Échanges plasmatiques en néphrologie : techniques et indications

A case of hyperviscosity syndrome associated with Waldenström macroglobulinemia treated with membrane plasma exchange without predilution

A 75-year-old man with blurred vision and nasal bleeding was diagnosed with hyperviscosity syndrome and central retinal vein occlusion secondary to Waldenström macroglobulinemia. Serum total protein and IgM levels were undetectable. Because of the severe symptoms, we determined that immediate plasma-exchange treatment was required to decrease the blood viscosity. The initial plasma exchange was performed using the membrane isolation method with a predilution standby. A saline predilution replacement was prepared to decrease the total membrane pressure (TMP); however, the predilution protocol was not used because the planned treatment volume could be achieved without increasing the TMP. After two consecutive days of membrane plasma exchange, all serum biochemical tests were measurable, and IgM was below 4000 mg/dL. After chemotherapy, his visual symptoms improved, and he was discharged. Since it is difficult to assess the risk of elevated TMP prior to initial plasma exchange, membrane plasma exchange with a predilution standby may be a useful strategy for initial plasma exchange for hyperviscosity syndrome in terms of safety and efficiency.

Case report: Eculizumab plus obinutuzumab induction in a deceased donor kidney transplant recipient with DEAP-HUS

The wide-spread use of the anti-complement component 5 monoclonal antibody (moAb) eculizumab has greatly reduced the incidence of relapsing atypical hemolytic uremic syndrome (aHUS) after kidney transplantation (KT). However, the optimal management of aHUS transplant candidates with anti-Complement Factor H (CFH) antibodies remains debated. In these patients, the benefits of chronic eculizumab administration should be weighed against the risk of fatal infections, repeated hospital admissions, and excessive costs. We report the case of a 45-year-old female patient with CFHR1/CFHR3 homozygous deletion-associated aHUS who underwent deceased-donor KT despite persistently elevated anti-CFH antibody titers. As induction and aHUS prophylaxis, she received a combination of eculizumab and obinutuzumab, a humanized type 2 anti-CD20 moAb. The post-operative course was uneventful. After 1-year of follow-up, she is doing well with excellent allograft function, undetectable anti-CFH antibodies, sustained B-cell depletion, and no signs of aHUS activity. A brief review summarizing current literature on the topic is also included. Although anecdotal, our experience suggests that peri-operative obinutuzumab administration can block anti-CFH antibodies production safely and effectively, thus ensuring long-lasting protection from post-transplant aHUS relapse, at a reasonable cost. For the first time, we have demonstrated in vivo that obinutuzumab B-cell depleting properties are not significantly affected by eculizumab-induced complement inhibition.

Multidisciplinary management of anti-PP1Pk or anti-P alloimmunization during pregnancy: A new case with anti-P and a literature review

BACKGROUND

Red blood cell alloimmunization is the first cause of fetal and neonatal anemia. Alloimmunizations with anti-PP1P^k or anti-P can cause recurrent miscarriages and hemolytic disease of the fetus and newborn in the 2nd and 3rd trimesters of pregnancy. We report on a pregnant patient immunized with anti-P and a history of recurrent miscarriages.

CASE REPORT

This P₂ ^k (GLOB:-1; P1PK:-1,3) patient had a first pregnancy marked by a caesarean at 38 weeks of gestation (WG) for non-reassuring fetal heart rate. Then, she had three early spontaneous miscarriages. The fifth pregnancy began with a high titer of anti-P at 128. Early initiation of treatment with Intravenous Immunoglobulins (IVIg) and plasma exchanges (PE) starting at 5 WG permitted us to reduce the titer of anti-P below 32. A healthy infant was delivered by caesarean at 38 WG without anemia at birth and no exchange transfusion was required.

DISCUSSION AND REVIEW OF THE LITERATURE

The P and P^k antigens are expressed on placental, trophoblastic, and embryonic cells. This explains why P₁ ^k (GLOB:-1; P1PK:1,3), P₂ ^k (GLOB:-1; P1PK:-1,3), or Tj(a-)/p (GLOB:-1; P1PK:-1,-3) patients are prone to recurrent abortions in the first trimester of pregnancy. A literature review demonstrated 87% (68/78) of miscarriages in p patients. However, publication biases are possible with the most severe cases being reported.

CONCLUSION

Immunizations to P and PP1P^k antigens differ from others in their physiopathology and precocity. The association of PE and IVIg seems to be an effective treatment in the management of anti-PP1P^k or anti-P fetomaternal incompatibilities.

[How to implement a complete apheresis program within a hemodialysis unit]

Many apheresis techniques can be performed in a blood-bank facility or a hemodialysis (HD) facility. However, it makes sense to perform apheresis in a hemodialysis facility as apheresis involves extra-corporeal circuits and because HD can be performed at the same time as apheresis (tandem procedure). Apheresis techniques comprise therapeutic plasma exchange, double-filtration plasmapheresis, and its derivative (rheopheresis and LDL-apheresis), and immunoadsorption (specific and semi-specific). We have setup an apheresis platform in our hospital that fulfills health recommendations. This process has involved financial investment and significant human resources, and has enabled us to network with different specialties (neurology, hematology, vascular medicine). We have setup protocols according to the type of pathology to be treated by apheresis, and to monitor clinical and biological data for each apheresis session. The main side effects of apheresis are a fall in blood pressure when a session is initiated, an increase in fluid overload, hypocalcemia, and the loss of some essential plasmatic factors. However, these side-effects are easily identified and can be properly managed in real time. Within two-years, we have performed 1845 apheresis sessions (134 patients). Of these, 66 received apheresis before and/or after kidney transplantation for ABO and/or HLA incompatibility (desensitization), for humoral rejection, or in the setting of relapsing focal-segmental glomerulosclerosis. Our patients' outcomes have been similar to those reported in the literature. The other 68 patients had various conditions. Because our program is now well-established, we are currently forming a specialist center to train physicians and nurses in the various apheresis techniques/procedures.

Therapeutic plasma exchange: Experience in a third level hospital, 2013-2016, Lima (Peru)

BACKGROUND

Therapeutic plasma exchange (TPE) is an extracorporeal procedure which consists of removing the patient's plasma and replacing it with an appropriate replacement fluid. Plasma and blood cells are separated by a centrifugation process. Our department has used TPE for several years, and in 2013 we introduced an institutional apheresis protocol. The main objective of this report is to describe the TPE procedures performed between 2013 and 2016 in the Peruvian population.

METHODS

We analyzed the technical and clinical aspects of 864 centrifugal TPE procedures as well as the associated complications. We evaluated 230 patients treated in our institution.

RESULTS

The therapeutic indications included 16 different diseases: 89.5% (N = 206/230) neurological, 7.3% (N = 17/230) hematological, 1.7% (N = 4/230) rheumatologic, 0.8% (N = 2/230) dermatological and 0.4% (N = 1/230) nephrological. 70.4% (N = 142/230) of patients were diagnosed with Guillain-Barré syndrome. Albumin 5% solution was the most frequent replacement solution, used in 65.8% (N = 569/864) of the procedures. The mean plasma volume (PV) replaced was 2451.73 ml, corresponding to 1.0 PV in all procedures. Complications occurred in 10.9% (N = 95/864) of the sessions. Allergic reactions were the most common events and cardiopulmonary arrests were recorded in two patients.

CONCLUSION

This is the first report of TPE performed in the Peruvian population. The use of an institutional apheresis protocol was beneficial to improve registries in our service and our professional health attention. This study reports a low rate of complications, suggesting that TPE is safe. There is a need to create a multicenter Peruvian apheresis registry to assess the benefits and risks of TPE in Peru.