Plasmapheresis therapy in pemphigus vulgaris and bullous pemphigoid

1. Introduction 

Pemphigus vulgaris (PV) and bullous pemphigoid (BP) are immunologically mediated diseases, characterized by the presence of cutaneous blisters and circulating autoantibodies against keratinocyte cell surface antigens [1], [2].

PV is the most common form of pemphigus. Mean age of onset of disease is about 40–50 years with men and women equally affected. PV is a chronic and progressive disease, characterized by fragile intraepithelial blisters and by mucocutaneus ulcers, mediated by autoantibodies against desmoglein 1 and 3, that are keratinocyte surface antigens. Direct immunofluorescence of affected skin and mucous shows IgG and complement components on the surface of epithelial cells in perilesional skin [1], [2]. Skin biopsy shows suprabasilar acantholysis, while neither inflammatory infiltration or basement membrane zone interest are not present [1], [2]. Indirect immunofluorescence of serum detected the presence of antikeratinocyte IgG autoantibodies whose circulating levels correlate with disease activity [3]. All patients have antibodies against desmoglein 3, while those in symptomatic progression and with cutaneous involvement also against desmoglein 1 [4]. The prognosis is severe, since the natural course of the disease, if not treated, brings to death, almost always from sepsis, within 5 years of its appearance [1].

BP is the most common autoimmune blistering skin disease, predominantly seen in the elderly [1], [5], [6]. The oral lesions are seen in a minority of patients and they are usually transient and non-symptomatic. The histological screening shows the formation of subepidermal blisters with an inflammatory infiltrate rich in eosinophils along the basement membrane and within the blisters themselves [1], [5], [6]. Direct immunofluorescence of healthy perilesional skin shows in most patients linear basement membrane zone deposits of IgG and C3. Indirect immunofluorescence of serum reveals, in approximately 65% of the BP patients, circulating IgG autoantibodies able to tie bind the basement membrane of the human skin [1], [5]. If not treated, BP can persist for years with periods of exacerbation and partial remission, but the disease may be fatal in debilitated patients.

Systemic corticosteroids and immunosuppressants are the mainstay of treatment of these two diseases.

Therapy of the PV is directed towards lowering the levels of the circulating autoantibodies by the employment of corticosteroids, associating immunosuppressive drugs, when daily dosing of prednisone requires excessive doses (>1 mg/kg/bw). Azathioprine, cyclophosphamide, mycophenolate, clorambucil and cyclosporine are among the most used immunosuppressive agents, although not without serious collateral side effects related to prolonged immunosuppression that is often the cause of fatal opportunistic infections or enhanced susceptibility in developing malignancies [1], [7], [8], [9], [10]. Today the PV mortality is at 5–10% and is associated in good part to the side effects of the glucocorticoid therapy [1], [7], [8].

In the BP, systemic corticosteroids are used to lower the inflammatory state and they usually stop the appearance of new blisters within 24–48 h of therapy initiation [1]. In the patients with wide lesions the association of immunosuppressive drugs such as azathioprine, cyclophosphamide or mycophenolate is required to reduce autoantibody production [1], [5], [6], [9], [11]. In this way the morbidity/mortality of the disease is reduced but it still remains elevated [5], [6] because most of patients are elderly or debilitated and because of the side effects of the corticosteroid therapy.

This has led to search alternative treatments, besides the immunosuppressive drugs above quoted, to use as corticosteroid––sparing agents in patients with moderate or severe disease.

As in treatment of other autoimmune diseases, IVIg have been used in doses of 2 g/kg/cycle for patients who do not respond to conventional therapy and to induce and maintain the clinical remission [12], [13].

Cotterill in 1978 performed the first therapeutic plasma exchange (TPE) on a PV patient, since then the plasmapheresis has remained a therapy with many indications in the treatment of blistering skin disease. However it is unable to control the rebound phenomenon in the 7–14 days post-plasmapheresis, the TPE is normally associated with the use of immunosuppressive agents [7], [8], [14], [15]. Intravenous administration immediately after TPE or oral subministration in the 7–14 days following immunosuppressive therapy, are able to inhibit the autoantibody production of pathogenic B lymphocytes. Proliferous cells of the pathogenic clone, stimulated by different apheretic procedures, are in fact more vulnerable to cytotoxic agents when they are in the maximum secretive activity

Despite isolated studies in chronic apheretic treatment of the PV, the cost/benefit evaluation of a similar behavior is not clear [16]. Therefore TPE can reveal to be useful in the PV and in the BP: (a) for rapid control of severe active disease, (b) integrated to the corticosteroid and immunosuppressive therapy to reduce the drug dosage, (c) when steroids or immunosuppressive agents are contraindicated and finally (d) in resistant drug therapy patients [7], [8], [17], [18].

2. Materials and methods 

2.1. Patients 

The present study was carried out on five patients. Of the five patients, one was female and four were males. Their mean age was 68.4 years, with to range of 51–78 years. Main duration of disease before TPE was 74 days (from 40 to 120 days). Characteristic clinical, immunological, histological and immunofluorescence studies were performed: four patients had BP with only cutaneous blisters and one patient had PV with cutaneous and mucosal blisters. The disease severity, based on body surface area (BSA) involved by blisters or erosions, was classified as “mild” (0–24% BSA), “moderate” (25–49% BSA), “severe” (50–100% BSA). The PV patient did not have a great cutaneous extension of the lesions but the erosion of the orofaringe and of the mucosa of the primary airways were quite extended and highly symptomatic.

The PV patient’s pre-TPE circulating intercellular antibody titer peaked at 1:640.

Patient details are giving in following Table 1.

Table 1. Characteristics of the patients

	Patient	Sex	Age (Y)	Blistering disease	Preexisting medical conditions	Disease severity and duration before TPE	TPE indication
	1 (SG)	F	51	BP	Multiple sclerosis	Mild 120 days	Non-responder to drug therapy
	2 (CG)	M	78	BP	Type II diabetes	Moderate 60 days	Reduction drug dose
	3 (BG)	M	71	BP	Type II diabetes	Moderate 40 days	Reduction drug dose and severe immunosuppressant side effects
	4 (PM)	M	68	PV		Severe 60 days	Non-responder to drug therapy and rapid control of severe clinical manifestations
	5 (EGC)	M	74	BP		Severe 90 days	Partial responder to drug therapy and severe prednisone side effects

3. Results 

We only had one plasmapheresis side effect (hypotension at the end of the procedures), solved without pharmacological treatment. All patients responded to the apheretic treatment with complete remission of symptomatology. A complete remission was considered when no new blisters appeared, while the older ones were healing. Patient no. 1 after the first 9 TPE had not shown evidence of new blisters even if the recovery of the preexisting lesions was still incomplete. After treatment she went into complete remission. Patient no. 5 had immediately shown, after the first 2 TPE, a clean improvement of the old blisters and no new blisters. Also the PV patient (no. 4) had shown a rapid improvement of the cutaneous lesions, but for the erosions of the mucous ones it was necessary to attend the execution of at least 10 TPE before noticing a symptomatic improvement.

In the patients 2–3, in which a rapid reduction of the therapy was necessary, a prednisone dosage reduction until 70% was obtained, maintaining the complete remission.

The follow up of the first four patients has shown only one relapse of illness, checked pharmacologically, (patient no. 2) 15 months after the suspension of the TPE, while the other patients were free from illness after a mean of 51 months (30–75 months).The follow up of patient no. 5 is limited to 3 months, considering the recent presentation.

In the PV patient, after TPE, circulating antikeratinocyte antibody levels remained zero.

Result details are giving in following Table 2.

Table 2. Plasmapheresis details, therapy and outcome

	Patient	Blistering disease	Therapy before TPE	No. of TPE procedures	Side effects	Outcome	Therapy after TPE	Therapy 3 months post-TPE	Therapy 6 months post-TPE	Relapse after TPE
	1 (SG)	BP	S (125 mg/day) I (150 mg/day)	14a		Remission	S (40 mg/day) I (100 mg/day) IVIgb	S (30 mg/day) I (75 mg/day)	S (20 mg/day) I (50 mg/day)
	2 (CG)	BP	S (120 mg/day) I (175 mg/day)	8c		Remission	S (35 mg/day) I (175 mg/day) IVIgb	S (22.5 mg/day) I (75 mg/day)	S (15 mg/day) I (50 mg/day)	15 months
	3 (BG)	BP	S (110 mg/day) I (150 mg/day)	9d	Hypotension at the end of TPE	Remission	S (75 mg/day)	S (35 mg/day)	S (25 mg/day)
	4 (PM)	PV	S (150 mg/day) I (150 mg/day)	14a		Remission	S (22.5 mg/day) I (150 mg/day)	S (15 mg/day) I (100 mg/day)	S (10 mg/day) I (75 mg/day)
	5 (EGC)	BP	S (60 mg/day) I (150 mg/day)	7e		Remission	S (37.5 mg/day) I (125 mg/day)	S (20 mg/day) I (75 mg/day)	Not applicable

S: prednisone, I: azathioprine, IVIg: intravenous immunoglobulin.

a 3 TPE/first week, 2 TPE/week×4 weeks, 1 TPE/week×3 weeks. b IVIg 0.4 mg/kg/day×5 days×2 cycles. c 3 TPE/first week, 2 TPE/week×2 weeks, 1 TPE/week. d 3 TPE/first week, 2 TPE/week×3 weeks. e 2 TPE/first week, 2 TPE/week×2 weeks, 1 TPE/week.

4. Discussion 

TPE is a procedure utilized to remove patient’s plasma and replace it with a crystalloid or colloid solution, maintaining a normovolemic state. The objective is to remove toxic substances (autoantibody, alloantibody, immune complex, monoclonal proteins or toxins) from the plasma. Removal of the antibodies by TPE determines however a phenomenon of rebound with a rapid new antibody synthesis, that replaces and overshoots that which has been removed. For this reason, the TPE should be supported by an immunosuppressive therapy that prevents the antibody feedback [8], [14].

While the clinical significance of autoantibody removal is clear in the PV, in the BP there is no correlation between the severity of the illness, the clinical improvement and the antibody titer. Probably the removal of the toxic substances and the cytokines released during the inflammatory cascade determines the rapid improvement of the clinical symptomatology.

The aim of our program is to give immunosuppressive agents when the B lymphocytes, stimulated by different TPE procedures, are activated and proliferous, and for this reason more vulnerable to cytotoxic drug. The aim is to inhibit the serologic rebound of the immunoglobulins stimulated by their removal and at the same time to remove toxins and inflammatory cytokines.

In our study, the apheretic treatment was necessary due to one missed or partial response of pharmacological therapy (Cases 1, 4 and 5) or to reduce the prednisone/azathioprine dosage (Cases 2–3). Apheretic treatment was also necessary to suspend the immunosuppressive therapy (Case 3) and to have a rapid control of disease (Case 4).

Synchronization of TPE/pulse of cyclophosphamide (treatment course consisted of 6 monthly regimens of TPE on 3 consecutive days followed by intravenous cyclophosphamide), in view of the results obtained in the PV and in other serious autoimmune diseases, could be the best treatment in non-responder patients, especially in those with severe form of PV [18], [19]. In the patients 1 and 4, non-responders to drug therapy, synchronization TPE/pulse of cyclophosphamide was not utilized, since patient no. 1 could not be treated with cyclophosphamide, while the PV patient immediately after the first TPE had shown a clean cutaneous improvement and a reduction of the antibody titer to induce us to avoid the problems related to intravenous infusion high doses of the cyclophosphamide.

IVIg are powerful immunomodulators and have been employed for years in numerous autoimmune diseases. IVIg contains anti-idiotypic (anti-V region) activities, directed towards idiotypes of several autoantibodies, are able to: (a) neutralize the functional activity of circulating autoantibodies and/or inhibit the binding of autoantibodies to autoantigens (b) modulate and/or inhibit the autoantibody production and finally (c) increase its clearance [20]. The IVIg can also inhibit the complement mediated attack of target cells, block the Fc receptor on the macrophages, increase activity of T suppressor cells, inhibit the proinflammatory cytokine production and/or induce cytokine antagonists production [21].

The increase of the antiidiotype antibody/autoantibody ratio resulting from the synchronization of TPE+IVIg may have an added effect of possibly inhibiting with antiidiotype antibody, the lymphocyte B clones involved in its own autoantibody production at the moment of maximum reduction of circulating autoantibodies and maximum clone stimulation. Our small experience suggests that rapid TPE+IVIg synchronization could be effective in those patients who are not responding to TPE integrated with the pharmacological therapy. Employment of the IVIg for at least three cycles after the plasmapheresis could be a valid alternative to a long period of TPE reducing corticosteroids and maintaining clinical remission. We have used TPE/immunosuppressants and IVIg synchronization in one patient (Case 1), affected for many years by a serious autoimmune disease, to maintain clinical remission without continuing TPE and in another patient (Case 2), in whom it was necessary to reduce the azathioprine dosage, which was still too high at the end of the apheretic therapy. The last however has been the only one that had a relapse after 15 months.

According to recent data in literature and to our experience, we are convinced that for patients with a blistering disease such as PV or BP, who are non-responders to only pharmacological treatment or in which, a rapid control of disease is necessary, there is an indication for an integrated treatment TPE+steroids and immunosuppressive agents [1], [17], [18], [22]. It is necessary to consider that they are often older patients, with preexisting diseases such as hypertension and diabetes, in which the treatment with high dosage of steroids can reveal extremely dangerous if not fatal in a long term. Employment of the immunosuppressive agents in these patients, at high risk of infections, sometimes determines a very severe leucopenia.

For these reasons, apheretic treatment is an effective steroid/immunosuppressive sparing therapy. The use of IVIg in these patients could be useful after the plasmapheresis as a maintenance therapy to consolidate the clinical remission.