Renal Involvement in Antiphospholipid Syndrome

Epidemiology of antiphospholipid syndrome: macro- and microvascular manifestations

Antiphospholipid syndrome (APS) is a systemic autoimmune disease characterized by thrombotic and non-thrombotic macro- and microvascular manifestations and pregnancy complications in the setting of persistent antiphospholipid antibodies (aPL), namely anticardiolipin antibodies, anti-β2 glycoprotein-I antibodies and lupus anticoagulant. Four decades after its first description, APS prevalence and incidence are still not completely understood due to the limited number of well-designed, population-based multi-ethnic studies. Furthermore, despite decades of efforts to standardise aPL immunoassays, considerable intraassay and interlaboratory variances in aPL measures still exist. Large multicentre APS cohorts have shown a 10-year survival of ∼91% and the presence of catastrophic APS occurs in about 1% of the entire population, associated with a 50% mortality rate. Clinically, any organ can be affected in the context of large, medium or small vessel (artery and/or vein) thrombosis. Macrovascular thrombosis is the hallmark of the disease and veins are more frequently affected than arteries. Deep vein thrombosis/pulmonary embolism thromboembolic disease is the most common APS manifestation, while stroke and transient ischaemic attack are the most frequent arterial thrombosis events. Myocardial infarction can also occur and contributes to increased mortality in APS. A minority of patients present with thrombosis affecting the intraabdominal organs, including the liver, spleen, small and large bowel, and the kidneys. Microvascular thrombosis, including APS nephropathy, chronic skin ulcers and livedoid vasculopathy represent a diagnostic challenge requiring histologic confirmation. In this narrative review we summarize the available evidence on APS epidemiology, focusing on the description of the prevalence of macro- and microvascular manifestations of the disease.

Efforts to Better Characterize "Antiphospholipid Antibody Nephropathy" for the 2023 ACR/EULAR Antiphospholipid Syndrome Classification Criteria: Renal Pathology Subcommittee Report

OBJECTIVE

Antiphospholipid antibody (aPL) nephropathy (-N) can be challenging to recognize due to a lack of established classification or diagnostic criteria. As part of efforts to develop new antiphospholipid syndrome (APS) classification criteria (CC), the APS CC Renal Pathology Subcommittee aimed to better characterize the entity of aPL-N.

METHODS

We used a 4-pronged approach that included (1) administering Delphi surveys to worldwide APS physicians to generate aPL-N terminology; (2) conducting a literature review to demonstrate the association of nephropathy with aPL and identify published aPL-N histopathological terminology and descriptions; (3) evaluating aPL-N terminology used in renal biopsy reports from an international patient registry; and (4) evaluating proposed kidney pathologic features for aPL-N by assessment of international Renal Pathology Society (RPS) members.

RESULTS

After completing our metaanalysis demonstrating an association between nephropathy and aPL, we used Delphi surveys, a literature review, and international renal biopsy reports to develop a preliminary definition of aPL-N. The preliminary definition included include specific terms associated with acute (ie, thrombotic microangiopathy in glomeruli or arterioles/arteries) and chronic (ie, organized arterial or arteriolar microthrombi with or without recanalization, organized glomerular thrombi, fibrous and fibrocellular [arterial or arteriolar] occlusions, focal cortical atrophy with or without thyroidization, and fibrous intimal hyperplasia) lesions. Most RPS survey respondents agreed with this terminology and the importance of knowing aPL results for histopathological diagnosis.

CONCLUSION

Our results support the inclusion of aPL-N in the 2023 American College of Rheumatology/European Alliance of Associations for Rheumatology APS CC, and provide the most widely accepted terminology to date for both acute and chronic pathologic lesions of aPL-N.

Causal relationship between gut microbiota and kidney diseases: a two-sample Mendelian randomization study

Background

The interplay between gut microbiome genera and inflammatory kidney-related diseases, such as nephrotic syndrome, glomerulonephritis, tubulo-interstitial nephritis, and chronic kidney disease, has been observed. However, the causal relationships between specific bacterial genera and these renal diseases have not been fully elucidated.

Objective

To investigate the potential causal links between different genera of the gut microbiome and the susceptibility to various renal conditions utilizing two-sample Mendelian randomization (MR) analyses.

Materials and methods

Genome-wide association study (GWAS) summary statistics of gut microbiota and inflammatory kidney-related diseases were obtained from published GWASs. Two-sample MR analyses were conducted using methods including inverse-variance weighted (IVW), MR Egger, and others to identify potential causal links between gut microbial genera and renal conditions. Sensitivity analyses, including Cochran's Q test and the MR-PRESSO global test, were performed to validate the robustness of the results and detect horizontal pleiotropy. In addition, a reverse MR analysis was conducted to assess reverse causation possibilities.

Results

By synthesizing insights from both primary and sensitivity analyses, this study unveiled critical associations of 12 bacterial genera with nephrotic syndrome, 7 bacterial genera with membranous nephropathy, 3 bacterial genera with glomerulonephritis, 4 bacterial genera with acute tubulo-interstitial nephritis, 6 bacterial genera with chronic tubulo-interstitial nephritis, and 7 bacterial genera with chronic kidney disease. Various genera were pinpointed as having either positive or negative causal relationships with these renal conditions, as evidenced by specific ranges of IVW-OR values (all P< 0.05). The congruence of the sensitivity analyses bolstered the primary findings, displaying no marked heterogeneity or horizontal pleiotropy. Notably, the reverse MR analysis with nephritis as the exposure did not reveal any causal relationships, thereby strengthening the resilience and validity of the primary associations.

Conclusion

This study explored the causal associations between several gut microbial genera and the risk of several inflammatory kidney-related diseases, uncovering several associations between specific gut microbial genera and nephrotic syndrome, membranous nephropathy, glomerulonephritis, tubulo-interstitial nephritis, and chronic kidney disease. These findings enhance our understanding of the complex interplay between the gut microbiome and kidney diseases, and they will be beneficial for early diagnosis and subsequent treatment.

Assessing the Risk of Stroke in the Elderly in the Context of Long-COVID, Followed Through the Lens of Family Medicine

BACKGROUND/AIM

Patients infected with COVID-19 may experience a range of acute and chronic neurological disorders. While severe neurological complications like strokes and seizures were less common during the acute or post-COVID period, the long-term effects of COVID-19, known as long COVID, have received limited attention. This study aimed to examine the lasting consequences of SARS-CoV-2 infection and establish potential connections with related diseases.

PATIENTS AND METHODS

We followed a group of 157 patients for one year, predominantly from urban areas (61.8%), divided into three groups based on the presence of associated diseases that pose health risks: the control (43 patients), low-risk (67 patients), and high-risk (47 patients) groups.

RESULTS

We observed an inverse relationship between oxygen saturation and erythrocyte sedimentation rate, as well as a direct relationship between varicose disease and dyslipidemia, and gastrointestinal disease. Additionally, we noticed a less significant improvement in oxygen saturation and increased prevalence of psychoanxiety disorders in individuals undergoing anticoagulant treatment.

CONCLUSION

The impact of long COVID and its secondary effects, which persist for an extended period and are influenced by associated diseases, can be effectively monitored and addressed by primary care physicians. These findings can serve as a basis for developing more efficient approaches to managing the long-term consequences of COVID-19.

Calcinosis Cutis and Calciphylaxis in Autoimmune Connective Tissue Diseases

Calcinosis represents a severe complication of several autoimmune disorders. Soft-tissue calcifications have been classified into five major types: dystrophic, metastatic, idiopathic, iatrogenic, and calciphylaxis. Autoimmune diseases are usually associated with dystrophic calcifications, including calcinosis cutis, occurring in damaged or devitalized tissues in the presence of normal serum levels of calcium and phosphate. In particular, calcinosis cutis has been described in dermatomyositis, polymyositis, juvenile dermatomyositis, systemic sclerosis, systemic lupus erythematosus, primary Sjögren's syndrome, overlap syndrome, mixed connective tissue disease, and rheumatoid arthritis. Calciphylaxis, a severe and life-threatening syndrome presenting with vascular calcifications and thrombosis, has also been associated with some autoimmune conditions. Due to the potentially disabling character of calcinosis cutis and calciphylaxis, physicians' awareness about the clinical presentation and management of these diseases should be increased to select the most appropriate treatment option and avoid long-term complications. In this review, we aim to analyze the clinical features of calcinosis cutis and calciphylaxis associated with autoimmune diseases, and the main treatment strategies evaluated up to now for treating this potentially disabling disease.

Retroperitoneal Hemorrhage Due to Spontaneous Renal Rupture as the First Presentation of Antiphospholipid Syndrome: A Case Report

Spontaneous renal rupture (SRR) with retroperitoneal hemorrhage is an extremely rare medical emergency and is rather challenging for the surgical team. Management of SRR often requires surgical intervention and nephrectomy as it is life-threatening. Antiphospholipid syndrome (APLS) is an autoimmune disease that affects several organs, including kidneys, causing significant abnormalities. Current data suggest that APLS can result in renal artery stenosis, renal vein thrombosis, arterial hypertension, thrombotic microangiopathy, and antiphospholipid syndrome nephropathy where there is renal involvement. Here, we report the case of a 49-year-old man who presented to the Emergency Department with sudden-onset abdominal pain in the context of retroperitoneal bleeding due to SRR. The patient developed hemodynamic instability and underwent a total nephrectomy. The surgical specimen revealed APLS-related lesions. Serological tests confirmed the diagnosis of APLS, which was managed with acenocoumarol and hydroxychloroquine. Since then, he has not experienced any thromboembolic or hemorrhagic episodes. This article aims to present for the first time a case of SRR as the first presentation of APLS as well as to analyze the possible associated mechanisms.

Haemolytic uraemic syndrome

Haemolytic uraemic syndrome (HUS) is a heterogeneous group of diseases that result in a common pathology, thrombotic microangiopathy, which is classically characterised by the triad of non-immune microangiopathic haemolytic anaemia, thrombocytopenia, and acute kidney injury. In this Seminar, different causes of HUS are discussed, the most common being Shiga toxin-producing Escherichia coli HUS. Identifying the underlying thrombotic microangiopathy trigger can be challenging but is imperative if patients are to receive personalised disease-specific treatment. The quintessential example is complement-mediated HUS, which once carried an extremely high mortality but is now treated with anti-complement therapies with excellent long-term outcomes. Unfortunately, the high cost of anti-complement therapies all but precludes their use in low-income countries. For many other forms of HUS, targeted therapies are yet to be identified.

The trends in the incidence and thrombosis-related comorbidities of antiphospholipid syndrome: a 14-year nationwide population-based study

Background

This study aims to provide 14-year nationwide epidemiology data to evaluate the incidence ratio of APS in Taiwan and the condition of comorbidities by analyzing the National Health Insurance Research Database.

Methods

Nineteen thousand one hundred sixty-three patients newly diagnosed as having APS during the 2000–2013 period and 76,652 controls (with similar distributions of age and sex) were analyzed.

Results

The incidence of APS increased from 4.87 to 6.49 per 10,000 person-years in the Taiwan population during 2000–2013. The incidence of APS increased with age after 20 years old, especially in the female population, and it rose rapidly after age over 60 years old. In addition, APS cohorts presented a higher proportion of diabetes mellitus, hypertension, hyperlipidemia, stroke, heart failure, atrial fibrillation, myocardial infarction, PAOD, chronic kidney disease, COPD, deep vein thrombosis, pulmonary embolism, SLE, rheumatoid arthritis, Sjogren’s syndrome, and polymyositis.

Conclusions

Our study indicated an increasing trend in APS incidence among the Taiwanese population and a relationship between APS and potential comorbidities. This large national study found that the APS risk is heavily influenced by sex and age. Thus, the distinctive sex and age patterns might be constructive given exploring potential causal mechanisms. Furthermore, our findings indicate that clinicians should have a heightened awareness of the probability of APS, especially in women in certain age groups presenting with symptoms of APS.

A Case Report of a Young Female With Renal Infarction Secondary to Breakthrough COVID Infection

COVID-19 infection is a disease that induces a hypercoagulable state that appears to be more aggressive than other conditions related to endothelial damage. The kidney, a highly vascularized organ rich in Angiotensin-Converting Enzyme 2 (ACE2) receptors, is commonly affected by COVID-19 infection. Acute kidney injury (AKI) is common in these patients and has been linked to worse outcomes. Furthermore, kidney infarction, although uncommon, has also been reported. We present the case of a 21-year-old otherwise healthy female presenting with flank pain who was found to have renal infarction in the setting of breakthrough COVID-19 infection and Oral contraceptive pill (OCP) use. Despite getting appropriate vaccination, the patient was infected. She was not hypoxic, and her kidney function was preserved. CT angiography demonstrated peripheral hypoattenuation in the right kidney compatible with infarct but no evidence of a thrombus. The patient was medically managed with anticoagulation, and supportive therapy was offered for pain control. She had clinical improvement. The follow-up at three weeks showed normal renal function. She was continued with novel oral anticoagulation (NOAC). This case demonstrates that COVID-19 infection may present renal infarction in otherwise healthy young individuals even after appropriate vaccination. Early recognition is essential so that appropriate therapy can be given. Long-term anticoagulation and outcomes of this entity must be studied.

Salivary microbiota analysis of patients with membranous nephropathy

The oral microbiota are closely related to human health. Nonetheless, to the best of our knowledge, their relationship with membranous nephropathy (MN) remains unstudied. The saliva microbiota collected from 22 patients with MN and 15 healthy controls were analyzed by next-generation sequencing, and bioinformatics analysis of the 16S ribosomal RNA gene was subsequently carried out. The Chao1 and Shannon indices in patients with MN were higher than those in healthy controls. Analysis of similarities revealed that the oral microbiota in the patient group were significantly different from those in the healthy controls. At the genus level, the abundance of Alloprevotella, Granulicatella, Prevotella, Streptococcus and Prevotella_7 was markedly higher in patients with MN than in healthy controls. Six operational taxonomic units (OTUs; OTU5, OTU28, OTU9, OTU15, OTU33 and OTU38) were found to be markedly correlated with the clinical factors creatinine, proteinuria in 24 h, estimated glomerular filtration rate and systolic blood pressure. A total of 28 Kyoto Encyclopedia of Genes and Genomes pathways were obtained from the significant OTUs. The oral microbiota of patients with MN were investigated and it was found that OTU5, OTU28, OTU9, OTU15, OTU33 and OTU38 may be used as biomarkers. The present findings may assist in the diagnosis of patients with MN.

Primary antiphospholipid syndrome in pediatrics: beyond thrombosis. Report of 32 cases and review of the evidence

OBJECTIVE

Describe the frequency of thrombotic and non-thrombotic clinical manifestations, laboratory, treatment and prognosis in patients with pediatric primary antiphospholipid syndrome.

MATERIAL AND METHODS

A retrospective study was carried out in patients with a diagnosis of primary antiphospholipid antibody syndrome, under 16 years of age, under follow-up by the pediatric rheumatology service of the General Hospital, National Medical Center, La Raza, from January 2013 to December 2020. The antiphospholipid syndrome was defined when it met the laboratory criteria of the Sidney criteria and the presence of thrombosis or non-criteria manifestations of the disease (hematological, neurological, cutaneous, renal, cardiac or pulmonary). Demographic, clinical, laboratory, treatment, and prognosis data were collected.

RESULTS

We report 32 patients, 21 female (65%) and 11 male (35%), mean age 11.75 years, evolution time 16 weeks. Thrombosis 9 patients (28%), 1 arterial and 8 venous. Non-thrombotic manifestations; Hematologic: thrombocytopenia 22 patients (69%), autoimmune hemolytic anemia 13 (40%), Fisher-Evans syndrome 6 (19%), lupus anticoagulant with hypoprothrombinemia syndrome 2 (6%). Dermatological: livedo reticularis 20 (62%), skin ulcers 2 (6%), Raynaud's phenomenon 8 (25%). Neurological: epilepsy 1 (3%), migraine 3 (9%), chorea 1 (3%) and cognitive impairment 3 (9%). Renal in 4 (13%). Laboratory: prolonged aPTT 30 (93%), lupus anticoagulant 32 (100%), positive IgG anticardiolipin 20 (62%), positive IgM anticardiolipin 19 (60%). AntiB2GPI was performed in only 3 patients, being positive in all.

TREATMENT

anticoagulation in patients with thrombosis, antiplatelet in 23 (72%), steroid 30 (94%), immunosuppressant 30 (94%) and rituximab 4 (12.5%). No deaths were reported.

CONCLUSIONS

The clinical characteristics of patients with pediatric primary antiphospholipid syndrome differ from those presented in adults, since non-thrombotic manifestations are more frequent in children, for which classification criteria that include these manifestations are necessary for a better characterization of the disease in pediatric population.

Lupus podocytopathy and antiphospholipid syndrome in a child with SLE: A case report and literature review

Lupus podocytopathy is a glomerular lesion in systemic lupus erythematosus (SLE) characterized by diffuse podocyte foot process effacement (FPE) without immune complex (IC) deposition or with only mesangial IC deposition. It is rarely seen in children with SLE. A 13-year-old girl met the 2019 European League Against Rheumatism (EULAR)/ American College of Rheumatology (ACR) Classification Criteria for SLE based on positive ANA; facial rash; thrombocytopenia; proteinuria; and positive antiphospholipid (aPL) antibodies, including lupus anticoagulant (LAC), anti-β2 glycoprotein-I antibody (anti-β2GPI), and anti-cardiolipin antibody (aCL). The renal lesion was characterized by 3+ proteinuria, a 4.2 mg/mg spot (random) urine protein to creatinine ratio, and hypoalbuminemia (26.2 g/l) at the beginning of the disease. Kidney biopsy findings displayed negative immunofluorescence (IF) for immunoglobulin A (IgA), IgM, fibrinogen (Fb), C3, and C1q, except faint IgG; a normal glomerular appearance under a light microscope; and diffuse podocyte foot process effacement (FPE) in the absence of subepithelial or subendothelial deposition by electron microscopy (EM). Histopathology of the epidermis and dermis of the pinna revealed a hyaline thrombus in small vessels. The patient met the APS classification criteria based on microvascular thrombogenesis and persistently positive aPL antibodies. She responded to a combination of glucocorticoids and immunosuppressive agents. Our study reinforces the need to consider the potential cooccurrence of LP and APS. Clinicians should be aware of the potential presence of APS in patients with a diagnosis of LP presenting with NS and positivity for aPL antibodies, especially triple aPL antibodies (LCA, anti-β2GPI, and aCL).

Antiphospholipid Antibodies From Women With Pregnancy Morbidity and Vascular Thrombosis Induce Endothelial Mitochondrial Dysfunction, mTOR Activation, and Autophagy

Antiphospholipid syndrome (APS) is an autoimmune disease characterized by thrombosis and pregnancy morbidity (PM) obstetric events together with persistent high titers of circulating antiphospholipid antibodies (aPL). Several mechanisms that explain the development of thrombosis and PM in APS include the association of aPL with alterations in the coagulation cascade and inflammatory events. Other mechanisms disturbing cellular homeostases, such as mitochondrial dysfunction, autophagy, and cell proliferation, have been described in other autoimmune diseases. Therefore, the objective of this study was to investigate the impact of aPL from different patient populations on endothelial cell mitochondrial function, activation of the mammalian target of rapamycin (mTOR) and autophagy pathways, and cellular growth. Using an in vitro model, human umbilical vein endothelial cells (HUVECs) were treated with polyclonal immunoglobulin G (IgG) purified from the serum of women with both PM and vascular thrombosis (PM/VT), with VT only (VT), or with PM and non-criteria aPL (seronegative-obstetric APS, SN-OAPS). We included IgG from women with PM without aPL (PM/aPL-) and healthy women with previous uncomplicated pregnancies (normal human serum, NHS) as control groups. Mitochondrial function, mTOR activation, autophagy, and cell proliferation were evaluated by Western blotting, flow cytometry, and functional assays. IgG from women with PM/VT increased HUVEC mitochondrial hyperpolarization and activation of the mTOR and autophagic pathways, while IgG from patients with VT induced endothelial autophagy and cell proliferation in the absence of elevated mTOR activity or mitochondrial dysfunction. IgG from the SN-OAPS patient group had no effect on any of these HUVEC responses. In conclusion, aPL from women with PM and vascular events induce cellular stress evidenced by mitochondrial hyperpolarization and increased activation of the mTOR and autophagic pathways which may play a role in the pathogenesis of obstetric APS.

Evaluation of antidiabetic and hypolipidemic activity of Barleria cristata Linn. leaves in alloxan-induced diabetic rats

The present study was undertaken to evaluate the antidiabetic and hypolipidemic action of leaf extract of Barleria cristata Linn in rats. Diabetes was induced in the rats by a single intraperitoneal (IP) injection of alloxan (150 mg/kg) and randomly divided into 7 groups. Animals were treated with low (250 mg/kg) and high (500 mg/kg) doses of ethyl acetate leaf extract (EALE) and hydro-alcoholic leaf extract (HALE) up to 21 days. The body weight and blood glucose level (BGL) were measured on weekly basis. The rats were killed under mild ether anesthesia on 21st day, blood and the vital organ were collected to estimate biochemical parameters and to study histopathological changes. A single-dose administration of alloxan induced hyperglycemia in all the groups. A regular increase in BGL was observed in toxic control groups when compared with the normal control. Daily oral administration of rats with extracts (HALE and EALE) and standard drug (Glimepiride, 5 mg/kg), reduced elevated BGL significantly (p < 0.001), and body weight was regained in diabetic rats. The extract treatment also improved the normal functioning of the liver and kidneys as evidenced by the restoration of the biochemical profile. The study revealed that B. cristata possesses promising antidiabetic and hypolipidemic activity.

Non-Criteria Manifestations of Juvenile Antiphospholipid Syndrome

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder mainly characterised by increased risks of thrombosis and pregnancy morbidity and persistent positive test results for antiphospholipid antibodies (aPLs). The criteria for diagnosing juvenile APS have yet to be validated, while the Sydney classification criteria do not contain several non-thrombotic clinical manifestations associated with the presence of aPLs. As such, difficulties have been encountered in the diagnosis of patients who have no certain thrombotic occlusions. Moreover, extra-criteria manifestations (i.e., clinical manifestations not listed in the classification criteria), including neurologic manifestations (chorea, myelitis and migraine), haematologic manifestations (thrombocytopenia and haemolytic anaemia), livedo reticularis, nephropathy and valvular heart disease have been reported, which suggests that the clinical spectrum of aPL-related manifestations extends beyond that indicated in the classification criteria. Studies have demonstrated that more than 40% of children with aPLs demonstrated non-thrombotic aPL-related clinical manifestations alone. Moreover, our results showed that the pathogenesis of non-criteria manifestations is characterised by “APS vasculopathy”. The present review introduces the characteristics and findings of non-criteria manifestations observed in juvenile APS.

Artemisinin analogue SM934 protects against lupus-associated antiphospholipid syndrome via activation of Nrf2 and its targets

Kidney is a major target organ in both antiphospholipid syndrome (APS) and systemic lupus erythematosus (SLE). The etiology of antiphospholipid syndrome nephropathy associated lupus nephritis (APSN-LN) is intricate and remains largely unrevealed. We proposed in present work, that generation of antiphospholipid antibodies (aPLs), especially those directed towards the oxidized neoepitopes, are largely linked with the redox status along with disease progression. Moreover, we observed that compromised antioxidative capacity coincided with turbulence of inflammatory cytokine profile in the kidney of male NZW×BXSB F1 mice suffered from APSN-LN. SM934 is an artemisinin derivative that has been proved to have potent immunosuppressive properties. In current study, we elaborated the therapeutic benefits of SM934 in male NZW×BXSB F1 mice, a murine model develops syndrome resembled human APS associated with SLE, for the first time. SM934 treatment comprehensively impeded autoantibodies production, inflammatory cytokine accumulation and excessive oxidative stress in kidney. Among others, we interpreted in present work that both anti-inflammatory and antioxidative effects of SM934 is closely correlated with the enhancement of Nrf2 signaling and expression of its targets. Collectively, our finding confirmed that therapeutic strategy simultaneously exerting antioxidant and anti-inflammatory efficacy provide a novel feasible remedy for treating APSN-LN.

Complement in Secondary Thrombotic Microangiopathy

Thrombotic microangiopathy (TMA) is a condition characterized by thrombocytopenia and microangiopathic hemolytic anemia (MAHA) with varying degrees of organ damage in the setting of normal international normalized ratio and activated partial thromboplastin time. Complement has been implicated in the etiology of TMA, which are classified as primary TMA when genetic and acquired defects in complement proteins are the primary drivers of TMA (complement-mediated TMA or atypical hemolytic uremic syndrome, aHUS) or secondary TMA, when complement activation occurs in the context of other disease processes, such as infection, malignant hypertension, autoimmune disease, malignancy, transplantation, pregnancy, and drugs. It is important to recognize that this classification is not absolute because genetic variants in complement genes have been identified in patients with secondary TMA, and distinguishing complement/genetic-mediated TMA from secondary causes of TMA can be challenging and lead to potentially harmful delays in treatment. In this review, we focus on data supporting the involvement of complement in aHUS and in secondary forms of TMA associated with malignant hypertension, drugs, autoimmune diseases, pregnancy, and infections. In aHUS, genetic variants in complement genes are found in up to 60% of patients, whereas in the secondary forms, the finding of genetic defects is variable, ranging from almost 60% in TMA associated with malignant hypertension to less than 10% in drug-induced TMA. On the basis of these findings, a new approach to management of TMA is proposed.

Renal Papillary Necrosis Following Mesenteric Artery Stenting

A 62-year-old man presented with left flank pain and hematuria four days after undergoing mesenteric artery balloon angioplasty and stent placement. Imaging revealed left renal infarction with associated papillary necrosis and a thrombus in the left collecting system causing acute renal obstruction. Complete obstruction was confirmed using MAG3 Renal Scan with Lasix. A nephrostomy tube was inserted under CT guidance by interventional radiology with complete resolution of obstruction and hematuria.

A 75-year-old woman with primary antiphospholipid syndrome presenting with livedoid vasculopathy

The clinical presentation of primary antiphospholipid syndrome (PAPS) can vary, often mimicking many other medical conditions. Therefore, it is difficult to diagnose at the first presentation because of the absence of classical symptoms. We described an unusual presentation of PAPS mimicking livedoid vasculopathy (LV), where the only diagnostic clue at the initial presentation was skin lesions in both lower legs. A 75-year-old Han Chinese woman presented with features mimicking LV, without clinically significant antiphospholipid syndrome (APS). After many relevant laboratory examinations and histopathological examination, the patient was finally diagnosed as having PAPS. LV should not be treated as an independent disease, but as a skin manifestation. A high degree of suspicion of APS is needed in patients presenting or diagnosed with LV. Early interventions are necessary to prevent and reduce the risk of thrombosis. This case presents a rare clinical manifestation and provides significant information on PAPS.

Catastrophic antiphospholipid syndrome: is life-long anticoagulation therapy required?

Catastrophic antiphospholipid syndrome (CAPS) is an unusual complication of antiphospholipid syndrome (APS) occurring in about 1% of patients. If left untreated, mortality can be as high as 50%. Therapy of APS and its complication CAPS is hampered by the lack of validated prospective, controlled, intervention clinical trials, although there is consensus that treatment should include anticoagulation therapy. But there are issues that need to be addressed such as duration and intensity of therapy. The present report describes our experience in 7 patients with CAPS in whom anticoagulation was discontinued after 6 months of therapy. During an average follow-up of 5.5 years, only 2 patients exhibited one episode each of recurrent venous thrombosis, but none of the patients in whom anticoagulation was discontinued experienced recurrent CAPS.Key Points• Discontinuation of long-term anticoagulation therapy in CAPS patients was not followed by recurrence of CAPS.

The Role of Cardiolipin and Mitochondrial Damage in Kidney Transplant

Chronic kidney disease (CKD) is highly incident and prevalent in the world. The death of patients with CKD is primarily due to cardiovascular disease. Renal transplantation (RT) emerges as the best management alternative for patients with CKD. However, the incidence of acute renal graft dysfunction is 11.8% of the related living donor and 17.4% of the cadaveric donor. Anticardiolipin antibodies (ACAs) or antiphospholipid antibodies (APAs) are important risk factors for acute renal graft dysfunction. The determination of ACA or APA to candidates for RT could serve as prognostic markers of early graft failure and would indicate which patients could benefit from anticoagulant therapy. Cardiolipin is a fundamental molecule that plays an important role in the adequate conformation of the mitochondrial cristae and the correct assembly of the mitochondrial respiratory supercomplexes and other proteins essential for proper mitochondrial function. Cardiolipin undergoes a nonrandom oxidation process by having pronounced specificity unrelated to the polyunsaturation pattern of its acyl groups. Accumulation of hydroxyl derivatives and cardiolipin hydroperoxides has been observed in the affected tissues, and recent studies showed that oxidation of cardiolipin is carried out by a cardiolipin-specific peroxidase activity of cardiolipin-bound cytochrome c. Cardiolipin could be responsible for the proapoptotic production of death signals. Cardiolipin modulates the production of energy and participates in inflammation, mitophagy, and cellular apoptosis. The determination of cardiolipin or its antibodies is an attractive therapeutic, diagnostic target in RT and kidney diseases.

Antiphospholipid Syndrome Nephropathy and Other Thrombotic Microangiopathies Among Patients With Systemic Lupus Erythematosus

Antiphospholipid syndrome (APS) and other causes of thrombotic microangiopathy (TMA) negatively impact the renal outcomes of patients with systemic lupus erythematosus (SLE) and lupus nephritis. Here we review the diagnosis and management of occlusive renal vascular lesions due to APS and other TMAs, with a focus on patients with SLE and lupus nephritis. The presence of a thrombotic event, unexplained hypertension, thrombocytopenia, or hemolytic anemia should prompt consideration for TMA syndromes. The differential diagnosis of a TMA in a patient with SLE includes APS, thrombocytopenic purpura, complement-mediated or infection-associated hemolytic uremic syndrome, drug-mediated TMA (particularly due to calcineurin inhibitor toxicity), and malignant hypertension. Treatment of APS with a documented thrombotic event focuses on anticoagulation to reduce the risk for further thrombotic events. Treatment of classic presentations of thrombocytopenic purpura and hemolytic uremic syndrome in the SLE population is the same as in patients without SLE. Treatment of APS nephropathy or TMA when it is diagnosed by biopsy with concomitant lupus nephritis presents a challenge to clinicians because there is no clear standard of care. Small and retrospective studies suggest potential benefit of complement inhibition, mammalian target of rapamycin (mTOR) inhibition, B cell depleting therapy, and plasma exchange therapy for patients with lupus nephritis and TMA, and prospective investigation of these therapies should be a research priority.

Clinical performance of non-criteria antibodies to phospholipids in Chinese patients with antiphospholipid syndrome

BACKGROUND

Increasing evidence suggests the role of non-criteria aPLs as important supplements to the current criteria aPLs in APS. In this study, we evaluated the clinical performance of a panel of non-criteria antibodies to phospholipid antigens, including, phosphatidylserine (aPS), phosphatidylinositol (aPI), sphingomyelin (aSM), phosphatidylcholine (aPC) and phosphatidylethanolamine (aPE) in a well-defined Chinese APS cohort.

METHODS

A total of 229 subjects were tested, including 86 patients with APS, 104 disease controls (DCs) and 39 healthy controls (HCs). Serum IgG/IgM aCL, IgG/IgM aβ2GP1, IgG/IgM aPS, IgG/IgM aPI, IgG/IgM aSM, IgG/IgM aPC, and IgG/IgM aPE were tested by ELISA.

RESULTS

The presence of aPE, aPS, aPI, aPC, and aSM in patients with APS and Disease Controls were 8.1% (7/86) and 1.0% (1/104), 37.2% (32/86) and 9.6% (10/104), 50.0% (43/86) and 8.7% (9/104), 23.3% (20/86) and 1.0% (1/104), and 18.6% (16/86) and 1.9% (2/104), respectively. In criteria aPLs, aCL IgG demonstrated the highest positive likelihood ratio (LR+) of 35.75, followed by LA (LR+ of 13.51) and aCL IgM (LR+ of 11.64). In non-criteria aPLs, aPC IgG demonstrated the highest LR+ of 24.94 followed by aSM IgM (LR+ of 14.97). Importantly, the non-criteria aPLs were detected in 18.8% (3/16) of seronegative APS patients. The criteria aPLs, including LA, IgG aCL and IgG aβ2GPI, were significantly correlated with both arterial thrombosis and venous thrombosis, while the non-criteria aPLs, including IgG aPS, IgM aPS, IgG aPI and IgG aPC were significantly associated with arterial thrombosis but not venous thrombosis.

CONCLUSIONS

In summary, our findings indicate that those non-criteria aPLs may be particularly helpful for patients in whom APS is highly suspected, but conventional aPLs are repeatedly negative as well as for predicting APS patients with arterial thrombosis.