Eculizumab therapy and complement regulation in a case of resistant catastrophic antiphospholipid syndrome

Catastrophic antiphospholipid syndrome (CAPS) is a life-threatening form of antiphospholipid syndrome characterised by diffuse arterial and venous thrombosis, in the presence of positive antiphospholipid antibodies. The multiple sites of thrombosis in small, medium and large vessels progress to multiorgan failure, accounting for the high mortality rate associated with CAPS. Unregulated complement activation is increasingly recognised as critical to the pathogenesis of CAPS. Early diagnosis is essential to initiate prompt life-saving treatment with the triple therapy of anticoagulation, immunosuppression and either plasmapheresis or intravenous immunoglobulin. Among other immunosuppressive agents, eculizumab, a complement inhibitor has demonstrated efficacy in treatment-resistant cases.We report an instructive case of a woman presenting with both clinical and laboratory findings consistent with primary CAPS, resistant to initial treatment and responsive to eculizumab, with emphasis on genetic testing and implications for future therapy.

Increased retinal drusen in IgA glomerulonephritis are further evidence for complement activation in disease pathogenesis

Drusen are retinal deposits comprising cell debris, immune material and complement that are characteristic of macular degeneration but also found in glomerulonephritis. This was a pilot cross-sectional study to determine how often drusen occurred in IgA glomerulonephritis and their clinical significance. Study participants underwent non-mydriatic retinal photography, and their deidentified retinal images were examined for drusen by two trained graders, who compared central drusen counts, counts ≥ 10 and drusen size with those of matched controls. The cohort comprised 122 individuals with IgA glomerulonephritis including 89 males (73%), 49 individuals (40%) of East Asian or Southern European ancestry, with an overall median age of 54 years (34-64), and median disease duration of 9 years (4-17). Thirty-nine (33%) had an eGFR < 60 ml/min/1.73 m² and 72 had previously reached kidney failure (61%). Overall mean drusen counts were higher in IgA glomerulonephritis (9 ± 27) than controls (2 ± 7, p < 0.001). Central counts ≥ 10 were also more common (OR = 3.31 (1.42-7.73, p = 0.006), and were associated with longer disease duration (p = 0.03) but not kidney failure (p = 0.31). Larger drusen were associated with more mesangial IgA staining (p = 0.004). Increased drusen counts were also present in IgA glomerulonephritis secondary to Crohn's disease but not with Henoch-Schonlein purpura. The finding of retinal drusen in IgA glomerulonephritis is consistent with complement activation and represents a model for better understanding glomerular immune deposition and a supporting argument for treatment with anti-complement therapies.

Taking the challenge: A protocolized approach to optimize Pneumocystis pneumonia prophylaxis in renal transplant recipients

While trimethoprim-sulfamethoxazole is considered first-line therapy for Pneumocystis pneumonia prevention in renal transplant recipients, reported adverse drug reactions may limit use and increase reliance on costly and less effective alternatives, often aerosolized pentamidine. We report our experience implementing a protocolized approach to trimethoprim-sulfamethoxazole adverse drug reaction assessment and rechallenge to optimize prophylaxis in this patient cohort. We retrospectively reviewed 119 patients receiving Pneumocystis pneumonia prophylaxis prior to and after protocol implementation. Forty-two patients (35%) had 48 trimethoprim-sulfamethoxazole adverse drug reactions documented either at baseline or during the prophylaxis period, of which 83% were non-immune-mediated and 17% were immune-mediated. Significantly more patients underwent trimethoprim-sulfamethoxazole rechallenge after protocol implementation (4/22 vs 23/27; P = .0001), with no recurrence of adverse drug reactions in 74%. In those who experienced a new or recurrent reaction (26%), all were mild and self-limiting with only 1 recurrence of an immune-mediated reaction. After protocol implementation, aerosolized pentamidine-associated costs were reduced. The introduction of a standard approach to trimethoprim-sulfamethoxazole rechallenge in the context of both prior immune and non-immune-mediated reactions was safe and successful in improving the uptake of first-line Pneumocystis pneumonia prophylaxis in renal transplant recipients.

Retinal disease in the C3 glomerulopathies and the risk of impaired vision

BACKGROUND

Dense deposit disease and atypical hemolytic uremic syndrome are often caused by Complement Factor H (CFH) mutations. This study describes the retinal abnormalities in dense deposit disease and, for the first time, atypical haemolytic uremic syndrome. It also reviews our understanding of drusen pathogenesis and their relevance for glomerular disease.

METHODS

Six individuals with dense deposit disease and one with atypical haemolytic uremic syndrome were studied from 2 to 40 years after presentation. Five had renal transplants. All four who had genetic testing had CFH mutations. Individuals underwent ophthalmological review and retinal photography, and in some cases, optical coherence tomography, and further tests of retinal function.

RESULTS

All subjects with dense deposit disease had impaired night vision and retinal drusen or whitish-yellow deposits. Retinal atrophy, pigmentation, and hemorrhage were common. In late disease, peripheral vision was restricted, central vision was distorted, and there were scotoma from sub-retinal choroidal neovascular membranes and atypical serous retinopathy. Drusen were present but less prominent in the young person with atypical uremic syndrome due to a heterozygous CFH mutation.

CONCLUSIONS

Drusen are common in forms of C3 glomerulopathy caused by compound heterozygous or heterozygous CFH mutations. They are useful diagnostically but also impair vision. Drusen have an identical composition to glomerular deposits. They are also identical to the drusen of age-related macular degeneration, and may respond to the same treatments. Individuals with a C3 glomerulopathy should be assessed ophthalmologically at diagnosis, and monitored regularly for vision-threatening complications.

Use of swine model in transplantation of vascularized skeletal tissue allografts

Permanent tolerance to vascularized skeletal tissue allografts can be induced in miniature swine with minor antigen differences using a 12-day course of CsA. Demonstration of skeletal tissue allograft survival in a large animal model without long-term immunosuppression represents an important step toward transplantation of skeletal tissue allografts in humans.