Comparison of renal disease severity and outcome in patients with primary antiphospholipid syndrome, antiphospholipid syndrome secondary to systemic lupus erythematosus (SLE) and SLE alone

Renal and vascular outcomes in patients with isolated antiphospholipid syndrome nephropathy

BACKGROUND

Antiphospholipid syndrome (APS) nephropathy (APSN) is a rare pattern with specific features resulting from microvascular lesions. The prognosis of APSN, outside of lupus nephritis, is unknown. The aim of this study was to describe the renal, vascular and overall outcomes of patients with APSN.

METHODS

Retrospective multicenter study of patients with antiphospholipid antibodies (aPL) associated with histological APSN lesions and no other nephropathy, identified through a national call for medical records. End-stage renal disease (ESRD)-free survival, thrombosis recurrence-free survival and overall survival were assessed.

RESULTS

Thirty patients were included (19 women) with a median age of 40 years (34-52 years). Fifteen patients had APS, 26/28 had lupus anticoagulant, and 15/26 had triple positivity for aPL. Median eGFR was 50 (31-60) mL/min/1.73 m². Glomerular thrombotic microangiopathy was found in 12/24 cases, fibrous intimal hyperplasia in 12/22 cases and focal cortical atrophy in 17/29 cases. Nineteen patients had moderate to severe interstitial fibrosis (>25%). Six patients developed ESRD at a median follow-up of 6.2 (1.8-9.1) years. The ESRD-free survival rates at 5 and 10 years were 80.0% (95% CI 57.6%-91.4%) and 72.7% (95% CI, 46.9%-87.4%) respectively. None of the histological factors considered was significantly associated with a decrease in eGFR at 12 months. Thrombosis recurrence-free survival was 77.8% (95% CI 48.2%-91.6%) at 10 years. Overall survival was 94% at 10 years (95% CI 65.0%-99.2%).

CONCLUSIONS

The renal prognosis of isolated APSN is poor. The severe fibrotic lesions observed are suggestive of late diagnosis.

Increased risk of acute and chronic microvascular renal lesions associated with antiphospholipid antibodies in patients with systemic lupus erythematosus: A systematic review and meta-analysis

BACKGROUND

Microvascular renal lesions have been described in patients with antiphospholipid antibodies (aPL), however their association with aPL is inconsistent among studies. Therefore, our objective was to investigate associations between microvascular renal lesions and aPL among systemic lupus erythematosus (SLE) patients.

METHODS

Studies were selected if they included SLE patients with and without aPL positivity with a description of kidney biopsy identifying acute and/or chronic microvascular renal lesions as well as lupus nephritis. Data sources were Pubmed, Embase, Cochrane Library, hand search, congress abstracts, and reference lists of studies, without language restrictions. Risk estimates were independently extracted by 2 investigators. Pooled effect estimates were obtained by using the Mantel-Haenszel method (random effects).

RESULTS

Of 1860 identified records obtained between 1991 and 2021, 35 published studies (10 cohorts, 7 case-control, 18 cross-sectional) met inclusion criteria, including 3035 SLE patients according to American College of Rheumatology criteria and 454 cases of microvascular renal lesions. Frequency of microvascular renal lesions in aPL-positive vs. aPL-negative SLE patients was 31.3% vs. 10.4%, respectively. The overall pooled odds ratios (OR) for microvascular renal lesions in aPL-positive vs. aPL-negative SLE patients was 3.03 (95% confidence interval [CI], 2.25-4.09). The risk of microvascular renal lesions was the highest for lupus anticoagulant (OR = 4.84 [95% CI, 2.93 to 8.02]) and IgG anticardiolipin antibodies (OR = 3.12 [95% CI,1.08-9.02]) while the association with anti-β₂-glycoprotein I antibodies (OR = 1.88 [95% CI, 0.25-14.14]) did not reach statistical significance. Furthermore, aPL were not associated with any classes of lupus nephritis.

CONCLUSION

In SLE patients, aPL-positivity is associated with a significant 3- to 5-fold increased risk for specific microvascular renal lesions. This risk is mainly driven by lupus anticoagulant and IgG anticardiolipin antibodies. Our results support the inclusion of microvascular renal lesions as new criteria for definite antiphospholipid syndrome.

Lupus Vasculitis: An Overview

Lupus vasculitis (LV) is one of the secondary vasculitides occurring in the setting of systemic lupus erythematosus (SLE) in approximately 50% of patients. It is most commonly associated with small vessels, but medium-sized vessels can also be affected, whereas large vessel involvement is very rare. LV may involve different organ systems and present in a wide variety of clinical manifestations according to the size and site of the vessels involved. LV usually portends a poor prognosis, and a prompt diagnosis is fundamental for a good outcome. The spectrum of involvement ranges from a relatively mild disease affecting small vessels or a single organ to a multiorgan system disease with life-threatening manifestations, such as mesenteric vasculitis, pulmonary hemorrhage, or mononeuritis multiplex. Treatment depends upon the organs involved and the severity of the vasculitis process. In this review, we provide an overview of the different forms of LV, describing their clinical impact and focusing on the available treatment strategies.

Starting off on the right foot: A 22-year-old woman with leg swelling

A previously healthy 22-year-old woman was in the second trimester of her first pregnancy when she developed new lower extremity edema. Her pregnancy course had been unremarkable, and she was receiving routine obstetric care from her family physician. One week prior to admission she developed progressive swelling in her legs.

Systemic lupus erythematosus: a case-based presentation of renal, neurologic, and hematologic emergencies

INTRODUCTION

Systemic lupus erythematosus (SLE) is a chronic autoimmune disorder with systemic manifestations and multiorgan involvement. Although primarily diagnosed, and managed in the outpatient setting, it can occasionally present with life-threatening complications that require rapid assessment and urgent aggressive therapy. Areas covered: In our review, we explore three organ systems that are often affected in SLE, but have the potential to present as medical emergencies; these are the kidney, the central nervous system, and the hematologic system. We take a case-based approach to each clinical scenario, with information given sequentially in order to reflect "real-life" situations where management decisions need to be made with limited information. We review the acute management, pathophysiology, diagnostic approach, and treatment along with a review of the literature, for lupus nephritis presenting as rapidly progressive glomerulonephritis, acute lupus transverse myelitis, and refractory antiphospholipid syndrome. Expert commentary: At the conclusion of each section, we provide an expert commentary regarding each issue, relating to diagnosis, early management, and current evidence behind treatment recommendations.

Primary antiphospholipid syndrome and antiphospholipid syndrome associated to systemic lupus: Are they different entities?

Primary antiphospholipid syndrome (PAPS) and antiphospholipid syndrome associated to lupus (SAPS) have several overlapping characteristics. As systemic manifestations are also reported in patients with PAPS, and as a subgroup of PAPS patients could evaluate to a SAPS, the differentiation between the two types of APS could be performed based on the clinical experience of the medical teams and is related to a variety of clinical, biological, histological and genetic features. Several data are available in the literature with respect to the identification of distinctive features between these two entities. However, there are some limitation in the interpretation of results issued from studies performed prior to updated Sydney criteria. Based on recent data, a certain number of features more frequent in one type of APS as compared to the other could be distinguished. The major differentiation between these two entities is genetical. New genetic data allowing the identification of specific subgroups of APS are ongoing.

Renal involvement in antiphospholipid syndrome

This is a review of scientific publications on renal involvement in antiphospholipid syndrome (APS), with focus on clinical and histopathological findings and treatment. A search for English-language articles on renal involvement in APS covering the period 1980-2017 was conducted in Medline/PubMed and Scopus databases using the MeSH terms "antiphospholipid syndrome", "antiphospholipid antibodies", "glomerulonephritis" and "thrombotic microangiopathy" (TMA). APS nephropathy is primarily the result of thromboses in renal arteries or veins, intraparenchymatous arteries and glomerular capillaries. On histology, APS nephropathy is characterized by TMA, but chronic vaso-occlusive lesions are also commonly observed (fibrous intimal hyperplasia, focal cortical atrophy, fibrous occlusions of arteries). Anticardiolipin and lupus anticoagulant are the most prevalent antibodies in patients with APS nephropathy. The spectrum of renal manifestations includes renal vein thrombosis, renal artery thrombosis/stenosis, TMA, increased allograft vascular thrombosis and malignant hypertension. Anticoagulation is the standard treatment of thrombotic events. In systemic lupus erythematosus (SLE) patients with antiphospholipid antibodies (aPL), kidney failure due to SLE nephritis (immune-complex disease) should be clearly distinguished from kidney failure due to APS-related TMA. In such cases, renal biopsy is mandatory. SLE nephritis requires immunosuppressive therapy, whereas APS nephropathy is usually treated with anticoagulants. Recently, eculizumab and sirolimus have been proposed as a rescue therapy. Based on our review, APS nephropathy appears to be a distinct clinical condition. TMA is a characteristic histopathological finding in APS and is strongly associated with the presence of aPL. This has important therapeutic implications and allows distinguishing APS nephropathy from lupus nephritis.

Renal protective effect of antiplatelet therapy in antiphospholipid antibody-positive lupus nephritis patients without antiphospholipid syndrome

Objective

We sought to evaluate the effect of antiplatelet therapy in addition to conventional immunosuppressive therapy for lupus nephritis (LN) patients positive for antiphospholipid antibodies (aPL) without definite antiphospholipid syndrome (APS).

Methods

Patients with biopsy-proven LN class III or IV were retrospectively evaluated. We selected patients positive for anticardiolipin antibody (aCL) or lupus anticoagulant (LA) who did not meet the criteria for a diagnosis of APS. The patients were divided into two subgroups according to whether antiplatelet therapy was received. The cumulative complete renal response (CR) rate, relapse-free rate, and change in estimated glomerular filtration rate (eGFR) over 3 years after induction therapy were calculated.

Results

We identified 17 patients who received antiplatelet therapy and 21 who did not. Baseline clinicopathological characteristics and immunosuppressive therapy did not show a significant difference between the two groups except for a higher incidence of LN class IV in the treatment group (p = 0.03). There was no difference in cumulative CR rate, relapse-free rate, or eGFR change between these subgroups. However, when data on LA-positive patients were assessed, an improvement in eGFR was found (p = 0.04) in patients receiving antiplatelet treatment.

Conclusion

Addition of anti-platelet therapy was associated with an improvement of eGFR in LA-positive patients with LN class III or IV.

Kidney disease in primary anti-phospholipid antibody syndrome

APS is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for aPL. APS can be isolated (primary APS) or associated with other autoimmune diseases. The kidney is a major target organ in APS, and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal vasculature and renal veins). Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal involvement in patients with definite APS is treated with long-term anticoagulants as warfarin, but new treatments are being tried. The aim of this article is to review the links between primary APS and kidney disease.

Renal involvement in primary antiphospholipid syndrome

Antiphospholipid syndrome is an autoimmune disorder characterized by recurrent venous or arterial thrombosis and/or pregnancy-related problems associated with persistently elevated levels of antiphospholipid antibodies. The kidney is a major target organ in both primary and secondary antiphospholipid syndrome. This review describes several aspects of the renal involvement in the primary form of the syndrome, in particular the histological pattern of the so-called antiphospholipid syndrome nephropathy (APSN). APSN is a vascular nephropathy characterized by small vessel vaso-occlusive lesions associated with fibrous intimal hyperplasia of interlobular arteries, recanalizing thrombi in arteries and arterioles, and focal atrophy, a constellation of morphological lesions suggestive of primary antiphospholipid syndrome.

Resistant hypertension due to unilateral renal artery occlusion as the first presentation of antiphospholipid syndrome

Resistant hypertension in the setting of renal artery occlusion should prompt further investigation for secondary causes in a young patient. We present renal artery occlusion in the setting of antiphospholipid syndrome as the initial presentation successfully treated with percutaneous intervention. This case is followed by review of the literature.

The challenges of antiphospholipid syndrome: experience from diagnosis to self-care

A young woman presented to our unit with pancreatitis and acute kidney injury (AKI) 4 weeks after initiation of an oral contraceptive. She subsequently developed seizures due to posterior reversible encephalopathy syndrome and required ongoing haemodialysis for oliguric AKI. Routine antiphospholipid antibody screen was normal, but arterial and venous thromboses were identified on renal biopsy. Further coagulation studies identified an antiphospholipid-dependent inhibitor confirming the suspected diagnosis of antiphospholipid syndrome. She remained seizure free with control of hypertension and was established on anticoagulation. She remained haemodialysis dependent performing this independently at a new self-care unit. She provides us with valuable insights into her experience encouraging us to reconsider our current methods of education and communication in our younger population of patients living with chronic disease.

Renal involvement in antiphospholipid syndrome

Antiphospholipid syndrome (APS) is an autoimmune disease defined by the presence of arterial or venous thrombotic events and/or pregnancy morbidity in patients who test positive for antiphospholipid antibodies (aPLs). APS can be isolated (known as primary APS) or associated with other autoimmune diseases, such as systemic lupus erythematosus (SLE; known as secondary APS). The kidney is a major target organ in APS and renal thrombosis can occur at any level within the vasculature of the kidney (renal arteries, intrarenal arteries, glomerular capillaries and renal veins); events reflect the site and size of the involved vessels. Histological findings vary widely, including ischaemic glomeruli and thrombotic lesions without glomerular or arterial immune deposits on immunofluorescence. Renal prognosis is affected by the presence of aPLs in patients with lupus nephritis and can be poor. In patients with SLE and aPLs, biopsy should be performed because inflammatory and thrombotic lesions require different therapeutic approaches. Renal involvement in patients with definite APS is treated by anticoagulation with long-term warfarin. The range of renal manifestations associated with APS is broadening and, therefore, aPLs have increasing relevance in end-stage renal disease, transplantation and pregnancy.

What nephrolopathologists need to know about antiphospholipid syndrome-associated nephropathy: Is it time for formulating a classification for renal morphologic lesions?

CONTEXT

Antiphospholipid syndrome (APS) is a systemic autoimmune disorder which commonly affects kidneys.

EVIDENCE ACQUISITIONS

Directory of Open Access Journals (DOAJ), Google Scholar, PubMed (NLM), LISTA (EBSCO) and Web of Science have been searched.

RESULTS

There is sufficient epidemiological, clinical and histopathological evidence to show that antiphospholipid syndrome is a distinctive lesion caused by antiphospholipid antibodies in patients with different forms of antiphospholipid syndrome. It is now time to devise a classification for an accurate diagnosis and prognostication of the disease.

CONCLUSIONS

Now that the morphological lesions of APSN are sufficiently well characterized, it is prime time to devise a classification which is of diagnostic and prognostic utility in this disease.

Prevalence of the antiphospholipid syndrome and its effect on survival in 679 Chinese patients with systemic lupus erythematosus: a cohort study

In this work we evaluate the prevalence of the antiphospholipid syndrome (APS) and its impact on survival in Chinese patients with systemic lupus erythematosus (SLE). We studied a prospective cohort of southern Chinese patients who fulfilled ≥4 American College of Rheumatology criteria for SLE. The cumulative rate of survival over time was calculated by the Kaplan-Meier method. APS was defined by the 2006 updated consensus criteria. We evaluated the prevalence and manifestations of APS, and compared the survival of patients with and without APS. We followed 679 patients with SLE (92% women; age of onset, 32.5 ± 14 yr) for 9.7 ± 7.3 years. Sixty-eight (10%) patients died and 33 (4.9%) patients were lost to follow-up. Forty-four (6.5%) patients met the criteria for APS, manifested by the following: ischemic stroke (55%), deep venous thrombosis (32%), obstetric morbidity (14%), cardiovascular events (9%), and peripheral vascular disease (9%). Nine (9/44 [20%]) APS patients died, which was more frequent than the non-APS patients (59/635 [9%]; p = 0.02). The cumulative mortality of patients with APS was 4.6% at 5 years, 7.8% at 10 years, and 22.2% at 15 years, which was not significantly higher than that of non-APS patients (5.4% at 5 years, 9.2% at 10 years, and 11.3% at 15 years; p = 0.14). However, if we considered only patients with APS caused by arterial thrombosis, the presence of APS was significantly associated with mortality (hazard ratio, 2.29; 95% confidence interval, 1.13-4.64; p = 0.02). We conclude that the presence of APS increases the mortality risk of Chinese patients with SLE, which is mainly contributed by arterial thrombotic events.

CLINICAL SIGNIFICANCE

1) APS is infrequent in southern Chinese patients with SLE compared to white patients. 2) Arterial thrombosis is a more common manifestation of APS than venous thrombosis in Chinese SLE patients. 3) APS related to arterial thrombosis is associated with increased mortality in Chinese patients with SLE.

Rituximab in the treatment of resistant lupus nephritis: therapy failure in rapidly progressive crescentic lupus nephritis

OBJECTIVE

The objective of this paper is to report the clinical outcome of B cell depletion therapy in 18 patients with refractory lupus nephritis (LN).

METHODS

Eighteen patients received rituximab on an open-label basis with prospective evaluations. All patients had renal disease refractory to conventional immunosuppressive therapy, including intravenous cyclophosphamide (CyC). All patients fulfilled the revised ACR classification criteria for SLE. Rituximab was given as 2 × 1 g infusions with 500 mg iv CyC and 500 mg iv methylprednisolone, two weeks apart. Complete remission (CR) of nephritis at six months was defined as normal serum creatinine and serum albumin levels, inactive urine sediment, and proteinuria < 0.5 g/day; partial remission (PR) was defined as a ≥50% improvement in all renal parameters that were abnormal at baseline. Clinical response was assessed by the British Isles Lupus Assessment Group (BILAG) score pre- and post-rituximab treatment, and efficacy was recorded by extent and duration of B lymphocyte depletion (normal range 0.100-0.500 × 10(9)/l). Follow-up data were collected at six months, one year post-treatment and at the most recent clinic visit.

RESULTS

At six months, 11/18 patients reached renal CR and two of 18 PR. The mean global BILAG scores for responders decreased from 15 (SD 10) to 5 (SD 3), and a total of ten A scores disappeared. Five patients failed to show complete or partial renal response despite peripheral B lymphocyte count depletion, and progressed to end-stage renal failure (ESRF) and dialysis. Four of these patients had severe proliferative, crescentic nephritis, of whom three had Class IV-G, one Class III and one late membranous glomerulonephritis. One patient died six years after rituximab therapy from overwhelming sepsis while on long-term haemodialysis.

CONCLUSION

Rituximab therapy achieved a response in 13/18 patients with refractory LN. However, in patients with rapidly progressive crescentic LN, when there is already evidence of significant renal impairment, rituximab therapy may not prevent progression to ESRF and dialysis. Our data also suggest that severe Class IV-G LN may be associated with a poor response to therapy.

Joint European League Against Rheumatism and European Renal Association-European Dialysis and Transplant Association (EULAR/ERA-EDTA) recommendations for the management of adult and paediatric lupus nephritis

OBJECTIVES

To develop recommendations for the management of adult and paediatric lupus nephritis (LN).

METHODS

The available evidence was systematically reviewed using the PubMed database. A modified Delphi method was used to compile questions, elicit expert opinions and reach consensus.

RESULTS

Immunosuppressive treatment should be guided by renal biopsy, and aiming for complete renal response (proteinuria <0.5 g/24 h with normal or near-normal renal function). Hydroxychloroquine is recommended for all patients with LN. Because of a more favourable efficacy/toxicity ratio, as initial treatment for patients with class III-IV(A) or (A/C) (±V) LN according to the International Society of Nephrology/Renal Pathology Society 2003 classification, mycophenolic acid (MPA) or low-dose intravenous cyclophosphamide (CY) in combination with glucocorticoids is recommended. In patients with adverse clinical or histological features, CY can be prescribed at higher doses, while azathioprine is an alternative for milder cases. For pure class V LN with nephrotic-range proteinuria, MPA in combination with oral glucocorticoids is recommended as initial treatment. In patients improving after initial treatment, subsequent immunosuppression with MPA or azathioprine is recommended for at least 3 years; in such cases, initial treatment with MPA should be followed by MPA. For MPA or CY failures, switching to the other agent, or to rituximab, is the suggested course of action. In anticipation of pregnancy, patients should be switched to appropriate medications without reducing the intensity of treatment. There is no evidence to suggest that management of LN should differ in children versus adults.

CONCLUSIONS

Recommendations for the management of LN were developed using an evidence-based approach followed by expert consensus.

Emerging uses for pediatric hematopoietic stem cells

Many new therapies are emerging that use hematopoietic stem and progenitor cells. In this review, we focus on five promising emerging trends that are altering stem cell usage in pediatrics: (i) The use of hematopoietic stem cell (HSC) transplantation, autologous or allogeneic, in the treatment of autoimmune disorders is one. (ii) The use of cord blood transplantation in patients with inherited metabolic disorders such as Hurler syndrome shows great benefit, even more so than replacement enzyme therapy. (iii) Experience with the delivery of gene therapy through stem cells is increasing, redefining the potential and limitations of this therapy. (iv) It has recently been shown that human immunodeficiency virus (HIV) infection can be cured by the use of selected stem cells. (v) Finally, it has long been postulated that HSC-transplantation can be used to induce tolerance in solid-organ transplant recipients. A new approach to tolerance induction using myeloid progenitor cells will be described.

Association of PTPN22 gene polymorphism and systemic lupus erythematosus in a cohort of Egyptian patients: impact on clinical and laboratory results

To assess the possible association between the protein tyrosine phosphatases non-receptor 22 (PTPN22) gene 1858 CT polymorphism and the predisposition to systemic lupus erythematosus (SLE) in Egyptian patients and its influence on clinical and laboratory parameters. PTPN22 gene 1858 CT polymorphisms were analyzed in forty SLE patients and 20 normal controls by real-time polymerase chain reaction (PCR) technology, using the TaqMan 5-allele discrimination assay. Detailed history, clinical examination, and investigations were done to detect various organ involvement. The homozygous genotype TT was absent in both SLE and controls. The CC genotype was observed in 47.5% SLE and 80% controls; the CT genotype was found in 52.5% patients and 20% controls. The frequencies of the C and T alleles were 74 and 26% in SLE and 90 and 10% in controls, respectively. The presence of CT genotype increased the risk for developing SLE by 4.42. Renal involvement was significantly higher in SLE patients with CT (76.2%) compared to those with CC genotype (42.1%).

Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations (I): catastrophic APS, APS nephropathy and heart valve lesions

The objectives of the 'Task Force on Catastrophic Antiphospholipid Syndrome (APS) and Non-criteria APS Manifestations' were to assess the clinical utility of the international consensus statement on classification criteria and treatment guidelines for the catastrophic APS, to identify and grade the studies that analyse the relationship between the antiphospholipid antibodies and the non-criteria APS manifestations and to present the current evidence regarding the accuracy of these non-criteria APS manifestations for the detection of patients with APS. This article summarizes the studies analysed on the catastrophic APS, APS nephropathy and heart valve lesions, and presents the recommendations elaborated by the Task Force after this analysis.

Hematopoietic stem cell transplantation for pediatric autoimmune disease: where we stand and where we need to go

In children, autoimmune diseases and their therapies cause significant morbidity, especially in those with severe or refractory disease. The constant development of new immunosuppressants and targeted biological therapies leads to a unique 'moving target' with regard to the gold standard of treatment for these patients. However, incidental findings of cure after hematopoietic stem cell transplant (HSCT) in patients with concomitant benign or malignant hematologic disorders and autoimmune disease raise the question of whether HSCT can be used as upfront therapy for patients with severe autoimmune diseases. Animal data have been helpful in investigating both the efficacy of this modality and the mechanisms underlying cure. The potential for a therapeutic 'graft vs autoimmunity' (GVA) effect with an allogeneic approach highlights the already acknowledged need for clinical trials of allogeneic vs autologous transplant in these diseases where an autologous transplant would be the 'intuitive' albeit potentially erroneous choice. We critically review the data generated in the field thus far, and emphasize the need for an organized, interdisciplinary approach to conduct prospective clinical trials to answer these and other questions and advance the field.

A case of catastrophic antiphospholipid syndrome in an adolescent girl with parvovirus B19 infection

Antiphospholipid syndrome is an autoimmune disease characterized by recurrent thrombosis and the presence of antiphospholipid antibodies. Clinical presentations are dependent on the affected vessels and organs. The most common presentation of antiphospholipid syndrome is arterial or venous thrombosis. An unusual presentation of the disease is characterized by microvascular thrombosis with multiorgan involvement, which is termed catastrophic antiphospholipid syndrome. The diagnosis of catastrophic antiphospholipid syndrome can be difficult because of the heterogeneity of the different clinical forms. Clinical manifestations of catastrophic antiphospholipid syndrome are complex with multiple organ involvement, resulting in renal insufficiency, heart failure, acute respiratory distress syndrome, and liver involvement. Early diagnosis and aggressive therapies are essential in this condition because of the extremely high mortality rate. Herein, the case of a 14-year-old girl with catastrophic antiphospholipid syndrome that was previously misdiagnosed as a vasculitis related to parvovirus B19 infection is presented.

Antiphospholipid syndrome and the kidneys

OBJECTIVES

To study the relationship between antiphospholipid antibodies and kidney diseases.

METHODS

We reviewed the medical literature from 1968 to 2005 using MEDLINE and the keywords antiphospholipid syndrome, anticardiolipin antibodies, lupus anticoagulant, hypertension, renal artery stenosis, renal vascular thrombosis, thrombotic microangiopathy, and glomerulonephritis.

RESULTS

The renal manifestations of the antiphospholipid syndrome may result from thrombosis occurring at any location within the renal vasculature, that is, in the renal artery trunk or branches, intraparenchymal arteries and arterioles, glomerular capillaries, and the renal veins. The spectrum of these manifestations includes renal artery stenosis and/or malignant hypertension, renal infarction, renal vein thrombosis, thrombotic microangiopathy, increased allograft vascular thrombosis, and reduced survival of renal allografts. More recently nonthrombotic conditions like glomerulonephritis have also been reported.

CONCLUSION

The kidney appears to be a major target organ in both primary and secondary APS. Early detection of renal involvement may improve the prognosis of these patients.

The R620W C/T polymorphism of the gene PTPN22 is associated with SLE independently of the association of PDCD1

The gene PTPN22 is located on chromosome 1p13 and encodes a protein tyrosine phosphatase called the lymphoid-specific phosphatase (Lyp). Lyp is expressed in lymphocytes, where it physically associates through its proline-rich motif (called P1) with the SH3 domain of the protein tyrosine kinase Csk, an important suppressor of the Src family of kinases Lck and Fyn, which mediate TCR signaling. Therefore, it is said that interaction between Lyp and Csk enables these effectors to inhibit T-cell activation synergistically. It was reported that a missense single nucleotide polymorphism , R620W (rs2476601), 1858C->T encodes an amino-acid change in the P1 proline-rich motif of the gene PTPN22 and is associated with SLE in North American white individuals. PTPN22 gene polymorphisms were genotyped in 571 Swedish SLE patients and 1042 healthy controls using TaqMan SNP Genotyping Assay. Differences were observed between cases and control subjects at both the allele (chi(2)=11.2895;P=0.0007,1df) and genotype (chi(2)=10.2243;P=0.0013, 1df) levels. We also found evidence of a genetic association between PTPN22 and renal disorder (chi(2)=9.5660;P=0.0019). We then analyzed if in patients with renal disorder associations with PDCD1 and PTPN22 were independent. Our data suggest that this appears to be the case although we observed some degree of interaction.

Renal manifestations of the antiphospholipid syndrome

Renal thrombotic manifestations have been reported since the earliest descriptions of the antiphospholipid (Hughes) syndrome (APS). The spectrum of clinical features associated with antiphospholipid nephropathy continues to widen. This review will highlight recent developments such as the prevalence of hypertension, livedo reticularis and renal artery stenosis as well as the ultrastructural changes seen in antiphospholipid nephropathy. The increasing risks of renal transplantation in antiphospholipid antibody positive patients is also discussed leading some authors to question whether these patients should undergo transplantation at all.

New therapies for systemic lupus erythematosus

In the past 40 years, prognosis for patients with systemic lupus erythematosus (SLE) has improved, with 10-year survival now approximately 90%. This is due probably to a combination of earlier disease diagnosis and diagnosis of milder disease, due in part to availability of multiple serological tests for SLE, use of steroids and other immunosuppressive agents, and availability of renal dialysis and transplantation. Despite this, however, the potential for significant morbidity and mortality remains in the group of patients with partially responsive or treatment resistant disease. More recently, advancements in the understanding of molecular mechanisms involved in the pathogenesis of SLE have translated to the development of novel therapies, offering possible alternatives to this patient cohort. Discussion of these pharmacological options and ongoing research forms the basis of this review.

Primary versus secondary antiphospholipid syndrome: is this lupus or not?

Antiphospholipid syndrome is a hypercoaguable state characterized by recurrent venous and/or arterial thrombosis and/or pregnancy complications of fetal loss, pre-eclampsia, or eclampsia in the presence of antiphospholipid antibodies. It was first described in the setting of systemic lupus erythematosus and subsequently recognized to also exist as an independent condition and in conjunction with a variety of other autoimmune, infectious, and malignant illnesses. These diseases have been called primary antiphospholipid syndrome and secondary antiphospholipid syndrome. However, the two conditions can have significant overlapping features. This paper reviews the similarities and the differences between the two conditions.

Unusual and aggressive thrombotic onset in two children with antiphospholipid-antibody syndrome and systemic lupus erythematosus

We report two pediatric patients with unusual, aggressive initial manifestation of antiphospholipid antibody syndrome secondary to systemic lupus erythematosus. The first patient, a 13-year-old girl, presented with bilateral amaurosis and ischemic cerebral lesions. The second, another 13-year-old girl, presented with cerebral venous sinus thrombosis and membranous glomerulonephritis. Both patients improve after treatment with anticoagulants and immunosuppressive drugs, two therapies that are aimed at modulating the immune response or towards preventing thromboembolic events. However, there is no consensus regarding the duration and intensity of oral anticoagulation in children with antiphospholipid antibody syndrome.

Lupus anticoagulants in children

Lupus anticoagulant and ACAs are made up of heterogeneous IgG and IgM antibodies that prolong in vitro clotting times and are associated with increased risks of venous and arterial thrombosis, recurrent fetal loss, and autoimmune thrombocytopenia and anemia. These clinical findings with the appropriate laboratory results make up the antiphospholipid antibody syndrome. The antiphospholipid antibodies found in this syndrome are directed against a variety of phospholipid binding proteins of which beta2-glycoprotein and prothrombin are considered to be common antigens. Children who present with thrombosis and are positive for lupus anticoagulant and ACAs have similar clinical presentations and prognoses as adults. Isolated lupus anticoagulant and ACAs in children who are asymptomatic likely do not lead to clinical complications and are transient.

Lupus nephritis: current issues

Despite the development of new modalities, cyclophosphamide (CYC) remains the preferred initial treatment for severe proliferative lupus nephritis. Controversies continue about the best route, dosage, and duration of CYC treatment. For recalcitrant disease, new immunosuppressive and immunomodulating agents, immunoablative high dose CYC, nucleoside analogues, apheresis, and the biological response modifiers can be considered.

Antiphospholipid antibodies in pediatrics

Antiphospholipid antibody syndrome has been associated with vascular thrombosis, thrombocytopenia, hemolytic anemia, livedo reticularis, neurologic disorders, and recurrent fetal loss. The diagnosis of antiphospholipid syndrome is given in the presence of an elevated anticardiolipin antibody lupus anticoagulant in addition to a thrombotic event. Antiphospholipid antibodies are responsible for a majority of thrombotic events in children. These antibodies can present as a primary syndrome or secondary to other diseases, such as systemic lupus erythematosus. Anticoagulation therapy with heparin and low-dose aspirin is the recommended treatment in pediatric patients.

Nephrological and obstetric complications of the antiphospholipid syndrome

The antiphospholipid syndrome (APS) is a disorder of hypercoagulability, characterised by thromboembolic events, repeated miscarriages and thrombocytopenia in association with circulating antiphospholipid antibodies. These antibodies are directed against epitopes on either oxidised phospholipids complexed with a glycoprotein, beta 2-glycoprotein I, or against the glycoprotein itself. Renal manifestations of the APS are varied and depend on the type of renal pathology present. The renal vasculature may be affected by either a small vessel, thrombotic microangiopathy process or by large vessel thrombosis. In patients with end stage renal disease, the prevalence of antiphospholipid antibodies may increase with time on dialysis. Anticardiolipin antibodies have been associated with a high incidence of haemodialysis access clotting, a major source of morbidity and hospitalisation in end stage renal disease patients. In renal transplant recipients, antiphospholipid antibodies may be associated with a higher incidence of primary graft non-function, particularly in patients without a history of pretransplantation haemodialysis. Complications of the APS during pregnancy span all trimesters and include intrauterine growth retardation, placental abruption, pre-eclampsia, preterm labour and recurrent fetal loss. As these women have a high risk of recurrent fetal loss, multiple treatment modalities have been investigated, including aspirin, heparin, prednisone and intravenous immunoglobulin. Various treatment strategies for the APS have been developed and are based on a combination of anticoagulant therapy with either warfarin or heparin, along with antiplatelet therapy with aspirin. Experimental treatments involving immunomodulatory therapy with intravenous immunoglobulin, apheresis and novel antibody therapy are being investigated with hopes of successful clinical applications.