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IgA nephropathy with leucocytoclastic vasculitis

Leucocytoclastic vasculitis is a rare type of allergic disease caused by immune complexes. IgA nephropathy is a glomerulopathy characterized by recurrent episodes of gross haematuria or microscopic haematuria and IgA deposition in the glomerular mesangial region. IgA nephropathy complicating leucocytoclastic vasculitis is rare documented. We present a case of IgA nephropathy in a 47-year-old woman with leucocytoclastic vasculitis and discuss the clinical and pathological data, aiming to promote the diagnosis and treatment of this specific clinical manifestation.


Introduction
Leucocytoclastic vasculitis (LCV), also known as allergic vasculitis (AV), is a type III allergic disease caused by immune complexes, infections, and medications. It is a typical small-vessel (small arteries/veins and capillaries) vasculitis that may be confined to the skin or exhibit systematic manifestations involving other organs, the most common of which is the kidney, comprising approximately 20% of LCV cases. 1 IgA nephropathy (IgAN) is a glomerulopathy that is characterized by recurrent episodes of gross haematuria or microscopic haematuria and IgA deposition in the glomerular mesangial region. IgAN in patients with LCV is rare described. Here, we present a case of LCV and concomitant IgAN in a 47-year-old woman and discuss the clinical and pathological data in the case. We hope to promote the diagnosis and treatment of this specific clinical manifestation.

Case report
A 47-year-old woman presented with extensive palpable purpuric lesions and areas of necrosis and haemorrhagic blisters on her bilateral lower extremities, 15 months prior to admission. Previous laboratory examination showed IgA 4.65 g/L, erythrocyte sedimentation rate (ESR) 31 mm/hour, urine red blood cell 288.2 /mL. Skin biopsy was highly suggestive of LCV. After treatment with ampicillin and methylprednisolone, the lesions were resolved.
The patient on admission complained of oedema of the lower extremities and urinary foam. Physical examination was unremarkable except for moderate pitting oedema of the bilateral lower extremities. Laboratory test results are shown in Table 1. Kidney biopsy showed mesangial proliferation ( Figure 1), with glomeruli focal segmental hyperplasia and sclerosis (Figure 2), accompanied by crescent formation; immunofluorescence showed IgA granular/mass-like deposition (Figure 3), consistent with the characteristics of IgA nephropathy.
The patient received a diagnosis of LCV and IgAN. After the initial treatment of corticosteroids (1 mg/kg/day of oral prednisone for 1 week, slowly tapered over the following 3 weeks) and other symptomatic treatment, the oedema of the lower extremities and rash resolved.
At 1-and 3-month follow-ups, notable regression was recorded: urine protein was 1þ, urine occult blood 1þ, blood haemoglobin 95 g/L, no lesions or oedema of the lower extremities. The patient's family gave written consent for the publication of her clinical data. The study was approved by the ethics committee of the First Affiliated Hospital of Xi'an Jiaotong University.

Discussion
The LCV of our patient was initially diagnosed in another hospital and it is unfortunate that we could not obtain a skin biopsy specimen or report. However, her clinical manifestations, laboratory tests, and response to hormone therapy are all in accordance with the original diagnosis. Further, a diagnosis of Henoch-Sch€ onlein purpura (HSP) was excluded based on the following four points. (1) HSP is more common in children and teenagers. (2) The pathological changes of HSP are mostly located in the superficial dermis and primarily invade the small blood vessels of the dermal papilla, so these lesions are relatively simple and mainly manifest as purpura; the pathological changes in a case of LCV are deeper, such that the entire layer of dermis and subcutaneous tissue can be involved, with a rash that is usually pleomorphic and severe: blood blisters, necrosis and ulcers may occur on purpura and purpura macular papules. (3) HSP is a type of systemic vasculitis that can be eliminated by the absence of joint or abdominal pain. (4) More than half of the HSP patients exhibit haematuria, proteinuria, nephrotic syndrome, and, in some cases, renal failure; thus, HSP is more prone to renal damage than LCV, and the damage is more serious with a poorer prognosis.
Vasculitis diseases often lead to kidney involvement because of the special distribution of renal blood vessels. Systemic lupus    erythematosus/HSP-related kidney damage can manifest as IgA nephropathy; 2 antineutrophil cytoplasmic autoantibodyassociated vasculitis 3 can combine with IgA nephropathy. As an important type of vasculitis disease, LCV can also cause kidney damage, typically manifesting as microscopic haematuria and proteinuria. Individuals with LCV are characterized by a high propensity for renal dysfunction, including chronic renal failure. Several previous literatures have referred to the pathological changes in LCV-related renal injury, among them only seven cases in six articles included IgA deposits found in renal biopsies of patients with concurrent LCV. [4][5][6][7][8][9] The clinical characteristics of the cases are summarized in Table 2. Four of the previous cases were caused by rheumatism, two cases were caused by infection, and one was caused by medicine; however, the onset of lesions and renal injury occurred with no obvious cause in our patient. All of the prior patients developed severe lesions on the lower extremities, as well as haematuria and proteinuria, similar to the case in our report. Of the previous seven patients, one improved and was withdrawn from warfarin. This patient was discharged from the hospital but recrudesced 3 days later and died. Of the remaining six patients, four dramatically improved through treatment for primary diseases and two improved through hormone therapy. The present case underwent initial treatment with corticosteroids and had recovered well at follow-up.
For our patient, since the lesions initially occurred with haematuria, renal involvement was indicated; this was further confirmed by the findings of oedema of the lower extremities, urinary foam, moderate anaemia, urine occult blood þ, a small amount of urine protein, increased serum IgA, and biopsy supporting the pathological diagnosis of IgAN. IgAN and LCVinduced lesions occurred simultaneously and both showed a remarkable response to the glucocorticoid treatment. We hypothesize that the concurrence of these two conditions is not a matter of coincidence; therefore, we speculate that the IgAN was induced by LCV with the following possible explanation. Serum IgA immune complexes increase in LCV; immune complexes with specific sizes then combine with receptors on the surface of mesangial cells and deposit in the mesangial area; these deposits activate complement, stimulate the proliferation of mesangial cells, promote the secretion of mesangial matrix and cytokines, and eventually cause IgAN. However, the specific mechanisms underlying IgAN induction by LCV remain unclear.
There are no uniform treatments for LCV, but a combination of adrenal cortical hormone and cytotoxic drugs are used empirically. In this patient, the oedema, rash, urine occult blood, and urinary protein were alleviated by comprehensive treatment strategies, including prednisone (20 mg/day), combined with other symptomatic treatment. Thus, renal function should be further characterized when haematuria appears in LCV patients. LCV often includes renal involvement; effective treatment as early as possible can significantly improve the prognosis.