affect this dissociation between C4d and C5b-9 on PTC. The intensive deposition of C5b-9 on TBM in acute rejection cases may suggest an independent immunological injury attacking tubular cells.

Acute Disease↗