Circulating IgA-immune complexes in Henoch-Schönlein purpura. A longitudinal study of their relationship to disease activity and vascular deposition of IgA

IgA nephropathy

IgA nephropathy (IgAN), the most prevalent primary glomerulonephritis worldwide, carries a considerable lifetime risk of kidney failure. Clinical manifestations of IgAN vary from asymptomatic with microscopic or intermittent macroscopic haematuria and stable kidney function to rapidly progressive glomerulonephritis. IgAN has been proposed to develop through a 'four-hit' process, commencing with overproduction and increased systemic presence of poorly O-glycosylated galactose-deficient IgA1 (Gd-IgA1), followed by recognition of Gd-IgA1 by antiglycan autoantibodies, aggregation of Gd-IgA1 and formation of polymeric IgA1 immune complexes and, lastly, deposition of these immune complexes in the glomerular mesangium, leading to kidney inflammation and scarring. IgAN can only be diagnosed by kidney biopsy. Extensive, optimized supportive care is the mainstay of therapy for patients with IgAN. For those at high risk of disease progression, the 2021 KDIGO Clinical Practice Guideline suggests considering a 6-month course of systemic corticosteroid therapy; however, the efficacy of systemic steroid treatment is under debate and serious adverse effects are common. Advances in understanding the pathophysiology of IgAN have led to clinical trials of novel targeted therapies with acceptable safety profiles, including SGLT2 inhibitors, endothelin receptor blockers, targeted-release budesonide, B cell proliferation and differentiation inhibitors, as well as blockade of complement components.

Immune-Mediated Muscle Diseases of the Horse

In horses, immune-mediated muscle disorders can arise from an overzealous immune response to concurrent infections or potentially from an inherent immune response to host muscle antigens. Streptococcus equi ss. equi infection or vaccination can result in infarctive purpura hemorrhagica (IPH) in which vascular deposition of IgA-streptococcal M protein complexes produces ischemia and complete focal infarction of skeletal muscle and internal organs. In Quarter Horse–related breeds with immune-mediated myositis, an apparent abnormal immune response to muscle antigens results in upregulation of major histocompatibility complex class (MHC) I and II on muscle cell membranes, lymphocytic infiltration of lumbar and gluteal myofibers, and subsequent gross muscle atrophy. Rarely, an inflammatory event results in myositis with subsequent systemic calcinosis characterized by a pathognomonic hyperphosphatemia and high fatality rate. This review presents an overview of these immune-mediated myopathies and highlights clinical and pathological features as well as the suspected pathophysiology.

Clinical features and outcomes of diffuse endocapillary proliferation Henoch-Schönlein purpura nephritis in children

OBJECTIVE

To investigate the outcomes of childhood diffuse endocapillary proliferation Henoch-Schönlein purpura nephritis (DEP-HSPN) in response to early diagnosis and prompt treatment.

METHODS

Eleven cases of DEP-HSPN in children were investigated in comparison to HSPN without diffuse endocapillary proliferation (non-DEP-HSPN).

RESULTS

DEP-HSPN had a higher prevalence of nephrotic syndrome but a lower prevalence of hematuria compared to non-DEP-HSPN. IgA, IgG and IgM antibody deposition was found in DEP-HSPN by histopathological examination. Proteinuria cleared in all 11 cases through treatment with steroids and/or immunosuppressive drugs. However, half of the DEP-HSPN patients continuously had hematuria after treatment.

CONCLUSION

The early diagnosis and prompt initiation of immunosuppressive treatment based on renal biopsy are important for achieving favorable outcomes.

Moh Daha, a successful scientist with a strong personality, who loves to stimulate and support his colleagues

Mohammed R. Daha is a successful and very productive scientist. He is internationally recognised for his expertise of Complement. In addition, he contributed to many other fields of Immunology, in particular Clinical Immunology within Internal Medicine. He did not only contribute to Nephrology and Transplantation, but also to Rheumatology, Infectious diseases and Pulmonology. He enjoyed teaching and he was also appreciated for his guidance of biomedical and clinical PhD's.

Effects of Cyclophosphamide Pulse Therapy on the Clinical and Histopathological Findings, Particularly Crescent Formation, in a Patient with Adult-onset Steroid-refractory Henoch-Schönlein Purpura Nephritis

A 29-year-old woman was diagnosed with Henoch-Schönlein purpura nephritis (HSPN) based on the presence of purpura and histopathological findings showing crescent formation, mesangial proliferation and IgA deposition in the glomerular mesangium. She was treated with high-dose steroids; however, the nephritic syndrome persisted. Therefore, we diagnosed her with steroid-resistant HSPN and decided to add treatment with cyclosphamide pulse therapy. After one year of treatment, the histopathological findings, including crescent formation and IgA deposition, improved, as confirmed on a renal biopsy, and the patient fulfilled the criteria for complete remission. Cyclophosphamide pulse therapy may be considered an effective treatment for intractable HSPN.

Immune complexes in acute adult-onset Henoch-Schonlein nephritis

BACKGROUND

Adult-onset Henoch-Schönlein purpura nephritis (HSPN) and primary IgA (IgAN) nephropathy have been considered indistinguishable immunohistopathologically and are often considered as two extremes of one disease entity. We postulate that adult-onset Henoch-Schönlein can be distinguished histologically from primary IgAN and that both diseases differ in their immunopathological mechanisms.

METHODS

Twenty consecutive patients with adult-onset HSPN were studied. Serum was analysed for circulating IgA immune complexes; renal biopsies were analysed by light and electron microscopy (EM). As disease controls, 40 IgAN patients were studied.

RESULTS

Intracapillary leukocyte margination was seen in 15 of the 20 patients and cellular crescent formation in all renal biopsies of the HSPN patients. IgAN biopsies showed a few small crescents without intracapillary leukocytes. In 16 HSPN patients, EM was performed and in 10, no dense deposits were found. In all biopsies of IgAN patients, typical 'humps' were found. In 6 of 9 analysed HSPN patients, intermediate to large circulating immune complexes were found, whereas in 4 of 28 analysed patients with primary IgAN small circulating immune complexes were found.

CONCLUSIONS

We consider adult-onset HSPN distinguishable in histology and ultrastructure from primary IgAN. We believe adult-onset Henoch-Schönlein to be a circulating immune complex disease.

Clinical impact of altered immunoglobulin levels in Henoch-Schönlein purpura

BACKGROUND

The aim of the present study was the identification of immunological features, present at the time of diagnosis, that would predict the severity of Henoch-Schönlein purpura and its outcome.

METHODS

A cohort study was carried out in a tertiary pediatric hospital of 69 children with Henoch-Schönlein purpura, in whom serum complement components C3, C4 and IgA, IgM, IgG were repeatedly determined.

RESULTS

During the acute phase of the disease in 54/69 patients (78.3%) immunological imbalances were observed. In 24/54 cases (44.4%) certain complications involving the kidneys and the gastrointestinal tract were noted as opposed to in 3/15 children (20%) without immunologic abnormalities. In 50/69 children (72.5%), elevated serum IgA was detected and 16 of them (32%) developed renal involvement while only 1/19 children (5.3%) with normal IgA concentration had renal involvement. Considering separately the group of 9/69 children (13%) with increased IgM and those with normal IgM levels (53/69; 76.8%), irrespective of IgA and IgG concentration, we found a comparable percentage of children who had both renal and intestinal involvement without, however, developing severe complications, which were exclusively seen in patients with increased IgA (5/7 children) and reduced IgM levels. Serum C3 fraction was elevated in 26 children (37.7%) and in 73% of cases it was associated with increased serum IgA values.

CONCLUSION

Renal involvement was seen in 32% of children with increased IgA values. Most importantly, elevated IgA concentration along with reduced IgM levels was associated with higher prevalence of severe complications.

Serum immunoglobulin sedimentation patterns and circulating immune complexes in IgA glomerulonephritis and Schönlein-Henoch nephritis

Sera from 8 patients with IgA glomerulonephritis and from 6 patients with Schönlein-Henoch nephritis were investigated by the C1q-binding assay (C1q-BA) test and by sucrose gradient centrifugation followed by sensitive solid phase radioimmunoassay determinations of IgA, IgG and IgM in each fraction obtained. Abnormal sedimentation profiles were found in sera from 3 of 8 patients with IgA nephritis and in 3 of 6 patients with Schönlein-Henoch nephritis. The abnormal fraction consisted of low molecular weight IgA in 2 patients, IgG in 1 patient and IgM in 4 patients. The absolute level of polymeric IgA was increased in 3 of 8 patients with IgA nephritis, but the relative distribution was normal. An abnormal sedimentation pattern of immunoglobulins was correlated to a positive C1q-BA test (p less than 0.001).

[Schönlein-Henoch purpura with intestinal involvement: a clinic exposure]

Vasculitides are a group of diseases characterized by inflammation of the blood vessels and can affect any type of blood vessel in the body. Schönlein-Henoch purpura is a type of vasculitis secondary to hypersensitivity that affects the small blood vessels. Due to the rarity of this association, we present the case of a male patient with cutaneous purpura and intestinal involvement.

Recurrent Henoch-Schönlein Purpura in Children

BACKGROUND

Henoch-Schönlein purpura (HSP), also known as anaphylactoid purpura is a clinically recognizable systemic disorder occurring in children, mainly from ages 3 to 10 years.

OBJECTIVES

To describe the clinical, epidemiological, and laboratory findings in a group of patients with recurrent HSP, admitted to a tertiary pediatric center.

METHODS

Retrospective analysis of medical records of patients hospitalized due to HSP between 1969 and 2004.

RESULTS

Two hundred sixty children (56.7% males) were hospitalized due to HSP, 7 (2.7%) more than once. There were no statistically significant differences in demographic or clinical characteristics between the patients with 1 event of HSP and patients with recurrence. Mean age of the subgroup with recurrence was 3.67 years (10 months to 7.4 years) at the first episode, and 5.03 years (2.2-10 years) at the second one, with a mean lag period of 13.5 +/- 2.8 months (range 2-26). The duration of the recurrent clinical symptoms ranged from 9 to 30 days, and in 72% of those patients, resolution took more than 14 days.

CONCLUSION

In our inpatient population, no clinical or laboratory characteristics were found to be predictive of recurrence; the second episode was longer than the first and the lag period between the 2 episodes was substantially longer than previously reported. Hospital admissions for recurrent HSP are not common. Nevertheless, a good prognosis was the rule of our admitted patients.

Henoch-Schönlein purpura after etanercept therapy for psoriasis

Etanercept is a recombinant dimeric fusion protein consisting of a tumor necrosis factor-alpha receptor ligand-binding region linked to the Fc portion of human IgG. It is approved for use in the treatment of rheumatoid arthritis, ankylosing spondylitis, juvenile rheumatoid arthritis, psoriasis, and psoriatic arthritis. Since 1998, there have been reports of vasculitic adverse events, including necrotizing vasculitis and leukocytoclastic vasculitis. In addition, the adverse events reporting system of the U.S. Food and Drug Administration has recorded 35 cases of leukocytoclastic vasculitis, 20 after etanercept therapy and 15 after infliximab. Most cases of cutaneous vasculitis describe development of symptoms within 3 months of etanercept use. In only one case report was direct immunofluorescence performed on tissue and no specific immunoreactivity found. We describe the first case of Henoch-Schönlein purpura with acute renal failure associated with increase in etanercept dose after 11 months of use for treatment of psoriasis. Discontinuation of the drug and treatment with a course of systemic steroids led to the complete resolution of the vasculitis and improvement of renal function. Vasculitis occurring even during chronic use of antitumor necrosis factor agents must be considered as possibly related to the therapy.

Circulating IgA from acute stage of childhood Henoch-Schönlein purpura can enhance endothelial interleukin (IL)-8 production through MEK/ERK signalling pathway

Recently, sera from children with active Henoch-Schönlein purpura (HSP) have been found to enhance interleukin (IL)-8 production by human umbilical venous endothelial cells (HUVEC). To further determine the possible factor with the ability to enhance endothelial IL-8 production in sera from acute stage of HSP, 10 children with HSP at the acute stage and 10 healthy controls were enrolled. IgA antiendothelial cell antibodies (AECA) were detected by cell-based ELISA. Active sera with or without pretreatment with anti-human IgA antibody, sera of controls, and immunoglobulin A (IgA) derived from sera were used to stimulate the HUVEC. The ability of these factors to enhance endothelial IL-8 production was evaluated. Furthermore, signalling pathways were also assayed by different inhibitors, and confirmed by immunoblotting. Serum levels of IgA AECA in HPS patients at the acute stage were significantly higher than in controls (P < 0.001). The active sera could enhance endothelial IL-8 production (P = 0.004, compared with control sera), and the ability of these sera was mostly abolished when pretreated with fixed anti-human IgA antibody. The supernatant IL-8 levels of endothelial cells stimulated by IgA derived from acute stage of HSP were statistically higher than controls (P < 0.001). PD98059, an inhibitor of ERK phosphorylation, significantly reduced IgA AECA-stimulated endothelial IL-8. IgA AECA also enhanced the phosphorylation of ERK1 with a time-dependent manner. Together with these findings, it is concluded that IgA AECA derived from acute stage of HSP may bind to endothelial and enhance endothelial cells to produce IL-8 via MEK/REK signalling pathway.

Infarctive purpura hemorrhagica in five horses

Five horses were examined because of signs of muscle stiffness, colic, or both. All 5 had been exposed to Streptococcus equi within 3 weeks prior to examination or had high serum titers of antibodies against the M protein of S equi. Horses had signs of unrelenting colic-like pain and focal areas of muscle swelling. Four horses were euthanatized. The fifth responded to treatment with penicillin and dexamethasone; after 3 weeks of treatment with dexamethasone, prednisolone was administered for an additional 10 weeks. Common hematologic and serum biochemical abnormalities included neutrophilia with a left shift and toxic changes, hyperproteinemia, hypoalbuminemia, and high serum creatine kinase and aspartate transferase activities. Necropsy revealed extensive infarction of the skeletal musculature, skin, gastrointestinal tract, pancreas, and lungs. Histologic lesions included leukocytoclastic vasculitis in numerous tissues and acute coagulative necrosis resembling infarction. These horses appeared to have a severe form of purpura hemorrhagica resembling Henoch-Schönlein purpura in humans and characterized by infarction of skeletal muscles. Early recognition of focal muscle swelling, abdominal discomfort, neutrophilia, hypoalbuminemia, and high serum creatine kinase activity combined with antimicrobial and corticosteroid treatment may enhance the likelihood of a successful outcome.

Henoch-Schonlein purpura with hypocomplementemia in children

BACKGROUND

The clinical course and prognosis of Henoch-Schonlein purpura (HSP) associated with hypocomplementemia are not clear.

METHODS

The clinical findings of 10 children with HSP and hypocomplementemia were studied.

RESULTS

Purpuric rash in all patients, abdominal pain in five, and arthralgia in nine were noted. The findings in HSP were not different from others with HSP. In eight patients, infection preceded hypocomplementemia. Serum levels of CH50, C3 or C4 were depressed variously. Complement levels returned to normal within 5 weeks in all patients. Antistreptolysin-O (ASO) titer was elevated in all patients and nephritis occurred in eight patients. Six patients had generalized edema and hypertension. Macroscopic hematuria occurred in two patients and heavy proteinuria in five patients. One patient was diagnosed as having poststreptococcal acute glomerulonephritis (PSAGN) combined with HSP nephritis according to renal biopsy findings. In three of eight patients with nephritis, abnormal urinary findings continued for more than 1 year.

CONCLUSIONS

Hypocomplementemia in children with HSP was transient and was not related to severity of HSP. Incidences of elevated ASO titer and nephritis were high. The nephritis resembled PSAGN during the acute stage and long-term clinical courses varied. These findings suggest PSAGN may be associated with HSP nephritis.

Henoch-Schönlein purpura

Henoch-Schönlein purpura (HSP) is a multisystem immunoglobulin A-mediated vasculitis with a self-limited course affecting the skin, joints, gastrointestinal tract, and kidneys. HSP occurs most often in children between the ages of 3 and 10 years, and presents classically with a unique distribution of the rash to the lower extremities and the buttocks area. For this reason, a skin biopsy in children is rarely necessary for diagnosis. However, in the very young age children and adults, the rash is not classically distributed, and therefore a skin biopsy is often needed. Although there are currently no prospective controlled studies on the treatment of the different manifestations of HSP, there are several retrospectively designed studies and other physicians' personal experiences supporting the use of steroids in patients with severe gastrointestinal, severe renal, central nervous system, and testicular involvements. Severe renal and central nervous system disease may lead to life-threatening conditions, and immunosuppressive agents and plasmapheresis may be needed. The overall prognosis in HSP is excellent, but the long-term morbidity depends on the renal and neurologic involvement. One third to one half of these patients will have one or more recurrences of symptoms, usually within 6 weeks, but may occur as late as 3 to 7 years later.

Enhanced expression of the CD71 mesangial IgA1 receptor in Berger disease and Henoch-Schönlein nephritis: association between CD71 expression and IgA deposits

ABSTRACT. IgA nephropathy (IgA-N) that comprises Berger disease and Henoch-Schönlein Purpura (HSP) nephritis is defined by mesangial IgA deposits. Recently, this group has characterized a new receptor for IgA, the transferrin receptor (CD71), expressed on mesangial cells. To assess whether CD71 was involved in the pathogenesis of IgA-N, its expression was analyzed together with IgA deposits on 16 kidney biopsies from 16 patients with Berger disease (n = 4) or HSP (n = 12). These biopsies were compared with 17 kidney biopsies of a group of 15 patients (control group) with other glomerulonephritis, including systemic lupus erythematosus, poststreptococcal acute glomerulonephritis, membranoproliferative glomerulonephritis, steroid-sensitive minimal change nephrotic syndrome, steroid-resistant idiopathic nephrotic syndrome with focal and segmental glomerulosclerosis, and persistent and isolated proteinuria with minimal change on kidney biopsy. In this control group, IgA deposits could be observed in eight kidney biopsies of seven patients. These biopsies were also compared with normal kidney specimens (normal group). In normal kidney, it was found that CD71 was linearly expressed on tubular epithelium but was either not expressed or very dimly in glomeruli. In contrast, CD71 was strongly expressed in 105 of the 107 glomeruli of the kidney biopsies from the IgA-N group. For the control group, it was found that expression of CD71 in glomeruli was correlated to the presence of IgA deposits. Indeed, among the 87 glomeruli of nine kidney biopsies (eight patients) without IgA fixation, 78 exhibited no CD71 expression and nine exhibited a very dim one. On the other hand, all 49 glomeruli of the eight kidney biopsies (seven patients) in which IgA deposits were detected exhibited CD71 expression (P < 10(-4)). Performance of dual-labeling studies with confocal microscopy on kidney biopsies of IgA-N patients demonstrated that most of the IgA deposits co-localized with CD71. It was also demonstrated that the intensity of the expression of CD71 was not linked to the intensity of clinical or biologic findings but to the intensity of cellular proliferation in both IgA-N and control groups. These results show that mesangial CD71 expression is not specific to IgA-N. However, the association between IgA deposits and CD71 expression and their co-localization in the mesangium provide strong evidence that CD71 is a major IgA receptor on mesangial cells.

Rheumatologic diseases in the intensive care unit: epidemiology, clinical approach, management, and outcome

Patients with systemic rheumatic diseases may be admitted to the ICU because of worsening of or development of a new manifestation of the rheumatic disease, infections caused by immunosuppression, or adverse effects of drugs used to treat rheumatic diseases. Sometimes an unrelated, acute disorder may become life threatening because of the underlying rheumatic disorder. Rheumatoid arthritis is the most common rheumatic disease seen in ICU patients, followed by systemic lupus erythematosus and scleroderma. These three conditions together account for up to 75% of rheumatic cases admitted to the ICU. The respiratory system is the organ system most commonly affected in the acute process, followed by the renal, gastrointestinal, and nervous systems. More than 50% of admissions result from infections, and 25% to 35% result from exacerbation of the underlying rheumatic condition. In about 20% of patients, the rheumatic disorder may be diagnosed for the first time in the ICU. An aggressive approach should be pursued to establish the diagnosis of either disease exacerbation or infection. Delay in instituting appropriate immunosuppressive or antimicrobial therapy may result in multiple organ system failure and a poor outcome. The mortality rate in patients with rheumatic disease exceeds that predicted by the APACHE II or SAPS II scores and is higher than that in nonrheumatologic ICU admissions. The mortality may exceed 50% in patients admitted for infection; the prognosis is comparatively better for patients with exacerbations of disease activity. Renal failure, coma, and acute abdomen are predictors of poor outcome. Early recognition of abdominal complications requiring surgical intervention may help reduce mortality.

Schönlein-henoch purpura in children and adults: diagnosis, pathophysiology and management

Schönlein-Henoch syndrome is a form of systemic small-vessel vasculitis, characterised by vascular and/or mesangial immunoglobulin A1 deposits. The main clinical manifestations are vascular purpura, predominating on the lower limbs, and articular, gastrointestinal and renal symptoms. Pulmonary, cardiac, genital and neurological symptoms have also be observed. The syndrome usually affects children, whereas it is rare in adults. The frequency of renal involvement varies between individual studies (from 20 to 100%). Renal manifestations are usually mild and transient, although chronic nephropathies may occur. Overall, an estimated 2% of children with Schönlein-Henoch purpura progress to renal failure and up to 20% of children with nephritis treated in specialised centres require haemodialysis. The renal prognosis appears to be worse in adults. Aetiological investigations are required, as a triggering factor is found in approximately half the patients (e.g. viral, bacterial and parasitic infections, drugs, toxins, systemic diseases and cancer). Dapsone has beneficial effects on cutaneous, gastrointestinal and articular manifestations in adults, especially those with chronic forms. Corticosteroids may be useful for refractory abdominal pain. Methylprednisolone pulse therapy, immunosuppressive drugs (e.g. cyclophosphamide and azathioprine), plasma exchange and polyclonal immunoglobulin therapy are beneficial in very rare life-threatening forms of the disease and in rare instances where renal function is compromised.

What is the difference between IgA nephropathy and Henoch-Schönlein purpura nephritis?

Henoch-Schönlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are considered to be related diseases since both can be encountered consecutively in the same patient, they have been described in twins, and bear identical pathological and biological abnormalities. Apart from the presence of extrarenal clinical signs found only in HSPN, other differences are noticed between the two diseases. The peak age ranges between 15 and 30 years for a diagnosis of IgAN, whereas HSPN is mainly seen in childhood. Nephritic and/or nephrotic syndromes are more often seen at presentation in HSPN. In contrast to IgAN, HSPN has been described in association with hypersensitivity. Endocapillary and extracapillary inflammations as well as fibrin deposits in the glomerulus are more frequent in HSPN. No major biological differences have been found between the two illnesses, except for a larger size of circulating IgA-containing complexes (IgA-CC) and a greater incidence of increased plasma IgE levels in HSPN. As tissue infiltration by leukocytes is a major feature of HSPN vasculitis, a possible role of a more potent activation of the latter cells by IgA-CC and/or circulating chemokines in HSPN should be considered. Further studies are required to elucidate this possible mechanism as well as the role of hypersensitivity in HSPN.

Relapsing Henoch-Schönlein purpura associated with Pseudomonas aeruginosa pyelonephritis

Henoch-Schönlein purpura is a systemic vasculitis of unknown cause. It is frequently triggered by a streptococcal upper respiratory tract infection. Other bacteria have been implicated as triggering agents. We report a recurring case of Henoch-Schönlein purpura in a patient with Pseudomonas pyelonephritis. The Henoch-Schönlein purpura remitted only when the infection was eradicated. Pseudomonas infection should be added to the list of bacteria that can trigger Henoch-Schönlein purpura.

Henoch-Schönlein purpura in children. Report of 100 patients and review of the literature

Henoch-Schönlein purpura (HSP) is an acute leukocytoclastic vasculitis that primarily affects children. In the current report, the author presents the clinical features of 100 children with HSP and reviews the literature, placing particular emphasis on new information concerning the etiology, immunopathogenesis, and treatment of HSP. The dominant clinical features of HSP are cutaneous purpura (100%), arthritis (82%), abdominal pain (63%), gastrointestinal bleeding (33%), and nephritis (40%). The etiology of HSP remains unknown, but it is clear that IgA plays a critical role in the immunopathogenesis of HSP, as evidenced by increased serum IgA concentrations, IgA-containing circulating immune complexes, and IgA deposition in vessel walls and renal mesangium. There are 2 subclasses of IgA, but HSP is associated with abnormalities involving IgA1 exclusively, and not IgA2. This finding may be a consequence of abnormal glycosylation of O-linked oligosaccharides unique to the hinge region of IgA1 molecules. Although several lines of evidence suggest a genetic susceptibility to HSP, the fundamental basis for the abnormalities involving IgA remain unclear. In general, HSP is an acute, self-limited illness, but one-third of patients will have 1 or more recurrences of symptoms. Corticosteroid therapy may hasten the resolution of arthritis and abdominal pain, but does not prevent recurrences. To date, no form of therapy has been shown to shorten appreciably the duration of HSP. The long-term prognosis of HSP is directly dependent on the severity of renal involvement. Corticosteroids in usual doses have no effect on established nephritis. Evidence is emerging that treatment with high-dose intravenous pulse methylprednisolone coupled with azathioprine or cyclophosphamide may be beneficial in patients with severe nephritis.

Is there IgA from gut mucosal origin in the serum of children with Henoch-Schönlein purpura?

Thirty-two children with Henoch-Schönlein purpura with or without renal symptoms were studied to characterize the IgA hyperglobulinemia observed in the serum of most patients. It was shown that only the IgA1 subclass concentration was increased. Secretory IgA and IgA to gliadin levels were frequently increased in serum, with a good correlation between them. Circulating IgA immune complexes were detected often and contained high activity to gliadin. In contrast, IgA activity to tetanus toxoid did not change. We failed to show any differences in renal involvement. These data suggest that elevation of serum IgA in Henoch-Schönlein purpura is due in part to a disturbance of the gut mucosal immune system, and the presence of circulating IgA immune complexes with dietary antigens can be postulated but cannot explain the occurrence of urinary symptoms.

Purpura in infants and children

Hemorrhage into the skin (purpura) may result from abnormalities in any of the three components of hemostasis: platelets, plasma coagulation factors, and blood vessels. The morphology, size, and distribution of the hemorrhagic lesions are helpful diagnostic features. The main causes of purpura in the newborn and the more common hemorrhagic disorders in children are reviewed.

Laboratory findings in the vasculitides

The primary vasculitides are diseases of unknown aetiology. They are characterized by inflammation of blood vessel walls. Measuring non-specific laboratory markers of inflammation is useful in the monitoring of patients with vasculitis. The diagnostic specificity of these markers is, however, restricted. In the last decade, autoantibodies reacting with myeloid granule proteins have been detected in the sera from patients with Wegener's granulomatosis, microscopic polyangiitis, Churg-Strauss syndrome, and the renal limited form of these vasculitides (i.e. idiopathic rapidly progressive glomerulonephritis). Anti-neutrophil cytoplasmic antibodies (ANCA) in the aforementioned disorders react with proteinase 3 (Pr3) or myeloperoxidase (MPO), and only incidentally to other antigens such as elastase and bactericidal-permeability increasing protein. The presence of ANCA alone, in particular perinuclear ANCA, as detected by indirect immunofluorescence, has a low specificity for those vasculitides. However, in combination with the presence of anti-Pr3 or anti-MPO antibodies as detected by enzyme-linked immunosorbent assay, sensitivity and specificity for the vasculitides is high. Several in vitro and in vivo data have suggested a pathophysiological role for anti-Pr3 and anti-MPO in the associated disorders. Measuring levels of the autoantibodies seems useful for the follow-up of patients with these vasculitides. The sensitivity and specificity of rises in ANCA levels for ensuing relapses appears somewhat lower than previously suggested. Refinement of the assays, for example, by measuring subclasses and functional characteristics of the autoantibodies, may improve their value in monitoring patients with vasculitides.

IgA multiple myeloma presenting as Henoch-Schönlein purpura/polyarteritis nodosa overlap syndrome

We report the unusual case of a man with a 5-year history of relapsing Henoch-Schonlein purpura (HSP) and macroscopic polyarteritis nodosa (PAN) as early manifestations of IgA kappa multiple myeloma. The glomeruli contained monoclonal IgA kappa deposits, without other immunoglobulins or lambda light chains. Glomerular deposits lacked the usual electron density but could be demonstrated by immunoelectron microscopy. Multisystem large vessel vasculitis (antineutrophil cytoplasmic antibody negative) produced aneurysms of renal and hepatic arteries, whereas small vessel vasculitis affected the skin and glomeruli, producing a symptom complex of HSP with dermal and glomerular deposits of IgA. We conclude that HSP/overlap syndrome may be the initial manifestation of IgA myeloma and should be considered within the spectrum of monoclonal IgA deposition disease.

Alteration of lung diffusion capacity in IgA nephropathy

OBJECTIVE

To establish whether changes of lung transfer for carbon monoxide (TLCO) are related to the phase of IgA nephropathy.

METHODS

Respiratory function was tested in 12 children with IgA nephropathy assessed by percutaneous renal biopsy. This was done during acute exacerbations or haematuria-free phases of the disease.

RESULTS

TLCO was low in 12/13 measurements made in the haematuric phase of IgA nephropathy or during the month following gross haematuria (mean TLCO 64% of expected values). Lung volumes and blood gas values were normal and only minor radiological signs of interstial lung involvement were observed in 11/12 patients. When respiratory tests were performed more than three months after gross haematuria, TLCO was low in 4/9 patients, with no relation to the significance of residual proteinuria or severity of findings at renal biopsy. There was a significant difference between tests performed when haematuria was present or recent and those performed more than three months after an episode of gross haematuria (p < 0.01).

CONCLUSIONS

The decrease of TLCO in the acute phases of the disease is probably related to alterations of the lung alveolarcapillary membrane by immune complexes containing IgA. This non-invasive technique, easy to perform and repeat, could be of value in the diagnosis of IgA nephropathy in haematuric children.

Intestinal IgA deposition in Henoch-Schönlein purpura with severe gastro-intestinal manifestations

In patients with Henoch-Schönlein purpura (HSP) presenting with severe gastro-intestinal (GI) symptoms, IgA deposition was studied in endoscopically obtained mucosal biopsies. A total number of 11 patients (male, 7; female, 4) were enrolled in this study; 7 patients underwent upper GI endoscopy and biopsy 1 underwent sigmoidoscopy and 3 underwent both. Upper GI endoscopy in each patient showed various mucosal changes including redness, petechiae, erosions, and ulcerations, most predominant in the second part of the duodenum. Sigmoidoscopy demonstrated no abnormality in two of four patients. Intestinal deposition of IgA was positive in 7 of 11 patients with HSP. Histological examination showed non-specific inflammation of varying degrees in each patient, but no small vessel vasculitis was observed. IgA deposits were seen in only 2 of 23 control subjects with various GI diseases. Positive rate of IgA deposition per patient was significantly higher in patients with HSP than in controls (P < 0.005).

CONCLUSION

IgA deposition in the GI tract, as in the skin and kidneys, is characteristic of HSP. Intestinal IgA deposition complements the diagnostic criteria of HSP.

von Willebrand factor and factor XIII in children with Henoch-Schonlein purpura

levels of von Willebrand factor antigen (vWf:Ag) and factor XIII activity (F XIII) were studied in relation to the severity of clinical symptoms (scored from 0 to 3) and to immunological parameters [IgA, C3, C4, and circulating immune complexes (CIC)] in 16 children (7 males, 9 females, aged 3-11 years) with Henoch-Schonlein purpura (HSP) at presentation. vWf:Ag was increased in 7 patients, F XIII activity was decreased in 6. In all children we found high levels of IgA, while C3 and C4 levels were normal; CIC were elevated in 11. vWf:Ag correlated with clinical score and with IgA and CIC, probably as a result of immune-mediated endothelial cell damage. The haemostatic alterations observed in HSP are important for understanding the pathophysiology of the disease.

Glomerulonephritis in Henoch-Schöenlein purpura without mesangial IgA deposition

Ten patients with Henoch-Schöenlein purpura (HSP) were selected for study because their early renal biopsies showed focal and segmental hypercellularity, with IgA present only in deposits at the periphery of the lobules. Mesangial deposits of IgA were absent. All had laboratory evidence of nephrotic syndrome and/or renal compromise. The glomerular hypercellularity was largely the result of the infiltration of monocytes whose cytoplasm often contained tubular lysosomes and wrapping lysosomal membranes, evidence of monocyte activation. Mean levels of C3 were normal but those of C4 and properdin significantly depressed. This complement profile, as well as a glomerular monocytic infiltrate, are also seen in essential cryoglobulinemia in the adult. Of follow-up biopsies in six patients, the glomeruli were normal in three, with no IgA deposition. In the other three, mesangial deposits of IgA typical of HSP were present. The initial focal-segmental glomerulitis of these patients appeared to be the benign first phase of a disease which had the potential to culminate in mesangial IgA deposition. Patients like the three who escaped mesangial IgA would be among those responsible for the observed dissociation between severity of the initial illness and ultimate prognosis.

Antineutrophil cytoplasm antibodies (ANCA) of IgA isotype in adult Henoch-Schönlein purpura

ANCA are associated with certain forms of systemic vasculitis, and have been reported previously to be of the IgG and IgM isotype. We examined the possible association between IgA ANCA and the IgA-related diseases Henoch-Schönlein purpura (HSP) and IgA nephropathy (IgAN). IgA and IgG ANCA were detected by isotype-specific solid-phase assays with a crude neutrophil extract, and their presence was confirmed by antigen-specific fluid-phase competitive inhibition tests and by indirect immunofluorescence. The possible interference by IgA rheumatoid factor was excluded. IgA ANCA were detected in sera from 11/14 HSP patients (79%), from 1/30 IgAN patients (3%), from 1/40 patients with vasculitides classically associated with IgG ANCA (2.5%), and in none of 60 sera from healthy blood donors. IgG ANCA were present with IgA ANCA in three patients with HSP. Only one HSP serum had anti-myeloperoxidase (MPO) activity by both IgA and IgG isotype-specific ELISA, and none was positive for proteinase 3 (PR3). Western blot analysis performed with neutrophil extract showed that the four strongest IgA ANCA-positive HSP sera reacted with a 51-kD protein; Western blot performed on cellular fractions showed that this protein is primarily membrane-associated, and different from fibronectin. Our study suggests that adult HSP is closely associated with circulating IgA ANCA, which may be directed against a different autoantigen than that recognized by IgG ANCA.

Recurrent post-infective Henoch-Schönlein syndrome: a genetic influence related to HLA B35?

The clinical features, laboratory findings, infection stimuli and HLA phenotypes of five young adults with recurrent episodes of Henoch-Schönlein syndrome (HSS) are reported. We define recurrences as the reappearance of the characteristic purpuric rash and associated symptoms more than 8 weeks after the onset of the original episode of purpura. All patients had documented evidence of a bacterial or viral infection before one or more of the relapses, the periods between which varied from 1 to 13 years. Four of our five patients possessed the HLA B35 phenotype and two of these four patients were also HLA B18 antigen positive. Those with the HLA B35 haplotype had recurrent episodes of purpura with nephritis triggered by minor pharyngeal (viral or bacterial) infections. The HLA B35 haplotype has a frequency of 4% in the indigenous Scottish population and has previously been linked with single episodes of the Henoch-Schönlein syndrome with nephritis in German, Slavic and French patients. It has not previously been related to recurrent episodes of the syndrome. We postulate that patients who are HLA B35 positive may be genetically more susceptible to recurrent episodes of HSS with nephritis, stimulated by a heterogeneous group of infective stimuli and resulting in a protracted illness with significant renal involvement.

Impairment of lung diffusion capacity in Schönlein-Henoch purpura

Twenty-nine children with typical Schönlein-Henoch purpura (SHP) were tested at the initial phase of the disease for respiratory function. Of the 29 patients, 28 had a decrease of lung transfer for carbon monoxide (TLCO) as measured by a steady-state method. Lung volumes and blood gas values were normal; slight radiologic signs of interstitial lung involvement were observed in 18 of 26 patients. There was a decrease in TLCO to 56.8% of normal values for height and gender and to 58.5% when normal values were volume-adjusted to functional residual capacity. In 19 of 25 patients, TLCO measurements were performed at 3-month intervals during follow-up. In all cases, normalization of TLCO values was observed only after complete clinical recovery from SHP. All children with persisting symptoms, even limited to microscopic hematuria or slight proteinuria, had low TLCO values. In one patient low TLCO during follow-up preceded a late relapse of SHP in the form of acute nephritic disease with characteristic IgA deposits on renal biopsy. We conclude that low TLCO in SHP is probably related to alteration of the alveolar-capillary membrane by circulating immune complexes. This noninvasive technique may be useful in diagnosis, and during the follow-up of the disease as an early indicator of reactivation.

Effectiveness of early prednisone treatment in preventing the development of nephropathy in anaphylactoid purpura

A prospective study was performed to verify whether early administration of prednisone could be useful in preventing the development of nephropathy in anaphylactoid purpura. Only patients without signs of nephropathy upon initial presentation entered into the study. A total of 84 patients received delta-prednisone (1 mg/kg per day per os for 2 weeks), and 84 patients did not receive steroids. The patients were followed for 24-36 months. None of the 84 patients treated with steroids and 10 (11.9%) of the 84 control patients developed nephropathy 2-6 weeks after the acute episode. In 2 other patients of the untreated group, signs of renal involvement appeared 2 and 6 years after the acute episode respectively. The difference in the prevalence of nephropathy between the two groups is highly significant (P less than 0.001).