Retrospective study of 59 cases of cancer-associated thrombotic microangiopathy: presentation and treatment characteristics

Background

Cancer-associated thrombotic microangiopathy (TMA) is a rare disease, with a poor prognosis. The classical treatment is urgent chemotherapy. Few data are available on the efficacy of plasma exchange (PE) and eculizumab in these patients.

Methods

Cases of cancer-related TMA treated between January 2008 and December 2019 in 12 French treatment centres were retrospectively analysed, excluding cases associated with chemotherapy and stem cell transplantation. Patients were divided into four groups depending on the treatment received: none, PE therapy alone, chemotherapy, with or without PE therapy, or eculizumab, with or without chemotherapy and PE therapy.

Results

The data of 59 patients with cancer-associated TMA were analysed. Twenty of these cases were related to a cancer recurrence. The cancer was metastatic in 90% of cases (53/59). Bone marrow invasion was observed in 20/41 biopsies. Some laboratory results, including DIC, high ferritin and CRP, were suggestive of cancer. None of the 16 patients whose alternative complement pathway was assessed had abnormal levels of protein expression or activity. The median survival time was 27 days. Chemotherapy was significantly associated with improved survival, with a 30-day survival rate of 85% (17/20) among patients who received PE and chemotherapy, versus 20% (3/15) among patients who received PE alone. Patients treated with eculizumab in addition to chemotherapy and PE therapy did not have longer overall survival or higher haematological remission rates than those treated with chemotherapy and PE therapy alone. Renal remission rates were non-significantly higher, and times to remission non-significantly shorter, in the eculizumab group.

Conclusions

Nephrologists and oncologists should make themselves aware of cancer diagnoses in patients with TMA and bone marrow biopsies should be performed systematically in these cases. All 59 patients had poor survival outcomes, but patients treated with urgent initiation of chemotherapy survived significantly longer than those who were not.

FC034: Genomic Approach of the Undetermined Kidney Disease

BACKGROUND AND AIMS

Chronic kidney disease (CKD) is considered as a public health problem. Almost 20%–25% of patients with end-stage kidney disease have been reported with an undetermined kidney disease (UKD) in large national registry. Recent data have shown that the number of monogenic disease-causing variants among patients with CKD is about 20%–30%. Monogenic disease-causing variants are underdiagnosed. We performed whole exome sequencing on patients in our centre with UKD.

METHOD

All patients gave their written informed consent for genetic testing. Whole exome sequencing by next-generation sequencing was proposed in routine care practice to patient with UKD between January 2019 and December 2021. High and reproducible coverage achieved by our sequencing approach enabled copy-number variation (CNV) analysis. All patients with inconclusive biopsy results were included. Only one patient from the same pedigree was included. We excluded patients with a typical presentation of ADPKD, familial IgA nephropathy, patients with typical presentation of Gitelman or Bartter syndrome or established genetic diagnosis in the family.

RESULTS

A total of 211 adult patients were included (120 males) with a median age of 48 years (range 37–62 years). Of these, 50 patients were treated with haemodialysis, 34 patients had a kidney transplantation. A total of 156 had self-declared Caucasian. Consanguinity was reported by 12 patients and suspected in 11 patients. Family history of kidney disease was present in 108 patients with both first and second degree affected in 38 patients. Kidney biopsy were inconclusive in 62 patients. Kidney biopsy was impossible in 57 incidents patients with CKD during the study period. A WES was performed first to avoid kidney biopsy in nine patients. A negative genetic testing prior to the WES with gene panel has been performed in 31 patients. We detected 27 monogenic renal disorders in 73 patients with either pathogenic or likely pathogenic variants and 5 copy number variants among 211 patients (37%). The glomerular disease represent the first yielded diagnostic subgroup in which Alport diseases (COL4A3/4/5) represent the dominant diagnostic (COL4A4 n = 18; COL4A3 n = 12; COL4A5 n = 7; TTC21B n = 3; APOL1 = 2; INF2 n = 2; PAX2 n = 2; TRPC6 n = 2; TREX1 n = 1; COQ8B n = 1; NPHS1 n = 1). Tubulointerstitial diseases is the second yielded diagnostic subgroup (UMOD n = 7; NPHP1 n = 2; NPHP3 n = 1; CCL5 n = 1; HNF1B n = 1; CNM4 n = 1; KCNJ1 n = 1). Cystic disease and CAKUT is the third yielded diagnostic subgroup (PKHD1 n = 3; DNAJB11 n = 2; VHL n = 1; PKD1 n = 1; GREB1L n = 1; PBX1 n = 1). In addition, we find two patients with pathogenic complement variation (CFH et C3), one patient with TTR amyloidosis and one patient with familial renal glucosuria (SLC5A2). Six of the nine patients with WES first to avoid renal biopsy, have positive diagnostic (five Alport disease and one APOL1 nephropathy). Interestingly, one of these nine patients had a WES for nephrotic syndrome during type-I diabetes and a dialysis sister with undetermined glomerular disease and consanguineous parents, which detected a known variation in TTC21B gene (P209L) at a heterozygote state that did not explain the nephrotic syndrome. We performed Sanger sequencing for her sister and revealed the same variation at a homozygous state and explain her renal phenotype. Among 57 patients with impossible kidney biopsy, the WES was positive for 18 patients. The diagnostic yield of WES was higher in consanguineous patients (P = 0.04) and familial history of kidney disease (P < 0.0001). The diagnostic yielded reach 60.5% when the patient had family history of renal disease in both first and second degree of the pedigree.

CONCLUSION

WES identified a molecular diagnosis in almost 40% of patients with UKD in our centre. An exome first may have a high diagnostic yielded and avoid an invasive procedure like kidney biopsy or when it is impossible. WES must be included as a standard of care for patients with UKD.

[Minimal change nephropathy and IgA deposits associated with a Sezary syndrome]

INTRODUCTION

The Sézary syndrome (SS) is an aggressive form of cutaneous T-cell lymphoma (CTCL) requiring a rapid diagnosis due to its poor prognosis.

CASE REPORT

We report the first case of an eighty-nine-year-old woman who presented with concomitant Sezary syndrome and anasarca, revealing a nephrotic syndrome caused by a minimal change nephropathy associated with immunoglobulin A (IgA) deposits. Scarce literature described rare cases associating these two entities (nephrotic syndrome and nephropathy). However, the nephrotic syndrome was delayed from disease onset, secondary to immunosuppressive treatment of SS, or due to the weaning of SS therapy. Thus, the direct link between the glomerular lesion and the cutaneous lymphoma was difficult to establish. However, the synchronous occurrence of both SS and glomerulopathy in our patient, along with Sezary cells in both urines (urinary cytology) and biopsy, and resolution of nephropathy after treatment of SS, support the likely attributability of SS in glomerulopathy.

CONCLUSION

Practitioners must acknowledge the possible occurrence of glomerular involvement in SS.

MO163FIFTY-NINE CASES OF CANCER-ASSOCIATED THROMBOTIC MICROANGIOPATHY: TYPICAL PRESENTATION AND TREATMENT

Background and Aims

Thrombotic microangiopathy (TMA) are a heterogeneous group of diseases characterized by mechanical hemolytic anemia, peripheral thrombocytopenia, and organ failure of variable severity. In patients with cancer, TMAs are frequently induced by antineoplastic drugs but may be related to the malignant disease itself. Small series have reported poor prognosis. Only chemotherapy succeeded in lengthening life expectancy, even if few reports have described efficacy of therapeutic plasma exchange (TPE) or Eculizumab. Complement regulation was not studied in these publications, as the pathophysiology was rarely explored. In this study, we investigated retrospectively 59 cases of cancer-associated TMAs, to describe characteristics at diagnosis and efficacy of treatment.

Method

We conducted a retrospective multicentric observational study including all patients with a diagnosis of cancer-associated TMA, hospitalized in nephrological intensive care units (members of the French Intensive Care Network), between 2008 and 2019. We excluded patients receiving chemotherapy known to cause TMAs. We analyzed clinical and biological characteristics at diagnosis. We reported complement analysis when available. We defined four distinct treatment groups: No treatment (N), Plasmapheresis (P), Chemotherapy with or without chemotherapy (C+P), Eculizumab with or without Chemotherapy or Plasmapheresis (E+C+P). Renal remission and global survival were compared according to treatment group.

Results

We included 59 patients admitted to intensive care units for cancer-associated TMA. Twenty patients had a past history of cancer. Fifty percent was female, and mean age was 62.8 years. The primary cancer was breast (23.7%), lung (18.6%), stomach (10.2%), and prostate (10.2%). Adenocarcinoma was the most frequent histologic subtype (47.5%). The cancer was metastatic in almost cases (89.8%). At presentation, TMA manifestations were pulmonary (57.6%), neurologic (49.2%), bone pain (30.5%), and disseminated intravascular coagulopathy (DIVC) (55.9%). Forty-one patients had a bone marrow aspiration and/or biopsy. Among them, medullar metastases were found in 20 patients (48.7%). We observed low C3 in 14.7% of cases suggesting an activation of the alternative pathway. No genetic analysis was performed. Only one patient had an undetectable ADAMTS13 <5% without inhibitory ADAMTS13 antibodies. Renal failure was seen in 28 patients whom 63.7% had severe grade 3 acute kidney injury. Renal biopsy was performed in 6 patients with severe arteriolar TMA lesions. Seventeen patients had no treatment (N), fifteen patients were treated with TPE (P), twenty patients received chemotherapy with TPE (C+P), and seven patients received Eculizumab with TPE (E). Hematological and renal remission was not significantly different between treatment groups (p=0.74 and p=0.10 respectively). Mortality was high, 52.5% at one month, 90% after one year of follow-up. The median duration of survival was 27 days [8.5;95.5] in patients who received treatment. Survival was improved in (C+P) and (E+C+P) groups, significantly (p<0.0001).

Conclusion

We report the largest series of cancer-associated TMAS since the advent of Eculizumab for the treatment of HUS. Typical presentation included old age, bone pain, dyspnea, and DIVC. These symptoms, when associated with TMA, should therefore suggest a diagnosis of cancer. Bone marrow aspiration or biopsy led to diagnosis of cancer in half of cases, and should be systematically performed to rapidly confirm diagnosis. The overall prognosis remained dramatically poor, with a mortality rate of 90% in the first year. Chemotherapy is probably the most efficient therapy to delay the death. C3 serum level was decreased in only 7 patients, suggesting that the pathophysiology of cancer-associated TMA is not linked to complement activation. As a result, neither TPE nor Eculizumab improved survival rate.

Risk factors for severity of COVID-19 in chronic dialysis patients from a multicentre French cohort

BACKGROUND

Coronavirus disease 2019 (COVID-19) is an emerging infectious disease, related to severe acute respiratory syndrome coronavirus 2 infection. Few data are available in patients with end-stage renal disease (ESRD).

METHODS

We conducted an observational cohort study of COVID-19 patients at 11 dialysis centres in two distinct districts of France to examine the epidemiological and clinical characteristics of COVID-19 in this population, and to determine risk factors of disease severity (defined as a composite outcome including intensive care unit admission or death) and mortality.

RESULTS

Among the 2336 patients enrolled, 5.5% had confirmed COVID-19 diagnosis. Of the 122 patients with a follow-up superior to 28 days, 37% reached the composite outcome and 28% died. Multivariate analysis showed that oxygen therapy on diagnosis and a decrease in lymphocyte count were independent risk factors associated with disease severity and with mortality. Chronic use of angiotensin II receptor blockers (ARBs) (18% of patients) was associated with a protective effect on mortality. Treatment with azithromycin and hydroxychloroquine (AZT/HCQ) (46% of patients) were not associated with the composite outcome and with death in univariate and multivariate analyses.

CONCLUSIONS

COVID-19 is a severe disease with poor prognosis in patients with ESRD. Usual treatment with ARBs seems to be protective of critical evolution and mortality. There is no evidence of clinical benefit with the combination of AZT/HCQ.

Short- and long-term renal outcomes following severe rhabdomyolysis: a French multicenter retrospective study of 387 patients

Background

Rhabdomyolysis is a life-threatening disease that can lead to severe hyperkalemia, acute kidney injury (AKI) and hypovolemic shock. The predictive factors of AKI and acute to chronic kidney disease (CKD) transition remain poorly described.

Methods

This multicenter retrospective study enrolled 387 patients with severe rhabdomyolysis (CPK > 5000 U/L). Primary end-point was the development of severe AKI, defined as stage 2 or 3 of KDIGO classification. Secondary end-points included the incidence of AKI to CKD transition.

Results

Among the 387 patients, 315 (81.4%) developed AKI, including 171 (44.1%) with stage 3 AKI and 103 (26.6%) requiring RRT. Stage 2–3 AKI was strongly correlated with serum phosphate, potassium and bicarbonate at admission, as well as myoglobin over 8000 U/L and the need for mechanical ventilation. 42 patients (10.8%) died before day 28. In the 80 patients with available eGFR values both before and 3 months after the rhabdomyolysis, the decrease in eGFR (greater than 20 mL/min/1.73 m² in 23 patients; 28.8%) was correlated to the severity of the AKI and serum myoglobin levels > 8000 U/L at admission.

Conclusions

Severe rhabdomyolysis leads to AKI in most patients admitted to an ICU. Mechanical ventilation and severity of the rhabdomyolysis, including myoglobin level, are associated with the risk of stage 2–3 AKI. The long-term renal decline is correlated to serum myoglobin at admission.

Clinical and genetic heterogeneity in familial steroid-sensitive nephrotic syndrome

BACKGROUND

Familial steroid-sensitive nephrotic syndrome (SSNS) is a rare condition. The disease pathophysiology remains elusive. However, bi-allelic mutations in the EMP2 gene were identified, and specific variations in HLA-DQA1 were linked to a high risk of developing the disease.

METHODS

Clinical data were analyzed in 59 SSNS families. EMP2 gene was sequenced in families with a potential autosomal recessive (AR) inheritance. Exome sequencing was performed in a subset of 13 families with potential AR inheritance. Two variations in HLA-DQA1 were genotyped in the whole cohort.

RESULTS

Transmission was compatible with an AR (n = 33) or autosomal dominant (AD, n = 26) inheritance, assuming that familial SSNS is a monogenic trait. Clinical features did not differ between AR and AD groups. All patients, including primary (n = 7) and secondary steroid resistant nephrotic syndrone (SRNS), (n = 13) were sensitive to additional immunosuppressive therapy. Both HLA-DQA1 variations were found to be highly linked to the disease (OR = 4.34 and OR = 4.89; p < 0.001). Exome sequencing did not reveal any pathogenic mutation, neither did EMP2 sequencing.

CONCLUSIONS

Taken together, these results highlight the clinical and genetic heterogeneity in familial SSNS. Clinical findings sustain an immune origin in all patients, whatever the initial steroid-sensitivity. The absence of a variant shared by two families and the HLA-DQA1 variation enrichments suggest a complex mode of inheritance.

Plasma Xanthine Oxidase Activity Is Predictive of Cardiovascular Disease in Patients with Chronic Kidney Disease, Independently of Uric Acid Levels

BACKGROUND

Chronic kidney disease (CKD) is associated with increased cardiovascular morbidity and mortality. Oxidative stress seems to play a pivotal role in this process, and purine metabolism may be involved in CKD-related oxidative stress. Xanthine oxidase (XO) is an enzyme involved in purine metabolism and is also responsible for the production of reactive oxygen species.

METHODS

This prospective study aimed to analyze the relation between plasma dosages of molecules involved in redox balance, purine metabolism and cardiovascular events in patients with non-diabetic CKD stages 3-5 or on chronic hemodialysis (HD). CKD (n = 51) and HD (n = 50) patients were compared to matched healthy controls (n = 38) and followed-up for 3 years.

RESULTS

Both CKD and HD patients had decreased plasma levels of antioxidants (selenium, zinc, vitamin C). HD patients had decreased levels of the antioxidant enzyme superoxide dismutase and increased levels of oxidation products (ischemia-modified albumin, malondialdehyde [MDA]). The following substrates and enzymes involved in purine metabolism were increased in the HD cohort: adenosine, adenosine deaminase and the pro-oxidant XO. XO activity was negatively correlated with super oxide dismutase and positively with MDA. Interestingly, XO activity was an independent predictor of cardiovascular events in CKD and HD patients, regardless of uric acid levels. Uric acid was not predictive of events.

CONCLUSION

This highlights a possible role of XO itself in CKD-related cardiovascular disease (CVD) and raises the hypothesis that beneficial effects observed with XO inhibitors on CVD in CKD may also be due to the reduction of oxidative stress.