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Subcutaneous lipoatrophy

Introduction
Cause
Examine
Diagnosis

Introduction

Introduction Fat malnutrition is also known as subcutaneous fat atrophy and fatty dystrophy. In 1885, Weir-Miechell first reported partial lipodystrophy (lipodystrophy), and later reported that the patient had neck, arms, chest and abdomen fat malnutrition, with increased fat deposition in the hips and legs, Lawrence reported in 1946 Complete fat dystrophy, patients with malnutrition are systemic, completely or patchy, and fat deficiency is often accompanied by a series of metabolic disorders.

Cause

Cause

(1) Causes of the disease

Congenital lipodystrophy is an autosomal recessive inheritance, and patients have a blood relationship; acquired people may have no genetic basis and often have prodromal symptoms of viral infection. Acquired systemic and partial lipodystrophy are considered to be autoimmune diseases.

(two) pathogenesis

The pathogenesis of this disease is still unclear. Various hypotheses proposed in epidemiology, genetics and clinical research suggest that systemic lipodystrophy is associated with extensive metabolic and systemic abnormalities, and that sympathetic activity may be enhanced. Strengthen the decomposition of fat; the pituitary may secrete fat mobilization substances, but pituitary resection failed to correct fat malnutrition. Others have found that CRF melanocyte release factor and FSH release factor increase, so the hypothalamus is considered to be the main site of damage. The autoimmune destruction theory of adipose tissue has also been proposed, but many patients have patchy lesions that seem difficult to explain with this theory. The relationship between the pathogenesis of kidney disease and lipodystrophy is also unknown.

The most prominent serological abnormality of this disease is a decrease in blood C3, but hypocomplementemia and/or complement activation are not necessary factors for the development of glomerulonephritis. Renal damage often occurs in patients with lipodystrophy, with an incidence of 15% to 30%. The main type of renal damage was type II membranous proliferative glomerulonephritis or dense deposit disease (80%), and the other 20% was caused by extensive peripheral mesangial migration. The morphological and histochemical characteristics of these two glomerulonephritis are the same as those of non-fatty dystrophy patients. A type III variant has been reported that is sensitive to glucocorticoids in patients with this phenotype and low serum complement and nephrotic syndrome.

Non-diabetic nephropathy is often found because complete fat malnutrition often occurs simultaneously with diabetes. Its pathological manifestations are indistinguishable from diabetic nephropathy without fat malnutrition. It has been reported in patients without diabetes, the pathological manifestations of glomerulonephritis. The relationship between lipodystrophy and glomerulopathy is unknown. Tuck et al reported that their patients had a small fraction of capillaries with peripheral mesenteric implants, subepithelial and intramembranous deposits, but in general there were no special features. The patient's serum complement C3 levels were normal, no proteinuria, and only a slight decrease in renal function.

Examine

an examination

Related inspection

Blood routine urine analysis

1. Urine examination: visible proteinuria, gross hematuria, microscopic hematuria, pyuria, a small number of nephrotic syndrome in the range of nephrotic syndrome.

2. Blood tests: hyperlipidemia, hyperproteinemia, hyperglycemia, hyperinsulinemia, elevated blood urea nitrogen, creatinine, and decreased serum complement C3.

Regular X-ray, B-ultrasound, CT, EMG, etc., can be found in kidney size, structural abnormalities and urinary calculi.

Diagnosis

Differential diagnosis

Differential diagnosis of subcutaneous lipoatrophy:

1. Muscle atrophy: The human skeletal muscle is generally not less than 434 pieces, which accounts for 25% of the body weight of the newborn and 40-45% of the adult body weight. All human activities are done by the contraction movement of the muscles. The blood supply for muscle activity accounts for 12% of total cardiac output, accounting for 18% of total systemic oxygen consumption. Muscle is one of the important organs of human metabolism, especially sugar metabolism. The striated muscle has many juxtaposed muscle fibers. The muscle fibers are muscle cells, which are cylindrical, with sarcoplasmic inside, serosal membrane, several muscle nucleus in sarcoplasm, many small organelles such as mitochondria and ribosomes, and many longitudinal and The transverse tubular sarcoplasmic reticulum is penetrated. Some parts of the sarcoplasmic reticulum store calcium ions, and there is a concave wrinkle on the serosa, and the motor nerve endings constitute the endplate of the movement, which is the synapse.

When the nerve impulse arrives, the nerve endings release the chemical transmitter acetylcholine, which temporarily binds to the receptor on the endplate, increasing the permeability of the sarcolemma to the sodium, allowing extracellular sodium ions to enter the cell, thereby ending The membrane potential of the plate region is depolarized; when a certain threshold is reached, an action potential is generated on the surrounding sarcolemma. The action potential is transmitted to the sarcoplasmic reticulum, causing it to release calcium ions into the sarcoplasm; the latter can promote the breakdown of adenosine triphosphate, release energy and make certain protein molecules in the muscle cells closely fit, causing contraction of muscle cell length.

2, myotonic atrophy: myotonicdystrophy (myotonicdystrophy) is a rare family hereditary disease, with distal muscle atrophy and muscle rigidity as the main symptoms. Often complicated by atrophy other than muscles such as gonad atrophy, alopecia, cataracts and so on. The incidence is mostly in adolescence, but it can also occur in infants and young children. It belongs to chromosomal dominant inheritance.

3, progressive lipodystrophy: progressive lipodystrophy (progressive lipodystrophy) is a rare autonomic nervous system disease characterized by adipose tissue metabolism disorders, clinical and histological features of the slow progressive bilateral distribution is basically symmetrical, border Clear, subcutaneous fat tissue atrophy or disappear, sometimes combined with limited adipose tissue hyperplasia, hypertrophy.