Bullous pemphigoid associated with acute glomerulonephritis

Staphylococcus aureus Infection-Related Glomerulonephritis with Dominant IgA Deposition

Since 1995, when we reported the case of a patient with glomerulonephritis with IgA deposition that occurred after a methicillin-resistant Staphylococcus aureus (MRSA) infection, many reports of MRSA infection-associated glomerulonephritis have accumulated. This disease is being systematized as Staphylococcus infection-associated glomerulonephritis (SAGN) in light of the apparent cause of infection, and as immunoglobulin A-dominant deposition infection-related glomerulonephritis (IgA-IRGN) in light of its histopathology. This glomerulonephritis usually presents as rapidly progressive glomerulonephritis or acute kidney injury with various degrees of proteinuria and microscopic hematuria along with an ongoing infection. Its renal pathology has shown several types of mesangial and/or endocapillary proliferative glomerulonephritis with various degrees of crescent formation and tubulointerstitial nephritis. IgA, IgG, and C₃ staining in the mesangium and along the glomerular capillary walls have been observed on immunofluorescence examinations. A marked activation of T cells, an increase in specific variable regions of the T-cell receptor β-chain-positive cells, hypercytokinemia, and increased polyclonal immune complexes have also been observed in this glomerulonephritis. In the development of this disease, staphylococcal enterotoxin may be involved as a superantigen, but further investigations are needed to clarify the mechanisms underlying this disease. Here, we review 336 cases of IgA-IRGN and 218 cases of SAGN.

Patients affected by a new variant of endemic pemphigus foliaceus have autoantibodies colocalizing with MYZAP, p0071, desmoplakins 1-2 and ARVCF, causing renal damage

BACKGROUND

We have previously reported that about 30% of patients affected by a new variant of endemic pemphigus foliaceus (EPF) in El Bagre, Colombia (termed El Bagre-EPF or pemphigus Abreu-Manu) have systemic compromise. In the current study, we focused on studying autoreactivity to the kidney and its pathological correlations.

AIM

To investigate patients with El Bagre-EPF for renal compromise.

METHODS

We performed a case-control study, enrolling 57 patients with El Bagre-EPF and 57 controls from the endemic area, matched by age, sex, race, work activity, demographics and comorbidities. We took skin and renal biopsies; performed direct and indirect immunofluorescence, immunohistochemistry (IHC), confocal microscopy, immunoblotting, direct and indirect immune electron microscopy; and tested kidney function in all living patients. We also used IHC to study seven kidney autopsy samples.

RESULTS

Of the 57 patients, 19 had autoantibodies to kidney, with polyclonal reactivity (P < 0.01). Most cases were positive along the basement membrane of the proximal tubules, but in some cases there was also positivity against the glomeruli and/or mixed patterns. Fifteen patients had increases in serum urea and creatinine compared with controls (P < 0.01). The autoantibodies colocalized with commercial antibodies to desmoplakins I and II, p0071, armadillo repeat gene deleted in velo-cardio-facial syndrome (ARCVF) and myocardium-enriched zonula occludens-1-associated protein (MYZAP) (P < 0.01). All of the kidney disease autopsies showed alterations, mostly in the vessels.

CONCLUSION

We demonstrate for the first time that one-third of patients with El Bagre-EPF have polyclonal autoantibodies to kidney. The kidneys showed a mixed histological pattern resembling lupus nephritis, with a diffuse proliferative Class IV (G) global diffuse pattern in active lesions, and additional interposition of membranoproliferative glomerulonephritis.

Clinicopathologic features of IgA-dominant infection-associated glomerulonephritis: a pooled analysis of 78 cases

BACKGROUNDS

IgA-dominant infection-associated glomerulonephritis (IgA-dominant IAGN) is a unique form of glomerulonephritis. There are numerous case reports in the literature. However, the risk factors, treatment approach, and outcomes of the disease are not clearly characterized.

METHODS

We completed a pooled analysis based on published literature. Clinical features, laboratory findings, and histopathological changes were analyzed. A logistic regression model was employed to identify the determinants of disease outcome, for example, end-stage renal disease (ESRD) or death.

RESULTS

Seventy-eight patients with IgA-dominant IAGN from 28 reports were analyzed. All of these patients showed granular IgA deposits predominantly along the glomerular peripheral capillary walls using immunofluorescence and majority showed subepithelial 'hump-shaped' electron-dense deposits using electron microscopy. The majority of patients had hematuria (76/78), proteinuria (75/78), acute kidney injury (AKI) (66/78) and hypocomplementemia (43/75) without a previous history of renal disease. All of the patients had clinical infections at the time of presentation. Skin infections (19/78) and visceral abscesses (15/78) were frequently encountered, and staphylococcus was the most common pathogen. After treatment with antibiotics and/or supportive therapy, the renal function of 42 patients (54.5%) improved, 9 patients (11.7%) had persistent renal dysfunction, 15 patients (19.5%) progressed to ESRD, and 11 patients (14.3%) died. A multivariate regression analysis revealed that age (odds ratio [OR], 30.71; 95% confidence interval [CI], 2.53-373.07; p = 0.007) and diabetes mellitus (DM) (OR, 16.65; 95% CI, 1.18-235.84; p = 0.038) were independent risk factors for ESRD or death.

CONCLUSIONS

IgA-dominant IAGN has unique clinicopathological manifestations and treatment responses. Age and DM are independent risk factors associated with an unfavorable prognosis for IgA-dominant IAGN.

Methicillin-resistant Staphylococcus aureus-related glomerulonephritis in a child

BACKGROUND

Methicillin-resistant Staphylococcus aureus-associated glomerulonephritis (MRSA-GN), a syndrome in which superantigens play an important role in the pathogenesis of the infection, has been well described in adult patients but not previously recognized in children.

CASE DIAGNOSIS/TREATMENT

We report the case of a 6-year-old girl with MRSA-GN. She presented multiple malformations, including tracheal stenosis necessitating tracheotomy. She was admitted to our hospital because of acute pneumonia caused by a MRSA infection and was found to have proteinuria and abnormal renal function. MRSA was detected in her sputum, and this MRSA isolate produced toxic shock syndrome toxin-1, which acts as a superantigen and stimulates Vβ2(+) T cells. A blood test revealed that the number of circulating Vβ2(+) T cells expressing CD45RO, a marker of activation, was increased along with a concomitant elevation in the levels of serum immunoglobulins. Both are hallmarks of MRSA-GN. The eradication of MRSA using appropriate antibiotics resulted in the disappearance of the proteinuria; in contrast, corticosteroid treatment failed. To the best of our knowledge, this is the youngest patient to be diagnosed with MRSA-GN.

CONCLUSIONS

In summary, there should be a high index of suspicion for MRSA-GN, even in the very young, in order to avoid the unnecessary use of immune suppressants in this context.

Autoimmune bullous diseases associations

The presence of one autoimmune disorder helps lead to the discovery of other autoimmune conditions. It is thought that diseases in which autoimmunity is a feature tend to be associated together more often than one can ascribe to chance. A variety of diseases have been implicated in the onset of intraepidermal and subepidermal autoimmune diseases. The presence of one autoimmune disease should alert the physician to watch for a second immunologic disorder. A list of autoimmune bullous diseases associations includes autoimmune bullous diseases, pemphigus, pemphigoid, epidermolysis bullosa acquisita, dermatitis herpetiformis (Duhring), linear immunoglobulin A disease, and multiple autoimmune syndrome.

Community-acquired Staphylococcus aureus pneumonia accompanied by rapidly progressive glomerulonephritis and hemophagocytic syndrome

A 59-year-old woman without underlying disease was admitted to a local hospital because of lung abscess, cytopenias and renal failure. 3 days before admission, she was diagnosed as influenza infection and was under antiviral therapy. Blood cultures were positive for methicillin-sensitive Staphylococcus aureus (MSSA). She was transferred to our hospital on the 15th day at the local hospital because the clinical manifestations could not improve even though she was treated with multiple intravenous antibiotics directed against MSSA. Sputum cultures yielded methicillin-resistant S. aureus (MRSA) producing toxic shock syndrome toxin-1 (TSST-1) and serologic test indicated hypercytokinemia. She was diagnosed as rapidly progressive glomerulonephritis and hemophagocytic syndrome associated with staphylococcal infection. The pulmonary lesions, cytopenias and renal dysfunction improved as a result of long-term antimicrobial treatment including vancomycin, hemodialysis, short-term administration of corticosteroid and other supportive cares. She was finally weaned from hemodialysis on the 73rd hospital day. In recent years, the number of cases of S. aureus producing TSST-1 and enterotoxin has been increasing and in cases of staphylococcal infections, close attention should be given to toxin-mediated as well as non-toxin-mediated clinical manifestations.

Bullous Pemphigoid

Bullous pemphigoid (BP) is a chronic, autoimmune, blistering disease observed primarily in the elderly population. Several clinical variants have been described, including classic (bullous), localised, nodular, vegetating, erythrodermic, erosive, childhood and drug-induced forms. Autoantibodies target the BP230 and BP180 antigens, located in the hemidesmosomal complex of the skin basement membrane zone. Subsequent complement activation recruits chemical and cellular immune mediators to the skin, ultimately resulting in blister formation. Both autoantibodies and complement may be detected by various immunofluorescent, immune electron microscopy and molecular biology techniques. Recent trials suggest that potent topical corticosteroids should be considered as first-line therapy. Tetracycline with or without nicotinamide may benefit a subset of patients with mild BP. Oral corticosteroids should rarely exceed 0.75 mg/kg/day and corticosteroid-sparing agents may be useful for recalcitrant disease.

Crescentic glomerulonephritis and subepidermal blisters with autoantibodies to alpha5 and alpha6 chains of type IV collagen

We describe a novel autoimmune disease characterized by severe subepidermal bullous eruption and crescentic glomerulonephritis with autoantibodies directed against the noncollagenous domain of the alpha5 and alpha6 chains of type IV collagen. Biopsy of perilesional skin revealed a subepidermal blister with marked polymorphonuclear infiltrate with linear deposits of IgA and C3. Light microscopy of a kidney biopsy specimen revealed a crescentic glomerulonephritis, and immunofluorescence microscopy showed linear basement membrane staining for IgA (3+), C3 (1+), and IgG (1+). No electron-dense deposits were observed by transmission electron microscopy. The patient's autoantibodies reacted with normal human skin and kidney: IgA (3+) and IgG (1+) antibodies stained the basement membrane zones of skin, renal glomerulus, and some tubules. The identity of the target antigen was determined by immunochemical analyses of candidate antigens using the patient's autoantibodies. The patient's IgA and IgG autoantibodies reacted with a 185- to 190-kDa antigen from a human dermal extract that was distinguished from the other dermal or epidermal antigens, including the 145- to 290-kDa (type VII collagen) epidermolysis bullosa acquisita antigen, the 165- to 200-kDa alpha3 laminin mucous membrane cicatricial pemphigoid antigen, and the 230-kDa and the 180-kDa bullous pemphigoid antigens. Patient's IgA and IgG autoantibodies further reacted with the alpha5(IV) and weakly with the alpha6(IV) chains of type IV collagen by Western blot and ELISA. This report expands the repertoire of bullous skin disorders and provides an explanation for the association of anti-type IV collagen autoantibodies and glomerulonephritis with subepidermal blisters.

Bullous pemphigoid induced by cephalexin

Two young men developed severe bullous eruptions with a distinctive clinical picture of severe flexural involvement and extensive mucosal ulceration. Biopsies showed subepidermal bullae and associated inflammation consisted of predominantly neutrophils. Both had IgG and C3 staining of the dermal-epidermal junction on direct immunofluorescence. Bullous pemphigoid was diagnosed on the basis of clinical, histopathological and immunofluorescence findings. Both cases occurred after recent ingestion of cephalexin. We believe they represent the first reported cases of bullous pemphigoid induced by cephalexin.